From: Robert Richter <rric@kernel.org>
To: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Arnaldo Carvalho de Melo <acme@infradead.org>,
Jiri Olsa <jolsa@redhat.com>,
linux-kernel@vger.kernel.org, Borislav Petkov <bp@suse.de>,
Robert Richter <robert.richter@linaro.org>,
Robert Richter <rric@kernel.org>
Subject: [PATCH v2 02/14] perf: Add persistent events
Date: Tue, 11 Jun 2013 18:42:28 +0200 [thread overview]
Message-ID: <1370968960-22527-3-git-send-email-rric@kernel.org> (raw)
In-Reply-To: <1370968960-22527-1-git-send-email-rric@kernel.org>
From: Borislav Petkov <bp@alien8.de>
Add the needed pieces for persistent events which makes them
process-agnostic. Also, make their buffers read-only when mmaping them
from userspace.
While at it, do not return a void function, as caught by Fengguang's
build robot.
Changes made by Robert Richter <robert.richter@linaro.org>:
* mmap should return EACCES error if fd can not be opened writable.
This error code also helps userland to map buffers readonly on
failure.
Signed-off-by: Borislav Petkov <bp@suse.de>
[ Return -EACCES if mapped buffers must be readonly ]
Signed-off-by: Robert Richter <robert.richter@linaro.org>
Signed-off-by: Robert Richter <rric@kernel.org>
---
include/uapi/linux/perf_event.h | 3 ++-
kernel/events/core.c | 10 +++++++++-
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index fb104e5..6032361 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -272,8 +272,9 @@ struct perf_event_attr {
exclude_callchain_kernel : 1, /* exclude kernel callchains */
exclude_callchain_user : 1, /* exclude user callchains */
+ persistent : 1, /* always-on event */
- __reserved_1 : 41;
+ __reserved_1 : 40;
union {
__u32 wakeup_events; /* wakeup every n events */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b790ab6..a13e457 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3713,6 +3713,11 @@ static void perf_mmap_close(struct vm_area_struct *vma)
{
struct perf_event *event = vma->vm_file->private_data;
+ if (event->attr.persistent) {
+ atomic_dec(&event->mmap_count);
+ return;
+ }
+
if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) {
unsigned long size = perf_data_size(event->rb);
struct user_struct *user = event->mmap_user;
@@ -3756,9 +3761,12 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
if (event->cpu == -1 && event->attr.inherit)
return -EINVAL;
- if (!(vma->vm_flags & VM_SHARED))
+ if (!(vma->vm_flags & VM_SHARED) && !event->attr.persistent)
return -EINVAL;
+ if (event->attr.persistent && (vma->vm_flags & VM_WRITE))
+ return -EACCES;
+
vma_size = vma->vm_end - vma->vm_start;
nr_pages = (vma_size / PAGE_SIZE) - 1;
--
1.8.1.1
next prev parent reply other threads:[~2013-06-11 16:42 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-11 16:42 [PATCH v2 00/14] perf, persistent: Kernel updates for perf tool integration Robert Richter
2013-06-11 16:42 ` [PATCH v2 01/14] perf, ring_buffer: Use same prefix Robert Richter
2013-06-11 16:42 ` Robert Richter [this message]
2013-06-24 9:28 ` [PATCH v2 02/14] perf: Add persistent events Peter Zijlstra
2013-06-24 19:24 ` Borislav Petkov
2013-06-25 8:46 ` Robert Richter
2013-06-11 16:42 ` [PATCH v2 03/14] perf: Add persistent event facilities Robert Richter
2013-06-14 2:15 ` Namhyung Kim
2013-06-14 7:20 ` Robert Richter
2013-06-24 9:32 ` Peter Zijlstra
2013-06-25 8:47 ` Robert Richter
2013-06-24 9:44 ` Peter Zijlstra
2013-06-25 8:41 ` Robert Richter
2013-06-24 9:48 ` Peter Zijlstra
2013-06-24 19:26 ` Borislav Petkov
2013-06-25 7:44 ` Peter Zijlstra
2013-06-25 9:24 ` Robert Richter
2013-06-25 9:37 ` Borislav Petkov
2013-06-25 10:51 ` Robert Richter
2013-06-25 15:29 ` Borislav Petkov
2013-06-25 16:14 ` Robert Richter
2013-06-11 16:42 ` [PATCH v2 04/14] MCE: Enable persistent event Robert Richter
2013-06-11 16:42 ` [PATCH v2 05/14] perf, persistent: Rework struct pers_event_desc Robert Richter
2013-06-11 16:42 ` [PATCH v2 06/14] perf, persistent: Remove rb_put() Robert Richter
2013-06-11 16:42 ` [PATCH v2 07/14] perf, persistent: Introduce get_persistent_event() Robert Richter
2013-06-11 16:42 ` [PATCH v2 08/14] perf, persistent: Reworking perf_get_persistent_event_fd() Robert Richter
2013-06-11 16:42 ` [PATCH v2 09/14] perf, persistent: Protect event lists with mutex Robert Richter
2013-06-11 16:42 ` [PATCH v2 10/14] perf, persistent: Avoid adding identical events Robert Richter
2013-06-11 16:42 ` [PATCH v2 11/14] perf, persistent: Implementing a persistent pmu Robert Richter
2013-06-11 16:42 ` [PATCH v2 12/14] perf, persistent: Name each persistent event Robert Richter
2013-06-11 16:42 ` [PATCH v2 13/14] perf, persistent: Exposing persistent events using sysfs Robert Richter
2013-06-14 2:36 ` Namhyung Kim
2013-06-14 8:57 ` Robert Richter
2013-06-11 16:42 ` [PATCH v2 14/14] perf, persistent: Allow multiple users for an event Robert Richter
2013-06-24 10:08 ` [PATCH v2 00/14] perf, persistent: Kernel updates for perf tool integration Peter Zijlstra
2013-06-25 10:46 ` Robert Richter
2013-06-24 10:22 ` Peter Zijlstra
2013-06-25 16:56 ` Robert Richter
2013-06-24 10:24 ` Peter Zijlstra
2013-06-24 15:25 ` Peter Zijlstra
2013-06-24 19:45 ` Ingo Molnar
2013-06-25 17:57 ` Robert Richter
2013-06-25 19:16 ` Borislav Petkov
2013-06-26 8:12 ` Robert Richter
2013-06-26 8:24 ` Borislav Petkov
2013-06-26 9:46 ` Ingo Molnar
2013-06-26 9:56 ` Borislav Petkov
2013-06-26 10:11 ` Robert Richter
2013-06-26 11:45 ` Ingo Molnar
2013-06-26 12:25 ` Ingo Molnar
2013-06-26 12:44 ` Robert Richter
2013-06-27 5:46 ` Namhyung Kim
2013-06-27 8:35 ` Borislav Petkov
2013-06-27 8:50 ` Ingo Molnar
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