kernel.git/arch/arm64/kernel/stacktrace.c, branch linux-5.19.y

arm64: stacktrace: use non-atomic __set_bit

2022-08-17T13:14:00Z

[ Upstream commit 446297b28a21244e4045026c4599d1b14a67e2ce ] Use the non-atomic version of set_bit() in arch/arm64/kernel/stacktrace.c, as there is no concurrent accesses to frame->prev_type. This speeds up stack trace collection and improves the boot time of Generic KASAN by 2-5%. Suggested-by: Mark Rutland Acked-by: Mark Rutland Signed-off-by: Andrey Konovalov Link: https://lore.kernel.org/r/23dfa36d1cc91e4a1059945b7834eac22fb9854d.1653317461.git.andreyknvl@google.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

arm64: kasan: do not instrument stacktrace.c

2022-08-17T13:13:59Z

[ Upstream commit 802b91118d11227b527153849ea761b280691373 ] Disable KASAN instrumentation of arch/arm64/kernel/stacktrace.c. This speeds up Generic KASAN by 5-20%. As a side-effect, KASAN is now unable to detect bugs in the stack trace collection code. This is taken as an acceptable downside. Also replace READ_ONCE_NOCHECK() with READ_ONCE() in stacktrace.c. As the file is now not instrumented, there is no need to use the NOCHECK version of READ_ONCE(). Suggested-by: Mark Rutland Acked-by: Mark Rutland Signed-off-by: Andrey Konovalov Link: https://lore.kernel.org/r/c4c944a2a905e949760fbeb29258185087171708.1653317461.git.andreyknvl@google.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

arm64: stacktrace: align with common naming

2022-04-22T14:33:14Z

For historical reasons, the naming of parameters and their types in the arm64 stacktrace code differs from that used in generic code and other architectures, even though the types are equivalent. For consistency and clarity, use the generic names. There should be no functional change as a result of this patch. Signed-off-by: Madhavan T. Venkataraman Signed-off-by: Mark Rutland Reviewed-by: Mark Brown Reviewed-by: Kalesh Singh for the series. Link: https://lore.kernel.org/r/20220413145910.3060139-7-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: stacktrace: rename stackframe to unwind_state

2022-04-22T14:33:14Z

Rename "struct stackframe" to "struct unwind_state" for consistency and better naming. Accordingly, rename variable/argument "frame" to "state". There should be no functional change as a result of this patch. Signed-off-by: Madhavan T. Venkataraman Reviewed-by: Mark Brown Signed-off-by: Mark Rutland Reviewed-by: Kalesh Singh for the series. Link: https://lore.kernel.org/r/20220413145910.3060139-6-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: stacktrace: rename unwinder functions

2022-04-22T14:33:14Z

Rename unwinder functions for consistency and better naming. - Rename start_backtrace() to unwind_init(). - Rename unwind_frame() to unwind_next(). - Rename walk_stackframe() to unwind(). There should be no functional change as a result of this patch. Signed-off-by: Madhavan T. Venkataraman Reviewed-by: Mark Brown Signed-off-by: Mark Rutland Reviewed-by: Kalesh Singh for the series. Link: https://lore.kernel.org/r/20220413145910.3060139-5-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: stacktrace: make struct stackframe private to stacktrace.c

2022-04-22T14:33:13Z

Now that arm64 uses arch_stack_walk() consistently, struct stackframe is only used within stacktrace.c. To make it easier to read and maintain this code, it would be nicer if the definition were there too. Move the definition into stacktrace.c. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Madhavan T. Venkataraman Cc: Mark Brown Cc: Will Deacon Reviewed-by: Madhavan T. Venkataraman Reviwed-by: Mark Brown Reviewed-by: Kalesh Singh for the series. Link: https://lore.kernel.org/r/20220413145910.3060139-4-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: stacktrace: delete PCS comment

2022-04-22T14:33:13Z

The comment at the top of stacktrace.c isn't all that helpful, as it's not associated with the code which inspects the frame record, and the code example isn't representative of common code generation today. Delete it. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Madhavan T. Venkataraman Cc: Mark Brown Cc: Will Deacon Reviewed-by: Madhavan T. Venkataraman Reviewed-by: Mark Brown Reviewed-by: Kalesh Singh for the series. Link: https://lore.kernel.org/r/20220413145910.3060139-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: stacktrace: remove NULL task check from unwind_frame()

2022-04-22T14:33:13Z

Currently, there is a check for a NULL task in unwind_frame(). It is not needed since all current callers pass a non-NULL task. There should be no functional change as a result of this patch. Signed-off-by: Madhavan T. Venkataraman Reviewed-by: Mark Brown Signed-off-by: Mark Rutland Reviewed-by: Kalesh Singh for the series. Link: https://lore.kernel.org/r/20220413145910.3060139-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: Mark start_backtrace() notrace and NOKPROBE_SYMBOL

2022-01-24T14:25:20Z

Mark the start_backtrace() as notrace and NOKPROBE_SYMBOL because this function is called from ftrace and lockdep to get the caller address via return_address(). The lockdep is used in kprobes, it should also be NOKPROBE_SYMBOL. Fixes: b07f3499661c ("arm64: stacktrace: Move start_backtrace() out of the header") Cc: # 5.13.x Signed-off-by: Masami Hiramatsu Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/164301227374.1433152.12808232644267107415.stgit@devnote2 Signed-off-by: Catalin Marinas

arm64: Make some stacktrace functions private

2021-12-10T14:06:04Z

Now that open-coded stack unwinds have been converted to arch_stack_walk(), we no longer need to expose any of unwind_frame(), walk_stackframe(), or start_backtrace() outside of stacktrace.c. Make those functions private to stacktrace.c, removing their prototypes from and marking them static. Signed-off-by: Mark Rutland Reviewed-by: Mark Brown Cc: Madhavan T. Venkataraman Link: https://lore.kernel.org/r/20211129142849.3056714-10-mark.rutland@arm.com Signed-off-by: Catalin Marinas