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2014-07-27Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A bunch of fixes for perf and kprobes: - revert a commit that caused a perf group regression - silence dmesg spam - fix kprobe probing errors on ia64 and ppc64 - filter kprobe faults from userspace - lockdep fix for perf exit path - prevent perf #GP in KVM guest - correct perf event and filters" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kprobes: Fix "Failed to find blacklist" probing errors on ia64 and ppc64 kprobes/x86: Don't try to resolve kprobe faults from userspace perf/x86/intel: Avoid spamming kernel log for BTS buffer failure perf/x86/intel: Protect LBR and extra_regs against KVM lying perf: Fix lockdep warning on process exit perf/x86/intel/uncore: Fix SNB-EP/IVT Cbox filter mappings perf/x86/intel: Use proper dTLB-load-misses event on IvyBridge perf: Revert ("perf: Always destroy groups on exit")
2014-07-16Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Tooling fixes and an Intel PMU driver fixlet" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Do not allow optimized switch for non-cloned events perf/x86/intel: ignore CondChgd bit to avoid false NMI handling perf symbols: Get kernel start address by symbol name perf tools: Fix segfault in cumulative.callchain report
2014-07-16perf: Fix lockdep warning on process exitPeter Zijlstra
Sasha Levin reported: > While fuzzing with trinity inside a KVM tools guest running the latest -next > kernel I've stumbled on the following spew: > > ====================================================== > [ INFO: possible circular locking dependency detected ] > 3.15.0-next-20140613-sasha-00026-g6dd125d-dirty #654 Not tainted > ------------------------------------------------------- > trinity-c578/9725 is trying to acquire lock: > (&(&pool->lock)->rlock){-.-...}, at: __queue_work (kernel/workqueue.c:1346) > > but task is already holding lock: > (&ctx->lock){-.....}, at: perf_event_exit_task (kernel/events/core.c:7471 kernel/events/core.c:7533) > > which lock already depends on the new lock. > 1 lock held by trinity-c578/9725: > #0: (&ctx->lock){-.....}, at: perf_event_exit_task (kernel/events/core.c:7471 kernel/events/core.c:7533) > > Call Trace: > dump_stack (lib/dump_stack.c:52) > print_circular_bug (kernel/locking/lockdep.c:1216) > __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182) > lock_acquire (./arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) > _raw_spin_lock (include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:151) > __queue_work (kernel/workqueue.c:1346) > queue_work_on (kernel/workqueue.c:1424) > free_object (lib/debugobjects.c:209) > __debug_check_no_obj_freed (lib/debugobjects.c:715) > debug_check_no_obj_freed (lib/debugobjects.c:727) > kmem_cache_free (mm/slub.c:2683 mm/slub.c:2711) > free_task (kernel/fork.c:221) > __put_task_struct (kernel/fork.c:250) > put_ctx (include/linux/sched.h:1855 kernel/events/core.c:898) > perf_event_exit_task (kernel/events/core.c:907 kernel/events/core.c:7478 kernel/events/core.c:7533) > do_exit (kernel/exit.c:766) > do_group_exit (kernel/exit.c:884) > get_signal_to_deliver (kernel/signal.c:2347) > do_signal (arch/x86/kernel/signal.c:698) > do_notify_resume (arch/x86/kernel/signal.c:751) > int_signal (arch/x86/kernel/entry_64.S:600) Urgh.. so the only way I can make that happen is through: perf_event_exit_task_context() raw_spin_lock(&child_ctx->lock); unclone_ctx(child_ctx) put_ctx(ctx->parent_ctx); raw_spin_unlock_irqrestore(&child_ctx->lock); And we can avoid this by doing the change below. I can't immediately see how this changed recently, but given that you say it's easy to reproduce, lets fix this. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Dave Jones <davej@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140623141242.GB19860@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16perf: Revert ("perf: Always destroy groups on exit")Peter Zijlstra
Vince reported that commit 15a2d4de0eab5 ("perf: Always destroy groups on exit") causes a regression with grouped events. In particular his read_group_attached.c test fails. https://github.com/deater/perf_event_tests/blob/master/tests/bugs/read_group_attached.c Because of the context switch optimization in perf_event_context_sched_out() the 'original' event may end up in the child process and when that exits the change in the patch in question destroys the actual grouping. Therefore revert that change and only destroy inherited groups. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-zedy3uktcp753q8fw8dagx7a@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-03Merge tag 'trace-fixes-v3.16-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Oleg Nesterov found and fixed a bug in the perf/ftrace/uprobes code where running: # perf probe -x /lib/libc.so.6 syscall # echo 1 >> /sys/kernel/debug/tracing/events/probe_libc/enable # perf record -e probe_libc:syscall whatever kills the uprobe. Along the way he found some other minor bugs and clean ups that he fixed up making it a total of 4 patches. Doing unrelated work, I found that the reading of the ftrace trace file disables all function tracer callbacks. This was fine when ftrace was the only user, but now that it's used by perf and kprobes, this is a bug where reading trace can disable kprobes and perf. A very unexpected side effect and should be fixed" * tag 'trace-fixes-v3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Remove ftrace_stop/start() from reading the trace file tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable() tracing/uprobes: Kill the bogus UPROBE_HANDLER_REMOVE code in uprobe_dispatcher() uprobes: Change unregister/apply to WARN() if uprobe/consumer is gone tracing/uprobes: Revert "Support mix of ftrace and perf"
2014-07-02perf: Do not allow optimized switch for non-cloned eventsJiri Olsa
The context check in perf_event_context_sched_out allows non-cloned context to be part of the optimized schedule out switch. This could move non-cloned context into another workload child. Once this child exits, the context is closed and leaves all original (parent) events in closed state. Any other new cloned event will have closed state and not measure anything. And probably causing other odd bugs. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1403598026-2310-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-30uprobes: Change unregister/apply to WARN() if uprobe/consumer is goneOleg Nesterov
Add WARN_ON's into uprobe_unregister() and uprobe_apply() to ensure that nobody tries to play with the dead uprobe/consumer. This helps to catch the bugs like the one fixed by the previous patch. In the longer term we should fix this poorly designed interface. uprobe_register() should return "struct uprobe *" which should be passed to apply/unregister. Plus other semantic changes, see the changelog in commit 41ccba029e94. Link: http://lkml.kernel.org/p/20140627170140.GA18322@redhat.com Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-14Merge branch 'perf/core' into perf/urgent, to pick up the latest fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-12Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more perf updates from Ingo Molnar: "A second round of perf updates: - wide reaching kprobes sanitization and robustization, with the hope of fixing all 'probe this function crashes the kernel' bugs, by Masami Hiramatsu. - uprobes updates from Oleg Nesterov: tmpfs support, corner case fixes and robustization work. - perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo et al: * Add support to accumulate hist periods (Namhyung Kim) * various fixes, refactorings and enhancements" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) perf: Differentiate exec() and non-exec() comm events perf: Fix perf_event_comm() vs. exec() assumption uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates perf/documentation: Add description for conditional branch filter perf/x86: Add conditional branch filtering support perf/tool: Add conditional branch filter 'cond' to perf record perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND' uprobes: Teach copy_insn() to support tmpfs uprobes: Shift ->readpage check from __copy_insn() to uprobe_register() perf/x86: Use common PMU interrupt disabled code perf/ARM: Use common PMU interrupt disabled code perf: Disable sampled events if no PMU interrupt perf: Fix use after free in perf_remove_from_context() perf tools: Fix 'make help' message error perf record: Fix poll return value propagation perf tools: Move elide bool into perf_hpp_fmt struct perf tools: Remove elide setup for SORT_MODE__MEMORY mode perf tools: Fix "==" into "=" in ui_browser__warning assignment perf tools: Allow overriding sysfs and proc finding with env var perf tools: Consider header files outside perf directory in tags target ...
2014-06-09Merge branch 'for-3.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "A lot of activities on cgroup side. Heavy restructuring including locking simplification took place to improve the code base and enable implementation of the unified hierarchy, which currently exists behind a __DEVEL__ mount option. The core support is mostly complete but individual controllers need further work. To explain the design and rationales of the the unified hierarchy Documentation/cgroups/unified-hierarchy.txt is added. Another notable change is css (cgroup_subsys_state - what each controller uses to identify and interact with a cgroup) iteration update. This is part of continuing updates on css object lifetime and visibility. cgroup started with reference count draining on removal way back and is now reaching a point where csses behave and are iterated like normal refcnted objects albeit with some complexities to allow distinguishing the state where they're being deleted. The css iteration update isn't taken advantage of yet but is planned to be used to simplify memcg significantly" * 'for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (77 commits) cgroup: disallow disabled controllers on the default hierarchy cgroup: don't destroy the default root cgroup: disallow debug controller on the default hierarchy cgroup: clean up MAINTAINERS entries cgroup: implement css_tryget() device_cgroup: use css_has_online_children() instead of has_children() cgroup: convert cgroup_has_live_children() into css_has_online_children() cgroup: use CSS_ONLINE instead of CGRP_DEAD cgroup: iterate cgroup_subsys_states directly cgroup: introduce CSS_RELEASED and reduce css iteration fallback window cgroup: move cgroup->serial_nr into cgroup_subsys_state cgroup: link all cgroup_subsys_states in their sibling lists cgroup: move cgroup->sibling and ->children into cgroup_subsys_state cgroup: remove cgroup->parent device_cgroup: remove direct access to cgroup->children memcg: update memcg_has_children() to use css_next_child() memcg: remove tasks/children test from mem_cgroup_force_empty() cgroup: remove css_parent() cgroup: skip refcnting on normal root csses and cgrp_dfl_root self css cgroup: use cgroup->self.refcnt for cgroup refcnting ...
2014-06-09Revert "perf: Disable PERF_RECORD_MMAP2 support"Don Zickus
This reverts commit 3090ffb5a2515990182f3f55b0688a7817325488. Re-enable the mmap2 interface as we will have a user soon. Since things have changed since perf disabled mmap2, small tweaks to the revert had to be done: o commit 9d4ecc88 forced (n!=8) to become (n<7) o a new libunwind test needed updating to use mmap2 interface Signed-off-by: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/r/1401461382-209586-1-git-send-email-dzickus@redhat.com Signed-off-by: Jiri Olsa <jolsa@kernel.org>
2014-06-09perf: Pass protection and flags bits through mmap2 interfacePeter Zijlstra
The mmap2 interface was missing the protection and flags bits needed to accurately determine if a mmap memory area was shared or private and if it was readable or not. Signed-off-by: Peter Zijlstra <peterz@infradead.org> [tweaked patch to compile and wrote changelog] Signed-off-by: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/r/1400526833-141779-2-git-send-email-dzickus@redhat.com Signed-off-by: Jiri Olsa <jolsa@kernel.org>
2014-06-06perf: Differentiate exec() and non-exec() comm eventsAdrian Hunter
perf tools like 'perf report' can aggregate samples by comm strings, which generally works. However, there are other potential use-cases. For example, to pair up 'calls' with 'returns' accurately (from branch events like Intel BTS) it is necessary to identify whether the process has exec'd. Although a comm event is generated when an 'exec' happens it is also generated whenever the comm string is changed on a whim (e.g. by prctl PR_SET_NAME). This patch adds a flag to the comm event to differentiate one case from the other. In order to determine whether the kernel supports the new flag, a selection bit named 'exec' is added to struct perf_event_attr. The bit does nothing but will cause perf_event_open() to fail if the bit is set on kernels that do not have it defined. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/537D9EBE.7030806@intel.com Cc: Paul Mackerras <paulus@samba.org> Cc: Dave Jones <davej@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-06Merge branch 'perf/urgent' into perf/core, to resolve conflict and to ↵Ingo Molnar
prepare for new patches Conflicts: arch/x86/kernel/traps.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-06perf: Fix perf_event_comm() vs. exec() assumptionPeter Zijlstra
perf_event_comm() assumes that set_task_comm() is only called on exec(), and in particular that its only called on current. Neither are true, as Dave reported a WARN triggered by set_task_comm() being called on !current. Separate the exec() hook from the comm hook. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20140521153219.GH5226@laptop.programming.kicks-ass.net [ Build fix. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into nextLinus Torvalds
Pull ARM updates from Russell King: - Major clean-up of the L2 cache support code. The existing mess was becoming rather unmaintainable through all the additions that others have done over time. This turns it into a much nicer structure, and implements a few performance improvements as well. - Clean up some of the CP15 control register tweaks for alignment support, moving some code and data into alignment.c - DMA properties for ARM, from Santosh and reviewed by DT people. This adds DT properties to specify bus translations we can't discover automatically, and to indicate whether devices are coherent. - Hibernation support for ARM - Make ftrace work with read-only text in modules - add suspend support for PJ4B CPUs - rework interrupt masking for undefined instruction handling, which allows us to enable interrupts earlier in the handling of these exceptions. - support for big endian page tables - fix stacktrace support to exclude stacktrace functions from the trace, and add save_stack_trace_regs() implementation so that kprobes can record stack traces. - Add support for the Cortex-A17 CPU. - Remove last vestiges of ARM710 support. - Removal of ARM "meminfo" structure, finally converting us solely to memblock to handle the early memory initialisation. * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (142 commits) ARM: ensure C page table setup code follows assembly code (part II) ARM: ensure C page table setup code follows assembly code ARM: consolidate last remaining open-coded alignment trap enable ARM: remove global cr_no_alignment ARM: remove CPU_CP15 conditional from alignment.c ARM: remove unused adjust_cr() function ARM: move "noalign" command line option to alignment.c ARM: provide common method to clear bits in CPU control register ARM: 8025/1: Get rid of meminfo ARM: 8060/1: mm: allow sub-architectures to override PCI I/O memory type ARM: 8066/1: correction for ARM patch 8031/2 ARM: 8049/1: ftrace/add save_stack_trace_regs() implementation ARM: 8065/1: remove last use of CONFIG_CPU_ARM710 ARM: 8062/1: Modify ldrt fixup handler to re-execute the userspace instruction ARM: 8047/1: rwsem: use asm-generic rwsem implementation ARM: l2c: trial at enabling some Cortex-A9 optimisations ARM: l2c: add warnings for stuff modifying aux_ctrl register values ARM: l2c: print a warning with L2C-310 caches if the cache size is modified ARM: l2c: remove old .set_debug method ARM: l2c: kill L2X0_AUX_CTRL_MASK before anyone else makes use of this ...
2014-06-05uprobes: Teach copy_insn() to support tmpfsOleg Nesterov
tmpfs is widely used but as Denys reports shmem_aops doesn't have ->readpage() and thus you can't probe a binary on this filesystem. As Hugh suggested we can use shmem_read_mapping_page() in this case, just we need to check shmem_mapping() if ->readpage == NULL. Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Suggested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140519184136.GB6750@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05uprobes: Shift ->readpage check from __copy_insn() to uprobe_register()Oleg Nesterov
copy_insn() fails with -EIO if ->readpage == NULL, but this error is not propagated unless uprobe_register() path finds ->mm which already mmaps this file. In this case (say) "perf record" does not actually install the probe, but the user can't know about this. Move this check into uprobe_register() so that this problem can be detected earlier and reported to user. Note: this is still not perfect, - copy_insn() and arch_uprobe_analyze_insn() should be called by uprobe_register() but this is not simple, we need vm_file for read_mapping_page() (although perhaps we can pass NULL), and we need ->mm for is_64bit_mm() (although this logic is broken anyway). - uprobe_register() should be called by create_trace_uprobe(), not by probe_event_enable(), so that an error can be detected at "perf probe -x" time. This also needs more changes in the core uprobe code, uprobe register/unregister interface was poorly designed from the very beginning. Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140519184054.GA6750@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05perf: Disable sampled events if no PMU interruptVince Weaver
Add common code to generate -ENOTSUPP at event creation time if an architecture attempts to create a sampled event and PERF_PMU_NO_INTERRUPT is set. This adds a new pmu->capabilities flag. Initially we only support PERF_PMU_NO_INTERRUPT (to indicate a PMU has no support for generating hardware interrupts) but there are other capabilities that can be added later. Signed-off-by: Vince Weaver <vincent.weaver@maine.edu> Acked-by: Will Deacon <will.deacon@arm.com> [peterz: rename to PERF_PMU_CAP_* and moved the pmu::capabilities word into a hole] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1405161708060.11099@vincent-weaver-1.umelst.maine.edu Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05perf: Fix use after free in perf_remove_from_context()Peter Zijlstra
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 <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Dave Jones <davej@redhat.com> Cc: acme@ghostprotocols.net Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140529170024.GA2315@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-05Merge branch 'perf/uprobes' into perf/coreIngo Molnar
These bits from Oleg are fully cooked, ship them to Linus. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-03Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
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 Kamensky
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 <victor.kamensky@linaro.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: David A. Long <dave.long@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-05-19perf/events/core: Drop unused variable after cleanupBorislav Petkov
... in 3a497f48637 ("perf: Simplify perf_event_exit_task_context()") Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1399720259-28275-1-git-send-email-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-19perf: Fix a race between ring_buffer_detach() and ring_buffer_attach()Peter Zijlstra
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 <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140507123526.GD13658@twins.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-19perf: Prevent false warning in perf_swevent_addJiri Olsa
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 <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: stable@vger.kernel.org Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1396861448-10097-1-git-send-email-jolsa@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-19perf: Limit perf_event_attr::sample_period to 63 bitsPeter Zijlstra
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 <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/n/tip-p25fhunibl4y3qi0zuqmyf4b@git.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-14uprobes/x86: Fix the wrong ->si_addr when xol triggers a trapOleg Nesterov
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 <oleg@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
2014-05-14uprobes: Add mem_cgroup_charge_anon() into uprobe_write_opcode()Oleg Nesterov
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 <hughd@google.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2014-05-13cgroup: rename css_tryget*() to css_tryget_online*()Tejun Heo
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 <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
2014-05-07perf: Simplify perf_event_exit_task_context()Peter Zijlstra
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 <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-tij931199thfkys8vbnokdpf@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07perf: Rework free pathsPeter Zijlstra
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 <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-rk9pvr6e1d0559lxstltbztc@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07perf: Validate locking assumptionPeter Zijlstra
Document and validate the locking assumption of event_sched_in(). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-sybq1publ9xt5no77cwvi0eo@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07perf: Always destroy groups on exitPeter Zijlstra
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 <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-426egt8zmsm12d2q8k2xz4tt@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07perf: Ensure consistent inherit state in groupsPeter Zijlstra
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 <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-r32tt8yldvic3jlcghd3g35u@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07Merge branch 'perf/urgent' into perf/core, to avoid conflictsIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07perf: Fix perf_event_init_context()Peter Zijlstra
perf_pin_task_context() can return NULL but perf_event_init_context() assumes it will not, correct this. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Link: http://lkml.kernel.org/r/20140505171428.GU26782@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07perf: Fix race in removing an eventPeter Zijlstra
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 <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Much-staring-at-traces-by: Vince Weaver <vincent.weaver@maine.edu> Much-staring-at-traces-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140505093124.GN17778@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-30uprobes: Refuse to insert a probe into MAP_SHARED vmaOleg Nesterov
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 <oleg@redhat.com>
2014-04-18perf: Allow building PMU drivers as modulesYan, Zheng
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 <zheng.z.yan@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1395133004-23205-1-git-send-email-zheng.z.yan@intel.com Cc: eranian@google.com Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-17uprobes/x86: Send SIGILL if arch_uprobe_post_xol() failsOleg Nesterov
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 <oleg@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
2014-04-17uprobes: Kill UPROBE_SKIP_SSTEP and can_skip_sstep()Oleg Nesterov
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 <oleg@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: David A. Long <dave.long@linaro.org> Reviewed-by: Jim Keniston <jkenisto@us.ibm.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2014-04-05Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds
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 Torvalds
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. Long
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 <dave.long@linaro.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
2014-02-27perf: Optimize group_sched_in()Peter Zijlstra
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 <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-sctoo9t2f3nn2c9g568928q3@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-27perf: Remove redundant PMU assignmentMark Rutland
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 <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1392054264-23570-3-git-send-email-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-27perf: Fix prototype of find_pmu_context()Mark Rutland
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 <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1392054264-23570-2-git-send-email-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-27Merge branch 'perf/urgent' into perf/coreIngo Molnar
Merge the latest fixes before queueing up new changes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-27perf: Fix hotplug splatPeter Zijlstra
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 <drew.richardson@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/n/tip-k6v5wundvusvcseqj1si0oz0@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>