Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1540401
| From | Josh Poimboeuf <jpoimboe@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) |
| Date | 2016-12-12 16:50 +0100 |
| Message-ID | <sNB1v-67R-11@gated-at.bofh.it> (permalink) |
| References | <sMSxr-4tj-7@gated-at.bofh.it> <sMTjP-4Ys-13@gated-at.bofh.it> <sMTDb-54T-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Sat, Dec 10, 2016 at 06:28:02PM +0100, Borislav Petkov wrote:
> On Sat, Dec 10, 2016 at 11:04:44AM -0600, Josh Poimboeuf wrote:
> > That's a new one. Was there anything else printed?
>
> It is the first line that appears in dmesg when I boot:
>
> [ 0.000000] WARNING: kernel stack frame pointer at ffffffffb5e03f40 in swapper:0 has bad value (null)
> [ 0.000000] Linux version 4.9.0-rc8+ (boris@gondor) (gcc version 6.2.0 20161109 (Debian 6.2.0-13) ) #1 SMP PREEMPT Sat Dec 10 13:25:29 CET 2016
> [ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.9.0-rc8+ root=/dev/sda7 ro earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 root=/dev/sda7 log_buf_len=10M resume=/dev/sda5 no_console_suspend ignore_loglevel
> [ 0.000000] KERNEL supported cpus:
> [ 0.000000] Intel GenuineIntel
> [ 0.000000] AMD AuthenticAMD
> [ 0.000000] Centaur CentaurHauls
> [ 0.000000] x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
> ...
>
> > Were you doing anything special when it happened?
>
> Not really - just booting ;-)
>
> > Do you see it reliably?
>
> 2 of 2 boots.
>
> > I should probably figure out a way to dump more data for that warning.
>
> Sure, I can test patches.
Can you try with this?
diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h
index c5a7f3a..6fa75b1 100644
--- a/arch/x86/include/asm/unwind.h
+++ b/arch/x86/include/asm/unwind.h
@@ -12,7 +12,7 @@ struct unwind_state {
struct task_struct *task;
int graph_idx;
#ifdef CONFIG_FRAME_POINTER
- unsigned long *bp;
+ unsigned long *bp, *orig_sp;
struct pt_regs *regs;
#else
unsigned long *sp;
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index ea7b7f9..1c93984 100644
--- a/arch/x86/kernel/unwind_frame.c
+++ b/arch/x86/kernel/unwind_frame.c
@@ -6,6 +6,36 @@
#define FRAME_HEADER_SIZE (sizeof(long) * 2)
+static void unwind_dump(struct unwind_state *state, unsigned long *sp)
+{
+ static bool dumped_before = false;
+ bool prev_zero, zero = false;
+ unsigned long word;
+
+ if (dumped_before)
+ return;
+
+ dumped_before = true;
+
+ printk_deferred("unwind stack type:%d next_sp:%p mask:%lx graph_idx:%d\n",
+ state->stack_info.type, state->stack_info.next_sp,
+ state->stack_mask, state->graph_idx);
+
+ for (sp = state->orig_sp; sp < state->stack_info.end; sp++) {
+ prev_zero = zero;
+ word = READ_ONCE_NOCHECK(*sp);
+ zero = word == 0;
+
+ if (zero) {
+ if (!prev_zero)
+ printk_deferred("%p: %016x ...\n", sp, 0);
+ continue;
+ }
+
+ printk_deferred("%p: %016lx (%pB)\n", sp, word, (void *)word);
+ }
+}
+
unsigned long unwind_get_return_address(struct unwind_state *state)
{
unsigned long addr;
@@ -25,6 +55,7 @@ unsigned long unwind_get_return_address(struct unwind_state *state)
"WARNING: unrecognized kernel stack return address %p at %p in %s:%d\n",
(void *)addr, addr_p, state->task->comm,
state->task->pid);
+ unwind_dump(state, addr_p);
return 0;
}
@@ -67,6 +98,7 @@ static bool update_stack_state(struct unwind_state *state, void *addr,
size_t len)
{
struct stack_info *info = &state->stack_info;
+ enum stack_type orig_type = info->type;
/*
* If addr isn't on the current stack, switch to the next one.
@@ -80,6 +112,9 @@ static bool update_stack_state(struct unwind_state *state, void *addr,
&state->stack_mask))
return false;
+ if (!state->orig_sp || info->type != orig_type)
+ state->orig_sp = addr;
+
return true;
}
@@ -178,11 +213,13 @@ bool unwind_next_frame(struct unwind_state *state)
"WARNING: kernel stack regs at %p in %s:%d has bad 'bp' value %p\n",
state->regs, state->task->comm,
state->task->pid, next_frame);
+ unwind_dump(state, (unsigned long *)state->regs);
} else {
printk_deferred_once(KERN_WARNING
"WARNING: kernel stack frame pointer at %p in %s:%d has bad value %p\n",
state->bp, state->task->comm,
state->task->pid, next_frame);
+ unwind_dump(state, state->bp);
}
the_end:
state->stack_info.type = STACK_TYPE_UNKNOWN;
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Borislav Petkov <bp@alien8.de> - 2016-12-10 17:20 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Josh Poimboeuf <jpoimboe@redhat.com> - 2016-12-10 18:10 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Borislav Petkov <bp@alien8.de> - 2016-12-10 18:30 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Josh Poimboeuf <jpoimboe@redhat.com> - 2016-12-12 16:50 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Borislav Petkov <bp@alien8.de> - 2016-12-12 19:00 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Josh Poimboeuf <jpoimboe@redhat.com> - 2016-12-12 19:20 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Josh Poimboeuf <jpoimboe@redhat.com> - 2016-12-12 22:20 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Borislav Petkov <bp@alien8.de> - 2016-12-12 22:40 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Josh Poimboeuf <jpoimboe@redhat.com> - 2016-12-12 23:20 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Borislav Petkov <bp@alien8.de> - 2016-12-12 23:40 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Josh Poimboeuf <jpoimboe@redhat.com> - 2016-12-13 00:10 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Josh Poimboeuf <jpoimboe@redhat.com> - 2016-12-13 15:40 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Andy Lutomirski <luto@amacapital.net> - 2016-12-13 18:00 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Borislav Petkov <bp@alien8.de> - 2016-12-13 18:30 +0100
Re: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Josh Poimboeuf <jpoimboe@redhat.com> - 2016-12-13 18:30 +0100
csiph-web