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authorKonstantin Khlebnikov <k.khlebnikov@samsung.com>2013-12-05 13:30:10 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2013-12-19 17:43:09 +0000
commit408c3658b0d49315974ce8b5aed385c8e1527595 (patch)
treefea73a527507df8c35ba1a2c0542a61dab4349e9 /arch/arm64/kernel/process.c
parent50afc33a90e710c02d9bbf2f3673936365f0e690 (diff)
downloadtalos-obmc-linux-408c3658b0d49315974ce8b5aed385c8e1527595.tar.gz
talos-obmc-linux-408c3658b0d49315974ce8b5aed385c8e1527595.zip
ARM64: check stack pointer in get_wchan
get_wchan() is lockless. Task may wakeup at any time and change its own stack, thus each next stack frame may be overwritten and filled with random stuff. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/process.c')
-rw-r--r--arch/arm64/kernel/process.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index de17c89985db..0adb8f0f4549 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -308,6 +308,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
unsigned long get_wchan(struct task_struct *p)
{
struct stackframe frame;
+ unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
@@ -315,9 +316,11 @@ unsigned long get_wchan(struct task_struct *p)
frame.fp = thread_saved_fp(p);
frame.sp = thread_saved_sp(p);
frame.pc = thread_saved_pc(p);
+ stack_page = (unsigned long)task_stack_page(p);
do {
- int ret = unwind_frame(&frame);
- if (ret < 0)
+ if (frame.sp < stack_page ||
+ frame.sp >= stack_page + THREAD_SIZE ||
+ unwind_frame(&frame))
return 0;
if (!in_sched_functions(frame.pc))
return frame.pc;
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