[PATCH 3/9] uprobes: allow ignoring of probe hits
Oleg Nesterov
oleg at redhat.com
Mon Oct 15 12:52:18 EDT 2012
On 10/14, Rabin Vincent wrote:
>
> 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.
Not sure I understand why we shouldn't call handlers in this case,
but OK, I know nothing about arm.
> 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;
This conflicts with other changes in
git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc uprobes/core
Could you re-diff?
I'll try to read 1-7 tomorrow.
Oleg.
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