diff options
| author | Johannes Berg | 2020-12-05 21:50:18 +0100 |
|---|---|---|
| committer | Richard Weinberger | 2020-12-13 22:38:06 +0100 |
| commit | ef4459a6da0955b533ebfc97a7d756ac090f50c9 (patch) | |
| tree | 5c1153080467c99b2f60942757f644d38338319b /arch/um/include | |
| parent | 963285b0b47a1b8e1dfa5481717855a7057ccec6 (diff) | |
um: allocate a guard page to helper threads
We've been running into stack overflows in helper threads
corrupting memory (e.g. because somebody put printf() or
os_info() there), so to avoid those causing hard-to-debug
issues later on, allocate a guard page for helper thread
stacks and mark it read-only.
Unfortunately, the crash dump at that point is useless as
the stack tracer will try to backtrace the *kernel* thread,
not the helper thread, but at least we don't survive to a
random issue caused by corruption.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/include')
| -rw-r--r-- | arch/um/include/shared/kern_util.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h index 2888ec812f6e..d8c279e3312f 100644 --- a/arch/um/include/shared/kern_util.h +++ b/arch/um/include/shared/kern_util.h @@ -19,7 +19,7 @@ extern int kmalloc_ok; #define UML_ROUND_UP(addr) \ ((((unsigned long) addr) + PAGE_SIZE - 1) & PAGE_MASK) -extern unsigned long alloc_stack(int order, int atomic); +extern unsigned long alloc_stack(int atomic); extern void free_stack(unsigned long stack, int order); struct pt_regs; |