diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-09-02 15:25:55 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-09-04 15:12:52 +0200 |
| commit | 4182e9436916a48f16207f0619562f1d3843a0c8 (patch) | |
| tree | 4cf848629c4725f1d0fb0d5248e56d963e3e4553 /arch/x86/kernel/traps.c | |
| parent | 7043679a989af969e9f20cc7d90195b36f54036f (diff) | |
x86/debug: Simplify #DB signal code
There's no point in calculating si_code if it's not going to be used.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200902133200.967434217@infradead.org
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 58bc434c75de..24e09f825a93 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -786,15 +786,14 @@ static __always_inline unsigned long debug_read_clear_dr6(void) static void handle_debug(struct pt_regs *regs, unsigned long dr6) { struct task_struct *tsk = current; - bool user_icebp; - int si_code; + bool icebp; /* * If dr6 has no reason to give us about the origin of this trap, * then it's very likely the result of an icebp/int01 trap. * User wants a sigtrap for that. */ - user_icebp = !dr6; + icebp = !dr6; /* Store the virtualized DR6 value */ tsk->thread.debugreg6 = dr6; @@ -813,6 +812,11 @@ static void handle_debug(struct pt_regs *regs, unsigned long dr6) goto out; } + /* + * Reload dr6, the notifier might have changed it. + */ + dr6 = tsk->thread.debugreg6; + if (WARN_ON_ONCE((dr6 & DR_STEP) && !user_mode(regs))) { /* * Historical junk that used to handle SYSENTER single-stepping. @@ -825,9 +829,8 @@ static void handle_debug(struct pt_regs *regs, unsigned long dr6) regs->flags &= ~X86_EFLAGS_TF; } - si_code = get_si_code(tsk->thread.debugreg6); - if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp) - send_sigtrap(regs, 0, si_code); + if (dr6 & (DR_STEP | DR_TRAP_BITS) || icebp) + send_sigtrap(regs, 0, get_si_code(dr6)); out: cond_local_irq_disable(regs); |