On Thu, Oct 17, 2019 at 11:07 PM Christoph Hellwig <h...@lst.de> wrote:
>
> If we always compile the get_break_insn_length inline function we can
> remove the ifdefs and let dead code elimination take care of the warn
> branch that is now unreadable because the report_bug stub always
> returns BUG_TRAP_TYPE_BUG.
>
> Signed-off-by: Christoph Hellwig <h...@lst.de>
> ---
> arch/riscv/kernel/traps.c | 26 ++++++--------------------
> 1 file changed, 6 insertions(+), 20 deletions(-)
>
> diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
> index 1ac75f7d0bff..10a17e545f43 100644
> --- a/arch/riscv/kernel/traps.c
> +++ b/arch/riscv/kernel/traps.c
> @@ -111,7 +111,6 @@ DO_ERROR_INFO(do_trap_ecall_s,
> DO_ERROR_INFO(do_trap_ecall_m,
> SIGILL, ILL_ILLTRP, "environment call from M-mode");
>
> -#ifdef CONFIG_GENERIC_BUG
> static inline unsigned long get_break_insn_length(unsigned long pc)
> {
> bug_insn_t insn;
> @@ -120,28 +119,15 @@ static inline unsigned long
> get_break_insn_length(unsigned long pc)
> return 0;
> return (((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) ? 4UL :
> 2UL);
> }
> -#endif /* CONFIG_GENERIC_BUG */
>
> asmlinkage void do_trap_break(struct pt_regs *regs)
> {
> - if (user_mode(regs)) {
> - force_sig_fault(SIGTRAP, TRAP_BRKPT,
> - (void __user *)(regs->sepc));
> - return;
> - }
> -#ifdef CONFIG_GENERIC_BUG
> - {
> - enum bug_trap_type type;
> -
> - type = report_bug(regs->sepc, regs);
> - if (type == BUG_TRAP_TYPE_WARN) {
> - regs->sepc += get_break_insn_length(regs->sepc);
> - return;
> - }
> - }
> -#endif /* CONFIG_GENERIC_BUG */
> -
> - die(regs, "Kernel BUG");
> + if (user_mode(regs))
> + force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user
> *)regs->sepc);
> + else if (report_bug(regs->sepc, regs) == BUG_TRAP_TYPE_WARN)
> + regs->sepc += get_break_insn_length(regs->sepc);
> + else
> + die(regs, "Kernel BUG");
> }
>
> #ifdef CONFIG_GENERIC_BUG
> --
> 2.20.1
>
>
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LGTM.
Reviewed-by: Anup Patel <a...@brainfault.org>
Regards,
Anup
