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Commit 006a1212 authored by Catalin Marinas's avatar Catalin Marinas Committed by Joonwoo Park
Browse files

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: default avatarCatalin Marinas <catalin.marinas@arm.com>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Git-commit: 15af1942dd61ee236a48b3de14d6f31c0b9e8116
Signed-off-by: default avatarJoonwoo Park <joonwoop@codeaurora.org>
parent ddae87d7

arch/arm64/include/uapi/asm/sigcontext.h

+7 −0
Original line number Diff line number Diff line
@@ -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 */

arch/arm64/kernel/signal.c

+10 −0
Original line number Diff line number Diff line
@@ -191,6 +191,16 @@ 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);