The following commit has been merged into the x86/entry branch of tip: Commit-ID: 4182e9436916a48f16207f0619562f1d3843a0c8 Gitweb: https://git.kernel.org/tip/4182e9436916a48f16207f0619562f1d3843a0c8 Author: Peter Zijlstra <[email protected]> AuthorDate: Wed, 02 Sep 2020 15:25:55 +02:00 Committer: Thomas Gleixner <[email protected]> CommitterDate: Fri, 04 Sep 2020 15:12:52 +02:00
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) <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Daniel Thompson <[email protected]> Link: https://lore.kernel.org/r/[email protected] --- arch/x86/kernel/traps.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 58bc434..24e09f8 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);
