Messages in this thread Patch in this message | | | From | Adrian Hunter <> | Subject | [PATCH RFC 3/5] perf: Add namespaces to the sideband ioctl | Date | Fri, 14 Apr 2023 11:22:58 +0300 |
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Support the case of output to an active event, and return an error if output is not possible in that case. Set PERF_RECORD_MISC_STATUS_ONLY to differentiate the ioctl status-only sideband event from a "real" sideband event.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- kernel/events/core.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c index 4e76596d3bfb..ed4af231853a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8364,8 +8364,7 @@ static int perf_event_namespaces_match(struct perf_event *event) return event->attr.namespaces; } -static void perf_event_namespaces_output(struct perf_event *event, - void *data) +static int perf_event_namespaces_output(struct perf_event *event, void *data) { struct perf_namespaces_event *namespaces_event = data; struct perf_output_handle handle; @@ -8374,7 +8373,7 @@ static void perf_event_namespaces_output(struct perf_event *event, int ret; if (!perf_event_namespaces_match(event)) - return; + return -ENOENT; perf_event_header__init_id(&namespaces_event->event_id.header, &sample, event); @@ -8395,6 +8394,7 @@ static void perf_event_namespaces_output(struct perf_event *event, perf_output_end(&handle); out: namespaces_event->event_id.header.size = header_size; + return ret; } static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info, @@ -8414,20 +8414,20 @@ static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info, } } -void perf_event_namespaces(struct task_struct *task) +static int __perf_event_namespaces(struct task_struct *task, struct perf_event *event) { struct perf_namespaces_event namespaces_event; struct perf_ns_link_info *ns_link_info; if (!atomic_read(&nr_namespaces_events)) - return; + return -ENOENT; namespaces_event = (struct perf_namespaces_event){ .task = task, .event_id = { .header = { .type = PERF_RECORD_NAMESPACES, - .misc = 0, + .misc = event ? PERF_RECORD_MISC_STATUS_ONLY : 0, .size = sizeof(namespaces_event.event_id), }, /* .pid */ @@ -8467,9 +8467,12 @@ void perf_event_namespaces(struct task_struct *task) task, &cgroupns_operations); #endif - perf_iterate_sb(perf_event_namespaces_output, - &namespaces_event, - NULL); + return perf_output_sb(perf_event_namespaces_output, &namespaces_event, NULL, event); +} + +void perf_event_namespaces(struct task_struct *task) +{ + __perf_event_namespaces(task, NULL); } /* @@ -12880,7 +12883,10 @@ static int perf_event_emit_fork(struct perf_event *event, struct task_struct *ta static int perf_event_emit_namespaces(struct perf_event *event, struct task_struct *task) { - return -EINVAL; + if (!event->attr.namespaces) + return -EINVAL; + + return __perf_event_namespaces(task, event); } static int perf_event_emit_comm(struct perf_event *event, struct task_struct *task) -- 2.34.1
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