The following commit has been merged into the x86/entry branch of tip: Commit-ID: f4f6b66fd8011eb5f24dec936faaa4cab2ca7ebc Gitweb: https://git.kernel.org/tip/f4f6b66fd8011eb5f24dec936faaa4cab2ca7ebc Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Thu, 05 Mar 2020 16:09:52 +01:00 Committer: Thomas Gleixner <t...@linutronix.de> CommitterDate: Tue, 19 May 2020 16:04:07 +02:00
x86/traps: Split int3 handler up For code simplicity split up the int3 handler into a kernel and user part which makes the code flow simpler to understand. Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.char...@oracle.com> Link: https://lkml.kernel.org/r/20200505135314.045220...@linutronix.de --- arch/x86/kernel/traps.c | 68 +++++++++++++++++++++++----------------- 1 file changed, 40 insertions(+), 28 deletions(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 0ad12df..21c8cfc 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -568,6 +568,35 @@ exit: cond_local_irq_disable(regs); } +static bool do_int3(struct pt_regs *regs) +{ + int res; + +#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP + if (kgdb_ll_trap(DIE_INT3, "int3", regs, 0, X86_TRAP_BP, + SIGTRAP) == NOTIFY_STOP) + return true; +#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ + +#ifdef CONFIG_KPROBES + if (kprobe_int3_handler(regs)) + return true; +#endif + res = notify_die(DIE_INT3, "int3", regs, 0, X86_TRAP_BP, SIGTRAP); + + return res == NOTIFY_STOP; +} + +static void do_int3_user(struct pt_regs *regs) +{ + if (do_int3(regs)) + return; + + cond_local_irq_enable(regs); + do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, 0, 0, NULL); + cond_local_irq_disable(regs); +} + DEFINE_IDTENTRY_RAW(exc_int3) { /* @@ -585,37 +614,20 @@ DEFINE_IDTENTRY_RAW(exc_int3) * because the INT3 could have been hit in any context including * NMI. */ - if (user_mode(regs)) + if (user_mode(regs)) { idtentry_enter(regs); - else - nmi_enter(); - - instrumentation_begin(); -#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP - if (kgdb_ll_trap(DIE_INT3, "int3", regs, 0, X86_TRAP_BP, - SIGTRAP) == NOTIFY_STOP) - goto exit; -#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ - -#ifdef CONFIG_KPROBES - if (kprobe_int3_handler(regs)) - goto exit; -#endif - - if (notify_die(DIE_INT3, "int3", regs, 0, X86_TRAP_BP, - SIGTRAP) == NOTIFY_STOP) - goto exit; - - cond_local_irq_enable(regs); - do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, 0, 0, NULL); - cond_local_irq_disable(regs); - -exit: - instrumentation_end(); - if (user_mode(regs)) + instrumentation_begin(); + do_int3_user(regs); + instrumentation_end(); idtentry_exit(regs); - else + } else { + nmi_enter(); + instrumentation_begin(); + if (!do_int3(regs)) + die("int3", regs, 0); + instrumentation_end(); nmi_exit(); + } } #ifdef CONFIG_X86_64
