diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-16 14:58:12 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-16 14:58:12 -0800 |
commit | 37507717de51a8332a34ee07fd88700be88df5bf (patch) | |
tree | d6eb5d00a798a4b1ce40c8c4c8ca74b0d22fe1df /kernel | |
parent | a68fb48380bb993306dd62a58cbd946b4348222a (diff) | |
parent | a66734297f78707ce39d756b656bfae861d53f62 (diff) | |
download | linux-stable-37507717de51a8332a34ee07fd88700be88df5bf.tar.gz linux-stable-37507717de51a8332a34ee07fd88700be88df5bf.tar.bz2 linux-stable-37507717de51a8332a34ee07fd88700be88df5bf.zip |
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf updates from Ingo Molnar:
"This series tightens up RDPMC permissions: currently even highly
sandboxed x86 execution environments (such as seccomp) have permission
to execute RDPMC, which may leak various perf events / PMU state such
as timing information and other CPU execution details.
This 'all is allowed' RDPMC mode is still preserved as the
(non-default) /sys/devices/cpu/rdpmc=2 setting. The new default is
that RDPMC access is only allowed if a perf event is mmap-ed (which is
needed to correctly interpret RDPMC counter values in any case).
As a side effect of these changes CR4 handling is cleaned up in the
x86 code and a shadow copy of the CR4 value is added.
The extra CR4 manipulation adds ~ <50ns to the context switch cost
between rdpmc-capable and rdpmc-non-capable mms"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks
perf/x86: Only allow rdpmc if a perf_event is mapped
perf: Pass the event to arch_perf_update_userpage()
perf: Add pmu callbacks to track event mapping and unmapping
x86: Add a comment clarifying LDT context switching
x86: Store a per-cpu shadow copy of CR4
x86: Clean up cr4 manipulation
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/events/core.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 8812d8e35f5b..f04daabfd1cf 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4101,7 +4101,8 @@ unlock: rcu_read_unlock(); } -void __weak arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now) +void __weak arch_perf_update_userpage( + struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) { } @@ -4151,7 +4152,7 @@ void perf_event_update_userpage(struct perf_event *event) userpg->time_running = running + atomic64_read(&event->child_total_time_running); - arch_perf_update_userpage(userpg, now); + arch_perf_update_userpage(event, userpg, now); barrier(); ++userpg->lock; @@ -4293,6 +4294,9 @@ static void perf_mmap_open(struct vm_area_struct *vma) atomic_inc(&event->mmap_count); atomic_inc(&event->rb->mmap_count); + + if (event->pmu->event_mapped) + event->pmu->event_mapped(event); } /* @@ -4312,6 +4316,9 @@ static void perf_mmap_close(struct vm_area_struct *vma) int mmap_locked = rb->mmap_locked; unsigned long size = perf_data_size(rb); + if (event->pmu->event_unmapped) + event->pmu->event_unmapped(event); + atomic_dec(&rb->mmap_count); if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) @@ -4513,6 +4520,9 @@ unlock: vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; vma->vm_ops = &perf_mmap_vmops; + if (event->pmu->event_mapped) + event->pmu->event_mapped(event); + return ret; } |