[PATCH 5.14 224/849] x86: Increase exception stack sizes
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-11-15 22:23:13
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Peter Zijlstra <peterz@infradead.org> [ Upstream commit 7fae4c24a2b84a66c7be399727aca11e7a888462 ] It turns out that a single page of stack is trivial to overflow with all the tracing gunk enabled. Raise the exception stacks to 2 pages, which is still half the interrupt stacks, which are at 4 pages. Reported-by: Michael Wang <redacted> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YUIO9Ye98S5Eb68w@hirez.programming.kicks-ass.net Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/x86/include/asm/page_64_types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index a8d4ad8565681..e9e2c3ba59239 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h@@ -15,7 +15,7 @@ #define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER) #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) -#define EXCEPTION_STACK_ORDER (0 + KASAN_STACK_ORDER) +#define EXCEPTION_STACK_ORDER (1 + KASAN_STACK_ORDER) #define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER) #define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER)
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2.33.0