From 9e75e74b07ab17e6407b567eb4a8b3d0c93de5f1 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 31 Oct 2022 19:24:50 +0000 Subject: [PATCH] arm64/signal: Document our convention for choosing magic numbers Szabolcs Nagy has pointed out that most of our signal frame magic numbers are chosen to be meaningful ASCII when dumped to aid manual parsing. This seems sensible since it might help someone parsing things out, let's document it so people implementing new signal contexts are aware of it and are more likely to follow it. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20221031192450.826159-1-broonie@kernel.org [will: Fixed typo and tweaked wording] Signed-off-by: Will Deacon --- arch/arm64/include/uapi/asm/sigcontext.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h index 4aaf31e3bf167..9525041e4a148 100644 --- a/arch/arm64/include/uapi/asm/sigcontext.h +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -62,6 +62,10 @@ struct sigcontext { * context. Such structures must be placed after the rt_sigframe on the stack * and be 16-byte aligned. The last structure must be a dummy one with the * magic and size set to 0. + * + * Note that the values allocated for use as magic should be chosen to + * be meaningful in ASCII to aid manual parsing, ZA doesn't follow this + * convention due to oversight but it should be observed for future additions. */ struct _aarch64_ctx { __u32 magic; -- 2.30.2