Re: [PATCH v3 07/11] perf: Add breakpoint information to siginfo on SIGTRAP
From: Peter Zijlstra <peterz@infradead.org>
Date: 2021-03-24 13:44:10
Also in:
linux-fsdevel, linux-kselftest, lkml
On Wed, Mar 24, 2021 at 02:21:37PM +0100, Peter Zijlstra wrote:
quoted hunk ↗ jump to hunk
--- a/kernel/events/core.c +++ b/kernel/events/core.c@@ -5652,13 +5652,17 @@ static long _perf_ioctl(struct perf_even return perf_event_query_prog_array(event, (void __user *)arg); case PERF_EVENT_IOC_MODIFY_ATTRIBUTES: { + struct perf_event_attr __user *uattr; struct perf_event_attr new_attr; - int err = perf_copy_attr((struct perf_event_attr __user *)arg, - &new_attr); + int err; + uattr = (struct perf_event_attr __user *)arg; + err = perf_copy_attr(uattr, &new_attr); if (err) return err; + event->siginfo.si_perf = (unsigned long)uattr;
Oh bugger; that wants updating for all children too..
quoted hunk ↗ jump to hunk
+ return perf_event_modify_attr(event, &new_attr); } default:@@ -12011,6 +12010,11 @@ SYSCALL_DEFINE5(perf_event_open, goto err_task; } + clear_siginfo(&event->siginfo); + event->siginfo.si_signo = SIGTRAP; + event->siginfo.si_code = TRAP_PERF; + event->siginfo.si_perf = (unsigned long)attr_uptr;
And inherit_event() / perf_event_alloc() want to copy/propagate that.
if (is_sampling_event(event)) {
if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
err = -EOPNOTSUPP;