Messages in this thread Patch in this message | | | From | Rabin Vincent <> | Subject | [PATCH 3/9] uprobes: allow ignoring of probe hits | Date | Sun, 14 Oct 2012 21:23:07 +0200 |
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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: Rabin Vincent <rabin@rab.in> --- include/linux/uprobes.h | 1 + kernel/events/uprobes.c | 14 +++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index ac90704..da21b66 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -128,6 +128,7 @@ extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs); 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 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 db4e3ab..a0e1a38 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1419,6 +1419,11 @@ static void mmf_recalc_uprobes(struct mm_struct *mm) clear_bit(MMF_HAS_UPROBES, &mm->flags); } +bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs) +{ + return false; +} + static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) { struct mm_struct *mm = current->mm; @@ -1469,6 +1474,7 @@ static void handle_swbp(struct pt_regs *regs) struct uprobe *uprobe; unsigned long bp_vaddr; int uninitialized_var(is_swbp); + bool ignored = false; bp_vaddr = uprobe_get_swbp_addr(regs); uprobe = find_active_uprobe(bp_vaddr, &is_swbp); @@ -1499,6 +1505,12 @@ static void handle_swbp(struct pt_regs *regs) goto cleanup_ret; } utask->active_uprobe = uprobe; + + if (arch_uprobe_ignore(&uprobe->arch, regs)) { + ignored = true; + goto cleanup_ret; + } + handler_chain(uprobe, regs); if (uprobe->flags & UPROBE_SKIP_SSTEP && can_skip_sstep(uprobe, regs)) goto cleanup_ret; @@ -1514,7 +1526,7 @@ cleanup_ret: utask->active_uprobe = NULL; utask->state = UTASK_RUNNING; } - if (!(uprobe->flags & UPROBE_SKIP_SSTEP)) + if (!ignored && !(uprobe->flags & UPROBE_SKIP_SSTEP)) /* * cannot singlestep; cannot skip instruction; -- 1.7.9.5
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