From bfeeeeb991cf75081e6c2f74d44ae5da05b50a94 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes@sipsolutions.net>
Date: Mon, 12 May 2008 21:21:14 +0200
Subject: stacktrace: don't crash on invalid stack trace structs
This patch makes the stacktrace printout code \warn when the entries
pointer is unset rather than crashing when trying to access it in an
attempt to make it a bit more robust.
I was saving a stacktrace into an skb and forgot to copy it across skb
copies... I have since fixed the code, but it would have been easier
had the kernel not crashed in an interrupt.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/stacktrace.c | 3 +++
1 file changed, 3 insertions(+)
(limited to 'kernel/stacktrace.c')
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index b71816e47a3..0914d0cbc83 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -13,6 +13,9 @@ void print_stack_trace(struct stack_trace *trace, int spaces)
{
int i, j;
+ if (WARN_ON(!trace->entries))
+ return;
+
for (i = 0; i < trace->nr_entries; i++) {
unsigned long ip = trace->entries[i];
--
cgit v1.2.3-70-g09d2
From a5a242dceed5d1c74fe46088762a9e4312c2d000 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@gmail.com>
Date: Fri, 13 Jun 2008 11:00:14 +0200
Subject: stacktrace: print_stack_trace() cleanup
- shorter code and better atomicity with regards to printk().
(It's been tested with the backtrace self-test code on i386 and x86_64.)
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/stacktrace.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
(limited to 'kernel/stacktrace.c')
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index 0914d0cbc83..7eaea9d02a5 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -11,17 +11,14 @@
void print_stack_trace(struct stack_trace *trace, int spaces)
{
- int i, j;
+ int i;
if (WARN_ON(!trace->entries))
return;
for (i = 0; i < trace->nr_entries; i++) {
- unsigned long ip = trace->entries[i];
-
- for (j = 0; j < spaces + 1; j++)
- printk(" ");
- print_ip_sym(ip);
+ printk("%*c", 1 + spaces, ' ');
+ print_ip_sym(trace->entries[i]);
}
}
--
cgit v1.2.3-70-g09d2
From 8594698ebddeef5443b7da8258ae33b3eaca61d5 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 27 Jun 2008 21:20:17 +0200
Subject: stacktrace: fix modular build, export print_stack_trace and
save_stack_trace
fix:
ERROR: "print_stack_trace" [kernel/backtracetest.ko] undefined!
ERROR: "save_stack_trace" [kernel/backtracetest.ko] undefined!
Signed-off-by: Ingo Molnar <mingo@elte.hu>
and fix:
Building modules, stage 2.
MODPOST 376 modules
ERROR: "print_stack_trace" [kernel/backtracetest.ko] undefined!
make[1]: *** [__modpost] Error 1
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/stacktrace.c | 2 ++
kernel/stacktrace.c | 2 ++
2 files changed, 4 insertions(+)
(limited to 'kernel/stacktrace.c')
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index c28c342c162..a03e7f6d90c 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -74,6 +74,7 @@ void save_stack_trace(struct stack_trace *trace)
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
+EXPORT_SYMBOL_GPL(save_stack_trace);
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
@@ -81,3 +82,4 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index 7eaea9d02a5..94b527ef1d1 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -6,6 +6,7 @@
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*/
#include <linux/sched.h>
+#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>
@@ -21,4 +22,5 @@ void print_stack_trace(struct stack_trace *trace, int spaces)
print_ip_sym(trace->entries[i]);
}
}
+EXPORT_SYMBOL_GPL(print_stack_trace);
--
cgit v1.2.3-70-g09d2