On Thu, Jul 06, 2017 at 03:34:39PM -0700, Palmer Dabbelt wrote:
> On Tue, 04 Jul 2017 14:54:01 PDT (-0700), j.neuschaefer@xxxxxxx wrote:
[...]
> >> +#define DO_ERROR_INFO(name, signo, code, str) \
> >> +asmlinkage void name(struct pt_regs *regs) \
> >> +{ \
> >> + do_trap_error(regs, signo, code, regs->sepc, "Oops - " str); \
> >> +}
> >> +
> >> +DO_ERROR_INFO(do_trap_unknown,
> >> + SIGILL, ILL_ILLTRP, "unknown exception");
> >> +DO_ERROR_INFO(do_trap_insn_misaligned,
> >> + SIGBUS, BUS_ADRALN, "instruction address misaligned");
> >> +DO_ERROR_INFO(do_trap_insn_fault,
> >> + SIGBUS, BUS_ADRALN, "instruction access fault");
> >
> > For a general instruction access fault, BUS_ADRALN seems wrong. A
> > variant of SIGSEGV seems more appropriate, IMHO.
>
> How does this look?
>
> diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
> index 4c693b5b9980..3ce9ac6e736e 100644
> --- a/arch/riscv/kernel/traps.c
> +++ b/arch/riscv/kernel/traps.c
> @@ -112,7 +112,7 @@ DO_ERROR_INFO(do_trap_unknown,
> DO_ERROR_INFO(do_trap_insn_misaligned,
> SIGBUS, BUS_ADRALN, "instruction address misaligned");
> DO_ERROR_INFO(do_trap_insn_fault,
> - SIGBUS, BUS_ADRALN, "instruction access fault");
> + SIGBUS, SEGV_ACCERR, "instruction access fault");
> DO_ERROR_INFO(do_trap_insn_illegal,
> SIGILL, ILL_ILLOPC, "illegal instruction");
> DO_ERROR_INFO(do_trap_load_misaligned,
I'm not familiar with the trap handling infrastructure, but looking at
include/uapi/asm-generic/siginfo.h, SEGV_ACCERR would alias to
BUS_ADRERR (both are defined as (__SI_FAULT|2)). So if you use SEGV_*,
you need to use SIGSEGV, too.
With DO_ERROR_INFO(..., SIGSEGV, SEGV_ACCERR, ...); it looks good to me.
Jonathan Neuschäfer
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