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2014-06-05perf: Fix use after free in perf_remove_from_context()Peter Zijlstra1-2/+2
While that mutex should guard the elements, it doesn't guard against the use-after-free that's from list_for_each_entry_rcu(). __perf_event_exit_task() can actually free the event. And because list addition/deletion is guarded by both ctx->mutex and ctx->lock, holding ctx->mutex is sufficient for reading the list, so we don't actually need the rcu list iteration. Fixes: 3a497f48637e ("perf: Simplify perf_event_exit_task_context()") Reported-by: Sasha Levin <[email protected]> Tested-by: Sasha Levin <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Dave Jones <[email protected]> Cc: [email protected] Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-06-05Merge branch 'perf/uprobes' into perf/coreIngo Molnar1-13/+22
These bits from Oleg are fully cooked, ship them to Linus. Signed-off-by: Ingo Molnar <[email protected]>
2014-06-03Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2-69/+79
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull perf updates from Ingo Molnar: "The tooling changes maintained by Jiri Olsa until Arnaldo is on vacation: User visible changes: - Add -F option for specifying output fields (Namhyung Kim) - Propagate exit status of a command line workload for record command (Namhyung Kim) - Use tid for finding thread (Namhyung Kim) - Clarify the output of perf sched map plus small sched command fixes (Dongsheng Yang) - Wire up perf_regs and unwind support for ARM64 (Jean Pihet) - Factor hists statistics counts processing which in turn also fixes several bugs in TUI report command (Namhyung Kim) - Add --percentage option to control absolute/relative percentage output (Namhyung Kim) - Add --list-cmds to 'kmem', 'mem', 'lock' and 'sched', for use by completion scripts (Ramkumar Ramachandra) Development/infrastructure changes and fixes: - Android related fixes for pager and map dso resolving (Michael Lentine) - Add libdw DWARF post unwind support for ARM (Jean Pihet) - Consolidate types.h for ARM and ARM64 (Jean Pihet) - Fix possible null pointer dereference in session.c (Masanari Iida) - Cleanup, remove unused variables in map_switch_event() (Dongsheng Yang) - Remove nr_state_machine_bugs in perf latency (Dongsheng Yang) - Remove usage of trace_sched_wakeup(.success) (Peter Zijlstra) - Cleanups for perf.h header (Jiri Olsa) - Consolidate types.h and export.h within tools (Borislav Petkov) - Move u64_swap union to its single user's header, evsel.h (Borislav Petkov) - Fix for s390 to properly parse tracepoints plus test code (Alexander Yarygin) - Handle EINTR error for readn/writen (Namhyung Kim) - Add a test case for hists filtering (Namhyung Kim) - Share map_groups among threads of the same group (Arnaldo Carvalho de Melo, Jiri Olsa) - Making some code (cpu node map and report parse callchain callback) global to be usable by upcomming changes (Don Zickus) - Fix pmu object compilation error (Jiri Olsa) Kernel side changes: - intrusive uprobes fixes from Oleg Nesterov. Since the interface is admin-only, and the bug only affects user-space ("any probed jmp/call can kill the application"), we queued these fixes via the development tree, as a special exception. - more fuzzer motivated race fixes and related refactoring and robustization. - allow PMU drivers to be built as modules. (No actual module yet, because the x86 Intel uncore module wasn't ready in time for this)" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits) perf tools: Add automatic remapping of Android libraries perf tools: Add cat as fallback pager perf tests: Add a testcase for histogram output sorting perf tests: Factor out print_hists_*() perf tools: Introduce reset_output_field() perf tools: Get rid of obsolete hist_entry__sort_list perf hists: Reset width of output fields with header length perf tools: Skip elided sort entries perf top: Add --fields option to specify output fields perf report/tui: Fix a bug when --fields/sort is given perf tools: Add ->sort() member to struct sort_entry perf report: Add -F option to specify output fields perf tools: Call perf_hpp__init() before setting up GUI browsers perf tools: Consolidate management of default sort orders perf tools: Allow hpp fields to be sort keys perf ui: Get rid of callback from __hpp__fmt() perf tools: Consolidate output field handling to hpp format routines perf tools: Use hpp formats to sort final output perf tools: Support event grouping in hpp ->sort() perf tools: Use hpp formats to sort hist entries ...
2014-05-25ARM: 8043/1: uprobes need icache flush after xol writeVictor Kamensky1-8/+17
After instruction write into xol area, on ARM V7 architecture code need to flush dcache and icache to sync them up for given set of addresses. Having just 'flush_dcache_page(page)' call is not enough - it is possible to have stale instruction sitting in icache for given xol area slot address. Introduce arch_uprobe_ixol_copy weak function that by default calls uprobes copy_to_page function and than flush_dcache_page function and on ARM define new one that handles xol slot copy in ARM specific way flush_uprobe_xol_access function shares/reuses implementation with/of flush_ptrace_access function and takes care of writing instruction to user land address space on given variety of different cache types on ARM CPUs. Because flush_uprobe_xol_access does not have vma around flush_ptrace_access was split into two parts. First that retrieves set of condition from vma and common that receives those conditions as flags. Note ARM cache flush function need kernel address through which instruction write happened, so instead of using uprobes copy_to_page function changed code to explicitly map page and do memcpy. Note arch_uprobe_copy_ixol function, in similar way as copy_to_user_page function, has preempt_disable/preempt_enable. Signed-off-by: Victor Kamensky <[email protected]> Acked-by: Oleg Nesterov <[email protected]> Reviewed-by: David A. Long <[email protected]> Signed-off-by: Russell King <[email protected]>
2014-05-19perf/events/core: Drop unused variable after cleanupBorislav Petkov1-1/+1
... in 3a497f48637 ("perf: Simplify perf_event_exit_task_context()") Signed-off-by: Borislav Petkov <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2014-05-19perf: Fix a race between ring_buffer_detach() and ring_buffer_attach()Peter Zijlstra1-60/+49
Alexander noticed that we use RCU iteration on rb->event_list but do not use list_{add,del}_rcu() to add,remove entries to that list, nor do we observe proper grace periods when re-using the entries. Merge ring_buffer_detach() into ring_buffer_attach() such that attaching to the NULL buffer is detaching. Furthermore, ensure that between any 'detach' and 'attach' of the same event we observe the required grace period, but only when strictly required. In effect this means that only ioctl(.request = PERF_EVENT_IOC_SET_OUTPUT) will wait for a grace period, while the normal initial attach and final detach will not be delayed. This patch should, I think, do the right thing under all circumstances, the 'normal' cases all should never see the extra grace period, but the two cases: 1) PERF_EVENT_IOC_SET_OUTPUT on an event which already has a ring_buffer set, will now observe the required grace period between removing itself from the old and attaching itself to the new buffer. This case is 'simple' in that both buffers are present in perf_event_set_output() one could think an unconditional synchronize_rcu() would be sufficient; however... 2) an event that has a buffer attached, the buffer is destroyed (munmap) and then the event is attached to a new/different buffer using PERF_EVENT_IOC_SET_OUTPUT. This case is more complex because the buffer destruction does: ring_buffer_attach(.rb = NULL) followed by the ioctl() doing: ring_buffer_attach(.rb = foo); and we still need to observe the grace period between these two calls due to us reusing the event->rb_entry list_head. In order to make 2 happen we use Paul's latest cond_synchronize_rcu() call. Cc: Paul Mackerras <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Andi Kleen <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Mike Galbraith <[email protected]> Reported-by: Alexander Shishkin <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2014-05-19perf: Prevent false warning in perf_swevent_addJiri Olsa1-1/+12
The perf cpu offline callback takes down all cpu context events and releases swhash->swevent_hlist. This could race with task context software event being just scheduled on this cpu via perf_swevent_add while cpu hotplug code already cleaned up event's data. The race happens in the gap between the cpu notifier code and the cpu being actually taken down. Note that only cpu ctx events are terminated in the perf cpu hotplug code. It's easily reproduced with: $ perf record -e faults perf bench sched pipe while putting one of the cpus offline: # echo 0 > /sys/devices/system/cpu/cpu1/online Console emits following warning: WARNING: CPU: 1 PID: 2845 at kernel/events/core.c:5672 perf_swevent_add+0x18d/0x1a0() Modules linked in: CPU: 1 PID: 2845 Comm: sched-pipe Tainted: G W 3.14.0+ #256 Hardware name: Intel Corporation Montevina platform/To be filled by O.E.M., BIOS AMVACRB1.86C.0066.B00.0805070703 05/07/2008 0000000000000009 ffff880077233ab8 ffffffff81665a23 0000000000200005 0000000000000000 ffff880077233af8 ffffffff8104732c 0000000000000046 ffff88007467c800 0000000000000002 ffff88007a9cf2a0 0000000000000001 Call Trace: [<ffffffff81665a23>] dump_stack+0x4f/0x7c [<ffffffff8104732c>] warn_slowpath_common+0x8c/0xc0 [<ffffffff8104737a>] warn_slowpath_null+0x1a/0x20 [<ffffffff8110fb3d>] perf_swevent_add+0x18d/0x1a0 [<ffffffff811162ae>] event_sched_in.isra.75+0x9e/0x1f0 [<ffffffff8111646a>] group_sched_in+0x6a/0x1f0 [<ffffffff81083dd5>] ? sched_clock_local+0x25/0xa0 [<ffffffff811167e6>] ctx_sched_in+0x1f6/0x450 [<ffffffff8111757b>] perf_event_sched_in+0x6b/0xa0 [<ffffffff81117a4b>] perf_event_context_sched_in+0x7b/0xc0 [<ffffffff81117ece>] __perf_event_task_sched_in+0x43e/0x460 [<ffffffff81096f1e>] ? put_lock_stats.isra.18+0xe/0x30 [<ffffffff8107b3c8>] finish_task_switch+0xb8/0x100 [<ffffffff8166a7de>] __schedule+0x30e/0xad0 [<ffffffff81172dd2>] ? pipe_read+0x3e2/0x560 [<ffffffff8166b45e>] ? preempt_schedule_irq+0x3e/0x70 [<ffffffff8166b45e>] ? preempt_schedule_irq+0x3e/0x70 [<ffffffff8166b464>] preempt_schedule_irq+0x44/0x70 [<ffffffff816707f0>] retint_kernel+0x20/0x30 [<ffffffff8109e60a>] ? lockdep_sys_exit+0x1a/0x90 [<ffffffff812a4234>] lockdep_sys_exit_thunk+0x35/0x67 [<ffffffff81679321>] ? sysret_check+0x5/0x56 Fixing this by tracking the cpu hotplug state and displaying the WARN only if current cpu is initialized properly. Cc: Corey Ashford <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: [email protected] Reported-by: Fengguang Wu <[email protected]> Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2014-05-19perf: Limit perf_event_attr::sample_period to 63 bitsPeter Zijlstra1-0/+3
Vince reported that using a large sample_period (one with bit 63 set) results in wreckage since while the sample_period is fundamentally unsigned (negative periods don't make sense) the way we implement things very much rely on signed logic. So limit sample_period to 63 bits to avoid tripping over this. Reported-by: Vince Weaver <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2014-05-14uprobes/x86: Fix the wrong ->si_addr when xol triggers a trapOleg Nesterov1-0/+10
If the probed insn triggers a trap, ->si_addr = regs->ip is technically correct, but this is not what the signal handler wants; we need to pass the address of the probed insn, not the address of xol slot. Add the new arch-agnostic helper, uprobe_get_trap_addr(), and change fill_trap_info() and math_error() to use it. !CONFIG_UPROBES case in uprobes.h uses a macro to avoid include hell and ensure that it can be compiled even if an architecture doesn't define instruction_pointer(). Test-case: #include <signal.h> #include <stdio.h> #include <unistd.h> extern void probe_div(void); void sigh(int sig, siginfo_t *info, void *c) { int passed = (info->si_addr == probe_div); printf(passed ? "PASS\n" : "FAIL\n"); _exit(!passed); } int main(void) { struct sigaction sa = { .sa_sigaction = sigh, .sa_flags = SA_SIGINFO, }; sigaction(SIGFPE, &sa, NULL); asm ( "xor %ecx,%ecx\n" ".globl probe_div; probe_div:\n" "idiv %ecx\n" ); return 0; } it fails if probe_div() is probed. Note: show_unhandled_signals users should probably use this helper too, but we need to cleanup them first. Signed-off-by: Oleg Nesterov <[email protected]> Reviewed-by: Masami Hiramatsu <[email protected]>
2014-05-14uprobes: Add mem_cgroup_charge_anon() into uprobe_write_opcode()Oleg Nesterov1-12/+11
Hugh says: The one I noticed was that it forgets all about memcg (because it was copied from KSM, and there the replacement page has already been charged to a memcg). See how mm/memory.c do_anonymous_page() does a mem_cgroup_charge_anon(). Hopefully not a big problem, uprobes is a system-wide thing and only root can insert the probes. But I agree, should be fixed anyway. Add mem_cgroup_{un,}charge_anon() into uprobe_write_opcode(). To simplify the error handling (and avoid the new "uncharge" label) the patch also moves anon_vma_prepare() up before we alloc/charge the new page. While at it fix the comment about ->mmap_sem, it is held for write. Suggested-by: Hugh Dickins <[email protected]> Signed-off-by: Oleg Nesterov <[email protected]>
2014-05-13cgroup: rename css_tryget*() to css_tryget_online*()Tejun Heo1-1/+2
Unlike the more usual refcnting, what css_tryget() provides is the distinction between online and offline csses instead of protection against upping a refcnt which already reached zero. cgroup is planning to provide actual tryget which fails if the refcnt already reached zero. Let's rename the existing trygets so that they clearly indicate that they're onliness. I thought about keeping the existing names as-are and introducing new names for the planned actual tryget; however, given that each controller participates in the synchronization of the online state, it seems worthwhile to make it explicit that these functions are about on/offline state. Rename css_tryget() to css_tryget_online() and css_tryget_from_dir() to css_tryget_online_from_dir(). This is pure rename. v2: cgroup_freezer grew new usages of css_tryget(). Update accordingly. Signed-off-by: Tejun Heo <[email protected]> Acked-by: Johannes Weiner <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Li Zefan <[email protected]> Cc: Vivek Goyal <[email protected]> Cc: Jens Axboe <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]>
2014-05-07perf: Simplify perf_event_exit_task_context()Peter Zijlstra1-16/+1
Instead of jumping through hoops to make sure to find (and exit) each event, do it the simple straight fwd way. Signed-off-by: Peter Zijlstra <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Vince Weaver <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-05-07perf: Rework free pathsPeter Zijlstra1-26/+40
Primarily make perf_event_release_kernel() into put_event(), this will allow kernel space to create per-task inherited events, and is safer in general. Also, document the free_event() assumptions. Signed-off-by: Peter Zijlstra <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Vince Weaver <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-05-07perf: Validate locking assumptionPeter Zijlstra1-0/+2
Document and validate the locking assumption of event_sched_in(). Signed-off-by: Peter Zijlstra <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Vince Weaver <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-05-07perf: Always destroy groups on exitPeter Zijlstra1-1/+1
Commit 38b435b16c36 ("perf: Fix tear-down of inherited group events") states that we need to destroy groups for inherited events, but it doesn't make any sense to not also destroy groups for normal events. And while it usually makes no difference (the normal events won't leak, and its very likely all the group events will die in quick succession) it does make the code more consistent and closes a potential hole for trouble. Signed-off-by: Peter Zijlstra <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Vince Weaver <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-05-07perf: Ensure consistent inherit state in groupsPeter Zijlstra1-3/+10
Make sure all events in a group have the same inherit state. It was possible for group leaders to have inherit set while sibling events would not have inherit set. In this case we'd still inherit the siblings, leading to some non-fatal weirdness. Signed-off-by: Peter Zijlstra <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Vince Weaver <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-05-07Merge branch 'perf/urgent' into perf/core, to avoid conflictsIngo Molnar1-21/+28
Signed-off-by: Ingo Molnar <[email protected]>
2014-05-07perf: Fix perf_event_init_context()Peter Zijlstra1-0/+2
perf_pin_task_context() can return NULL but perf_event_init_context() assumes it will not, correct this. Reported-by: Vince Weaver <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-05-07perf: Fix race in removing an eventPeter Zijlstra1-21/+26
When removing a (sibling) event we do: raw_spin_lock_irq(&ctx->lock); perf_group_detach(event); raw_spin_unlock_irq(&ctx->lock); <hole> perf_remove_from_context(event); raw_spin_lock_irq(&ctx->lock); ... raw_spin_unlock_irq(&ctx->lock); Now, assuming the event is a sibling, it will be 'unreachable' for things like ctx_sched_out() because that iterates the groups->siblings, and we just unhooked the sibling. So, if during <hole> we get ctx_sched_out(), it will miss the event and not call event_sched_out() on it, leaving it programmed on the PMU. The subsequent perf_remove_from_context() call will find the ctx is inactive and only call list_del_event() to remove the event from all other lists. Hereafter we can proceed to free the event; while still programmed! Close this hole by moving perf_group_detach() inside the same ctx->lock region(s) perf_remove_from_context() has. The condition on inherited events only in __perf_event_exit_task() is likely complete crap because non-inherited events are part of groups too and we're tearing down just the same. But leave that for another patch. Most-likely-Fixes: e03a9a55b4e ("perf: Change close() semantics for group events") Reported-by: Vince Weaver <[email protected]> Tested-by: Vince Weaver <[email protected]> Much-staring-at-traces-by: Vince Weaver <[email protected]> Much-staring-at-traces-by: Thomas Gleixner <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-04-30uprobes: Refuse to insert a probe into MAP_SHARED vmaOleg Nesterov1-1/+1
valid_vma() rejects the VM_SHARED vmas, but this still allows to insert a probe into the MAP_SHARED but not VM_MAYWRITE vma. Currently this is fine, such a mapping doesn't really differ from the private read-only mmap except mprotect(PROT_WRITE) won't work. However, get_user_pages(FOLL_WRITE | FOLL_FORCE) doesn't allow to COW in this case, and it would be safer to follow the same conventions as mm even if currently this happens to work. After the recent cda540ace6a1 "mm: get_user_pages(write,force) refuse to COW in shared areas" only uprobes can insert an anon page into the shared file-backed area, lets stop this and change valid_vma() to check VM_MAYSHARE instead. Signed-off-by: Oleg Nesterov <[email protected]>
2014-04-18perf: Allow building PMU drivers as modulesYan, Zheng1-0/+15
This patch adds support for building PMU driver as module. It exports the functions perf_pmu_{register,unregister}() and adds reference tracking for the PMU driver module. When the PMU driver is built as a module, each active event of the PMU holds a reference to the driver module. Signed-off-by: Yan, Zheng <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Cc: [email protected] Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-04-17uprobes/x86: Send SIGILL if arch_uprobe_post_xol() failsOleg Nesterov1-1/+7
Currently the error from arch_uprobe_post_xol() is silently ignored. This doesn't look good and this can lead to the hard-to-debug problems. 1. Change handle_singlestep() to loudly complain and send SIGILL. Note: this only affects x86, ppc/arm can't fail. 2. Change arch_uprobe_post_xol() to call arch_uprobe_abort_xol() and avoid TF games if it is going to return an error. This can help to to analyze the problem, if nothing else we should not report ->ip = xol_slot in the core-file. Note: this means that handle_riprel_post_xol() can be called twice, but this is fine because it is idempotent. Signed-off-by: Oleg Nesterov <[email protected]> Reviewed-by: Masami Hiramatsu <[email protected]> Reviewed-by: Jim Keniston <[email protected]>
2014-04-17uprobes: Kill UPROBE_SKIP_SSTEP and can_skip_sstep()Oleg Nesterov1-21/+2
UPROBE_COPY_INSN, UPROBE_SKIP_SSTEP, and uprobe->flags must die. This patch kills UPROBE_SKIP_SSTEP. I never understood why it was added; not only it doesn't help, it harms. It can only help to avoid arch_uprobe_skip_sstep() if it was already called before and failed. But this is ugly, if we want to know whether we can emulate this instruction or not we should do this analysis in arch_uprobe_analyze_insn(), not when we hit this probe for the first time. And in fact this logic is simply wrong. arch_uprobe_skip_sstep() can fail or not depending on the task/register state, if this insn can be emulated but, say, put_user() fails we need to xol it this time, but this doesn't mean we shouldn't try to emulate it when this or another thread hits this bp next time. And this is the actual reason for this change. We need to emulate the "call" insn, but push(return-address) can obviously fail. Per-arch notes: x86: __skip_sstep() can only emulate "rep;nop". With this change it will be called every time and most probably for no reason. This will be fixed by the next changes. We need to change this suboptimal code anyway. arm: Should not be affected. It has its own "bool simulate" flag checked in arch_uprobe_skip_sstep(). ppc: Looks like, it can emulate almost everything. Does it actually need to record the fact that emulate_step() failed? Hopefully not. But if yes, it can add the ppc- specific flag into arch_uprobe. TODO: rename arch_uprobe_skip_sstep() to arch_uprobe_emulate_insn(), Signed-off-by: Oleg Nesterov <[email protected]> Reviewed-by: Masami Hiramatsu <[email protected]> Reviewed-by: David A. Long <[email protected]> Reviewed-by: Jim Keniston <[email protected]> Acked-by: Srikar Dronamraju <[email protected]>
2014-04-05Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds1-0/+9
Pull ARM changes from Russell King: - Perf updates from Will Deacon: - Support for Qualcomm Krait processors (run perf on your phone!) - Support for Cortex-A12 (run perf stat on your FPGA!) - Support for perf_sample_event_took, allowing us to automatically decrease the sample rate if we can't handle the PMU interrupts quickly enough (run perf record on your FPGA!). - Basic uprobes support from David Long: This patch series adds basic uprobes support to ARM. It is based on patches developed earlier by Rabin Vincent. That approach of adding hooks into the kprobes instruction parsing code was not well received. This approach separates the ARM instruction parsing code in kprobes out into a separate set of functions which can be used by both kprobes and uprobes. Both kprobes and uprobes then provide their own semantic action tables to process the results of the parsing. - ARMv7M (microcontroller) updates from Uwe Kleine-König - OMAP DMA updates (recently added Vinod's Ack even though they've been sitting in linux-next for a few months) to reduce the reliance of omap-dma on the code in arch/arm. - SA11x0 changes from Dmitry Eremin-Solenikov and Alexander Shiyan - Support for Cortex-A12 CPU - Align support for ARMv6 with ARMv7 so they can cooperate better in a single zImage. - Addition of first AT_HWCAP2 feature bits for ARMv8 crypto support. - Removal of IRQ_DISABLED from various ARM files - Improved efficiency of virt_to_page() for single zImage - Patch from Ulf Hansson to permit runtime PM callbacks to be available for AMBA devices for suspend/resume as well. - Finally kill asm/system.h on ARM. * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (89 commits) dmaengine: omap-dma: more consolidation of CCR register setup dmaengine: omap-dma: move IRQ handling to omap-dma dmaengine: omap-dma: move register read/writes into omap-dma.c ARM: omap: dma: get rid of 'p' allocation and clean up ARM: omap: move dma channel allocation into plat-omap code ARM: omap: dma: get rid of errata global ARM: omap: clean up DMA register accesses ARM: omap: remove almost-const variables ARM: omap: remove references to disable_irq_lch dmaengine: omap-dma: cleanup errata 3.3 handling dmaengine: omap-dma: provide register read/write functions dmaengine: omap-dma: use cached CCR value when enabling DMA dmaengine: omap-dma: move barrier to omap_dma_start_desc() dmaengine: omap-dma: move clnk_ctrl setting to preparation functions dmaengine: omap-dma: improve efficiency loading C.SA/C.EI/C.FI registers dmaengine: omap-dma: consolidate clearing channel status register dmaengine: omap-dma: move CCR buffering disable errata out of the fast path dmaengine: omap-dma: provide register definitions dmaengine: omap-dma: consolidate setup of CCR dmaengine: omap-dma: consolidate setup of CSDP ...
2014-04-03Merge branch 'for-3.15' of ↵Linus Torvalds1-21/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "A lot updates for cgroup: - The biggest one is cgroup's conversion to kernfs. cgroup took after the long abandoned vfs-entangled sysfs implementation and made it even more convoluted over time. cgroup's internal objects were fused with vfs objects which also brought in vfs locking and object lifetime rules. Naturally, there are places where vfs rules don't fit and nasty hacks, such as credential switching or lock dance interleaving inode mutex and cgroup_mutex with object serial number comparison thrown in to decide whether the operation is actually necessary, needed to be employed. After conversion to kernfs, internal object lifetime and locking rules are mostly isolated from vfs interactions allowing shedding of several nasty hacks and overall simplification. This will also allow implmentation of operations which may affect multiple cgroups which weren't possible before as it would have required nesting i_mutexes. - Various simplifications including dropping of module support, easier cgroup name/path handling, simplified cgroup file type handling and task_cg_lists optimization. - Prepatory changes for the planned unified hierarchy, which is still a patchset away from being actually operational. The dummy hierarchy is updated to serve as the default unified hierarchy. Controllers which aren't claimed by other hierarchies are associated with it, which BTW was what the dummy hierarchy was for anyway. - Various fixes from Li and others. This pull request includes some patches to add missing slab.h to various subsystems. This was triggered xattr.h include removal from cgroup.h. cgroup.h indirectly got included a lot of files which brought in xattr.h which brought in slab.h. There are several merge commits - one to pull in kernfs updates necessary for converting cgroup (already in upstream through driver-core), others for interfering changes in the fixes branch" * 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (74 commits) cgroup: remove useless argument from cgroup_exit() cgroup: fix spurious lockdep warning in cgroup_exit() cgroup: Use RCU_INIT_POINTER(x, NULL) in cgroup.c cgroup: break kernfs active_ref protection in cgroup directory operations cgroup: fix cgroup_taskset walking order cgroup: implement CFTYPE_ONLY_ON_DFL cgroup: make cgrp_dfl_root mountable cgroup: drop const from @buffer of cftype->write_string() cgroup: rename cgroup_dummy_root and related names cgroup: move ->subsys_mask from cgroupfs_root to cgroup cgroup: treat cgroup_dummy_root as an equivalent hierarchy during rebinding cgroup: remove NULL checks from [pr_cont_]cgroup_{name|path}() cgroup: use cgroup_setup_root() to initialize cgroup_dummy_root cgroup: reorganize cgroup bootstrapping cgroup: relocate setting of CGRP_DEAD cpuset: use rcu_read_lock() to protect task_cs() cgroup_freezer: document freezer_fork() subtleties cgroup: update cgroup_transfer_tasks() to either succeed or fail cgroup: drop task_lock() protection around task->cgroups cgroup: update how a newly forked task gets associated with css_set ...
2014-03-18uprobes: allow ignoring of probe hitsDavid A. Long1-0/+9
Allow arches to decided to ignore a probe hit. ARM will use this to only call handlers if the conditions to execute a conditionally executed instruction are satisfied. Signed-off-by: David A. Long <[email protected]> Acked-by: Oleg Nesterov <[email protected]>
2014-02-27perf: Optimize group_sched_in()Peter Zijlstra1-1/+1
Use the ctx pmu instead of the event pmu. When a group leader is a software event but the group contains hardware events, the entire group is on the hardware PMU. Using the hardware PMU for the transaction makes most sense since that's the most expensive one to programm (and software PMUs generally don't have TXN support anyway). Signed-off-by: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-02-27perf: Remove redundant PMU assignmentMark Rutland1-2/+0
Currently perf_branch_stack_sched_in iterates over the set of pmus, checks that each pmu has a flush_branch_stack callback, then overwrites the pmu before calling the callback. This is either redundant or broken. In systems with a single hw pmu, pmu == cpuctx->ctx.pmu, and thus the assignment is redundant. In systems with multiple hw pmus (i.e. multiple pmus with task_ctx_nr == perf_hw_context) the pmus share the same perf_cpu_context. Thus the assignment can cause one of the pmus to flush its branch stack repeatedly rather than causing each of the pmus to flush their branch stacks. Worse still, if only some pmus have the callback the assignment can result in a branch to NULL. This patch removes the redundant assignment. Signed-off-by: Mark Rutland <[email protected]> Acked-by: Will Deacon <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-02-27perf: Fix prototype of find_pmu_context()Mark Rutland1-1/+1
For some reason find_pmu_context() is defined as returning void * rather than a __percpu struct perf_cpu_context *. As all the requisite types are defined in advance there's no reason to keep it that way. This patch modifies the prototype of pmu_find_context to return a __percpu struct perf_cpu_context *. Signed-off-by: Mark Rutland <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Reviewed-by: Dave Martin <[email protected]> Acked-by: Will Deacon <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-02-27Merge branch 'perf/urgent' into perf/coreIngo Molnar1-6/+6
Merge the latest fixes before queueing up new changes. Signed-off-by: Ingo Molnar <[email protected]>
2014-02-27perf: Fix hotplug splatPeter Zijlstra1-6/+6
Drew Richardson reported that he could make the kernel go *boom* when hotplugging while having perf events active. It turned out that when you have a group event, the code in __perf_event_exit_context() fails to remove the group siblings from the context. We then proceed with destroying and freeing the event, and when you re-plug the CPU and try and add another event to that CPU, things go *boom* because you've still got dead entries there. Reported-by: Drew Richardson <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Will Deacon <[email protected]> Cc: <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-02-21perf/x86: Warn to early_printk() in case irq_work is too slowPeter Zijlstra1-2/+7
On Mon, Feb 10, 2014 at 08:45:16AM -0800, Dave Hansen wrote: > The reason I coded this up was that NMIs were firing off so fast that > nothing else was getting a chance to run. With this patch, at least the > printk() would come out and I'd have some idea what was going on. It will start spewing to early_printk() (which is a lot nicer to use from NMI context too) when it fails to queue the IRQ-work because its already enqueued. It does have the false-positive for when two CPUs trigger the warn concurrently, but that should be rare and some extra clutter on the early printk shouldn't be a problem. Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Dave Hansen <[email protected]> Cc: [email protected] Fixes: 6a02ad66b2c4 ("perf/x86: Push the duration-logging printk() to IRQ context") Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2014-02-13cgroup: drop @skip_css from cgroup_taskset_for_each()Tejun Heo1-1/+1
If !NULL, @skip_css makes cgroup_taskset_for_each() skip the matching css. The intention of the interface is to make it easy to skip css's (cgroup_subsys_states) which already match the migration target; however, this is entirely unnecessary as migration taskset doesn't include tasks which are already in the target cgroup. Drop @skip_css from cgroup_taskset_for_each(). Signed-off-by: Tejun Heo <[email protected]> Acked-by: Li Zefan <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Daniel Borkmann <[email protected]>
2014-02-11cgroup: improve css_from_dir() into css_tryget_from_dir()Tejun Heo1-16/+1
css_from_dir() returns the matching css (cgroup_subsys_state) given a dentry and subsystem. The function doesn't pin the css before returning and requires the caller to be holding RCU read lock or cgroup_mutex and handling pinning on the caller side. Given that users of the function are likely to want to pin the returned css (both existing users do) and that getting and putting css's are very cheap, there's no reason for the interface to be tricky like this. Rename css_from_dir() to css_tryget_from_dir() and make it try to pin the found css and return it only if pinning succeeded. The callers are updated so that they no longer do RCU locking and pinning around the function and just use the returned css. This will also ease converting cgroup to kernfs. Signed-off-by: Tejun Heo <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Li Zefan <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Balbir Singh <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]>
2014-02-09perf/x86: Push the duration-logging printk() to IRQ contextPeter Zijlstra1-7/+21
Calling printk() from NMI context is bad (TM), so move it to IRQ context. This also avoids the problem where the printk() time is measured by the generic NMI duration goo and triggers a second warning. Signed-off-by: Peter Zijlstra <[email protected]> Cc: Don Zickus <[email protected]> Cc: Dave Hansen <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-02-08cgroup: clean up cgroup_subsys names and initializationTejun Heo1-5/+3
cgroup_subsys is a bit messier than it needs to be. * The name of a subsys can be different from its internal identifier defined in cgroup_subsys.h. Most subsystems use the matching name but three - cpu, memory and perf_event - use different ones. * cgroup_subsys_id enums are postfixed with _subsys_id and each cgroup_subsys is postfixed with _subsys. cgroup.h is widely included throughout various subsystems, it doesn't and shouldn't have claim on such generic names which don't have any qualifier indicating that they belong to cgroup. * cgroup_subsys->subsys_id should always equal the matching cgroup_subsys_id enum; however, we require each controller to initialize it and then BUG if they don't match, which is a bit silly. This patch cleans up cgroup_subsys names and initialization by doing the followings. * cgroup_subsys_id enums are now postfixed with _cgrp_id, and each cgroup_subsys with _cgrp_subsys. * With the above, renaming subsys identifiers to match the userland visible names doesn't cause any naming conflicts. All non-matching identifiers are renamed to match the official names. cpu_cgroup -> cpu mem_cgroup -> memory perf -> perf_event * controllers no longer need to initialize ->subsys_id and ->name. They're generated in cgroup core and set automatically during boot. * Redundant cgroup_subsys declarations removed. * While updating BUG_ON()s in cgroup_init_early(), convert them to WARN()s. BUGging that early during boot is stupid - the kernel can't print anything, even through serial console and the trap handler doesn't even link stack frame properly for back-tracing. This patch doesn't introduce any behavior changes. v2: Rebased on top of fe1217c4f3f7 ("net: net_cls: move cgroupfs classid handling into core"). Signed-off-by: Tejun Heo <[email protected]> Acked-by: Neil Horman <[email protected]> Acked-by: "David S. Miller" <[email protected]> Acked-by: "Rafael J. Wysocki" <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Aristeu Rozanski <[email protected]> Acked-by: Ingo Molnar <[email protected]> Acked-by: Li Zefan <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Balbir Singh <[email protected]> Cc: KAMEZAWA Hiroyuki <[email protected]> Cc: Serge E. Hallyn <[email protected]> Cc: Vivek Goyal <[email protected]> Cc: Thomas Graf <[email protected]>
2014-01-22Merge tag 'trace-3.14' of ↵Linus Torvalds1-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This pull request has a new feature to ftrace, namely the trace event triggers by Tom Zanussi. A trigger is a way to enable an action when an event is hit. The actions are: o trace on/off - enable or disable tracing o snapshot - save the current trace buffer in the snapshot o stacktrace - dump the current stack trace to the ringbuffer o enable/disable events - enable or disable another event Namhyung Kim added updates to the tracing uprobes code. Having the uprobes add support for fetch methods. The rest are various bug fixes with the new code, and minor ones for the old code" * tag 'trace-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (38 commits) tracing: Fix buggered tee(2) on tracing_pipe tracing: Have trace buffer point back to trace_array ftrace: Fix synchronization location disabling and freeing ftrace_ops ftrace: Have function graph only trace based on global_ops filters ftrace: Synchronize setting function_trace_op with ftrace_trace_function tracing: Show available event triggers when no trigger is set tracing: Consolidate event trigger code tracing: Fix counter for traceon/off event triggers tracing: Remove double-underscore naming in syscall trigger invocations tracing/kprobes: Add trace event trigger invocations tracing/probes: Fix build break on !CONFIG_KPROBE_EVENT tracing/uprobes: Add @+file_offset fetch method uprobes: Allocate ->utask before handler_chain() for tracing handlers tracing/uprobes: Add support for full argument access methods tracing/uprobes: Fetch args before reserving a ring buffer tracing/uprobes: Pass 'is_return' to traceprobe_parse_probe_arg() tracing/probes: Implement 'memory' fetch method for uprobes tracing/probes: Add fetch{,_size} member into deref fetch method tracing/probes: Move 'symbol' fetch method to kprobes tracing/probes: Implement 'stack' fetch method for uprobes ...
2014-11-13mmu_notifier: call mmu_notifier_invalidate_range() from VMMJoerg Roedel1-1/+1
Add calls to the new mmu_notifier_invalidate_range() function to all places in the VMM that need it. Signed-off-by: Joerg Roedel <[email protected]> Reviewed-by: Andrea Arcangeli <[email protected]> Reviewed-by: Jérôme Glisse <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Jay Cornwall <[email protected]> Cc: Oded Gabbay <[email protected]> Cc: Suravee Suthikulpanit <[email protected]> Cc: Jesse Barnes <[email protected]> Cc: David Woodhouse <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Oded Gabbay <[email protected]>
2014-01-16Merge branch 'perf/urgent' into perf/coreIngo Molnar1-3/+18
Pick up the latest fixes, refresh the development tree. Signed-off-by: Ingo Molnar <[email protected]>
2014-01-12perf: Introduce a flag to enable close-on-exec in perf_event_open()Yann Droneaud1-3/+9
Unlike recent modern userspace API such as: epoll_create1 (EPOLL_CLOEXEC), eventfd (EFD_CLOEXEC), fanotify_init (FAN_CLOEXEC), inotify_init1 (IN_CLOEXEC), signalfd (SFD_CLOEXEC), timerfd_create (TFD_CLOEXEC), or the venerable general purpose open (O_CLOEXEC), perf_event_open() syscall lack a flag to atomically set FD_CLOEXEC (eg. close-on-exec) flag on file descriptor it returns to userspace. The present patch adds a PERF_FLAG_FD_CLOEXEC flag to allow perf_event_open() syscall to atomically set close-on-exec. Having this flag will enable userspace to remove the file descriptor from the list of file descriptors being inherited across exec, without the need to call fcntl(fd, F_SETFD, FD_CLOEXEC) and the associated race condition between the current thread and another thread calling fork(2) then execve(2). Links: - Secure File Descriptor Handling (Ulrich Drepper, 2008) http://udrepper.livejournal.com/20407.html - Excuse me son, but your code is leaking !!! (Dan Walsh, March 2012) http://danwalsh.livejournal.com/53603.html - Notes in DMA buffer sharing: leak and security hole http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/dma-buf-sharing.txt?id=v3.13-rc3#n428 Signed-off-by: Yann Droneaud <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Al Viro <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/8c03f54e1598b1727c19706f3af03f98685d9fe6.1388952061.git.ydroneaud@opteya.com Signed-off-by: Ingo Molnar <[email protected]>
2014-01-12perf/x86: Fix active_entry initializationStephane Eranian1-0/+2
This patch fixes a problem with the initialization of the struct perf_event active_entry field. It is defined inside an anonymous union and was initialized in perf_event_alloc() using INIT_LIST_HEAD(). However at that time, we do not know whether the event is going to use active_entry or hlist_entry (SW). Or at last, we don't want to make that determination there. The problem is that hlist and list_head are not initialized the same way. One is okay with NULL (from kzmalloc), the other needs to pointers to point to self. This patch resolves this problem by dropping the union. This will avoid problems later on, if someone starts using active_entry or hlist_entry without verifying that they actually overlap. This also solves the initialization problem. Signed-off-by: Stephane Eranian <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2014-01-02uprobes: Allocate ->utask before handler_chain() for tracing handlersOleg Nesterov1-0/+4
uprobe_trace_print() and uprobe_perf_print() need to pass the additional info to call_fetch() methods, currently there is no simple way to do this. current->utask looks like a natural place to hold this info, but we need to allocate it before handler_chain(). This is a bit unfortunate, perhaps we will find a better solution later, but this is simple and should work right now. Signed-off-by: Oleg Nesterov <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Acked-by: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Signed-off-by: Namhyung Kim <[email protected]>
2013-12-17perf: Fix PERF_EVENT_IOC_PERIOD to force-reset the periodPeter Zijlstra1-1/+15
Vince Weaver reports that, on all architectures apart from ARM, PERF_EVENT_IOC_PERIOD doesn't actually update the period until the next event fires. This is counter-intuitive behaviour and is better dealt with in the core code. This patch ensures that the period is forcefully reset when dealing with such a request in the core code. A subsequent patch removes the equivalent hack from the ARM back-end. Reported-by: Vince Weaver <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Signed-off-by: Will Deacon <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2013-12-17perf: Disable all pmus on unthrottling and reschedulingAlexander Shishkin1-3/+18
Currently, only one PMU in a context gets disabled during unthrottling and event_sched_{out,in}(), however, events in one context may belong to different pmus, which results in PMUs being reprogrammed while they are still enabled. This means that mixed PMU use [which is rare in itself] resulted in potentially completely unreliable results: corrupted events, bogus results, etc. This patch temporarily disables PMUs that correspond to each event in the context while these events are being modified. Signed-off-by: Alexander Shishkin <[email protected]> Reviewed-by: Andi Kleen <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Alexander Shishkin <[email protected]> Link: http://lkml.kernel.org/r/1387196256-8030-1-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <[email protected]>
2013-12-11perf: Optimize ring-buffer write by depending on control dependenciesPeter Zijlstra1-16/+26
Remove a full barrier from the ring-buffer write path by relying on a control dependency to order a LOAD -> STORE scenario. Cc: "Paul E. McKenney" <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2013-11-27perf: Add active_entry list head to struct perf_eventStephane Eranian1-0/+1
This patch adds a new field to the struct perf_event. It is intended to be used to chain events which are active (enabled). It helps in the hardware layer for PMUs which do not have actual counter restrictions, i.e., free running read-only counters. Active events are chained as opposed to being tracked via the counter they use. To save space we use a union with hlist_entry as both are mutually exclusive (suggested by Jiri Olsa). Signed-off-by: Stephane Eranian <[email protected]> Reviewed-by: Andi Kleen <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2013-11-21Merge branch 'uprobes/core' of ↵Ingo Molnar1-17/+43
git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core Pull uprobes cleanups from Oleg Nesterov. Signed-off-by: Ingo Molnar <[email protected]>
2013-11-20uprobes: Document xol_area and arch_uprobe->insn/ixolOleg Nesterov1-0/+15
Document xol_area and arch_uprobe. Signed-off-by: Oleg Nesterov <[email protected]> Acked-by: Srikar Dronamraju <[email protected]>
2013-11-20uprobes: Cleanup !CONFIG_UPROBES decls, unexport xol_areaOleg Nesterov1-0/+19
1. Don't include asm/uprobes.h unconditionally, we only need it if CONFIG_UPROBES. 2. Move the definition of "struct xol_area" into uprobes.c. Perhaps we should simply kill struct uprobes_state, it buys nothing. 3. Kill the dummy definition of uprobe_get_swbp_addr(), nobody except handle_swbp() needs it. 4. Purely cosmetic, but move the decl of uprobe_get_swbp_addr() up, close to other __weak helpers. Signed-off-by: Oleg Nesterov <[email protected]> Acked-by: Srikar Dronamraju <[email protected]>
2013-11-20uprobes: Don't assume that arch_uprobe->insn/ixol is u8[MAX_UINSN_BYTES]Oleg Nesterov1-5/+5
arch_uprobe should be opaque as much as possible to the generic code, but currently it assumes that insn/ixol must be u8[] of the known size. Remove this unnecessary dependency, we can use "&" and and sizeof() with the same effect. Signed-off-by: Oleg Nesterov <[email protected]> Acked-by: Srikar Dronamraju <[email protected]>