Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1572282

[PATCH 5/5] perf/probe: Change MAX_CMDLEN

Show all headers | View raw

There are many SDT markers in powerpc whose uprobe definition goes
beyond current MAX_CMDLEN, especially when target filename is long
and sdt marker has long list of arguments. For example, definition
of sdt marker

  method__compile__end: 8@17 8@9 8@10 -4@8 8@7 -4@6 8@5 -4@4 1@37(28)

from file

  /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.91-2.b14.fc22.ppc64/jre/lib/\
     ppc64/server/libjvm.so

is

  p:sdt_hotspot/method__compile__end /usr/lib/jvm/java-1.8.0-openjdk-\
    1.8.0.91-2.b14.fc22.ppc64/jre/lib/ppc64/server/libjvm.so:0x4c4e00\
    arg1=%gpr17:u64 arg2=%gpr9:u64 arg3=%gpr10:u64 arg4=%gpr8:s32\
    arg5=%gpr7:u64 arg6=%gpr6:s32 arg7=%gpr5:u64 arg8=%gpr4:s32\
    arg9=+37(%gpr28):u8

Perf probe fails with seg fault for such markers. As uprobe_events file
accepts definition beyond 256 characters, increase value of MAX_CMDLEN
to 512.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
---
 tools/perf/util/probe-event.c | 1 -
 tools/perf/util/probe-file.c  | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 2c1bca2..5f3256f 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -47,7 +47,6 @@
 #include "probe-file.h"
 #include "session.h"
 
-#define MAX_CMDLEN 256
 #define PERFPROBE_GROUP "probe"
 
 bool probe_event_dry_run;	/* Dry run flag */
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 38eca3c..1580e26 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -29,7 +29,7 @@
 #include "session.h"
 #include "perf_regs.h"
 
-#define MAX_CMDLEN 256
+#define MAX_CMDLEN 512
 
 static void print_open_warning(int err, bool uprobe)
 {
-- 
2.9.3

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

[PATCH 5/5] perf/probe: Change MAX_CMDLEN Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> - 2017-02-02 12:20 +0100
  Re: [PATCH 5/5] perf/probe: Change MAX_CMDLEN Masami Hiramatsu <mhiramat@kernel.org> - 2017-02-07 02:50 +0100
    [PATCH v2] perf/probe: Change MAX_CMDLEN Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> - 2017-02-07 06:50 +0100

csiph-web