[PATCH v5 01/16] uprobes: allow ignoring of probe hits
From: David Long <hidden>
Date: 2014-01-23 20:06:13
Also in:
lkml
Subsystem:
performance events subsystem, the rest, uprobes · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Masami Hiramatsu, Oleg Nesterov
From: "David A. Long" <redacted> 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 <redacted> Acked-by: Oleg Nesterov <oleg@redhat.com> --- 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 319eae7..197a36e 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h@@ -134,6 +134,7 @@ 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 24b7d6c..4eec7ce 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c@@ -1778,6 +1778,11 @@ 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.
@@ -1828,7 +1833,11 @@ static void handle_swbp(struct pt_regs *regs) if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags))) goto out; + if (arch_uprobe_ignore(&uprobe->arch, regs)) + goto out; + handler_chain(uprobe, regs); + if (can_skip_sstep(uprobe, regs)) goto out;
--
1.8.1.2