Commit 480c240a authored Sep 15, 2021 by Peter Zijlstra Committed by Greg Kroah-Hartman Nov 17, 2021

x86: Increase exception stack sizes



[ 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 <yun.wang@linux.alibaba.com>
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>

parent 91b9c23b

arch/x86/include/asm/page_64_types.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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)