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Groups > linux.kernel > #1180696 > unrolled thread
| Started by | Wang Nan <wangnan0@huawei.com> |
|---|---|
| First post | 2015-07-09 14:40 +0200 |
| Last post | 2015-07-15 13:30 +0200 |
| Articles | 20 on this page of 31 — 3 participants |
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[GIT PULL 00/39] perf tools: filtering events using eBPF programs Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:40 +0200
[PATCH 36/39] perf tools: Use same BPF program if arguments are identical Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 25/39] perf tools: Attach eBPF program to perf event Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 27/39] perf record: Add clang options for compiling BPF scripts Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 34/39] perf tools: Add prologue for BPF programs for fetching arguments Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 31/39] perf tools: Move linux/filter.h to tools/include Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 26/39] perf tools: Suppress probing messages when probing by BPF loading Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 28/39] bpf tools: Load a program with different instances using preprocessor Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
Re: [PATCH 28/39] bpf tools: Load a program with different instances using preprocessor "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-13 08:00 +0200
[PATCH 13/39] perf tools: Call clang to compile C source to object code Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 32/39] perf tools: Add BPF_PROLOGUE config options for further patches Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 06/39] bpf tools: Create eBPF maps defined in an object file Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
Re: [PATCH 06/39] bpf tools: Create eBPF maps defined in an object file "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-14 06:10 +0200
[PATCH 35/39] perf tools: Generate prologue for BPF programs Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 30/39] perf probe: Reset args and nargs for probe_trace_event when failure Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 18/39] perf record: Enable passing bpf object file to --event Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 14/39] perf tools: Auto detecting kernel build directory Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 23/39] perf record: Load all eBPF object into kernel Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 24/39] perf tools: Add bpf_fd field to evsel and config it Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 22/39] perf record: Probe at kprobe points Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 15/39] perf tools: Auto detecting kernel include options Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 29/39] perf tools: Fix probe-event.h include Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 02/39] bpf tools: Collect eBPF programs from their own sections Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
Re: [PATCH 02/39] bpf tools: Collect eBPF programs from their own sections "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-10 05:20 +0200
Re: [PATCH 02/39] bpf tools: Collect eBPF programs from their own sections "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-14 06:10 +0200
[PATCH 21/39] perf probe: Attach trace_probe_event with perf_probe_event Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 09/39] bpf tools: Load eBPF programs in object files into kernel Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
[PATCH 37/39] perf record: Support custom vmlinux path Wang Nan <wangnan0@huawei.com> - 2015-07-09 14:50 +0200
perf test LLVM was: Re: [GIT PULL 00/39] perf tools: filtering events using eBPF programs Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-07-14 17:40 +0200
Re: perf test LLVM was: Re: [GIT PULL 00/39] perf tools: filtering events using eBPF programs "Wangnan (F)" <wangnan0@huawei.com> - 2015-07-15 13:10 +0200
Re: perf test LLVM was: Re: [GIT PULL 00/39] perf tools: filtering events using eBPF programs Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-07-15 13:30 +0200
Page 1 of 2 [1] 2 Next page →
| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:40 +0200 |
| Subject | [GIT PULL 00/39] perf tools: filtering events using eBPF programs |
| Message-ID | <pKjhn-9T-3@gated-at.bofh.it> |
Hi Arnaldo,
The following changes since commit 3381a29cbec5447086c0f726ee9a88c02e60becc:
bpf tools: Collect map definitions from 'maps' section (2015-07-07 13:41:45 -0300)
are available in the git repository at:
https://github.com/WangNan0/linux.git perf/ebpf-for-acme
for you to fetch changes up to 072b826c5dc6b2031f4f21c59c57eb6ca1dfa7c0:
perf tools: Support attach BPF program on uprobe events (2015-07-09 12:20:13 +0000)
----------------------------------------------------------------
This pull request is based on commit 3381a29cb on your perf/ebpf branch
as your suggestion. Following changes are made:
1. Commit messages improvements, especially 'bpf tools: Collect symbol
table from SHT_SYMTAB section', which you have collected. Please
change them.
2. Update interface of bpf_program accessors as your suggestion.
He Kuang (3):
perf tools: Move linux/filter.h to tools/include
perf tools: Introduce arch_get_reg_info() for x86
perf record: Support custom vmlinux path
Wang Nan (36):
bpf tools: Collect symbol table from SHT_SYMTAB section
bpf tools: Collect eBPF programs from their own sections
bpf tools: Collect relocation sections from SHT_REL sections
bpf tools: Record map accessing instructions for each program
bpf tools: Add bpf.c/h for common bpf operations
bpf tools: Create eBPF maps defined in an object file
bpf tools: Relocate eBPF programs
bpf tools: Introduce bpf_load_program() to bpf.c
bpf tools: Load eBPF programs in object files into kernel
bpf tools: Introduce accessors for struct bpf_program
bpf tools: Link all bpf objects onto a list
perf tools: Introduce llvm config options
perf tools: Call clang to compile C source to object code
perf tools: Auto detecting kernel build directory
perf tools: Auto detecting kernel include options
perf tests: Add LLVM test for eBPF on-the-fly compiling
perf tools: Make perf depend on libbpf
perf record: Enable passing bpf object file to --event
perf record: Compile scriptlets if pass '.c' to --event
perf tools: Parse probe points of eBPF programs during preparation
perf probe: Attach trace_probe_event with perf_probe_event
perf record: Probe at kprobe points
perf record: Load all eBPF object into kernel
perf tools: Add bpf_fd field to evsel and config it
perf tools: Attach eBPF program to perf event
perf tools: Suppress probing messages when probing by BPF loading
perf record: Add clang options for compiling BPF scripts
bpf tools: Load a program with different instances using preprocessor
perf tools: Fix probe-event.h include
perf probe: Reset args and nargs for probe_trace_event when failure
perf tools: Add BPF_PROLOGUE config options for further patches
perf tools: Add prologue for BPF programs for fetching arguments
perf tools: Generate prologue for BPF programs
perf tools: Use same BPF program if arguments are identical
perf probe: Init symbol as kprobe if any event is kprobe
perf tools: Support attach BPF program on uprobe events
tools/build/Makefile.feature | 6 +-
tools/include/linux/filter.h | 237 +++++++++++
tools/lib/bpf/Build | 2 +-
tools/lib/bpf/bpf.c | 85 ++++
tools/lib/bpf/bpf.h | 23 ++
tools/lib/bpf/libbpf.c | 745 ++++++++++++++++++++++++++++++++++
tools/lib/bpf/libbpf.h | 70 ++++
tools/perf/MANIFEST | 4 +
tools/perf/Makefile.perf | 19 +-
tools/perf/arch/x86/Makefile | 1 +
tools/perf/arch/x86/util/Build | 2 +
tools/perf/arch/x86/util/dwarf-regs.c | 104 +++--
tools/perf/builtin-probe.c | 4 +-
tools/perf/builtin-record.c | 47 ++-
tools/perf/config/Makefile | 31 +-
tools/perf/tests/Build | 1 +
tools/perf/tests/builtin-test.c | 4 +
tools/perf/tests/llvm.c | 85 ++++
tools/perf/tests/make | 4 +-
tools/perf/tests/tests.h | 1 +
tools/perf/util/Build | 3 +
tools/perf/util/bpf-loader.c | 631 ++++++++++++++++++++++++++++
tools/perf/util/bpf-loader.h | 46 +++
tools/perf/util/bpf-prologue.c | 442 ++++++++++++++++++++
tools/perf/util/bpf-prologue.h | 34 ++
tools/perf/util/config.c | 4 +
tools/perf/util/debug.c | 5 +
tools/perf/util/debug.h | 1 +
tools/perf/util/evlist.c | 41 ++
tools/perf/util/evlist.h | 1 +
tools/perf/util/evsel.c | 17 +
tools/perf/util/evsel.h | 1 +
tools/perf/util/include/dwarf-regs.h | 7 +
tools/perf/util/llvm-utils.c | 373 +++++++++++++++++
tools/perf/util/llvm-utils.h | 39 ++
tools/perf/util/parse-events.c | 16 +
tools/perf/util/parse-events.h | 2 +
tools/perf/util/parse-events.l | 6 +
tools/perf/util/parse-events.y | 29 +-
tools/perf/util/probe-event.c | 84 ++--
tools/perf/util/probe-event.h | 8 +-
tools/perf/util/probe-finder.c | 4 +
42 files changed, 3192 insertions(+), 77 deletions(-)
create mode 100644 tools/include/linux/filter.h
create mode 100644 tools/lib/bpf/bpf.c
create mode 100644 tools/lib/bpf/bpf.h
create mode 100644 tools/perf/tests/llvm.c
create mode 100644 tools/perf/util/bpf-loader.c
create mode 100644 tools/perf/util/bpf-loader.h
create mode 100644 tools/perf/util/bpf-prologue.c
create mode 100644 tools/perf/util/bpf-prologue.h
create mode 100644 tools/perf/util/llvm-utils.c
create mode 100644 tools/perf/util/llvm-utils.h
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 36/39] perf tools: Use same BPF program if arguments are identical |
| Message-ID | <pKjr3-dD-1@gated-at.bofh.it> |
| In reply to | #1180696 |
This patch allows creating only one BPF program for different
'probe_trace_event'(tev) generated by one 'perf_probe_event'(pev), if
their prologue are identical.
This is done by comparing argument list of different tev, and maps type
of prologue and tev using a mapping array. This patch utilizes qsort to
sort tevs. After sorting, tevs with identical argument list will group
together.
Signed-off-by: Wang Nan <wangnan0@hauwei.com>
---
tools/perf/util/bpf-loader.c | 133 ++++++++++++++++++++++++++++++++++++++++---
1 file changed, 126 insertions(+), 7 deletions(-)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 41bffdd..0a4e9ec 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -57,6 +57,8 @@ struct bpf_prog_priv {
struct perf_probe_event *pev;
bool need_prologue;
struct bpf_insn *insns_buf;
+ int nr_types;
+ int *type_mapping;
};
static void
@@ -68,6 +70,7 @@ bpf_prog_priv__clear(struct bpf_program *prog __maybe_unused,
if (priv->pev)
clear_perf_probe_event(priv->pev);
zfree(&priv->insns_buf);
+ zfree(&priv->type_mapping);
free(priv);
}
@@ -238,7 +241,7 @@ preproc_gen_prologue(struct bpf_program *prog, int n,
struct bpf_prog_priv *priv;
struct bpf_insn *buf;
size_t prologue_cnt = 0;
- int err;
+ int i, err;
err = bpf_program__get_private(prog, (void **)&priv);
if (err || !priv)
@@ -246,10 +249,20 @@ preproc_gen_prologue(struct bpf_program *prog, int n,
pev = priv->pev;
- if (n < 0 || n >= pev->ntevs)
+ if (n < 0 || n >= priv->nr_types)
goto errout;
- tev = &pev->tevs[n];
+ /* Find a tev belongs to that type */
+ for (i = 0; i < pev->ntevs; i++)
+ if (priv->type_mapping[i] == n)
+ break;
+
+ if (i >= pev->ntevs) {
+ pr_err("Internal error: prologue type %d not found\n", n);
+ return -EEXIST;
+ }
+
+ tev = &pev->tevs[i];
buf = priv->insns_buf;
err = bpf__gen_prologue(tev->args, tev->nargs,
@@ -280,6 +293,98 @@ errout:
return -EINVAL;
}
+/*
+ * compare_tev_args is reflexive, transitive and antisymmetric.
+ * I can show that but this margin is too narrow to contain.
+ */
+static int compare_tev_args(const void *ptev1, const void *ptev2)
+{
+ int i, ret;
+ const struct probe_trace_event *tev1 =
+ *(const struct probe_trace_event **)ptev1;
+ const struct probe_trace_event *tev2 =
+ *(const struct probe_trace_event **)ptev2;
+
+ ret = tev2->nargs - tev1->nargs;
+ if (ret)
+ return ret;
+
+ for (i = 0; i < tev1->nargs; i++) {
+ struct probe_trace_arg *arg1, *arg2;
+ struct probe_trace_arg_ref *ref1, *ref2;
+
+ arg1 = &tev1->args[i];
+ arg2 = &tev2->args[i];
+
+ ret = strcmp(arg1->value, arg2->value);
+ if (ret)
+ return ret;
+
+ ref1 = arg1->ref;
+ ref2 = arg2->ref;
+
+ while (ref1 && ref2) {
+ ret = ref2->offset - ref1->offset;
+ if (ret)
+ return ret;
+
+ ref1 = ref1->next;
+ ref2 = ref2->next;
+ }
+
+ if (ref1 || ref2)
+ return ref2 ? 1 : -1;
+ }
+
+ return 0;
+}
+
+static int map_prologue(struct perf_probe_event *pev, int *mapping,
+ int *nr_types)
+{
+ int i, type = 0;
+ struct {
+ struct probe_trace_event *tev;
+ int idx;
+ } *stevs;
+ size_t array_sz = sizeof(*stevs) * pev->ntevs;
+
+ stevs = malloc(array_sz);
+ if (!stevs) {
+ pr_err("No ehough memory: alloc stevs failed\n");
+ return -ENOMEM;
+ }
+
+ pr_debug("In map_prologue, ntevs=%d\n", pev->ntevs);
+ for (i = 0; i < pev->ntevs; i++) {
+ stevs[i].tev = &pev->tevs[i];
+ stevs[i].idx = i;
+ }
+ qsort(stevs, pev->ntevs, sizeof(*stevs),
+ compare_tev_args);
+
+ for (i = 0; i < pev->ntevs; i++) {
+ if (i == 0) {
+ mapping[stevs[i].idx] = type;
+ pr_debug("mapping[%d]=%d\n", stevs[i].idx,
+ type);
+ continue;
+ }
+
+ if (compare_tev_args(stevs + i, stevs + i - 1) == 0)
+ mapping[stevs[i].idx] = type;
+ else
+ mapping[stevs[i].idx] = ++type;
+
+ pr_debug("mapping[%d]=%d\n", stevs[i].idx,
+ mapping[stevs[i].idx]);
+ }
+ free(stevs);
+ *nr_types = type + 1;
+
+ return 0;
+}
+
static int hook_load_preprocessor(struct bpf_program *prog)
{
struct perf_probe_event *pev;
@@ -320,7 +425,19 @@ static int hook_load_preprocessor(struct bpf_program *prog)
return -ENOMEM;
}
- err = bpf_program__set_prep(prog, pev->ntevs,
+ priv->type_mapping = malloc(sizeof(int) * pev->ntevs);
+ if (!priv->type_mapping) {
+ pr_err("No enough memory: alloc type_mapping failed\n");
+ return -ENOMEM;
+ }
+ memset(priv->type_mapping, 0xff,
+ sizeof(int) * pev->ntevs);
+
+ err = map_prologue(pev, priv->type_mapping, &priv->nr_types);
+ if (err)
+ return err;
+
+ err = bpf_program__set_prep(prog, priv->nr_types,
preproc_gen_prologue);
return err;
}
@@ -415,9 +532,11 @@ int bpf__foreach_tev(bpf_prog_iter_callback_t func, void *arg)
for (i = 0; i < pev->ntevs; i++) {
tev = &pev->tevs[i];
- if (priv->need_prologue)
- fd = bpf_program__nth_fd(prog, i);
- else
+ if (priv->need_prologue) {
+ int type = priv->type_mapping[i];
+
+ fd = bpf_program__nth_fd(prog, type);
+ } else
fd = bpf_program__fd(prog);
if (fd < 0) {
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 25/39] perf tools: Attach eBPF program to perf event |
| Message-ID | <pKjr3-dD-3@gated-at.bofh.it> |
| In reply to | #1180696 |
This is the final patch which makes basic BPF filter work. After
applying this patch, users are allowed to use BPF filter like:
# perf record --event ./hello_world.c ls
In this patch PERF_EVENT_IOC_SET_BPF ioctl is used to attach eBPF
program to a newly created perf event. The file descriptor of the
eBPF program is passed to perf record using previous patches, and
stored into evsel->bpf_fd.
It is possible that different perf event are created for one kprobe
events for different CPUs. In this case, when trying to call the
ioctl, EEXIST will be return. This patch doesn't treat it as an error.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/evsel.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index fe80047..73c17f3 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1216,6 +1216,22 @@ retry_open:
err);
goto try_fallback;
}
+
+ if (evsel->bpf_fd >= 0) {
+ int evt_fd = FD(evsel, cpu, thread);
+ int bpf_fd = evsel->bpf_fd;
+
+ err = ioctl(evt_fd,
+ PERF_EVENT_IOC_SET_BPF,
+ bpf_fd);
+ if (err && errno != EEXIST) {
+ pr_err("failed to attach bpf fd %d: %s\n",
+ bpf_fd, strerror(errno));
+ err = -EINVAL;
+ goto out_close;
+ }
+ }
+
set_rlimit = NO_CHANGE;
/*
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 27/39] perf record: Add clang options for compiling BPF scripts |
| Message-ID | <pKjr3-dD-5@gated-at.bofh.it> |
| In reply to | #1180696 |
Although previous patch allows setting BPF compiler related options in
perfconfig, on some ad-hoc situation it still requires passing options
through cmdline. This patch introduces 2 options to 'perf record' for
this propose: --clang-path and --clang-opt.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/builtin-record.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index bd189b1..e89c045 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -30,6 +30,7 @@
#include "util/auxtrace.h"
#include "util/parse-branch-options.h"
#include "util/bpf-loader.h"
+#include "util/llvm-utils.h"
#include <unistd.h>
#include <sched.h>
@@ -1073,6 +1074,12 @@ struct option __record_options[] = {
"opts", "AUX area tracing Snapshot Mode", ""),
OPT_UINTEGER(0, "proc-map-timeout", &record.opts.proc_map_timeout,
"per thread proc mmap processing timeout in ms"),
+#ifdef HAVE_LIBBPF_SUPPORT
+ OPT_STRING(0, "clang-path", &llvm_param.clang_path, "clang path",
+ "clang binary to use for compiling BPF scriptlets"),
+ OPT_STRING(0, "clang-opt", &llvm_param.clang_opt, "clang options",
+ "options passed to clang when compiling BPF scriptlets"),
+#endif
OPT_END()
};
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 34/39] perf tools: Add prologue for BPF programs for fetching arguments |
| Message-ID | <pKjr3-dD-7@gated-at.bofh.it> |
| In reply to | #1180696 |
This patch generates prologue for a BPF program which fetch arguments
for it. With this patch, the program can have arguments as follow:
SEC("lock_page=__lock_page page->flags")
int lock_page(struct pt_regs *ctx, int err, unsigned long flags)
{
return 1;
}
This patch passes at most 3 arguments from r3, r4 and r5. r1 is still
the ctx pointer. r2 is used to indicate the successfulness of
dereferencing.
This patch uses r6 to hold ctx (struct pt_regs) and r7 to hold stack
pointer for result. Result of each arguments first store on stack:
low address
BPF_REG_FP - 24 ARG3
BPF_REG_FP - 16 ARG2
BPF_REG_FP - 8 ARG1
BPF_REG_FP
high address
Then loaded into r3, r4 and r5.
The output prologue for offn(...off2(off1(reg)))) should be:
r6 <- r1 // save ctx into a callee saved register
r7 <- fp
r7 <- r7 - stack_offset // pointer to result slot
/* load r3 with the offset in pt_regs of 'reg' */
(r7) <- r3 // make slot valid
r3 <- r3 + off1 // prepare to read unsafe pointer
r2 <- 8
r1 <- r7 // result put onto stack
call probe_read // read unsafe pointer
jnei r0, 0, err // error checking
r3 <- (r7) // read result
r3 <- r3 + off2 // prepare to read unsafe pointer
r2 <- 8
r1 <- r7
call probe_read
jnei r0, 0, err
...
/* load r2, r3, r4 from stack */
goto success
err:
r2 <- 1
/* load r3, r4, r5 with 0 */
goto usercode
success:
r2 <- 0
usercode:
r1 <- r6 // restore ctx
// original user code
If all of arguments reside in register (dereferencing is not
required), gen_prologue_fastpath() will be used to create
fast prologue:
r3 <- (r1 + offset of reg1)
r4 <- (r1 + offset of reg2)
r5 <- (r1 + offset of reg3)
r2 <- 0
P.S.
eBPF calling convention is defined as:
* r0 - return value from in-kernel function, and exit value
for eBPF program
* r1 - r5 - arguments from eBPF program to in-kernel function
* r6 - r9 - callee saved registers that in-kernel function will
preserve
* r10 - read-only frame pointer to access stack
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/Build | 1 +
tools/perf/util/bpf-prologue.c | 442 +++++++++++++++++++++++++++++++++++++++++
tools/perf/util/bpf-prologue.h | 34 ++++
3 files changed, 477 insertions(+)
create mode 100644 tools/perf/util/bpf-prologue.c
create mode 100644 tools/perf/util/bpf-prologue.h
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 3357e5a..f83d070 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -80,6 +80,7 @@ libperf-$(CONFIG_AUXTRACE) += auxtrace.o
libperf-y += parse-branch-options.o
libperf-$(CONFIG_LIBBPF) += bpf-loader.o
+libperf-$(CONFIG_BPF_PROLOGUE) += bpf-prologue.o
libperf-$(CONFIG_LIBELF) += symbol-elf.o
libperf-$(CONFIG_LIBELF) += probe-event.o
diff --git a/tools/perf/util/bpf-prologue.c b/tools/perf/util/bpf-prologue.c
new file mode 100644
index 0000000..2a5f4c7
--- /dev/null
+++ b/tools/perf/util/bpf-prologue.c
@@ -0,0 +1,442 @@
+/*
+ * bpf-prologue.c
+ *
+ * Copyright (C) 2015 He Kuang <hekuang@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ */
+
+#include <bpf/libbpf.h>
+#include "perf.h"
+#include "debug.h"
+#include "bpf-prologue.h"
+#include "probe-finder.h"
+#include <dwarf-regs.h>
+#include <linux/filter.h>
+
+#define BPF_REG_SIZE 8
+
+#define JMP_TO_ERROR_CODE -1
+#define JMP_TO_SUCCESS_CODE -2
+#define JMP_TO_USER_CODE -3
+
+struct bpf_insn_pos {
+ struct bpf_insn *begin;
+ struct bpf_insn *end;
+ struct bpf_insn *pos;
+};
+
+static inline int
+pos_get_cnt(struct bpf_insn_pos *pos)
+{
+ return pos->pos - pos->begin;
+}
+
+static int
+append_insn(struct bpf_insn new_insn, struct bpf_insn_pos *pos)
+{
+ if (!pos->pos)
+ return -ERANGE;
+
+ if (pos->pos + 1 >= pos->end) {
+ pr_err("bpf prologue: prologue too long\n");
+ pos->pos = NULL;
+ return -ERANGE;
+ }
+
+ *(pos->pos)++ = new_insn;
+ return 0;
+}
+
+static int
+check_pos(struct bpf_insn_pos *pos)
+{
+ if (!pos->pos || pos->pos >= pos->end)
+ return -ERANGE;
+ return 0;
+}
+
+/* Give it a shorter name */
+#define ins(i, p) append_insn((i), (p))
+
+/*
+ * Give a register name (in 'reg'), generate instruction to
+ * load register into an eBPF register rd:
+ * 'ldd target_reg, offset(ctx_reg)', where:
+ * ctx_reg is pre initialized to pointer of 'struct pt_regs'.
+ */
+static int
+gen_ldx_reg_from_ctx(struct bpf_insn_pos *pos, int ctx_reg,
+ const char *reg, int target_reg)
+{
+ int offset;
+
+ if (arch_get_reg_info(reg, &offset)) {
+ pr_err("bpf: prologue: failed to get register %s\n",
+ reg);
+ return -1;
+ }
+ ins(BPF_LDX_MEM(BPF_DW, target_reg, ctx_reg, offset), pos);
+
+ if (check_pos(pos))
+ return -ERANGE;
+ return 0;
+}
+
+/*
+ * Generate a BPF_FUNC_probe_read function call.
+ *
+ * src_base_addr_reg is a register holding base address,
+ * dst_addr_reg is a register holding dest address (on stack),
+ * result is:
+ *
+ * *[dst_addr_reg] = *([src_base_addr_reg] + offset)
+ *
+ * Arguments of BPF_FUNC_probe_read:
+ * ARG1: ptr to stack (dest)
+ * ARG2: size (8)
+ * ARG3: unsafe ptr (src)
+ */
+static int
+gen_read_mem(struct bpf_insn_pos *pos,
+ int src_base_addr_reg,
+ int dst_addr_reg,
+ long offset)
+{
+ /* mov arg3, src_base_addr_reg */
+ if (src_base_addr_reg != BPF_REG_ARG3)
+ ins(BPF_MOV64_REG(BPF_REG_ARG3, src_base_addr_reg), pos);
+ /* add arg3, #offset */
+ if (offset)
+ ins(BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG3, offset), pos);
+
+ /* mov arg2, #reg_size */
+ ins(BPF_ALU64_IMM(BPF_MOV, BPF_REG_ARG2, BPF_REG_SIZE), pos);
+
+ /* mov arg1, dst_addr_reg */
+ if (dst_addr_reg != BPF_REG_ARG1)
+ ins(BPF_MOV64_REG(BPF_REG_ARG1, dst_addr_reg), pos);
+
+ /* Call probe_read */
+ ins(BPF_EMIT_CALL(BPF_FUNC_probe_read), pos);
+ /*
+ * Error processing: if read fail, goto error code,
+ * will be relocated. Target should be the start of
+ * error processing code.
+ */
+ ins(BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, JMP_TO_ERROR_CODE),
+ pos);
+
+ if (check_pos(pos))
+ return -ERANGE;
+ return 0;
+}
+
+/*
+ * Each arg should be bare register. Fetch and save them into argument
+ * registers (r3 - r5).
+ *
+ * BPF_REG_1 should have been initialized with pointer to
+ * 'struct pt_regs'.
+ */
+static int
+gen_prologue_fastpath(struct bpf_insn_pos *pos,
+ struct probe_trace_arg *args, int nargs)
+{
+ int i;
+
+ for (i = 0; i < nargs; i++)
+ if (gen_ldx_reg_from_ctx(pos, BPF_REG_1, args[i].value,
+ BPF_PROLOGUE_START_ARG_REG + i))
+ goto errout;
+
+ if (check_pos(pos))
+ goto errout;
+ return 0;
+errout:
+ return -1;
+}
+
+/*
+ * Slow path:
+ * At least one argument has the form of 'offset($rx)'.
+ *
+ * Following code first stores them into stack, then loads all of then
+ * to r2 - r5.
+ * Before final loading, the final result should be:
+ *
+ * low address
+ * BPF_REG_FP - 24 ARG3
+ * BPF_REG_FP - 16 ARG2
+ * BPF_REG_FP - 8 ARG1
+ * BPF_REG_FP
+ * high address
+ *
+ * For each argument (described as: offn(...off2(off1(reg)))),
+ * generates following code:
+ *
+ * r7 <- fp
+ * r7 <- r7 - stack_offset // Ideal code should initialize r7 using
+ * // fp before generating args. However,
+ * // eBPF won't regard r7 as stack pointer
+ * // if it is generated by minus 8 from
+ * // another stack pointer except fp.
+ * // This is why we have to set r7
+ * // to fp for each variable.
+ * r3 <- value of 'reg'-> generated using gen_ldx_reg_from_ctx()
+ * (r7) <- r3 // skip following instructions for bare reg
+ * r3 <- r3 + off1 . // skip if off1 == 0
+ * r2 <- 8 \
+ * r1 <- r7 |-> generated by gen_read_mem()
+ * call probe_read /
+ * jnei r0, 0, err ./
+ * r3 <- (r7)
+ * r3 <- r3 + off2 . // skip if off2 == 0
+ * r2 <- 8 \ // r2 may be broken by probe_read, so set again
+ * r1 <- r7 |-> generated by gen_read_mem()
+ * call probe_read /
+ * jnei r0, 0, err ./
+ * ...
+ */
+static int
+gen_prologue_slowpath(struct bpf_insn_pos *pos,
+ struct probe_trace_arg *args, int nargs)
+{
+ int i;
+
+ for (i = 0; i < nargs; i++) {
+ struct probe_trace_arg *arg = &args[i];
+ const char *reg = arg->value;
+ struct probe_trace_arg_ref *ref = NULL;
+ int stack_offset = (i + 1) * -8;
+
+ pr_debug("prologue: fetch arg %d, base reg is %s\n",
+ i, reg);
+
+ /* value of base register is stored into ARG3 */
+ if (gen_ldx_reg_from_ctx(pos, BPF_REG_CTX, reg,
+ BPF_REG_ARG3)) {
+ pr_err("prologue: failed to get offset of register %s\n",
+ reg);
+ goto errout;
+ }
+
+ /* Make r7 the stack pointer. */
+ ins(BPF_MOV64_REG(BPF_REG_7, BPF_REG_FP), pos);
+ /* r7 += -8 */
+ ins(BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, stack_offset), pos);
+ /*
+ * Store r3 (base register) onto stack
+ * Ensure fp[offset] is set.
+ * fp is the only valid base register when storing
+ * into stack. We are not allowed to use r7 as base
+ * register here.
+ */
+ ins(BPF_STX_MEM(BPF_DW, BPF_REG_FP, BPF_REG_ARG3,
+ stack_offset), pos);
+
+ ref = arg->ref;
+ while (ref) {
+ pr_debug("prologue: arg %d: offset %ld\n",
+ i, ref->offset);
+ if (gen_read_mem(pos, BPF_REG_3, BPF_REG_7,
+ ref->offset)) {
+ pr_err("prologue: failed to generate probe_read function call\n");
+ goto errout;
+ }
+
+ ref = ref->next;
+ /*
+ * Load previous result into ARG3. Use
+ * BPF_REG_FP instead of r7 because verifier
+ * allows FP based addressing only.
+ */
+ if (ref)
+ ins(BPF_LDX_MEM(BPF_DW, BPF_REG_ARG3,
+ BPF_REG_FP, stack_offset), pos);
+ }
+ }
+
+ /* Final pass: read to registers */
+ for (i = 0; i < nargs; i++)
+ ins(BPF_LDX_MEM(BPF_DW, BPF_PROLOGUE_START_ARG_REG + i,
+ BPF_REG_FP, -BPF_REG_SIZE * (i + 1)), pos);
+
+ ins(BPF_JMP_IMM(BPF_JA, BPF_REG_0, 0, JMP_TO_SUCCESS_CODE), pos);
+
+ if (check_pos(pos))
+ goto errout;
+ return 0;
+errout:
+ return -1;
+}
+
+static int
+prologue_relocate(struct bpf_insn_pos *pos, struct bpf_insn *error_code,
+ struct bpf_insn *success_code, struct bpf_insn *user_code)
+{
+ struct bpf_insn *insn;
+
+ if (check_pos(pos))
+ return -ERANGE;
+
+ for (insn = pos->begin; insn < pos->pos; insn++) {
+ u8 class = BPF_CLASS(insn->code);
+ u8 opcode;
+
+ if (class != BPF_JMP)
+ continue;
+ opcode = BPF_OP(insn->code);
+ if (opcode == BPF_CALL)
+ continue;
+
+ switch (insn->off) {
+ case JMP_TO_ERROR_CODE:
+ insn->off = error_code - (insn + 1);
+ break;
+ case JMP_TO_SUCCESS_CODE:
+ insn->off = success_code - (insn + 1);
+ break;
+ case JMP_TO_USER_CODE:
+ insn->off = user_code - (insn + 1);
+ break;
+ default:
+ pr_err("bpf prologue: internal error: relocation failed\n");
+ return -1;
+ }
+ }
+ return 0;
+}
+
+int bpf__gen_prologue(struct probe_trace_arg *args, int nargs,
+ struct bpf_insn *new_prog, size_t *new_cnt,
+ size_t cnt_space)
+{
+ struct bpf_insn *success_code = NULL;
+ struct bpf_insn *error_code = NULL;
+ struct bpf_insn *user_code = NULL;
+ struct bpf_insn_pos pos;
+ bool fastpath = true;
+ int i;
+
+ if (!new_prog || !new_cnt)
+ return -EINVAL;
+
+ pos.begin = new_prog;
+ pos.end = new_prog + cnt_space;
+ pos.pos = new_prog;
+
+ if (!nargs) {
+ ins(BPF_ALU64_IMM(BPF_MOV, BPF_PROLOGUE_FETCH_RESULT_REG, 0),
+ &pos);
+
+ if (check_pos(&pos))
+ goto errout;
+
+ *new_cnt = pos_get_cnt(&pos);
+ return 0;
+ }
+
+ if (nargs > BPF_PROLOGUE_MAX_ARGS)
+ nargs = BPF_PROLOGUE_MAX_ARGS;
+ if (cnt_space > BPF_MAXINSNS)
+ cnt_space = BPF_MAXINSNS;
+
+ /* First pass: validation */
+ for (i = 0; i < nargs; i++) {
+ struct probe_trace_arg_ref *ref = args[i].ref;
+
+ if (args[i].value[0] == '@') {
+ /* TODO: fetch global variable */
+ pr_err("bpf: prologue: global %s%+ld not support\n",
+ args[i].value, ref ? ref->offset : 0);
+ return -ENOTSUP;
+ }
+
+ while (ref) {
+ /* fastpath is true if all args has ref == NULL */
+ fastpath = false;
+
+ /*
+ * Instruction encodes immediate value using
+ * s32, ref->offset is long. On systems which
+ * can't fill long in s32, refuse to process if
+ * ref->offset too large (or small).
+ */
+#ifdef __LP64__
+#define OFFSET_MAX ((1LL << 31) - 1)
+#define OFFSET_MIN ((1LL << 31) * -1)
+ if (ref->offset > OFFSET_MAX ||
+ ref->offset < OFFSET_MIN) {
+ pr_err("bpf: prologue: offset out of bound: %ld\n",
+ ref->offset);
+ return -E2BIG;
+ }
+#endif
+ ref = ref->next;
+ }
+ }
+ pr_debug("prologue: pass validation\n");
+
+ if (fastpath) {
+ /* If all variables are registers... */
+ pr_debug("prologue: fast path\n");
+ if (gen_prologue_fastpath(&pos, args, nargs))
+ goto errout;
+ } else {
+ pr_debug("prologue: slow path\n");
+
+ /* Initialization: move ctx to a callee saved register. */
+ ins(BPF_MOV64_REG(BPF_REG_CTX, BPF_REG_ARG1), &pos);
+
+ if (gen_prologue_slowpath(&pos, args, nargs))
+ goto errout;
+ /*
+ * start of ERROR_CODE (only slow pass needs error code)
+ * mov r2 <- 1
+ * goto usercode
+ */
+ error_code = pos.pos;
+ ins(BPF_ALU64_IMM(BPF_MOV, BPF_PROLOGUE_FETCH_RESULT_REG, 1),
+ &pos);
+
+ for (i = 0; i < nargs; i++)
+ ins(BPF_ALU64_IMM(BPF_MOV,
+ BPF_PROLOGUE_START_ARG_REG + i,
+ 0),
+ &pos);
+ ins(BPF_JMP_IMM(BPF_JA, BPF_REG_0, 0, JMP_TO_USER_CODE),
+ &pos);
+ }
+
+ /*
+ * start of SUCCESS_CODE:
+ * mov r2 <- 0
+ * goto usercode // skip
+ */
+ success_code = pos.pos;
+ ins(BPF_ALU64_IMM(BPF_MOV, BPF_PROLOGUE_FETCH_RESULT_REG, 0), &pos);
+
+ /*
+ * start of USER_CODE:
+ * Restore ctx to r1
+ */
+ user_code = pos.pos;
+ if (!fastpath) {
+ /*
+ * Only slow path needs restoring of ctx. In fast path,
+ * register are loaded directly from r1.
+ */
+ ins(BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_CTX), &pos);
+ if (prologue_relocate(&pos, error_code, success_code,
+ user_code))
+ goto errout;
+ }
+
+ if (check_pos(&pos))
+ goto errout;
+
+ *new_cnt = pos_get_cnt(&pos);
+ return 0;
+errout:
+ return -ERANGE;
+}
diff --git a/tools/perf/util/bpf-prologue.h b/tools/perf/util/bpf-prologue.h
new file mode 100644
index 0000000..f1e4c5d
--- /dev/null
+++ b/tools/perf/util/bpf-prologue.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2015, He Kuang <hekuang@huawei.com>
+ * Copyright (C) 2015, Huawei Inc.
+ */
+#ifndef __BPF_PROLOGUE_H
+#define __BPF_PROLOGUE_H
+
+#include <linux/compiler.h>
+#include <linux/filter.h>
+#include "probe-event.h"
+
+#define BPF_PROLOGUE_MAX_ARGS 3
+#define BPF_PROLOGUE_START_ARG_REG BPF_REG_3
+#define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2
+
+#ifdef HAVE_BPF_PROLOGUE
+int bpf__gen_prologue(struct probe_trace_arg *args, int nargs,
+ struct bpf_insn *new_prog, size_t *new_cnt,
+ size_t cnt_space);
+#else
+static inline int
+bpf__gen_prologue(struct probe_trace_arg *args __maybe_unused,
+ int nargs __maybe_unused,
+ struct bpf_insn *new_prog __maybe_unused,
+ size_t *new_cnt,
+ size_t cnt_space __maybe_unused)
+{
+ if (!new_cnt)
+ return -EINVAL;
+ *new_cnt = 0;
+ return 0;
+}
+#endif
+#endif /* __BPF_PROLOGUE_H */
--
1.8.3.4
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[toc] | [prev] | [next] | [standalone]
| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 31/39] perf tools: Move linux/filter.h to tools/include |
| Message-ID | <pKjr4-dD-9@gated-at.bofh.it> |
| In reply to | #1180696 |
From: He Kuang <hekuang@huawei.com>
This patch moves filter.h from include/linux/kernel.h to
tools/include/linux/filter.h to enable other libraries use macros in
it, like libbpf which will be introduced by further patches. Currenty,
the moved filter.h only contains the useful macros needed by libbpf
for not introducing too much dependence.
MANIFEST is also updated for 'make perf-*-src-pkg'.
One change:
imm field of BPF_EMIT_CALL becomes ((FUNC) - BPF_FUNC_unspec) to
suit user space code generator.
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/include/linux/filter.h | 237 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/MANIFEST | 1 +
2 files changed, 238 insertions(+)
create mode 100644 tools/include/linux/filter.h
diff --git a/tools/include/linux/filter.h b/tools/include/linux/filter.h
new file mode 100644
index 0000000..11d2b1c
--- /dev/null
+++ b/tools/include/linux/filter.h
@@ -0,0 +1,237 @@
+/*
+ * Linux Socket Filter Data Structures
+ */
+#ifndef __TOOLS_LINUX_FILTER_H
+#define __TOOLS_LINUX_FILTER_H
+
+#include <linux/bpf.h>
+
+/* ArgX, context and stack frame pointer register positions. Note,
+ * Arg1, Arg2, Arg3, etc are used as argument mappings of function
+ * calls in BPF_CALL instruction.
+ */
+#define BPF_REG_ARG1 BPF_REG_1
+#define BPF_REG_ARG2 BPF_REG_2
+#define BPF_REG_ARG3 BPF_REG_3
+#define BPF_REG_ARG4 BPF_REG_4
+#define BPF_REG_ARG5 BPF_REG_5
+#define BPF_REG_CTX BPF_REG_6
+#define BPF_REG_FP BPF_REG_10
+
+/* Additional register mappings for converted user programs. */
+#define BPF_REG_A BPF_REG_0
+#define BPF_REG_X BPF_REG_7
+#define BPF_REG_TMP BPF_REG_8
+
+/* BPF program can access up to 512 bytes of stack space. */
+#define MAX_BPF_STACK 512
+
+/* Helper macros for filter block array initializers. */
+
+/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
+
+#define BPF_ALU64_REG(OP, DST, SRC) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = 0, \
+ .imm = 0 })
+
+#define BPF_ALU32_REG(OP, DST, SRC) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = 0, \
+ .imm = 0 })
+
+/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
+
+#define BPF_ALU64_IMM(OP, DST, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
+ .dst_reg = DST, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = IMM })
+
+#define BPF_ALU32_IMM(OP, DST, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
+ .dst_reg = DST, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = IMM })
+
+/* Endianness conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
+
+#define BPF_ENDIAN(TYPE, DST, LEN) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
+ .dst_reg = DST, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = LEN })
+
+/* Short form of mov, dst_reg = src_reg */
+
+#define BPF_MOV64_REG(DST, SRC) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_MOV | BPF_X, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = 0, \
+ .imm = 0 })
+
+#define BPF_MOV32_REG(DST, SRC) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU | BPF_MOV | BPF_X, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = 0, \
+ .imm = 0 })
+
+/* Short form of mov, dst_reg = imm32 */
+
+#define BPF_MOV64_IMM(DST, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_MOV | BPF_K, \
+ .dst_reg = DST, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = IMM })
+
+#define BPF_MOV32_IMM(DST, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU | BPF_MOV | BPF_K, \
+ .dst_reg = DST, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = IMM })
+
+/* Short form of mov based on type,
+ * BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32
+ */
+
+#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = 0, \
+ .imm = IMM })
+
+#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = 0, \
+ .imm = IMM })
+
+/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
+
+#define BPF_LD_ABS(SIZE, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
+ .dst_reg = 0, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = IMM })
+
+/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
+
+#define BPF_LD_IND(SIZE, SRC, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
+ .dst_reg = 0, \
+ .src_reg = SRC, \
+ .off = 0, \
+ .imm = IMM })
+
+/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
+
+#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
+ ((struct bpf_insn) { \
+ .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = OFF, \
+ .imm = 0 })
+
+/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
+
+#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
+ ((struct bpf_insn) { \
+ .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = OFF, \
+ .imm = 0 })
+
+/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
+
+#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
+ ((struct bpf_insn) { \
+ .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
+ .dst_reg = DST, \
+ .src_reg = 0, \
+ .off = OFF, \
+ .imm = IMM })
+
+/* Conditional jumps against registers,
+ * if (dst_reg 'op' src_reg) goto pc + off16
+ */
+
+#define BPF_JMP_REG(OP, DST, SRC, OFF) \
+ ((struct bpf_insn) { \
+ .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = OFF, \
+ .imm = 0 })
+
+/* Conditional jumps against immediates,
+ * if (dst_reg 'op' imm32) goto pc + off16
+ */
+
+#define BPF_JMP_IMM(OP, DST, IMM, OFF) \
+ ((struct bpf_insn) { \
+ .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
+ .dst_reg = DST, \
+ .src_reg = 0, \
+ .off = OFF, \
+ .imm = IMM })
+
+/* Function call */
+
+#define BPF_EMIT_CALL(FUNC) \
+ ((struct bpf_insn) { \
+ .code = BPF_JMP | BPF_CALL, \
+ .dst_reg = 0, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = ((FUNC) - BPF_FUNC_unspec) })
+
+/* Raw code statement block */
+
+#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
+ ((struct bpf_insn) { \
+ .code = CODE, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = OFF, \
+ .imm = IMM })
+
+/* Program exit */
+
+#define BPF_EXIT_INSN() \
+ ((struct bpf_insn) { \
+ .code = BPF_JMP | BPF_EXIT, \
+ .dst_reg = 0, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = 0 })
+
+#endif /* __TOOLS_LINUX_FILTER_H */
diff --git a/tools/perf/MANIFEST b/tools/perf/MANIFEST
index 1b42f7c..b0b3998 100644
--- a/tools/perf/MANIFEST
+++ b/tools/perf/MANIFEST
@@ -43,6 +43,7 @@ tools/include/linux/compiler.h
tools/include/linux/export.h
tools/include/linux/hash.h
tools/include/linux/kernel.h
+tools/include/linux/filter.h
tools/include/linux/list.h
tools/include/linux/log2.h
tools/include/linux/poison.h
--
1.8.3.4
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 26/39] perf tools: Suppress probing messages when probing by BPF loading |
| Message-ID | <pKjr4-dD-21@gated-at.bofh.it> |
| In reply to | #1180696 |
This patch suppress message output by add_perf_probe_events() and
del_perf_probe_events() if they are triggered by BPF loading. Before
this patch, when using 'perf record' with BPF object/source as event
selector, following message will be output:
Added new event:
perf_bpf_probe:lock_page_ret (on __lock_page%return)
You can now use it in all perf tools, such as:
perf record -e perf_bpf_probe:lock_page_ret -aR sleep 1
...
Removed event: perf_bpf_probe:lock_page_ret
Which is misleading, especially 'use it in all perf tools' because they
will be removed after 'pref record' exit.
In this patch, a 'silent' field is appended into probe_conf to control
output. bpf__{,un}probe() set it to true when calling
{add,del}_perf_probe_events().
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/bpf-loader.c | 6 ++++++
tools/perf/util/probe-event.c | 22 ++++++++++++++++------
tools/perf/util/probe-event.h | 1 +
3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 7a152ad..bd2ebe1 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -199,6 +199,7 @@ static bool is_probing;
int bpf__unprobe(void)
{
struct strfilter *delfilter;
+ bool old_silent = probe_conf.silent;
int ret;
if (!is_probing)
@@ -210,7 +211,9 @@ int bpf__unprobe(void)
return -ENOMEM;
}
+ probe_conf.silent = true;
ret = del_perf_probe_events(delfilter);
+ probe_conf.silent = old_silent;
strfilter__delete(delfilter);
if (ret < 0 && is_probing)
pr_err("Error: failed to delete events: %s\n",
@@ -223,15 +226,18 @@ int bpf__unprobe(void)
int bpf__probe(void)
{
int err;
+ bool old_silent = probe_conf.silent;
if (nr_probe_events <= 0)
return 0;
+ probe_conf.silent = true;
probe_conf.max_probes = MAX_PROBES;
/* Let add_perf_probe_events keeps probe_trace_event */
err = add_perf_probe_events(probe_event_array,
nr_probe_events,
false);
+ probe_conf.silent = old_silent;
/* add_perf_probe_events return negative when fail */
if (err < 0)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 083e8b4..b9573c5 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -51,7 +51,9 @@
#define PERFPROBE_GROUP "probe"
bool probe_event_dry_run; /* Dry run flag */
-struct probe_conf probe_conf;
+struct probe_conf probe_conf = {
+ .silent = false,
+};
#define semantic_error(msg ...) pr_err("Semantic error :" msg)
@@ -2250,10 +2252,12 @@ static int show_perf_probe_event(const char *group, const char *event,
ret = perf_probe_event__sprintf(group, event, pev, module, &buf);
if (ret >= 0) {
- if (use_stdout)
+ if (use_stdout && !probe_conf.silent)
printf("%s\n", buf.buf);
- else
+ else if (!probe_conf.silent)
pr_info("%s\n", buf.buf);
+ else
+ pr_debug("%s\n", buf.buf);
}
strbuf_release(&buf);
@@ -2512,7 +2516,10 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
safename = (pev->point.function && !strisglob(pev->point.function));
ret = 0;
- pr_info("Added new event%s\n", (ntevs > 1) ? "s:" : ":");
+ if (!probe_conf.silent)
+ pr_info("Added new event%s\n", (ntevs > 1) ? "s:" : ":");
+ else
+ pr_debug("Added new event%s\n", (ntevs > 1) ? "s:" : ":");
for (i = 0; i < ntevs; i++) {
tev = &tevs[i];
/* Skip if the symbol is out of .text or blacklisted */
@@ -2569,7 +2576,7 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
warn_uprobe_event_compat(tev);
/* Note that it is possible to skip all events because of blacklist */
- if (ret >= 0 && event) {
+ if (ret >= 0 && event && !probe_conf.silent) {
/* Show how to use the event. */
pr_info("\nYou can now use it in all perf tools, such as:\n\n");
pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
@@ -2865,7 +2872,10 @@ static int __del_trace_probe_event(int fd, struct str_node *ent)
goto error;
}
- pr_info("Removed event: %s\n", ent->s);
+ if (!probe_conf.silent)
+ pr_info("Removed event: %s\n", ent->s);
+ else
+ pr_debug("Removed event: %s\n", ent->s);
return 0;
error:
pr_warning("Failed to delete event: %s\n",
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 4b7a951..116b0aa 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -13,6 +13,7 @@ struct probe_conf {
bool force_add;
bool no_inlines;
int max_probes;
+ bool silent;
};
extern struct probe_conf probe_conf;
extern bool probe_event_dry_run;
--
1.8.3.4
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 28/39] bpf tools: Load a program with different instances using preprocessor |
| Message-ID | <pKjr4-dD-23@gated-at.bofh.it> |
| In reply to | #1180696 |
In this patch, caller of libbpf is able to control the loaded programs
by installing a preprocessor callback for a BPF program. With
preprocessor, different instances can be created from one BPF program.
This patch will be used by perf to generate different prologue for
different 'struct probe_trace_event' instances matched by one
'struct perf_probe_event'.
bpf_program__set_prep() is added to support this feature. Caller
should pass libbpf the number of instances should be created and a
preprocessor function which will be called when doing real loading.
The callback should return instructions arrays for each instances.
fd field in bpf_programs is replaced by instance, which has an nr field
and fds array. bpf_program__nth_fd() is introduced for read fd of
instances. Old interface bpf_program__fd() is reimplemented by
returning the first fd.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: He Kuang <hekuang@huawei.com>
---
tools/lib/bpf/libbpf.c | 138 +++++++++++++++++++++++++++++++++++++++++++++----
tools/lib/bpf/libbpf.h | 22 ++++++++
2 files changed, 151 insertions(+), 9 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b37aab1..6fcd042 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -98,7 +98,11 @@ struct bpf_program {
} *reloc_desc;
int nr_reloc;
- int fd;
+ struct {
+ int nr;
+ int *fds;
+ } instance;
+ bpf_program_prep_t preprocessor;
struct bpf_object *obj;
void *priv;
@@ -152,10 +156,19 @@ struct bpf_object {
static void bpf_program__unload(struct bpf_program *prog)
{
+ int i;
+
if (!prog)
return;
- zclose(prog->fd);
+ if (prog->instance.nr < 0)
+ pr_warning("Internal error when unloading: instance is %d\n",
+ prog->instance.nr);
+ else
+ for (i = 0; i < prog->instance.nr; i++)
+ zclose(prog->instance.fds[i]);
+ prog->instance.nr = -1;
+ zfree(&prog->instance.fds);
}
static void bpf_program__clear(struct bpf_program *prog)
@@ -206,7 +219,8 @@ __bpf_program__new(void *data, size_t size, char *name, int idx,
memcpy(prog->insns, data,
prog->insns_cnt * sizeof(struct bpf_insn));
prog->idx = idx;
- prog->fd = -1;
+ prog->instance.fds = NULL;
+ prog->instance.nr = -1;
return 0;
errout:
@@ -798,13 +812,71 @@ static int
bpf_program__load(struct bpf_program *prog,
char *license, u32 kern_version)
{
- int err, fd;
+ int err = 0, fd, i;
+
+ if (prog->instance.nr < 0 || !prog->instance.fds) {
+ if (prog->preprocessor) {
+ pr_warning("Internal error: can't load program '%s'\n",
+ prog->section_name);
+ return -EINVAL;
+ }
- err = load_program(prog->insns, prog->insns_cnt,
- license, kern_version, &fd);
- if (!err)
- prog->fd = fd;
+ prog->instance.fds = malloc(sizeof(int));
+ if (prog->instance.fds) {
+ pr_warning("No enough memory for fds\n");
+ return -ENOMEM;
+ }
+ prog->instance.nr = 1;
+ prog->instance.fds[0] = -1;
+ }
+
+ if (!prog->preprocessor) {
+ if (prog->instance.nr != 1)
+ pr_warning("Program '%s' inconsistent: nr(%d) not 1\n",
+ prog->section_name, prog->instance.nr);
+
+ err = load_program(prog->insns, prog->insns_cnt,
+ license, kern_version, &fd);
+ if (!err)
+ prog->instance.fds[0] = fd;
+ goto out;
+ }
+
+ for (i = 0; i < prog->instance.nr; i++) {
+ struct bpf_prog_prep_result result;
+ bpf_program_prep_t preprocessor = prog->preprocessor;
+
+ bzero(&result, sizeof(result));
+ err = preprocessor(prog, i, prog->insns,
+ prog->insns_cnt, &result);
+ if (err) {
+ pr_warning("Preprocessing %dth instance of program '%s' failed\n",
+ i, prog->section_name);
+ goto out;
+ }
+
+ if (!result.new_insn_ptr || !result.new_insn_cnt) {
+ pr_debug("Skip loading %dth instance of program '%s'\n",
+ i, prog->section_name);
+ prog->instance.fds[i] = -1;
+ continue;
+ }
+
+ err = load_program(result.new_insn_ptr,
+ result.new_insn_cnt,
+ license, kern_version, &fd);
+
+ if (err) {
+ pr_warning("Loading %dth instance of program '%s' failed\n",
+ i, prog->section_name);
+ goto out;
+ }
+ if (result.pfd)
+ *result.pfd = fd;
+ prog->instance.fds[i] = fd;
+ }
+out:
if (err)
pr_warning("failed to load program '%s'\n",
prog->section_name);
@@ -1036,5 +1108,53 @@ const char *bpf_program__title(struct bpf_program *prog, bool dup)
int bpf_program__fd(struct bpf_program *prog)
{
- return prog->fd;
+ return bpf_program__nth_fd(prog, 0);
+}
+
+int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
+ bpf_program_prep_t prep)
+{
+ int *instance_fds;
+
+ if (nr_instance <= 0 || !prep)
+ return -EINVAL;
+
+ if (prog->instance.nr > 0 || prog->instance.fds) {
+ pr_warning("Can't set pre-processor after loading\n");
+ return -EINVAL;
+ }
+
+ instance_fds = malloc(sizeof(int) * nr_instance);
+ if (!instance_fds) {
+ pr_warning("alloc memory failed for instance of fds\n");
+ return -ENOMEM;
+ }
+
+ /* fill all fd with -1 */
+ memset(instance_fds, 0xff, sizeof(int) * nr_instance);
+
+ prog->instance.nr = nr_instance;
+ prog->instance.fds = instance_fds;
+ prog->preprocessor = prep;
+ return 0;
+}
+
+int bpf_program__nth_fd(struct bpf_program *prog, int n)
+{
+ int fd;
+
+ if (n >= prog->instance.nr || n < 0) {
+ pr_warning("Can't get the %dth fd from program %s: only %d instances\n",
+ n, prog->section_name, prog->instance.nr);
+ return -EINVAL;
+ }
+
+ fd = prog->instance.fds[n];
+ if (fd < 0) {
+ pr_warning("%dth instance of program '%s' is invalid\n",
+ n, prog->section_name);
+ return -ENOENT;
+ }
+
+ return fd;
}
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index ea8adc2..9fa7b09 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -65,6 +65,28 @@ const char *bpf_program__title(struct bpf_program *prog, bool dup);
int bpf_program__fd(struct bpf_program *prog);
+struct bpf_insn;
+struct bpf_prog_prep_result {
+ /*
+ * If not NULL, load new instruction array.
+ * If set to NULL, don't load this instance.
+ */
+ struct bpf_insn *new_insn_ptr;
+ int new_insn_cnt;
+
+ /* If not NULL, result fd is set to it */
+ int *pfd;
+};
+
+typedef int (*bpf_program_prep_t)(struct bpf_program *, int n,
+ struct bpf_insn *, int insn_cnt,
+ struct bpf_prog_prep_result *res);
+
+int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
+ bpf_program_prep_t prep);
+
+int bpf_program__nth_fd(struct bpf_program *prog, int n);
+
/*
* We don't need __attribute__((packed)) now since it is
* unnecessary for 'bpf_map_def' because they are all aligned.
--
1.8.3.4
--
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[toc] | [prev] | [next] | [standalone]
| From | "Wangnan (F)" <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-13 08:00 +0200 |
| Subject | Re: [PATCH 28/39] bpf tools: Load a program with different instances using preprocessor |
| Message-ID | <pLEWu-1cJ-7@gated-at.bofh.it> |
| In reply to | #1180706 |
On 2015/7/9 20:35, Wang Nan wrote:
> In this patch, caller of libbpf is able to control the loaded programs
> by installing a preprocessor callback for a BPF program. With
> preprocessor, different instances can be created from one BPF program.
>
> This patch will be used by perf to generate different prologue for
> different 'struct probe_trace_event' instances matched by one
> 'struct perf_probe_event'.
>
> bpf_program__set_prep() is added to support this feature. Caller
> should pass libbpf the number of instances should be created and a
> preprocessor function which will be called when doing real loading.
> The callback should return instructions arrays for each instances.
>
> fd field in bpf_programs is replaced by instance, which has an nr field
> and fds array. bpf_program__nth_fd() is introduced for read fd of
> instances. Old interface bpf_program__fd() is reimplemented by
> returning the first fd.
>
> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> Signed-off-by: He Kuang <hekuang@huawei.com>
> ---
> tools/lib/bpf/libbpf.c | 138 +++++++++++++++++++++++++++++++++++++++++++++----
> tools/lib/bpf/libbpf.h | 22 ++++++++
> 2 files changed, 151 insertions(+), 9 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index b37aab1..6fcd042 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -98,7 +98,11 @@ struct bpf_program {
> } *reloc_desc;
> int nr_reloc;
>
> - int fd;
> + struct {
> + int nr;
> + int *fds;
> + } instance;
> + bpf_program_prep_t preprocessor;
>
> struct bpf_object *obj;
> void *priv;
> @@ -152,10 +156,19 @@ struct bpf_object {
>
> static void bpf_program__unload(struct bpf_program *prog)
> {
> + int i;
> +
> if (!prog)
> return;
>
> - zclose(prog->fd);
> + if (prog->instance.nr < 0)
> + pr_warning("Internal error when unloading: instance is %d\n",
> + prog->instance.nr);
> + else
> + for (i = 0; i < prog->instance.nr; i++)
> + zclose(prog->instance.fds[i]);
> + prog->instance.nr = -1;
> + zfree(&prog->instance.fds);
> }
>
> static void bpf_program__clear(struct bpf_program *prog)
> @@ -206,7 +219,8 @@ __bpf_program__new(void *data, size_t size, char *name, int idx,
> memcpy(prog->insns, data,
> prog->insns_cnt * sizeof(struct bpf_insn));
> prog->idx = idx;
> - prog->fd = -1;
> + prog->instance.fds = NULL;
> + prog->instance.nr = -1;
>
> return 0;
> errout:
> @@ -798,13 +812,71 @@ static int
> bpf_program__load(struct bpf_program *prog,
> char *license, u32 kern_version)
> {
> - int err, fd;
> + int err = 0, fd, i;
> +
> + if (prog->instance.nr < 0 || !prog->instance.fds) {
> + if (prog->preprocessor) {
> + pr_warning("Internal error: can't load program '%s'\n",
> + prog->section_name);
> + return -EINVAL;
> + }
>
> - err = load_program(prog->insns, prog->insns_cnt,
> - license, kern_version, &fd);
> - if (!err)
> - prog->fd = fd;
> + prog->instance.fds = malloc(sizeof(int));
> + if (prog->instance.fds) {
I lost a '!' here. Should be:
+ if (!prog->instance.fds) {
...
My github tree has updated. Please check:
https://github.com/WangNan0/linux.git perf/ebpf-for-acme
> + pr_warning("No enough memory for fds\n");
> + return -ENOMEM;
> + }
> + prog->instance.nr = 1;
> + prog->instance.fds[0] = -1;
> + }
> +
> + if (!prog->preprocessor) {
> + if (prog->instance.nr != 1)
> + pr_warning("Program '%s' inconsistent: nr(%d) not 1\n",
> + prog->section_name, prog->instance.nr);
> +
> + err = load_program(prog->insns, prog->insns_cnt,
> + license, kern_version, &fd);
> + if (!err)
> + prog->instance.fds[0] = fd;
> + goto out;
> + }
> +
> + for (i = 0; i < prog->instance.nr; i++) {
> + struct bpf_prog_prep_result result;
> + bpf_program_prep_t preprocessor = prog->preprocessor;
> +
> + bzero(&result, sizeof(result));
> + err = preprocessor(prog, i, prog->insns,
> + prog->insns_cnt, &result);
> + if (err) {
> + pr_warning("Preprocessing %dth instance of program '%s' failed\n",
> + i, prog->section_name);
> + goto out;
> + }
> +
> + if (!result.new_insn_ptr || !result.new_insn_cnt) {
> + pr_debug("Skip loading %dth instance of program '%s'\n",
> + i, prog->section_name);
> + prog->instance.fds[i] = -1;
> + continue;
> + }
> +
> + err = load_program(result.new_insn_ptr,
> + result.new_insn_cnt,
> + license, kern_version, &fd);
> +
> + if (err) {
> + pr_warning("Loading %dth instance of program '%s' failed\n",
> + i, prog->section_name);
> + goto out;
> + }
>
> + if (result.pfd)
> + *result.pfd = fd;
> + prog->instance.fds[i] = fd;
> + }
> +out:
> if (err)
> pr_warning("failed to load program '%s'\n",
> prog->section_name);
> @@ -1036,5 +1108,53 @@ const char *bpf_program__title(struct bpf_program *prog, bool dup)
>
> int bpf_program__fd(struct bpf_program *prog)
> {
> - return prog->fd;
> + return bpf_program__nth_fd(prog, 0);
> +}
> +
> +int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
> + bpf_program_prep_t prep)
> +{
> + int *instance_fds;
> +
> + if (nr_instance <= 0 || !prep)
> + return -EINVAL;
> +
> + if (prog->instance.nr > 0 || prog->instance.fds) {
> + pr_warning("Can't set pre-processor after loading\n");
> + return -EINVAL;
> + }
> +
> + instance_fds = malloc(sizeof(int) * nr_instance);
> + if (!instance_fds) {
> + pr_warning("alloc memory failed for instance of fds\n");
> + return -ENOMEM;
> + }
> +
> + /* fill all fd with -1 */
> + memset(instance_fds, 0xff, sizeof(int) * nr_instance);
> +
> + prog->instance.nr = nr_instance;
> + prog->instance.fds = instance_fds;
> + prog->preprocessor = prep;
> + return 0;
> +}
> +
> +int bpf_program__nth_fd(struct bpf_program *prog, int n)
> +{
> + int fd;
> +
> + if (n >= prog->instance.nr || n < 0) {
> + pr_warning("Can't get the %dth fd from program %s: only %d instances\n",
> + n, prog->section_name, prog->instance.nr);
> + return -EINVAL;
> + }
> +
> + fd = prog->instance.fds[n];
> + if (fd < 0) {
> + pr_warning("%dth instance of program '%s' is invalid\n",
> + n, prog->section_name);
> + return -ENOENT;
> + }
> +
> + return fd;
> }
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index ea8adc2..9fa7b09 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -65,6 +65,28 @@ const char *bpf_program__title(struct bpf_program *prog, bool dup);
>
> int bpf_program__fd(struct bpf_program *prog);
>
> +struct bpf_insn;
> +struct bpf_prog_prep_result {
> + /*
> + * If not NULL, load new instruction array.
> + * If set to NULL, don't load this instance.
> + */
> + struct bpf_insn *new_insn_ptr;
> + int new_insn_cnt;
> +
> + /* If not NULL, result fd is set to it */
> + int *pfd;
> +};
> +
> +typedef int (*bpf_program_prep_t)(struct bpf_program *, int n,
> + struct bpf_insn *, int insn_cnt,
> + struct bpf_prog_prep_result *res);
> +
> +int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
> + bpf_program_prep_t prep);
> +
> +int bpf_program__nth_fd(struct bpf_program *prog, int n);
> +
> /*
> * We don't need __attribute__((packed)) now since it is
> * unnecessary for 'bpf_map_def' because they are all aligned.
--
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[toc] | [prev] | [next] | [standalone]
| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 13/39] perf tools: Call clang to compile C source to object code |
| Message-ID | <pKjr4-dD-29@gated-at.bofh.it> |
| In reply to | #1180696 |
This is the core patch for supporting eBPF on-the-fly compiling, does
the following work:
1. Search clang compiler using search_program().
2. Run command template defined in llvm-bpf-cmd-template option in
[llvm] config section using read_from_pipe(). Patch of clang and
source code path is injected into shell command using environment
variable using force_set_env().
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/llvm-utils.c | 225 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/llvm-utils.h | 3 +
2 files changed, 228 insertions(+)
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index fd5b1bc..dca16e7 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -43,3 +43,228 @@ int perf_llvm_config(const char *var, const char *value)
return -1;
return 0;
}
+
+static int
+search_program(const char *def, const char *name,
+ char *output)
+{
+ char *env, *path, *tmp;
+ char buf[PATH_MAX];
+ int ret;
+
+ output[0] = '\0';
+ if (def && def[0] != '\0') {
+ if (def[0] == '/') {
+ if (access(def, F_OK) == 0) {
+ strlcpy(output, def, PATH_MAX);
+ return 0;
+ }
+ } else if (def[0] != '\0')
+ name = def;
+ }
+
+ env = getenv("PATH");
+ if (!env)
+ return -1;
+ env = strdup(env);
+ if (!env)
+ return -1;
+
+ ret = -ENOENT;
+ path = strtok_r(env, ":", &tmp);
+ while (path) {
+ scnprintf(buf, sizeof(buf), "%s/%s", path, name);
+ if (access(buf, F_OK) == 0) {
+ strlcpy(output, buf, PATH_MAX);
+ ret = 0;
+ break;
+ }
+ path = strtok_r(NULL, ":", &tmp);
+ }
+
+ free(env);
+ return ret;
+}
+
+#define READ_SIZE 4096
+static int
+read_from_pipe(const char *cmd, void **p_buf, size_t *p_read_sz)
+{
+ int err = 0;
+ void *buf = NULL;
+ FILE *file = NULL;
+ size_t read_sz = 0, buf_sz = 0;
+
+ file = popen(cmd, "r");
+ if (!file) {
+ pr_err("ERROR: unable to popen cmd: %s\n",
+ strerror(errno));
+ return -EINVAL;
+ }
+
+ while (!feof(file) && !ferror(file)) {
+ /*
+ * Make buf_sz always have obe byte extra space so we
+ * can put '\0' there.
+ */
+ if (buf_sz - read_sz < READ_SIZE + 1) {
+ void *new_buf;
+
+ buf_sz = read_sz + READ_SIZE + 1;
+ new_buf = realloc(buf, buf_sz);
+
+ if (!new_buf) {
+ pr_err("ERROR: failed to realloc memory\n");
+ err = -ENOMEM;
+ goto errout;
+ }
+
+ buf = new_buf;
+ }
+ read_sz += fread(buf + read_sz, 1, READ_SIZE, file);
+ }
+
+ if (buf_sz - read_sz < 1) {
+ pr_err("ERROR: internal error\n");
+ err = -EINVAL;
+ goto errout;
+ }
+
+ if (ferror(file)) {
+ pr_err("ERROR: error occurred when reading from pipe: %s\n",
+ strerror(errno));
+ err = -EIO;
+ goto errout;
+ }
+
+ err = WEXITSTATUS(pclose(file));
+ file = NULL;
+ if (err) {
+ err = -EINVAL;
+ goto errout;
+ }
+
+ /*
+ * If buf is string, give it terminal '\0' to make our life
+ * easier. If buf is not string, that '\0' is out of space
+ * indicated by read_sz so caller won't even notice it.
+ */
+ ((char *)buf)[read_sz] = '\0';
+
+ if (!p_buf)
+ free(buf);
+ else
+ *p_buf = buf;
+
+ if (p_read_sz)
+ *p_read_sz = read_sz;
+ return 0;
+
+errout:
+ if (file)
+ pclose(file);
+ free(buf);
+ if (p_buf)
+ *p_buf = NULL;
+ if (p_read_sz)
+ *p_read_sz = 0;
+ return err;
+}
+
+static inline void
+force_set_env(const char *var, const char *value)
+{
+ if (value) {
+ setenv(var, value, 1);
+ pr_debug("set env: %s=%s\n", var, value);
+ } else {
+ unsetenv(var);
+ pr_debug("unset env: %s\n", var);
+ }
+}
+
+static void
+version_notice(void)
+{
+ pr_err(
+" \tLLVM 3.7 or newer is required. Which can be found from http://llvm.org\n"
+" \tYou may want to try git trunk:\n"
+" \t\tgit clone http://llvm.org/git/llvm.git\n"
+" \t\t and\n"
+" \t\tgit clone http://llvm.org/git/clang.git\n\n"
+" \tOr fetch the latest clang/llvm 3.7 from pre-built llvm packages for\n"
+" \tdebian/ubuntu:\n"
+" \t\thttp://llvm.org/apt\n\n"
+" \tIf you are using old version of clang, change 'clang-bpf-cmd-template'\n"
+" \toption in [llvm] section of ~/.perfconfig to:\n\n"
+" \t \"$CLANG_EXEC $CLANG_OPTIONS $KERNEL_INC_OPTIONS \\\n"
+" \t -working-directory $WORKING_DIR -c $CLANG_SOURCE \\\n"
+" \t -emit-llvm -o - | /path/to/llc -march=bpf -filetype=obj -o -\"\n"
+" \t(Replace /path/to/llc with path to your llc)\n\n"
+);
+}
+
+int llvm__compile_bpf(const char *path, void **p_obj_buf,
+ size_t *p_obj_buf_sz)
+{
+ int err;
+ char clang_path[PATH_MAX];
+ const char *clang_opt = llvm_param.clang_opt;
+ const char *template = llvm_param.clang_bpf_cmd_template;
+ void *obj_buf = NULL;
+ size_t obj_buf_sz;
+
+ if (!template)
+ template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;
+
+ err = search_program(llvm_param.clang_path,
+ "clang", clang_path);
+ if (err) {
+ pr_err(
+"ERROR:\tunable to find clang.\n"
+"Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
+" \tand 'clang-path' option in [llvm] section of ~/.perfconfig.\n");
+ version_notice();
+ return -ENOENT;
+ }
+
+ force_set_env("CLANG_EXEC", clang_path);
+ force_set_env("CLANG_OPTIONS", clang_opt);
+ force_set_env("KERNEL_INC_OPTIONS", NULL);
+ force_set_env("WORKING_DIR", ".");
+
+ /*
+ * Since we may reset clang's working dir, path of source file
+ * should be transferred into absolute path, except we want
+ * stdin to be source file (testing).
+ */
+ force_set_env("CLANG_SOURCE",
+ (path[0] == '-') ? path :
+ make_nonrelative_path(path));
+
+ pr_debug("llvm compiling command template: %s\n", template);
+ err = read_from_pipe(template, &obj_buf, &obj_buf_sz);
+ if (err) {
+ pr_err("ERROR:\tunable to compile %s\n", path);
+ pr_err("Hint:\tCheck error message shown above.\n");
+ version_notice();
+ pr_err("Hint:\tYou can also pre-compile it into .o\n");
+ goto errout;
+ }
+
+ if (!p_obj_buf)
+ free(obj_buf);
+ else
+ *p_obj_buf = obj_buf;
+
+ if (p_obj_buf_sz)
+ *p_obj_buf_sz = obj_buf_sz;
+ return 0;
+errout:
+ free(obj_buf);
+ if (p_obj_buf)
+ *p_obj_buf = NULL;
+ if (p_obj_buf_sz)
+ *p_obj_buf_sz = 0;
+ return err;
+}
diff --git a/tools/perf/util/llvm-utils.h b/tools/perf/util/llvm-utils.h
index 504b799..d23adbc 100644
--- a/tools/perf/util/llvm-utils.h
+++ b/tools/perf/util/llvm-utils.h
@@ -33,4 +33,7 @@ struct llvm_param {
extern struct llvm_param llvm_param;
extern int perf_llvm_config(const char *var, const char *value);
+
+extern int llvm__compile_bpf(const char *path, void **p_obj_buf,
+ size_t *p_obj_buf_sz);
#endif
--
1.8.3.4
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 32/39] perf tools: Add BPF_PROLOGUE config options for further patches |
| Message-ID | <pKjr5-dD-33@gated-at.bofh.it> |
| In reply to | #1180696 |
If both LIBBPF and DWARF is detected, it is possible to create prologue
for eBPF programs to help them accessing kernel data. HAVE_BPF_PROLOGUE
and CONFIG_BPF_PROLOGUE is added as flags for this feature.
PERF_HAVE_ARCH_GET_REG_OFFSET indicates an architecture supports
converting name of a register to its offset in 'struct pt_regs'.
Without this support, BPF_PROLOGUE should be turned off.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/config/Makefile | 12 ++++++++++++
tools/perf/util/include/dwarf-regs.h | 7 +++++++
2 files changed, 19 insertions(+)
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index 52722cf..d776f32 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -310,6 +310,18 @@ ifndef NO_LIBELF
CFLAGS += -DHAVE_LIBBPF_SUPPORT
$(call detected,CONFIG_LIBBPF)
endif
+
+ ifndef NO_DWARF
+ ifneq ($(origin PERF_HAVE_ARCH_GET_REG_INFO), undefined)
+ CFLAGS += -DHAVE_BPF_PROLOGUE
+ $(call detected,CONFIG_BPF_PROLOGUE)
+ else
+ msg := $(warning BPF prologue is not supported by architecture $(ARCH));
+ endif
+ else
+ msg := $(warning DWARF support is off, BPF prologue is disabled);
+ endif
+
endif # NO_LIBBPF
endif # NO_LIBELF
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
index 8f14965..3dda083 100644
--- a/tools/perf/util/include/dwarf-regs.h
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -5,4 +5,11 @@
const char *get_arch_regstr(unsigned int n);
#endif
+#ifdef HAVE_BPF_PROLOGUE
+/*
+ * Arch should support fetching the offset of a register in pt_regs
+ * by its name.
+ */
+int arch_get_reg_info(const char *name, int *offset);
+#endif
#endif
--
1.8.3.4
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 06/39] bpf tools: Create eBPF maps defined in an object file |
| Message-ID | <pKjr5-dD-35@gated-at.bofh.it> |
| In reply to | #1180696 |
This patch creates maps based on 'map' section in object file using
bpf_create_map(), and stores the fds into an array in 'struct
bpf_object'.
Previous patches parse ELF object file and collects required data, but
doesn't play with the kernel. They belong to the 'opening' phase. This
patch is the first patch in 'loading' phase. The 'loaded' field is
introduced in 'struct bpf_object' to avoid loading an object twice,
because the loading phase clears resources collected during the opening
which becomes useless after loading. In this patch, maps_buf is cleared.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-17-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/lib/bpf/libbpf.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++
tools/lib/bpf/libbpf.h | 4 ++
2 files changed, 106 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 4f13772..c214e1c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -21,6 +21,7 @@
#include <gelf.h>
#include "libbpf.h"
+#include "bpf.h"
#define __printf(a, b) __attribute__((format(printf, a, b)))
@@ -105,6 +106,13 @@ struct bpf_object {
struct bpf_program *programs;
size_t nr_programs;
+ int *map_fds;
+ /*
+ * This field is required because maps_buf will be freed and
+ * maps_buf_sz will be set to 0 after loaded.
+ */
+ size_t nr_map_fds;
+ bool loaded;
/*
* Information when doing elf related work. Only valid if fd
@@ -232,6 +240,7 @@ static struct bpf_object *bpf_object__new(const char *path,
obj->efile.obj_buf = obj_buf;
obj->efile.obj_buf_sz = obj_buf_sz;
+ obj->loaded = false;
return obj;
}
@@ -568,6 +577,62 @@ bpf_program__collect_reloc(struct bpf_program *prog,
return 0;
}
+static int
+bpf_object__create_maps(struct bpf_object *obj)
+{
+ unsigned int i;
+ size_t nr_maps;
+ int *pfd;
+
+ nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def);
+ if (!obj->maps_buf || !nr_maps) {
+ pr_debug("don't need create maps for %s\n",
+ obj->path);
+ return 0;
+ }
+
+ obj->map_fds = malloc(sizeof(int) * nr_maps);
+ if (!obj->map_fds) {
+ pr_warning("realloc perf_bpf_map_fds failed\n");
+ return -ENOMEM;
+ }
+ obj->nr_map_fds = nr_maps;
+
+ /* fill all fd with -1 */
+ memset(obj->map_fds, 0xff, sizeof(int) * nr_maps);
+
+ pfd = obj->map_fds;
+ for (i = 0; i < nr_maps; i++) {
+ struct bpf_map_def def;
+
+ def = *(struct bpf_map_def *)(obj->maps_buf +
+ i * sizeof(struct bpf_map_def));
+
+ *pfd = bpf_create_map(def.type,
+ def.key_size,
+ def.value_size,
+ def.max_entries);
+ if (*pfd < 0) {
+ size_t j;
+ int err = *pfd;
+
+ pr_warning("failed to create map: %s\n",
+ strerror(errno));
+ for (j = 0; j < i; j++)
+ zclose(obj->map_fds[j]);
+ obj->nr_map_fds = 0;
+ zfree(&obj->map_fds);
+ return err;
+ }
+ pr_debug("create map: fd=%d\n", *pfd);
+ pfd++;
+ }
+
+ zfree(&obj->maps_buf);
+ obj->maps_buf_sz = 0;
+ return 0;
+}
+
static int bpf_object__collect_reloc(struct bpf_object *obj)
{
int i, err;
@@ -671,6 +736,42 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
return __bpf_object__open("[buffer]", obj_buf, obj_buf_sz);
}
+int bpf_object__unload(struct bpf_object *obj)
+{
+ size_t i;
+
+ if (!obj)
+ return -EINVAL;
+
+ for (i = 0; i < obj->nr_map_fds; i++)
+ zclose(obj->map_fds[i]);
+ zfree(&obj->map_fds);
+ obj->nr_map_fds = 0;
+
+ return 0;
+}
+
+int bpf_object__load(struct bpf_object *obj)
+{
+ if (!obj)
+ return -EINVAL;
+
+ if (obj->loaded) {
+ pr_warning("object should not be loaded twice\n");
+ return -EINVAL;
+ }
+
+ obj->loaded = true;
+ if (bpf_object__create_maps(obj))
+ goto out;
+
+ return 0;
+out:
+ bpf_object__unload(obj);
+ pr_warning("failed to load object '%s'\n", obj->path);
+ return -EINVAL;
+}
+
void bpf_object__close(struct bpf_object *obj)
{
size_t i;
@@ -679,6 +780,7 @@ void bpf_object__close(struct bpf_object *obj)
return;
bpf_object__elf_finish(obj);
+ bpf_object__unload(obj);
zfree(&obj->maps_buf);
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6e75acd..3e69600 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -30,6 +30,10 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
size_t obj_buf_sz);
void bpf_object__close(struct bpf_object *object);
+/* Load/unload object into/from kernel */
+int bpf_object__load(struct bpf_object *obj);
+int bpf_object__unload(struct bpf_object *obj);
+
/*
* We don't need __attribute__((packed)) now since it is
* unnecessary for 'bpf_map_def' because they are all aligned.
--
1.8.3.4
--
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[toc] | [prev] | [next] | [standalone]
| From | "Wangnan (F)" <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-14 06:10 +0200 |
| Subject | Re: [PATCH 06/39] bpf tools: Create eBPF maps defined in an object file |
| Message-ID | <pLZHz-5Td-7@gated-at.bofh.it> |
| In reply to | #1180711 |
On 2015/7/14 3:54, Arnaldo Carvalho de Melo wrote:
> Em Thu, Jul 09, 2015 at 12:35:09PM +0000, Wang Nan escreveu:
>
> <SNIP>
>
>> +static int
>> +bpf_object__create_maps(struct bpf_object *obj)
>> +{
>> + unsigned int i;
>> + size_t nr_maps;
>> + int *pfd;
>> +
>> + nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def);
>> + if (!obj->maps_buf || !nr_maps) {
>> + pr_debug("don't need create maps for %s\n",
>> + obj->path);
>> + return 0;
>> + }
>> +
>> + obj->map_fds = malloc(sizeof(int) * nr_maps);
>> + if (!obj->map_fds) {
>> + pr_warning("realloc perf_bpf_map_fds failed\n");
>> + return -ENOMEM;
>> + }
>> + obj->nr_map_fds = nr_maps;
>> +
>> + /* fill all fd with -1 */
>> + memset(obj->map_fds, 0xff, sizeof(int) * nr_maps);
> Huh? Each entry is an int... If you want to set it all to -1, why don't
> you do it as:
>
> memset(obj->map_fds, -1, sizeof(int) * nr_maps);
>
> That way we can even remove that comment :) Doing it, please let me know
> if this has some magic twist that makes it be right as-is, if so, please
> provide a better comment.
Yes, it should be better.
Thank you,
> - Arnaldo
>
>> +
>> + pfd = obj->map_fds;
>> + for (i = 0; i < nr_maps; i++) {
>> + struct bpf_map_def def;
>> +
>> + def = *(struct bpf_map_def *)(obj->maps_buf +
>> + i * sizeof(struct bpf_map_def));
>> +
>> + *pfd = bpf_create_map(def.type,
>> + def.key_size,
>> + def.value_size,
>> + def.max_entries);
>> + if (*pfd < 0) {
>> + size_t j;
>> + int err = *pfd;
>> +
>> + pr_warning("failed to create map: %s\n",
>> + strerror(errno));
>> + for (j = 0; j < i; j++)
>> + zclose(obj->map_fds[j]);
>> + obj->nr_map_fds = 0;
>> + zfree(&obj->map_fds);
>> + return err;
>> + }
>> + pr_debug("create map: fd=%d\n", *pfd);
>> + pfd++;
>> + }
>> +
>> + zfree(&obj->maps_buf);
>> + obj->maps_buf_sz = 0;
>> + return 0;
>> +}
>> +
>> static int bpf_object__collect_reloc(struct bpf_object *obj)
>> {
>> int i, err;
>> @@ -671,6 +736,42 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
>> return __bpf_object__open("[buffer]", obj_buf, obj_buf_sz);
>> }
>>
>> +int bpf_object__unload(struct bpf_object *obj)
>> +{
>> + size_t i;
>> +
>> + if (!obj)
>> + return -EINVAL;
>> +
>> + for (i = 0; i < obj->nr_map_fds; i++)
>> + zclose(obj->map_fds[i]);
>> + zfree(&obj->map_fds);
>> + obj->nr_map_fds = 0;
>> +
>> + return 0;
>> +}
>> +
>> +int bpf_object__load(struct bpf_object *obj)
>> +{
>> + if (!obj)
>> + return -EINVAL;
>> +
>> + if (obj->loaded) {
>> + pr_warning("object should not be loaded twice\n");
>> + return -EINVAL;
>> + }
>> +
>> + obj->loaded = true;
>> + if (bpf_object__create_maps(obj))
>> + goto out;
>> +
>> + return 0;
>> +out:
>> + bpf_object__unload(obj);
>> + pr_warning("failed to load object '%s'\n", obj->path);
>> + return -EINVAL;
>> +}
>> +
>> void bpf_object__close(struct bpf_object *obj)
>> {
>> size_t i;
>> @@ -679,6 +780,7 @@ void bpf_object__close(struct bpf_object *obj)
>> return;
>>
>> bpf_object__elf_finish(obj);
>> + bpf_object__unload(obj);
>>
>> zfree(&obj->maps_buf);
>>
>> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
>> index 6e75acd..3e69600 100644
>> --- a/tools/lib/bpf/libbpf.h
>> +++ b/tools/lib/bpf/libbpf.h
>> @@ -30,6 +30,10 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf,
>> size_t obj_buf_sz);
>> void bpf_object__close(struct bpf_object *object);
>>
>> +/* Load/unload object into/from kernel */
>> +int bpf_object__load(struct bpf_object *obj);
>> +int bpf_object__unload(struct bpf_object *obj);
>> +
>> /*
>> * We don't need __attribute__((packed)) now since it is
>> * unnecessary for 'bpf_map_def' because they are all aligned.
>> --
>> 1.8.3.4
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 35/39] perf tools: Generate prologue for BPF programs |
| Message-ID | <pKjr5-dD-37@gated-at.bofh.it> |
| In reply to | #1180696 |
This patch generates prologue for each 'struct probe_trace_event' for
fetching arguments for BPF programs.
After bpf__probe(), iterate over each programs to check whether
prologue is required. If none of 'struct perf_probe_event' a program
will attach to has at least one argument, simply skip preprocessor
hooking. For those who prologue is required, calls bpf__gen_prologue()
and paste original instruction after prologue.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/bpf-loader.c | 132 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 130 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index bd2ebe1..41bffdd 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -5,10 +5,12 @@
* Copyright (C) 2015 Huawei Inc.
*/
+#include <linux/bpf.h>
#include <bpf/libbpf.h>
#include "perf.h"
#include "debug.h"
#include "bpf-loader.h"
+#include "bpf-prologue.h"
#include "llvm-utils.h"
#include "probe-event.h"
#include "probe-finder.h"
@@ -53,6 +55,8 @@ alloc_perf_probe_event(void)
struct bpf_prog_priv {
struct perf_probe_event *pev;
+ bool need_prologue;
+ struct bpf_insn *insns_buf;
};
static void
@@ -63,6 +67,7 @@ bpf_prog_priv__clear(struct bpf_program *prog __maybe_unused,
if (priv->pev)
clear_perf_probe_event(priv->pev);
+ zfree(&priv->insns_buf);
free(priv);
}
@@ -223,10 +228,109 @@ int bpf__unprobe(void)
return ret < 0 ? ret : 0;
}
+static int
+preproc_gen_prologue(struct bpf_program *prog, int n,
+ struct bpf_insn *orig_insns, int orig_insns_cnt,
+ struct bpf_prog_prep_result *res)
+{
+ struct probe_trace_event *tev;
+ struct perf_probe_event *pev;
+ struct bpf_prog_priv *priv;
+ struct bpf_insn *buf;
+ size_t prologue_cnt = 0;
+ int err;
+
+ err = bpf_program__get_private(prog, (void **)&priv);
+ if (err || !priv)
+ goto errout;
+
+ pev = priv->pev;
+
+ if (n < 0 || n >= pev->ntevs)
+ goto errout;
+
+ tev = &pev->tevs[n];
+
+ buf = priv->insns_buf;
+ err = bpf__gen_prologue(tev->args, tev->nargs,
+ buf, &prologue_cnt,
+ BPF_MAXINSNS - orig_insns_cnt);
+ if (err) {
+ const char *title;
+
+ title = bpf_program__title(prog, false);
+ if (!title)
+ title = "??";
+
+ pr_err("Failed to generate prologue for program %s\n",
+ title);
+ return err;
+ }
+
+ memcpy(&buf[prologue_cnt], orig_insns,
+ sizeof(struct bpf_insn) * orig_insns_cnt);
+
+ res->new_insn_ptr = buf;
+ res->new_insn_cnt = prologue_cnt + orig_insns_cnt;
+ res->pfd = NULL;
+ return 0;
+
+errout:
+ pr_err("Internal error in preproc_gen_prologue\n");
+ return -EINVAL;
+}
+
+static int hook_load_preprocessor(struct bpf_program *prog)
+{
+ struct perf_probe_event *pev;
+ struct bpf_prog_priv *priv;
+ bool need_prologue = false;
+ int err, i;
+
+ err = bpf_program__get_private(prog, (void **)&priv);
+ if (err || !priv) {
+ pr_err("Internal error when hook preprocessor\n");
+ return -EINVAL;
+ }
+
+ pev = priv->pev;
+ for (i = 0; i < pev->ntevs; i++) {
+ struct probe_trace_event *tev = &pev->tevs[i];
+
+ if (tev->nargs > 0) {
+ need_prologue = true;
+ break;
+ }
+ }
+
+ /*
+ * Since all tev doesn't have argument, we don't need generate
+ * prologue.
+ */
+ if (!need_prologue) {
+ priv->need_prologue = false;
+ return 0;
+ }
+
+ priv->need_prologue = true;
+ priv->insns_buf = malloc(sizeof(struct bpf_insn) *
+ BPF_MAXINSNS);
+ if (!priv->insns_buf) {
+ pr_err("No enough memory: alloc insns_buf failed\n");
+ return -ENOMEM;
+ }
+
+ err = bpf_program__set_prep(prog, pev->ntevs,
+ preproc_gen_prologue);
+ return err;
+}
+
int bpf__probe(void)
{
int err;
bool old_silent = probe_conf.silent;
+ struct bpf_object *obj, *tmp;
+ struct bpf_program *prog;
if (nr_probe_events <= 0)
return 0;
@@ -245,7 +349,27 @@ int bpf__probe(void)
else
is_probing = true;
- return err < 0 ? err : 0;
+ err = err < 0 ? err : 0;
+ if (err)
+ return err;
+
+ /*
+ * After probing, let's consider prologue, which
+ * add program fetcher to BPF programs.
+ *
+ * hook_load_preprocessorr() hooks pre-processor to bpf_program,
+ * let it generate prologue dynamically during loading.
+ */
+
+ bpf_object__for_each_safe(obj, tmp) {
+ bpf_object__for_each_program(prog, obj) {
+ err = hook_load_preprocessor(prog);
+ if (err)
+ return err;
+ }
+ }
+
+ return err;
}
int bpf__load(void)
@@ -291,7 +415,11 @@ int bpf__foreach_tev(bpf_prog_iter_callback_t func, void *arg)
for (i = 0; i < pev->ntevs; i++) {
tev = &pev->tevs[i];
- fd = bpf_program__fd(prog);
+ if (priv->need_prologue)
+ fd = bpf_program__nth_fd(prog, i);
+ else
+ fd = bpf_program__fd(prog);
+
if (fd < 0) {
pr_err("bpf: failed to get file descriptor\n");
return fd;
--
1.8.3.4
--
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[toc] | [prev] | [next] | [standalone]
| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 30/39] perf probe: Reset args and nargs for probe_trace_event when failure |
| Message-ID | <pKjr5-dD-41@gated-at.bofh.it> |
| In reply to | #1180696 |
When failure occures in add_probe_trace_event(), args in
probe_trace_event is incomplete. Since information in it may be used
in further, this patch frees the allocated memory and set it to NULL
to avoid dangling pointer.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/probe-finder.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 2da65a7..f533d19 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1243,6 +1243,10 @@ static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
end:
free(args);
+ if (ret) {
+ tev->nargs = 0;
+ zfree(&tev->args);
+ }
return ret;
}
--
1.8.3.4
--
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[toc] | [prev] | [next] | [standalone]
| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 18/39] perf record: Enable passing bpf object file to --event |
| Message-ID | <pKjr5-dD-43@gated-at.bofh.it> |
| In reply to | #1180696 |
By introducing new rules in tools/perf/util/parse-events.[ly], this
patch enables 'perf record --event bpf_file.o' to select events by
an eBPF object file. It calls parse_events_load_bpf() to load that
file, which uses bpf__prepare_load() and finally calls
bpf_object__open() for the object files.
Instead of introducing evsel to evlist during parsing, events
selected by eBPF object files are appended separately. The reason
is:
1. During parsing, the probing points have not been initialized.
2. Currently we are unable to call add_perf_probe_events() twice,
therefore we have to wait until all such events are collected,
then probe all points by one call.
The real probing and selecting is reside in following patches.
'bpf-loader.[ch]' are introduced in this patch. Which will be the
interface between perf and libbpf. bpf__prepare_load() resides in
bpf-loader.c. Dummy functions should be used because bpf-loader.c is
available only when CONFIG_LIBBPF is on.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/Build | 1 +
tools/perf/util/bpf-loader.c | 60 ++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/bpf-loader.h | 24 +++++++++++++++++
tools/perf/util/debug.c | 5 ++++
tools/perf/util/debug.h | 1 +
tools/perf/util/parse-events.c | 16 +++++++++++
tools/perf/util/parse-events.h | 2 ++
tools/perf/util/parse-events.l | 3 +++
tools/perf/util/parse-events.y | 18 ++++++++++++-
9 files changed, 129 insertions(+), 1 deletion(-)
create mode 100644 tools/perf/util/bpf-loader.c
create mode 100644 tools/perf/util/bpf-loader.h
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index bc24293..3357e5a 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -79,6 +79,7 @@ libperf-y += thread-stack.o
libperf-$(CONFIG_AUXTRACE) += auxtrace.o
libperf-y += parse-branch-options.o
+libperf-$(CONFIG_LIBBPF) += bpf-loader.o
libperf-$(CONFIG_LIBELF) += symbol-elf.o
libperf-$(CONFIG_LIBELF) += probe-event.o
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
new file mode 100644
index 0000000..7c750b6
--- /dev/null
+++ b/tools/perf/util/bpf-loader.c
@@ -0,0 +1,60 @@
+/*
+ * bpf-loader.c
+ *
+ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ */
+
+#include <bpf/libbpf.h>
+#include "perf.h"
+#include "debug.h"
+#include "bpf-loader.h"
+
+#define DEFINE_PRINT_FN(name, level) \
+static int libbpf_##name(const char *fmt, ...) \
+{ \
+ va_list args; \
+ int ret; \
+ \
+ va_start(args, fmt); \
+ ret = veprintf(level, verbose, pr_fmt(fmt), args);\
+ va_end(args); \
+ return ret; \
+}
+
+DEFINE_PRINT_FN(warning, 0)
+DEFINE_PRINT_FN(info, 0)
+DEFINE_PRINT_FN(debug, 1)
+
+static bool libbpf_initialized;
+
+int bpf__prepare_load(const char *filename)
+{
+ struct bpf_object *obj;
+
+ if (!libbpf_initialized)
+ libbpf_set_print(libbpf_warning,
+ libbpf_info,
+ libbpf_debug);
+
+ obj = bpf_object__open(filename);
+ if (!obj) {
+ pr_err("bpf: failed to load %s\n", filename);
+ return -EINVAL;
+ }
+
+ /*
+ * Throw object pointer away: it will be retrived using
+ * bpf_objects iterater.
+ */
+
+ return 0;
+}
+
+void bpf__clear(void)
+{
+ struct bpf_object *obj, *tmp;
+
+ bpf_object__for_each_safe(obj, tmp)
+ bpf_object__close(obj);
+}
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
new file mode 100644
index 0000000..39d8d1a
--- /dev/null
+++ b/tools/perf/util/bpf-loader.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2015, Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015, Huawei Inc.
+ */
+#ifndef __BPF_LOADER_H
+#define __BPF_LOADER_H
+
+#include <linux/compiler.h>
+#include "debug.h"
+
+#ifdef HAVE_LIBBPF_SUPPORT
+int bpf__prepare_load(const char *filename);
+
+void bpf__clear(void);
+#else
+static inline int bpf__prepare_load(const char *filename __maybe_unused)
+{
+ pr_err("ERROR: eBPF object loading is disabled during compiling.\n");
+ return -1;
+}
+
+static inline void bpf__clear(void) { }
+#endif
+#endif
diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index 2da5581..86d9c73 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -36,6 +36,11 @@ static int _eprintf(int level, int var, const char *fmt, va_list args)
return ret;
}
+int veprintf(int level, int var, const char *fmt, va_list args)
+{
+ return _eprintf(level, var, fmt, args);
+}
+
int eprintf(int level, int var, const char *fmt, ...)
{
va_list args;
diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
index caac2fd..8b9a088 100644
--- a/tools/perf/util/debug.h
+++ b/tools/perf/util/debug.h
@@ -50,6 +50,7 @@ void pr_stat(const char *fmt, ...);
int eprintf(int level, int var, const char *fmt, ...) __attribute__((format(printf, 3, 4)));
int eprintf_time(int level, int var, u64 t, const char *fmt, ...) __attribute__((format(printf, 4, 5)));
+int veprintf(int level, int var, const char *fmt, va_list args);
int perf_debug_option(const char *str);
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index a71eeb2..a2829ef 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -19,6 +19,7 @@
#include "thread_map.h"
#include "cpumap.h"
#include "asm/bug.h"
+#include "bpf-loader.h"
#define MAX_NAME_LEN 100
@@ -475,6 +476,21 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,
return add_tracepoint_event(list, idx, sys, event);
}
+int parse_events_load_bpf(struct list_head *list __maybe_unused,
+ int *idx __maybe_unused,
+ char *bpf_file_name)
+{
+ /*
+ * Currently don't link any event to list. BPF object files
+ * should be saved to a seprated list and processed together.
+ *
+ * Things could be changed if we solve perf probe reentering
+ * problem. After that probe events file by file is possible.
+ * However, probing cost is still need to be considered.
+ */
+ return bpf__prepare_load(bpf_file_name);
+}
+
static int
parse_breakpoint_type(const char *type, struct perf_event_attr *attr)
{
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 131f29b..41b962a 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -114,6 +114,8 @@ int parse_events__modifier_group(struct list_head *list, char *event_mod);
int parse_events_name(struct list_head *list, char *name);
int parse_events_add_tracepoint(struct list_head *list, int *idx,
char *sys, char *event);
+int parse_events_load_bpf(struct list_head *list, int *idx,
+ char *bpf_file_name);
int parse_events_add_numeric(struct parse_events_evlist *data,
struct list_head *list,
u32 type, u64 config,
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 13cef3c..8328b28 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -115,6 +115,7 @@ do { \
group [^,{}/]*[{][^}]*[}][^,{}/]*
event_pmu [^,{}/]+[/][^/]*[/][^,{}/]*
event [^,{}/]+
+bpf_object .*\.(o|bpf)
num_dec [0-9]+
num_hex 0x[a-fA-F0-9]+
@@ -159,6 +160,7 @@ modifier_bp [rwx]{1,3}
}
{event_pmu} |
+{bpf_object} |
{event} {
BEGIN(INITIAL);
REWIND(1);
@@ -261,6 +263,7 @@ r{num_raw_hex} { return raw(yyscanner); }
{modifier_event} { return str(yyscanner, PE_MODIFIER_EVENT); }
{name} { return pmu_str_check(yyscanner); }
+{bpf_object} { return str(yyscanner, PE_BPF_OBJECT); }
"/" { BEGIN(config); return '/'; }
- { return '-'; }
, { BEGIN(event); return ','; }
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 591905a..481f3cd 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -42,6 +42,7 @@ static inc_group_count(struct list_head *list,
%token PE_VALUE PE_VALUE_SYM_HW PE_VALUE_SYM_SW PE_RAW PE_TERM
%token PE_EVENT_NAME
%token PE_NAME
+%token PE_BPF_OBJECT
%token PE_MODIFIER_EVENT PE_MODIFIER_BP
%token PE_NAME_CACHE_TYPE PE_NAME_CACHE_OP_RESULT
%token PE_PREFIX_MEM PE_PREFIX_RAW PE_PREFIX_GROUP
@@ -53,6 +54,7 @@ static inc_group_count(struct list_head *list,
%type <num> PE_RAW
%type <num> PE_TERM
%type <str> PE_NAME
+%type <str> PE_BPF_OBJECT
%type <str> PE_NAME_CACHE_TYPE
%type <str> PE_NAME_CACHE_OP_RESULT
%type <str> PE_MODIFIER_EVENT
@@ -69,6 +71,7 @@ static inc_group_count(struct list_head *list,
%type <head> event_legacy_tracepoint
%type <head> event_legacy_numeric
%type <head> event_legacy_raw
+%type <head> event_bpf_file
%type <head> event_def
%type <head> event_mod
%type <head> event_name
@@ -198,7 +201,8 @@ event_def: event_pmu |
event_legacy_mem |
event_legacy_tracepoint sep_dc |
event_legacy_numeric sep_dc |
- event_legacy_raw sep_dc
+ event_legacy_raw sep_dc |
+ event_bpf_file
event_pmu:
PE_NAME '/' event_config '/'
@@ -420,6 +424,18 @@ PE_RAW
$$ = list;
}
+event_bpf_file:
+PE_BPF_OBJECT
+{
+ struct parse_events_evlist *data = _data;
+ struct list_head *list;
+
+ ALLOC_LIST(list);
+ ABORT_ON(parse_events_load_bpf(list, &data->idx, $1));
+ $$ = list;
+}
+
+
start_terms: event_config
{
struct parse_events_terms *data = _data;
--
1.8.3.4
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 14/39] perf tools: Auto detecting kernel build directory |
| Message-ID | <pKjr5-dD-47@gated-at.bofh.it> |
| In reply to | #1180696 |
This patch detects kernel build directory using a embedded shell
script 'kbuild_detector', which does this by checking existence of
include/generated/autoconf.h.
clang working directory is changed to kbuild directory if it is found,
to help user use relative include path. Following patch will detect
kernel include directory, which contains relative include patch so this
workdir changing is needed.
Users are allowed to set 'kbuild-dir = ""' manually to disable this
checking.
Signed-off-by: Wang Nan <wangnan0@hauwei.com>
---
tools/perf/util/llvm-utils.c | 56 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index dca16e7..2ca2bd6 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -204,6 +204,51 @@ version_notice(void)
);
}
+static const char *kbuild_detector =
+"#!/usr/bin/env sh\n"
+"DEFAULT_KBUILD_DIR=/lib/modules/`uname -r`/build\n"
+"if test -z \"$KBUILD_DIR\"\n"
+"then\n"
+" KBUILD_DIR=$DEFAULT_KBUILD_DIR\n"
+"fi\n"
+"if test -f $KBUILD_DIR/include/generated/autoconf.h\n"
+"then\n"
+" echo -n $KBUILD_DIR\n"
+" exit 0\n"
+"fi\n"
+"exit -1\n";
+
+static inline void
+get_kbuild_opts(char **kbuild_dir)
+{
+ int err;
+
+ if (!kbuild_dir)
+ return;
+
+ *kbuild_dir = NULL;
+
+ if (llvm_param.kbuild_dir && !llvm_param.kbuild_dir[0]) {
+ pr_debug("[llvm.kbuild-dir] is set to \"\" deliberately.\n");
+ pr_debug("Skip kbuild options detection.\n");
+ return;
+ }
+
+ force_set_env("KBUILD_DIR", llvm_param.kbuild_dir);
+ force_set_env("KBUILD_OPTS", llvm_param.kbuild_opts);
+ err = read_from_pipe(kbuild_detector,
+ ((void **)kbuild_dir),
+ NULL);
+ if (err) {
+ pr_warning(
+"WARNING:\tunable to get correct kernel building directory.\n"
+"Hint:\tSet correct kbuild directory using 'kbuild-dir' option in [llvm]\n"
+" \tsection of ~/.perfconfig or set it to \"\" to suppress kbuild\n"
+" \tdetection.\n\n");
+ return;
+ }
+}
+
int llvm__compile_bpf(const char *path, void **p_obj_buf,
size_t *p_obj_buf_sz)
{
@@ -211,6 +256,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
char clang_path[PATH_MAX];
const char *clang_opt = llvm_param.clang_opt;
const char *template = llvm_param.clang_bpf_cmd_template;
+ char *kbuild_dir = NULL;
void *obj_buf = NULL;
size_t obj_buf_sz;
@@ -228,10 +274,16 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
return -ENOENT;
}
+ /*
+ * This is an optional work. Even it fail we can continue our
+ * work. Needn't to check error return.
+ */
+ get_kbuild_opts(&kbuild_dir);
+
force_set_env("CLANG_EXEC", clang_path);
force_set_env("CLANG_OPTIONS", clang_opt);
force_set_env("KERNEL_INC_OPTIONS", NULL);
- force_set_env("WORKING_DIR", ".");
+ force_set_env("WORKING_DIR", kbuild_dir ? : ".");
/*
* Since we may reset clang's working dir, path of source file
@@ -252,6 +304,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
goto errout;
}
+ free(kbuild_dir);
if (!p_obj_buf)
free(obj_buf);
else
@@ -261,6 +314,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
*p_obj_buf_sz = obj_buf_sz;
return 0;
errout:
+ free(kbuild_dir);
free(obj_buf);
if (p_obj_buf)
*p_obj_buf = NULL;
--
1.8.3.4
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 23/39] perf record: Load all eBPF object into kernel |
| Message-ID | <pKjr5-dD-49@gated-at.bofh.it> |
| In reply to | #1180696 |
This patch utilizes bpf_load_object() provided by libbpf to load all
objects into kernel.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/builtin-record.c | 12 ++++++++++++
tools/perf/util/bpf-loader.c | 19 +++++++++++++++++++
tools/perf/util/bpf-loader.h | 2 ++
3 files changed, 33 insertions(+)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 33b213a..6d943a7 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1128,6 +1128,18 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
goto out_symbol_exit;
}
+ /*
+ * bpf__probe() also calls symbol__init() if there are probe
+ * events in bpf objects, so calling symbol_exit when failure
+ * is safe. If there is no probe event, bpf__load() always
+ * success.
+ */
+ err = bpf__load();
+ if (err) {
+ pr_err("Loading BPF programs failed\n");
+ goto out_symbol_exit;
+ }
+
symbol__init(NULL);
if (symbol_conf.kptr_restrict)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 10fe661..6861560 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -241,3 +241,22 @@ int bpf__probe(void)
return err < 0 ? err : 0;
}
+
+int bpf__load(void)
+{
+ struct bpf_object *obj, *tmp;
+ int err = 0;
+
+ bpf_object__for_each_safe(obj, tmp) {
+ err = bpf_object__load(obj);
+ if (err) {
+ pr_err("bpf: load objects failed\n");
+ goto errout;
+ }
+ }
+ return 0;
+errout:
+ bpf_object__for_each_safe(obj, tmp)
+ bpf_object__unload(obj);
+ return err;
+}
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index 374aec0..ae0dc9b 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -14,6 +14,7 @@
int bpf__prepare_load(const char *filename, bool source);
int bpf__probe(void);
int bpf__unprobe(void);
+int bpf__load(void);
void bpf__clear(void);
#else
@@ -26,6 +27,7 @@ static inline int bpf__prepare_load(const char *filename __maybe_unused,
static inline int bpf__probe(void) { return 0; }
static inline int bpf__unprobe(void) { return 0; }
+static inline int bpf__load(void) { return 0; }
static inline void bpf__clear(void) { }
#endif
#endif
--
1.8.3.4
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 24/39] perf tools: Add bpf_fd field to evsel and config it |
| Message-ID | <pKjr6-dD-59@gated-at.bofh.it> |
| In reply to | #1180696 |
This patch adds a bpf_fd field to 'struct evsel' then introduces method
to config it. In bpf-loader, a bpf__foreach_tev() function is added,
Which calls the callback function for each 'struct probe_trace_event'
events for each bpf program with their file descriptors. In evlist.c,
perf_evlist__add_bpf() is introduced to add all bpf events into evlist.
The event names are found from probe_trace_event structure.
'perf record' calls perf_evlist__add_bpf().
Since bpf-loader.c will not be built if libbpf is turned off, an empty
bpf__foreach_tev() is defined in bpf-loader.h to avoid compiling
error.
This patch iterates over 'struct probe_trace_event' instead of
'struct probe_trace_event' during the loop for further patches, which
will generate multiple instances form one BPF program and install then
onto different 'struct probe_trace_event'.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/builtin-record.c | 6 ++++++
tools/perf/util/bpf-loader.c | 42 ++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/bpf-loader.h | 13 +++++++++++++
tools/perf/util/evlist.c | 41 +++++++++++++++++++++++++++++++++++++++++
tools/perf/util/evlist.h | 1 +
tools/perf/util/evsel.c | 1 +
tools/perf/util/evsel.h | 1 +
7 files changed, 105 insertions(+)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 6d943a7..bd189b1 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1140,6 +1140,12 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
goto out_symbol_exit;
}
+ err = perf_evlist__add_bpf(rec->evlist);
+ if (err < 0) {
+ pr_err("Failed to add events from BPF object(s)\n");
+ goto out_symbol_exit;
+ }
+
symbol__init(NULL);
if (symbol_conf.kptr_restrict)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 6861560..7a152ad 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -260,3 +260,45 @@ errout:
bpf_object__unload(obj);
return err;
}
+
+int bpf__foreach_tev(bpf_prog_iter_callback_t func, void *arg)
+{
+ struct bpf_object *obj, *tmp;
+ struct bpf_program *prog;
+ int err;
+
+ bpf_object__for_each_safe(obj, tmp) {
+ bpf_object__for_each_program(prog, obj) {
+ struct probe_trace_event *tev;
+ struct perf_probe_event *pev;
+ struct bpf_prog_priv *priv;
+ int i, fd;
+
+ err = bpf_program__get_private(prog,
+ (void **)&priv);
+ if (err || !priv) {
+ pr_err("bpf: failed to get private field\n");
+ return -EINVAL;
+ }
+
+ pev = priv->pev;
+ for (i = 0; i < pev->ntevs; i++) {
+ tev = &pev->tevs[i];
+
+ fd = bpf_program__fd(prog);
+ if (fd < 0) {
+ pr_err("bpf: failed to get file descriptor\n");
+ return fd;
+ }
+
+ err = func(tev, fd, arg);
+ if (err) {
+ pr_err("bpf: call back failed, stop iterate\n");
+ return err;
+ }
+ }
+ }
+ }
+
+ return 0;
+}
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index ae0dc9b..ef9b3bb 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -6,10 +6,14 @@
#define __BPF_LOADER_H
#include <linux/compiler.h>
+#include "probe-event.h"
#include "debug.h"
#define PERF_BPF_PROBE_GROUP "perf_bpf_probe"
+typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev,
+ int fd, void *arg);
+
#ifdef HAVE_LIBBPF_SUPPORT
int bpf__prepare_load(const char *filename, bool source);
int bpf__probe(void);
@@ -17,6 +21,8 @@ int bpf__unprobe(void);
int bpf__load(void);
void bpf__clear(void);
+
+int bpf__foreach_tev(bpf_prog_iter_callback_t func, void *arg);
#else
static inline int bpf__prepare_load(const char *filename __maybe_unused,
bool source __maybe_unused)
@@ -29,5 +35,12 @@ static inline int bpf__probe(void) { return 0; }
static inline int bpf__unprobe(void) { return 0; }
static inline int bpf__load(void) { return 0; }
static inline void bpf__clear(void) { }
+
+static inline int
+bpf__foreach_tev(bpf_prog_iter_callback_t func __maybe_unused,
+ void *arg __maybe_unused)
+{
+ return 0;
+}
#endif
#endif
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index f7d9c77..5a01c7f 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -14,6 +14,7 @@
#include "target.h"
#include "evlist.h"
#include "evsel.h"
+#include "bpf-loader.h"
#include "debug.h"
#include <unistd.h>
@@ -194,6 +195,46 @@ error:
return -ENOMEM;
}
+static int add_bpf_event(struct probe_trace_event *tev, int fd,
+ void *arg)
+{
+ struct perf_evlist *evlist = arg;
+ struct perf_evsel *pos;
+ struct list_head list;
+ int err, idx, entries;
+
+ pr_debug("add bpf event %s:%s and attach bpf program %d\n",
+ tev->group, tev->event, fd);
+ INIT_LIST_HEAD(&list);
+ idx = evlist->nr_entries;
+
+ pr_debug("adding %s:%s\n", tev->group, tev->event);
+ err = parse_events_add_tracepoint(&list, &idx, tev->group,
+ tev->event);
+ if (err) {
+ struct perf_evsel *evsel, *tmp;
+
+ pr_err("Failed to add BPF event %s:%s\n",
+ tev->group, tev->event);
+ list_for_each_entry_safe(evsel, tmp, &list, node) {
+ list_del(&evsel->node);
+ perf_evsel__delete(evsel);
+ }
+ return -EINVAL;
+ }
+
+ list_for_each_entry(pos, &list, node)
+ pos->bpf_fd = fd;
+ entries = idx - evlist->nr_entries;
+ perf_evlist__splice_list_tail(evlist, &list, entries);
+ return 0;
+}
+
+int perf_evlist__add_bpf(struct perf_evlist *evlist)
+{
+ return bpf__foreach_tev(add_bpf_event, evlist);
+}
+
static int perf_evlist__add_attrs(struct perf_evlist *evlist,
struct perf_event_attr *attrs, size_t nr_attrs)
{
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 037633c..4e3b6b0 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -72,6 +72,7 @@ void perf_evlist__delete(struct perf_evlist *evlist);
void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry);
int perf_evlist__add_default(struct perf_evlist *evlist);
+int perf_evlist__add_bpf(struct perf_evlist *evlist);
int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
struct perf_event_attr *attrs, size_t nr_attrs);
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 83c0803..fe80047 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -206,6 +206,7 @@ void perf_evsel__init(struct perf_evsel *evsel,
evsel->leader = evsel;
evsel->unit = "";
evsel->scale = 1.0;
+ evsel->bpf_fd = -1;
INIT_LIST_HEAD(&evsel->node);
perf_evsel__object.init(evsel);
evsel->sample_size = __perf_evsel__sample_size(attr->sample_type);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index fe9f327..4bcd629 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -86,6 +86,7 @@ struct perf_evsel {
unsigned long *per_pkg_mask;
struct perf_evsel *leader;
char *group_name;
+ int bpf_fd;
};
union u64_swap {
--
1.8.3.4
--
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| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Date | 2015-07-09 14:50 +0200 |
| Subject | [PATCH 22/39] perf record: Probe at kprobe points |
| Message-ID | <pKjr6-dD-61@gated-at.bofh.it> |
| In reply to | #1180696 |
In this patch, kprobe points are created using add_perf_probe_events.
Since all events are already grouped together in an array, calling
add_perf_probe_events() creates all of them.
probe_conf.max_probes is set to MAX_PROBES to support glob matching.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/builtin-record.c | 18 ++++++++++++++++-
tools/perf/util/bpf-loader.c | 48 ++++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/bpf-loader.h | 4 ++++
3 files changed, 69 insertions(+), 1 deletion(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 283fe96..33b213a 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -29,6 +29,7 @@
#include "util/data.h"
#include "util/auxtrace.h"
#include "util/parse-branch-options.h"
+#include "util/bpf-loader.h"
#include <unistd.h>
#include <sched.h>
@@ -1111,7 +1112,21 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
if (err)
return err;
- err = -ENOMEM;
+ /*
+ * bpf__probe must be called before symbol__init() because we
+ * need init_symbol_maps. If called after symbol__init,
+ * symbol_conf.sort_by_name won't take effect.
+ *
+ * bpf__unprobe() is safe even if bpf__probe() failed, and it
+ * also calls symbol__init. Therefore, goto out_symbol_exit
+ * is safe when probe failed.
+ */
+ err = bpf__probe();
+ if (err) {
+ pr_err("Probing at events in BPF object failed.\n");
+ pr_err("Try perf probe -d '*' to remove existing probe events.\n");
+ goto out_symbol_exit;
+ }
symbol__init(NULL);
@@ -1172,6 +1187,7 @@ out_symbol_exit:
perf_evlist__delete(rec->evlist);
symbol__exit();
auxtrace_record__free(rec->itr);
+ bpf__unprobe();
return err;
}
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index e33995d..10fe661 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -193,3 +193,51 @@ void bpf__clear(void)
bpf_object__for_each_safe(obj, tmp)
bpf_object__close(obj);
}
+
+static bool is_probing;
+
+int bpf__unprobe(void)
+{
+ struct strfilter *delfilter;
+ int ret;
+
+ if (!is_probing)
+ return 0;
+
+ delfilter = strfilter__new(PERF_BPF_PROBE_GROUP ":*", NULL);
+ if (!delfilter) {
+ pr_err("Failed to create delfilter when unprobing\n");
+ return -ENOMEM;
+ }
+
+ ret = del_perf_probe_events(delfilter);
+ strfilter__delete(delfilter);
+ if (ret < 0 && is_probing)
+ pr_err("Error: failed to delete events: %s\n",
+ strerror(-ret));
+ else
+ is_probing = false;
+ return ret < 0 ? ret : 0;
+}
+
+int bpf__probe(void)
+{
+ int err;
+
+ if (nr_probe_events <= 0)
+ return 0;
+
+ probe_conf.max_probes = MAX_PROBES;
+ /* Let add_perf_probe_events keeps probe_trace_event */
+ err = add_perf_probe_events(probe_event_array,
+ nr_probe_events,
+ false);
+
+ /* add_perf_probe_events return negative when fail */
+ if (err < 0)
+ pr_err("bpf probe: failed to probe events\n");
+ else
+ is_probing = true;
+
+ return err < 0 ? err : 0;
+}
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index 5a3c954..374aec0 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -12,6 +12,8 @@
#ifdef HAVE_LIBBPF_SUPPORT
int bpf__prepare_load(const char *filename, bool source);
+int bpf__probe(void);
+int bpf__unprobe(void);
void bpf__clear(void);
#else
@@ -22,6 +24,8 @@ static inline int bpf__prepare_load(const char *filename __maybe_unused,
return -1;
}
+static inline int bpf__probe(void) { return 0; }
+static inline int bpf__unprobe(void) { return 0; }
static inline void bpf__clear(void) { }
#endif
#endif
--
1.8.3.4
--
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