From 15af1942dd61ee236a48b3de14d6f31c0b9e8116 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 16 Sep 2013 15:19:27 +0100 Subject: [PATCH] arm64: Expose ESR_EL1 information to user when SIGSEGV/SIGBUS This information is useful for instruction emulators to detect read/write and access size without having to decode the faulting instruction. The current patch exports it via sigcontext (struct esr_context) and is only valid for SIGSEGV and SIGBUS. Signed-off-by: Catalin Marinas --- arch/arm64/include/uapi/asm/sigcontext.h | 7 +++++++ arch/arm64/kernel/signal.c | 10 ++++++++++ 2 files changed, 17 insertions(+) diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h index 690ad51cc901..b72cf405b3fe 100644 --- a/arch/arm64/include/uapi/asm/sigcontext.h +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -53,5 +53,12 @@ struct fpsimd_context { __uint128_t vregs[32]; }; +/* ESR_EL1 context */ +#define ESR_MAGIC 0x45535201 + +struct esr_context { + struct _aarch64_ctx head; + u64 esr; +}; #endif /* _UAPI__ASM_SIGCONTEXT_H */ diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 7ff2eee96c6b..dc2ab1b0ac0d 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -194,6 +194,16 @@ static int setup_sigframe(struct rt_sigframe __user *sf, aux += sizeof(*fpsimd_ctx); } + /* fault information, if valid */ + if (current->thread.fault_code) { + struct esr_context *esr_ctx = + container_of(aux, struct esr_context, head); + __put_user_error(ESR_MAGIC, &esr_ctx->head.magic, err); + __put_user_error(sizeof(*esr_ctx), &esr_ctx->head.size, err); + __put_user_error(current->thread.fault_code, &esr_ctx->esr, err); + aux += sizeof(*esr_ctx); + } + /* set the "end" magic */ end = aux; __put_user_error(0, &end->magic, err); -- 2.34.1