Commit-ID: 8b4d801b2b123b6c09742f861fe44a8527b84d47 Gitweb: http://git.kernel.org/tip/8b4d801b2b123b6c09742f861fe44a8527b84d47 Author: Oleg Nesterov <oleg@xxxxxxxxxx> AuthorDate: Thu, 20 Jun 2013 17:50:06 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Thu, 20 Jun 2013 17:57:00 +0200 hw_breakpoint: Fix cpu check in task_bp_pinned(cpu) trinity fuzzer triggered WARN_ONCE("Can't find any breakpoint slot") in arch_install_hw_breakpoint() but the problem is not arch-specific. The problem is, task_bp_pinned(cpu) checks "cpu == iter->cpu" but this doesn't account the "all cpus" events with iter->cpu < 0. This means that, say, register_user_hw_breakpoint(tsk) can happily create the arbitrary number > HBP_NUM of breakpoints which can not be activated. toggle_bp_task_slot() is equally wrong by the same reason and nr_task_bp_pinned[] can have negative entries. Simple test: # perl -e 'sleep 1 while 1' & # perf record -e mem:0x10,mem:0x10,mem:0x10,mem:0x10,mem:0x10 -p `pidof perl` Before this patch this triggers the same problem/WARN_ON(), after the patch it correctly fails with -ENOSPC. Reported-by: Vince Weaver <vincent.weaver@xxxxxxxxx> Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Acked-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20130620155006.GA6324@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/events/hw_breakpoint.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index a64f8ae..a853dea 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -120,7 +120,7 @@ static int task_bp_pinned(int cpu, struct perf_event *bp, enum bp_type_idx type) list_for_each_entry(iter, &bp_task_head, hw.bp_list) { if (iter->hw.bp_target == tsk && find_slot_idx(iter) == type && - cpu == iter->cpu) + (iter->cpu < 0 || cpu == iter->cpu)) count += hw_breakpoint_weight(iter); } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html