Re: [PATCH 1/5] uprobes: Do not leak UTASK_BP_HIT iffind_active_uprobe() fails

From: Srikar Dronamraju
Date: Thu Sep 20 2012 - 10:00:35 EST


> If handle_swbp()->find_active_uprobe() fails we return with
> utask->state = UTASK_BP_HIT.
>
> Change handle_swbp() to reset utask->state at the start. Note
> that we do this unconditionally, see the next patch(es).
>
> Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
> ---
> kernel/events/uprobes.c | 5 ++++-
> 1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
> index 26f06a6..760acc1 100644
> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -1468,6 +1468,10 @@ static void handle_swbp(struct pt_regs *regs)
> bp_vaddr = uprobe_get_swbp_addr(regs);
> uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
>
> + utask = current->utask;
> + if (utask)
> + utask->state = UTASK_RUNNING;
> +
> if (!uprobe) {
> if (is_swbp > 0) {
> /* No matching uprobe; signal SIGTRAP. */
> @@ -1486,7 +1490,6 @@ static void handle_swbp(struct pt_regs *regs)
> return;
> }
>
> - utask = current->utask;
> if (!utask) {
> utask = add_utask();
> /* Cannot allocate; re-execute the instruction. */


Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>

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