From 6fe50a28ba6e5fafb4a549dea666dd15297dd8bd Mon Sep 17 00:00:00 2001 From: "David A. Long" Date: Mon, 3 Feb 2014 14:25:49 -0500 Subject: [PATCH] uprobes: allow ignoring of probe hits Allow arches to decided to ignore a probe hit. ARM will use this to only call handlers if the conditions to execute a conditionally executed instruction are satisfied. Signed-off-by: David A. Long Acked-by: Oleg Nesterov --- include/linux/uprobes.h | 1 + kernel/events/uprobes.c | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index e32251e00e62..edff2b97b864 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -126,6 +126,7 @@ extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk); extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data); extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs); extern unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs); +extern bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs); #else /* !CONFIG_UPROBES */ struct uprobes_state { }; diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 307d87c0991a..04709b66369d 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1804,6 +1804,11 @@ static bool handle_trampoline(struct pt_regs *regs) return true; } +bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs) +{ + return false; +} + /* * Run handler and ask thread to singlestep. * Ensure all non-fatal signals cannot interrupt thread while it singlesteps. @@ -1858,7 +1863,11 @@ static void handle_swbp(struct pt_regs *regs) if (!get_utask()) goto out; + if (arch_uprobe_ignore(&uprobe->arch, regs)) + goto out; + handler_chain(uprobe, regs); + if (can_skip_sstep(uprobe, regs)) goto out; -- 2.20.1