[PATCH 02/15] riscv: cleanup do_trap_break

From: Christoph Hellwig
Date: Thu Oct 17 2019 - 13:37:55 EST


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 <hch@xxxxxx>
---
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