ARM: 6468/1: backtrace: fix calculation of thread stack base (d33aadbf) · Commits · 戴 / test

When unwinding stack frames we must take care not to unwind areas of memory that lie outside of the known extent of the stack. This patch fixes an incorrect calculation of the stack base where THREAD_SIZE is added to the stack pointer after it has already been aligned to this value. Since the ALIGN macro performs this addition internally, we end up overshooting the base by 8k. Acked-by:

Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:

Will Deacon <will.deacon@arm.com> Signed-off-by:

Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/stacktrace.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -28,7 +28,7 @@ int notrace unwind_frame(struct stackframe *frame)

		/* only go to a higher address on the stack */
		low = frame->sp;
		high = ALIGN(low, THREAD_SIZE) + THREAD_SIZE;
		high = ALIGN(low, THREAD_SIZE);

		/* check current frame pointer is within bounds */
		if (fp < (low + 12) \|\| fp + 4 >= high)

arch/arm/kernel/unwind.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -279,7 +279,7 @@ int unwind_frame(struct stackframe *frame)

		/* only go to a higher address on the stack */
		low = frame->sp;
		high = ALIGN(low, THREAD_SIZE) + THREAD_SIZE;
		high = ALIGN(low, THREAD_SIZE);

		pr_debug("%s(pc = %08lx lr = %08lx sp = %08lx)\n", __func__,
		frame->pc, frame->lr, frame->sp);

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