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2019-10-19kernel/events/uprobes.c: only do FOLL_SPLIT_PMD for uprobe registerSong Liu
Attaching uprobe to text section in THP splits the PMD mapped page table into PTE mapped entries. On uprobe detach, we would like to regroup PMD mapped page table entry to regain performance benefit of THP. However, the regroup is broken For perf_event based trace_uprobe. This is because perf_event based trace_uprobe calls uprobe_unregister twice on close: first in TRACE_REG_PERF_CLOSE, then in TRACE_REG_PERF_UNREGISTER. The second call will split the PMD mapped page table entry, which is not the desired behavior. Fix this by only use FOLL_SPLIT_PMD for uprobe register case. Add a WARN() to confirm uprobe unregister never work on huge pages, and abort the operation when this WARN() triggers. Link: http://lkml.kernel.org/r/20191017164223.2762148-6-songliubraving@fb.com Fixes: 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT") Signed-off-by: Song Liu <songliubraving@fb.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-09perf/core: Fix corner case in perf_rotate_context()Song Liu
In perf_rotate_context(), when the first cpu flexible event fail to schedule, cpu_rotate is 1, while cpu_event is NULL. Since cpu_event is NULL, perf_rotate_context will _NOT_ call cpu_ctx_sched_out(), thus cpuctx->ctx.is_active will have EVENT_FLEXIBLE set. Then, the next perf_event_sched_in() will skip all cpu flexible events because of the EVENT_FLEXIBLE bit. In the next call of perf_rotate_context(), cpu_rotate stays 1, and cpu_event stays NULL, so this process repeats. The end result is, flexible events on this cpu will not be scheduled (until another event being added to the cpuctx). Here is an easy repro of this issue. On Intel CPUs, where ref-cycles could only use one counter, run one pinned event for ref-cycles, one flexible event for ref-cycles, and one flexible event for cycles. The flexible ref-cycles is never scheduled, which is expected. However, because of this issue, the cycles event is never scheduled either. $ perf stat -e ref-cycles:D,ref-cycles,cycles -C 5 -I 1000 time counts unit events 1.000152973 15,412,480 ref-cycles:D 1.000152973 <not counted> ref-cycles (0.00%) 1.000152973 <not counted> cycles (0.00%) 2.000486957 18,263,120 ref-cycles:D 2.000486957 <not counted> ref-cycles (0.00%) 2.000486957 <not counted> cycles (0.00%) To fix this, when the flexible_active list is empty, try rotate the first event in the flexible_groups. Also, rename ctx_first_active() to ctx_event_to_rotate(), which is more accurate. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <kernel-team@fb.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 8d5bce0c37fa ("perf/core: Optimize perf_rotate_context() event scheduling") Link: https://lkml.kernel.org/r/20191008165949.920548-1-songliubraving@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-09perf/core: Rework memory accounting in perf_mmap()Song Liu
perf_mmap() always increases user->locked_vm. As a result, "extra" could grow bigger than "user_extra", which doesn't make sense. Here is an example case: (Note: Assume "user_lock_limit" is very small.) | # of perf_mmap calls |vma->vm_mm->pinned_vm|user->locked_vm| | 0 | 0 | 0 | | 1 | user_extra | user_extra | | 2 | 3 * user_extra | 2 * user_extra| | 3 | 6 * user_extra | 3 * user_extra| | 4 | 10 * user_extra | 4 * user_extra| Fix this by maintaining proper user_extra and extra. Reviewed-By: Hechao Li <hechaol@fb.com> Reported-by: Hechao Li <hechaol@fb.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <kernel-team@fb.com> Cc: Jie Meng <jmeng@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190904214618.3795672-1-songliubraving@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-07perf/core: Fix inheritance of aux_output groupsAlexander Shishkin
Commit: ab43762ef010 ("perf: Allow normal events to output AUX data") forgets to configure aux_output relation in the inherited groups, which results in child PEBS events forever failing to schedule. Fix this by setting up the AUX output link in the inheritance path. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191004125729.32397-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-01perf_event_open: switch to copy_struct_from_user()Aleksa Sarai
Switch perf_event_open() syscall from it's own copying struct perf_event_attr from userspace to the new dedicated copy_struct_from_user() helper. The change is very straightforward, and helps unify the syscall interface for struct-from-userspace syscalls. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> [christian.brauner@ubuntu.com: improve commit message] Link: https://lore.kernel.org/r/20191001011055.19283-5-cyphar@cyphar.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2019-09-28Merge branch 'next-lockdown' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
2019-09-26Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more perf updates from Ingo Molnar: "The only kernel change is comment typo fixes. The rest is mostly tooling fixes, but also new vendor event additions and updates, a bigger libperf/libtraceevent library and a header files reorganization that came in a bit late" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (108 commits) perf unwind: Fix libunwind build failure on i386 systems perf parser: Remove needless include directives perf build: Add detection of java-11-openjdk-devel package perf jvmti: Include JVMTI support for s390 perf vendor events: Remove P8 HW events which are not supported perf evlist: Fix access of freed id arrays perf stat: Fix free memory access / memory leaks in metrics perf tools: Replace needless mmap.h with what is needed, event.h perf evsel: Move config terms to a separate header perf evlist: Remove unused perf_evlist__fprintf() method perf evsel: Introduce evsel_fprintf.h perf evsel: Remove need for symbol_conf in evsel_fprintf.c perf copyfile: Move copyfile routines to separate files libperf: Add perf_evlist__poll() function libperf: Add perf_evlist__add_pollfd() function libperf: Add perf_evlist__alloc_pollfd() function libperf: Add libperf_init() call to the tests libperf: Merge libperf_set_print() into libperf_init() libperf: Add libperf dependency for tests targets libperf: Use sys/types.h to get ssize_t, not unistd.h ...
2019-09-24uprobe: collapse THP pmd after removing all uprobesSong Liu
After all uprobes are removed from the huge page (with PTE pgtable), it is possible to collapse the pmd and benefit from THP again. This patch does the collapse by calling collapse_pte_mapped_thp(). Link: http://lkml.kernel.org/r/20190815164525.1848545-7-songliubraving@fb.com Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: kbuild test robot <lkp@intel.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLITSong Liu
Use the newly added FOLL_SPLIT_PMD in uprobe. This preserves the huge page when the uprobe is enabled. When the uprobe is disabled, newer instances of the same application could still benefit from huge page. For the next step, we will enable khugepaged to regroup the pmd, so that existing instances of the application could also benefit from huge page after the uprobe is disabled. Link: http://lkml.kernel.org/r/20190815164525.1848545-5-songliubraving@fb.com Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24uprobe: use original page when all uprobes are removedSong Liu
Currently, uprobe swaps the target page with a anonymous page in both install_breakpoint() and remove_breakpoint(). When all uprobes on a page are removed, the given mm is still using an anonymous page (not the original page). This patch allows uprobe to use original page when possible (all uprobes on the page are already removed, and the original page is in page cache and uptodate). As suggested by Oleg, we unmap the old_page and let the original page fault in. Link: http://lkml.kernel.org/r/20190815164525.1848545-3-songliubraving@fb.com Signed-off-by: Song Liu <songliubraving@fb.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-20perf/core: Fix several typos in commentsRoy Ben Shlomo
Fix typos in a few functions' documentation comments. Signed-off-by: Roy Ben Shlomo <royb@sentinelone.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: royb@sentinelone.com Link: http://lore.kernel.org/lkml/20190920171254.31373-1-royb@sentinelone.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-17Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core timer updates from Thomas Gleixner: "Timers and timekeeping updates: - A large overhaul of the posix CPU timer code which is a preparation for moving the CPU timer expiry out into task work so it can be properly accounted on the task/process. An update to the bogus permission checks will come later during the merge window as feedback was not complete before heading of for travel. - Switch the timerqueue code to use cached rbtrees and get rid of the homebrewn caching of the leftmost node. - Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a single function - Implement the separation of hrtimers to be forced to expire in hard interrupt context even when PREEMPT_RT is enabled and mark the affected timers accordingly. - Implement a mechanism for hrtimers and the timer wheel to protect RT against priority inversion and live lock issues when a (hr)timer which should be canceled is currently executing the callback. Instead of infinitely spinning, the task which tries to cancel the timer blocks on a per cpu base expiry lock which is held and released by the (hr)timer expiry code. - Enable the Hyper-V TSC page based sched_clock for Hyper-V guests resulting in faster access to timekeeping functions. - Updates to various clocksource/clockevent drivers and their device tree bindings. - The usual small improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) posix-cpu-timers: Fix permission check regression posix-cpu-timers: Always clear head pointer on dequeue hrtimer: Add a missing bracket and hide `migration_base' on !SMP posix-cpu-timers: Make expiry_active check actually work correctly posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build tick: Mark sched_timer to expire in hard interrupt context hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n posix-cpu-timers: Utilize timerqueue for storage posix-cpu-timers: Move state tracking to struct posix_cputimers posix-cpu-timers: Deduplicate rlimit handling posix-cpu-timers: Remove pointless comparisons posix-cpu-timers: Get rid of 64bit divisions posix-cpu-timers: Consolidate timer expiry further posix-cpu-timers: Get rid of zero checks rlimit: Rewrite non-sensical RLIMIT_CPU comment posix-cpu-timers: Respect INFINITY for hard RTTIME limit posix-cpu-timers: Switch thread group sampling to array posix-cpu-timers: Restructure expiry array posix-cpu-timers: Remove cputime_expires ...
2019-09-16Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann, Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers. As perf and the scheduler is getting bigger and more complex, document the status quo of current responsibilities and interests, and spread the review pain^H^H^H^H fun via an increase in the Cc: linecount generated by scripts/get_maintainer.pl. :-) - Add another series of patches that brings the -rt (PREEMPT_RT) tree closer to mainline: split the monolithic CONFIG_PREEMPT dependencies into a new CONFIG_PREEMPTION category that will allow the eventual introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches to go though. - Extend the CPU cgroup controller with uclamp.min and uclamp.max to allow the finer shaping of CPU bandwidth usage. - Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS). - Improve the behavior of high CPU count, high thread count applications running under cpu.cfs_quota_us constraints. - Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present. - Improve CPU isolation housekeeping CPU allocation NUMA locality. - Fix deadline scheduler bandwidth calculations and logic when cpusets rebuilds the topology, or when it gets deadline-throttled while it's being offlined. - Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from setscheduler() system calls without creating global serialization. Add new synchronization between cpuset topology-changing events and the deadline acceptance tests in setscheduler(), which were broken before. - Rework the active_mm state machine to be less confusing and more optimal. - Rework (simplify) the pick_next_task() slowpath. - Improve load-balancing on AMD EPYC systems. - ... and misc cleanups, smaller fixes and improvements - please see the Git log for more details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) sched/psi: Correct overly pessimistic size calculation sched/fair: Speed-up energy-aware wake-ups sched/uclamp: Always use 'enum uclamp_id' for clamp_id values sched/uclamp: Update CPU's refcount on TG's clamp changes sched/uclamp: Use TG's clamps to restrict TASK's clamps sched/uclamp: Propagate system defaults to the root group sched/uclamp: Propagate parent clamps sched/uclamp: Extend CPU's cgroup controller sched/topology: Improve load balancing on AMD EPYC systems arch, ia64: Make NUMA select SMP sched, perf: MAINTAINERS update, add submaintainers and reviewers sched/fair: Use rq_lock/unlock in online_fair_sched_group cpufreq: schedutil: fix equation in comment sched: Rework pick_next_task() slow-path sched: Allow put_prev_task() to drop rq->lock sched/fair: Expose newidle_balance() sched: Add task_struct pointer to sched_class::set_curr_task sched: Rework CPU hotplug task selection sched/{rt,deadline}: Fix set_next_task vs pick_next_task sched: Fix kerneldoc comment for ia64_set_curr_task ...
2019-09-16Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel side changes: - Improved kbprobes robustness - Intel PEBS support for PT hardware tracing - Other Intel PT improvements: high order pages memory footprint reduction and various related cleanups - Misc cleanups The perf tooling side has been very busy in this cycle, with over 300 commits. This is an incomplete high-level summary of the many improvements done by over 30 developers: - Lots of updates to the following tools: 'perf c2c' 'perf config' 'perf record' 'perf report' 'perf script' 'perf test' 'perf top' 'perf trace' - Updates to libperf and libtraceevent, and a consolidation of the proliferation of x86 instruction decoder libraries. - Vendor event updates for Intel and PowerPC CPUs, - Updates to hardware tracing tooling for ARM and Intel CPUs, - ... and lots of other changes and cleanups - see the shortlog and Git log for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (322 commits) kprobes: Prohibit probing on BUG() and WARN() address perf/x86: Make more stuff static x86, perf: Fix the dependency of the x86 insn decoder selftest objtool: Ignore intentional differences for the x86 insn decoder objtool: Update sync-check.sh from perf's check-headers.sh perf build: Ignore intentional differences for the x86 insn decoder perf intel-pt: Use shared x86 insn decoder perf intel-pt: Remove inat.c from build dependency list perf: Update .gitignore file objtool: Move x86 insn decoder to a common location perf metricgroup: Support multiple events for metricgroup perf metricgroup: Scale the metric result perf pmu: Change convert_scale from static to global perf symbols: Move mem_info and branch_info out of symbol.h perf auxtrace: Uninline functions that touch perf_session perf tools: Remove needless evlist.h include directives perf tools: Remove needless evlist.h include directives perf tools: Remove needless thread_map.h include directives perf tools: Remove needless thread.h include directives perf tools: Remove needless map.h include directives ...
2019-09-16Merge branch 'sched/rt' into sched/core, to pick up -rt changesIngo Molnar
Pick up the first couple of patches working towards PREEMPT_RT. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-06perf/hw_breakpoint: Fix arch_hw_breakpoint use-before-initializationMark-PK Tsai
If we disable the compiler's auto-initialization feature, if -fplugin-arg-structleak_plugin-byref or -ftrivial-auto-var-init=pattern are disabled, arch_hw_breakpoint may be used before initialization after: 9a4903dde2c86 ("perf/hw_breakpoint: Split attribute parse and commit") On our ARM platform, the struct step_ctrl in arch_hw_breakpoint, which used to be zero-initialized by kzalloc(), may be used in arch_install_hw_breakpoint() without initialization. Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alix Wu <alix.wu@mediatek.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: YJ Chiang <yj.chiang@mediatek.com> Link: https://lkml.kernel.org/r/20190906060115.9460-1-mark-pk.tsai@mediatek.com [ Minor edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-08-28perf: Allow normal events to output AUX dataAlexander Shishkin
In some cases, ordinary (non-AUX) events can generate data for AUX events. For example, PEBS events can come out as records in the Intel PT stream instead of their usual DS records, if configured to do so. One requirement for such events is to consistently schedule together, to ensure that the data from the "AUX output" events isn't lost while their corresponding AUX event is not scheduled. We use grouping to provide this guarantee: an "AUX output" event can be added to a group where an AUX event is a group leader, and provided that the former supports writing to the latter. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: kan.liang@linux.intel.com Link: https://lkml.kernel.org/r/20190806084606.4021-2-alexander.shishkin@linux.intel.com
2019-08-19lockdown: Lock down perf when in confidentiality modeDavid Howells
Disallow the use of certain perf facilities that might allow userspace to access kernel data. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <mjg59@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: James Morris <jmorris@namei.org>
2019-08-01perf/core: Mark hrtimers to expire in hard interrupt contextSebastian Andrzej Siewior
To guarantee that the multiplexing mechanism and the hrtimer driven events work on PREEMPT_RT enabled kernels it's required that the related hrtimers expire in hard interrupt context. Mark them so PREEMPT_RT kernels wont defer them to soft interrupt context. No functional change. [ tglx: Split out of larger combo patch. Added changelog ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726185753.169509224@linutronix.de
2019-07-25sched/core: Convert get_task_struct() to return the taskMatthew Wilcox (Oracle)
Returning the pointer that was passed in allows us to write slightly more idiomatic code. Convert a few users. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190704221323.24290-1-willy@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25perf/core: Fix creating kernel counters for PMUs that override event->cpuLeonard Crestez
Some hardware PMU drivers will override perf_event.cpu inside their event_init callback. This causes a lockdep splat when initialized through the kernel API: WARNING: CPU: 0 PID: 250 at kernel/events/core.c:2917 ctx_sched_out+0x78/0x208 pc : ctx_sched_out+0x78/0x208 Call trace: ctx_sched_out+0x78/0x208 __perf_install_in_context+0x160/0x248 remote_function+0x58/0x68 generic_exec_single+0x100/0x180 smp_call_function_single+0x174/0x1b8 perf_install_in_context+0x178/0x188 perf_event_create_kernel_counter+0x118/0x160 Fix this by calling perf_install_in_context with event->cpu, just like perf_event_open Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Frank Li <Frank.li@nxp.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/c4ebe0503623066896d7046def4d6b1e06e0eb2e.1563972056.git.leonard.crestez@nxp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-19Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted stuff" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: perf_event_get(): don't bother with fget_raw() vfs: update d_make_root() description
2019-07-13perf/core: Fix exclusive events' groupingAlexander Shishkin
So far, we tried to disallow grouping exclusive events for the fear of complications they would cause with moving between contexts. Specifically, moving a software group to a hardware context would violate the exclusivity rules if both groups contain matching exclusive events. This attempt was, however, unsuccessful: the check that we have in the perf_event_open() syscall is both wrong (looks at wrong PMU) and insufficient (group leader may still be exclusive), as can be illustrated by running: $ perf record -e '{intel_pt//,cycles}' uname $ perf record -e '{cycles,intel_pt//}' uname ultimately successfully. Furthermore, we are completely free to trigger the exclusivity violation by: perf -e '{cycles,intel_pt//}' -e '{intel_pt//,instructions}' even though the helpful perf record will not allow that, the ABI will. The warning later in the perf_event_open() path will also not trigger, because it's also wrong. Fix all this by validating the original group before moving, getting rid of broken safeguards and placing a useful one to perf_install_in_context(). Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: mathieu.poirier@linaro.org Cc: will.deacon@arm.com Fixes: bed5b25ad9c8a ("perf: Add a pmu capability for "exclusive" events") Link: https://lkml.kernel.org/r/20190701110755.24646-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-13perf/core: Fix race between close() and fork()Peter Zijlstra
Syzcaller reported the following Use-after-Free bug: close() clone() copy_process() perf_event_init_task() perf_event_init_context() mutex_lock(parent_ctx->mutex) inherit_task_group() inherit_group() inherit_event() mutex_lock(event->child_mutex) // expose event on child list list_add_tail() mutex_unlock(event->child_mutex) mutex_unlock(parent_ctx->mutex) ... goto bad_fork_* bad_fork_cleanup_perf: perf_event_free_task() perf_release() perf_event_release_kernel() list_for_each_entry() mutex_lock(ctx->mutex) mutex_lock(event->child_mutex) // event is from the failing inherit // on the other CPU perf_remove_from_context() list_move() mutex_unlock(event->child_mutex) mutex_unlock(ctx->mutex) mutex_lock(ctx->mutex) list_for_each_entry_safe() // event already stolen mutex_unlock(ctx->mutex) delayed_free_task() free_task() list_for_each_entry_safe() list_del() free_event() _free_event() // and so event->hw.target // is the already freed failed clone() if (event->hw.target) put_task_struct(event->hw.target) // WHOOPSIE, already quite dead Which puts the lie to the the comment on perf_event_free_task(): 'unexposed, unused context' not so much. Which is a 'fun' confluence of fail; copy_process() doing an unconditional free_task() and not respecting refcounts, and perf having creative locking. In particular: 82d94856fa22 ("perf/core: Fix lock inversion between perf,trace,cpuhp") seems to have overlooked this 'fun' parade. Solve it by using the fact that detached events still have a reference count on their (previous) context. With this perf_event_free_task() can detect when events have escaped and wait for their destruction. Debugged-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reported-by: syzbot+a24c397a29ad22d86c98@syzkaller.appspotmail.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 82d94856fa22 ("perf/core: Fix lock inversion between perf,trace,cpuhp") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-09Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "The main changes in this cycle on the kernel side were: - CPU PMU and uncore driver updates to Intel Snow Ridge, IceLake, KabyLake, AmberLake and WhiskeyLake CPUs. - Rework the MSR probing infrastructure to make it more robust, make it work better on virtualized systems and to better expose it on sysfs. - Rework PMU attributes group support based on the feedback from Greg. The core sysfs patch that adds sysfs_update_groups() was acked by Greg. There's a lot of perf tooling changes as well, all around the place: - vendor updates to Intel, cs-etm (ARM), ARM64, s390, - various enhancements to Intel PT tooling support: - Improve CBR (Core to Bus Ratio) packets support. - Export power and ptwrite events to sqlite and postgresql. - Add support for decoding PEBS via PT packets. - Add support for samples to contain IPC ratio, collecting cycles information from CYC packets, showing the IPC info periodically - Allow using time ranges - lots of updates to perf pmu, perf stat, perf trace, eBPF support, perf record, perf diff, etc. - please see the shortlog and Git log for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (252 commits) tools arch x86: Sync asm/cpufeatures.h with the with the kernel tools build: Check if gettid() is available before providing helper perf jvmti: Address gcc string overflow warning for strncpy() perf python: Remove -fstack-protector-strong if clang doesn't have it perf annotate TUI browser: Do not use member from variable within its own initialization perf tests: Fix record+probe_libc_inet_pton.sh for powerpc64 perf evsel: Do not rely on errno values for precise_ip fallback perf thread: Allow references to thread objects after machine__exit() perf header: Assign proper ff->ph in perf_event__synthesize_features() tools arch kvm: Sync kvm headers with the kernel sources perf script: Allow specifying the files to process guest samples perf tools metric: Don't include duration_time in group perf list: Avoid extra : for --raw metrics perf vendor events intel: Metric fixes for SKX/CLX perf tools: Fix typos / broken sentences perf jevents: Add support for Hisi hip08 L3C PMU aliasing perf jevents: Add support for Hisi hip08 HHA PMU aliasing perf jevents: Add support for Hisi hip08 DDRC PMU aliasing perf pmu: Support more complex PMU event aliasing perf diff: Documentation -c cycles option ...
2019-07-08Merge branch 'siginfo-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull force_sig() argument change from Eric Biederman: "A source of error over the years has been that force_sig has taken a task parameter when it is only safe to use force_sig with the current task. The force_sig function is built for delivering synchronous signals such as SIGSEGV where the userspace application caused a synchronous fault (such as a page fault) and the kernel responded with a signal. Because the name force_sig does not make this clear, and because the force_sig takes a task parameter the function force_sig has been abused for sending other kinds of signals over the years. Slowly those have been fixed when the oopses have been tracked down. This set of changes fixes the remaining abusers of force_sig and carefully rips out the task parameter from force_sig and friends making this kind of error almost impossible in the future" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits) signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus signal: Remove the signal number and task parameters from force_sig_info signal: Factor force_sig_info_to_task out of force_sig_info signal: Generate the siginfo in force_sig signal: Move the computation of force into send_signal and correct it. signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal signal: Remove the task parameter from force_sig_fault signal: Use force_sig_fault_to_task for the two calls that don't deliver to current signal: Explicitly call force_sig_fault on current signal/unicore32: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from ptrace_break signal/nds32: Remove tsk parameter from send_sigtrap signal/riscv: Remove tsk parameter from do_trap signal/sh: Remove tsk parameter from force_sig_info_fault signal/um: Remove task parameter from send_sigtrap signal/x86: Remove task parameter from send_sigtrap signal: Remove task parameter from force_sig_mceerr signal: Remove task parameter from force_sig signal: Remove task parameter from force_sigsegv ...
2019-07-08Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The changes in this cycle are: - RCU flavor consolidation cleanups and optmizations - Documentation updates - Miscellaneous fixes - SRCU updates - RCU-sync flavor consolidation - Torture-test updates - Linux-kernel memory-consistency-model updates, most notably the addition of plain C-language accesses" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits) tools/memory-model: Improve data-race detection tools/memory-model: Change definition of rcu-fence tools/memory-model: Expand definition of barrier tools/memory-model: Do not use "herd" to refer to "herd7" tools/memory-model: Fix comment in MP+poonceonces.litmus Documentation: atomic_t.txt: Explain ordering provided by smp_mb__{before,after}_atomic() rcu: Don't return a value from rcu_assign_pointer() rcu: Force inlining of rcu_read_lock() rcu: Fix irritating whitespace error in rcu_assign_pointer() rcu: Upgrade sync_exp_work_done() to smp_mb() rcutorture: Upper case solves the case of the vanishing NULL pointer torture: Suppress propagating trace_printk() warning rcutorture: Dump trace buffer for callback pipe drain failures torture: Add --trust-make to suppress "make clean" torture: Make --cpus override idleness calculations torture: Run kernel build in source directory torture: Add function graph-tracing cheat sheet torture: Capture qemu output rcutorture: Tweak kvm options rcutorture: Add trivial RCU implementation ...
2019-07-08Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "The timer and timekeeping departement delivers: Core: - The consolidation of the VDSO code into a generic library including the conversion of x86 and ARM64. Conversion of ARM and MIPS are en route through the relevant maintainer trees and should end up in 5.4. This gets rid of the unnecessary different copies of the same code and brings all architectures on the same level of VDSO functionality. - Make the NTP user space interface more robust by restricting the TAI offset to prevent undefined behaviour. Includes a selftest. - Validate user input in the compat settimeofday() syscall to catch invalid values which would be turned into valid values by a multiplication overflow - Consolidate the time accessors - Small fixes, improvements and cleanups all over the place Drivers: - Support for the NXP system counter, TI davinci timer - Move the Microsoft HyperV clocksource/events code into the drivers/clocksource directory so it can be shared between x86 and ARM64. - Overhaul of the Tegra driver - Delay timer support for IXP4xx - Small fixes, improvements and cleanups as usual" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) time: Validate user input in compat_settimeofday() timer: Document TIMER_PINNED clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic clocksource/drivers: Make Hyper-V clocksource ISA agnostic MAINTAINERS: Fix Andy's surname and the directory entries of VDSO hrtimer: Use a bullet for the returns bullet list arm64: vdso: Fix compilation with clang older than 8 arm64: compat: Fix __arch_get_hw_counter() implementation arm64: Fix __arch_get_hw_counter() implementation lib/vdso: Make delta calculation work correctly MAINTAINERS: Add entry for the generic VDSO library arm64: compat: No need for pre-ARMv7 barriers on an ARMv8 system arm64: vdso: Remove unnecessary asm-offsets.c definitions vdso: Remove superfluous #ifdef __KERNEL__ in vdso/datapage.h clocksource/drivers/davinci: Add support for clocksource clocksource/drivers/davinci: Add support for clockevents clocksource/drivers/tegra: Set up maximum-ticks limit properly clocksource/drivers/tegra: Cycles can't be 0 clocksource/drivers/tegra: Restore base address before cleanup clocksource/drivers/tegra: Add verbose definition for 1MHz constant ...
2019-07-08Merge tag 'v5.2' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-28Merge branch 'for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull rcu/next + tools/memory-model changes from Paul E. McKenney: - RCU flavor consolidation cleanups and optmizations - Documentation updates - Miscellaneous fixes - SRCU updates - RCU-sync flavor consolidation - Torture-test updates - Linux-kernel memory-consistency-model updates, most notably the addition of plain C-language accesses Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-26perf_event_get(): don't bother with fget_raw()Al Viro
... since we immediately follow that with check that it *is* an opened perf file, with O_PATH ones ending with with the same -EBADF we'd get for descriptor that isn't opened at all. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-06-24perf/cgroups: Don't rotate events for cgroups unnecessarilyIan Rogers
Currently perf_rotate_context assumes that if the context's nr_events != nr_active a rotation is necessary for perf event multiplexing. With cgroups, nr_events is the total count of events for all cgroups and nr_active will not include events in a cgroup other than the current task's. This makes rotation appear necessary for cgroups when it is not. Add a perf_event_context flag that is set when rotation is necessary. Clear the flag during sched_out and set it when a flexible sched_in fails due to resources. Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/20190601082722.44543-1-irogers@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-24perf/x86: Disable extended registers for non-supported PMUsKan Liang
The perf fuzzer caused Skylake machine to crash: [ 9680.085831] Call Trace: [ 9680.088301] <IRQ> [ 9680.090363] perf_output_sample_regs+0x43/0xa0 [ 9680.094928] perf_output_sample+0x3aa/0x7a0 [ 9680.099181] perf_event_output_forward+0x53/0x80 [ 9680.103917] __perf_event_overflow+0x52/0xf0 [ 9680.108266] ? perf_trace_run_bpf_submit+0xc0/0xc0 [ 9680.113108] perf_swevent_hrtimer+0xe2/0x150 [ 9680.117475] ? check_preempt_wakeup+0x181/0x230 [ 9680.122091] ? check_preempt_curr+0x62/0x90 [ 9680.126361] ? ttwu_do_wakeup+0x19/0x140 [ 9680.130355] ? try_to_wake_up+0x54/0x460 [ 9680.134366] ? reweight_entity+0x15b/0x1a0 [ 9680.138559] ? __queue_work+0x103/0x3f0 [ 9680.142472] ? update_dl_rq_load_avg+0x1cd/0x270 [ 9680.147194] ? timerqueue_del+0x1e/0x40 [ 9680.151092] ? __remove_hrtimer+0x35/0x70 [ 9680.155191] __hrtimer_run_queues+0x100/0x280 [ 9680.159658] hrtimer_interrupt+0x100/0x220 [ 9680.163835] smp_apic_timer_interrupt+0x6a/0x140 [ 9680.168555] apic_timer_interrupt+0xf/0x20 [ 9680.172756] </IRQ> The XMM registers can only be collected by PEBS hardware events on the platforms with PEBS baseline support, e.g. Icelake, not software/probe events. Add capabilities flag PERF_PMU_CAP_EXTENDED_REGS to indicate the PMU which support extended registers. For X86, the extended registers are XMM registers. Add has_extended_regs() to check if extended registers are applied. The generic code define the mask of extended registers as 0 if arch headers haven't overridden it. Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 878068ea270e ("perf/x86: Support outputting XMM registers") Link: https://lkml.kernel.org/r/1559081314-9714-1-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-24perf/ioctl: Add check for the sample_period valueRavi Bangoria
perf_event_open() limits the sample_period to 63 bits. See: 0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits") Make ioctl() consistent with it. Also on PowerPC, negative sample_period could cause a recursive PMIs leading to a hang (reported when running perf-fuzzer). Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: maddy@linux.vnet.ibm.com Cc: mpe@ellerman.id.au Fixes: 0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits") Link: https://lkml.kernel.org/r/20190604042953.914-1-ravi.bangoria@linux.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-22timekeeping: Use proper clock specifier names in functionsJason A. Donenfeld
This makes boot uniformly boottime and tai uniformly clocktai, to address the remaining oversights. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Link: https://lkml.kernel.org/r/20190621203249.3909-2-Jason@zx2c4.com
2019-06-17perf/core: Fix perf_sample_regs_user() mm checkPeter Zijlstra
perf_sample_regs_user() uses 'current->mm' to test for the presence of userspace, but this is insufficient, consider use_mm(). A better test is: '!(current->flags & PF_KTHREAD)', exec() clears PF_KTHREAD after it sets the new ->mm but before it drops to userspace for the first time. Possibly obsoletes: bf05fc25f268 ("powerpc/perf: Fix oops when kthread execs user process") Reported-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Reported-by: Young Xiao <92siuyang@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 4018994f3d87 ("perf: Add ability to attach user level registers dump to sample") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-03perf/core: Add attr_groups_update into struct pmuJiri Olsa
Adding attr_update attribute group into pmu, to allow having multiple attribute groups for same group name. This will allow us to update "events" or "format" directories with attributes that depend on various HW conditions. For example having group_format_extra group that updates "format" directory only if pmu version is 2 and higher: static umode_t exra_is_visible(struct kobject *kobj, struct attribute *attr, int i) { return x86_pmu.version >= 2 ? attr->mode : 0; } static struct attribute_group group_format_extra = { .name = "format", .is_visible = exra_is_visible, }; Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190512155518.21468-3-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-03perf/core: Allow non-privileged uprobe for user processesSong Liu
Currently, non-privileged user could only use uprobe with kernel.perf_event_paranoid = -1 However, setting perf_event_paranoid to -1 leaks other users' processes to non-privileged uprobes. To introduce proper permission control of uprobes, we are building the following system: A daemon with CAP_SYS_ADMIN is in charge to create uprobes via tracefs; Users asks the daemon to create uprobes; Then user can attach uprobe only to processes owned by the user. This patch allows non-privileged user to attach uprobe to processes owned by the user. The following example shows how to use uprobe with non-privileged user. This is based on Brendan's blog post [1] 1. Create uprobe with root: sudo perf probe -x 'readline%return +0($retval):string' 2. Then non-root user can use the uprobe as: perf record -vvv -e probe_bash:readline__return -p <pid> sleep 20 perf script [1] http://www.brendangregg.com/blog/2015-06-28/linux-ftrace-uprobe.html Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <kernel-team@fb.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190507161545.788381-1-songliubraving@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-28uprobes: Use DEFINE_STATIC_PERCPU_RWSEM() to initialize dup_mmap_semOleg Nesterov
Use DEFINE_STATIC_PERCPU_RWSEM() to initialize dup_mmap_sem. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-05-27signal: Remove task parameter from force_sigEric W. Biederman
All of the remaining callers pass current into force_sig so remove the task parameter to make this obvious and to make misuse more difficult in the future. This also makes it clear force_sig passes current into force_sig_info. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-05-24perf/ring-buffer: Use regular variables for nestingPeter Zijlstra
While the IRQ/NMI will nest, the nest-count will be invariant over the actual exception, since it will decrement equal to increment. This means we can -- carefully -- use a regular variable since the typical LOAD-STORE race doesn't exist (similar to preempt_count). This optimizes the ring-buffer for all LOAD-STORE architectures, since they need to use atomic ops to implement local_t. Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: mark.rutland@arm.com Cc: namhyung@kernel.org Cc: yabinc@google.com Link: http://lkml.kernel.org/r/20190517115418.481392777@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-24perf/ring-buffer: Always use {READ,WRITE}_ONCE() for rb->user_page dataPeter Zijlstra
We must use {READ,WRITE}_ONCE() on rb->user_page data such that concurrent usage will see whole values. A few key sites were missing this. Suggested-by: Yabin Cui <yabinc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: mark.rutland@arm.com Cc: namhyung@kernel.org Fixes: 7b732a750477 ("perf_counter: new output ABI - part 1") Link: http://lkml.kernel.org/r/20190517115418.394192145@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-24perf/ring_buffer: Add ordering to rb->nest incrementPeter Zijlstra
Similar to how decrementing rb->next too early can cause data_head to (temporarily) be observed to go backward, so too can this happen when we increment too late. This barrier() ensures the rb->head load happens after the increment, both the one in the 'goto again' path, as the one from perf_output_get_handle() -- albeit very unlikely to matter for the latter. Suggested-by: Yabin Cui <yabinc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: mark.rutland@arm.com Cc: namhyung@kernel.org Fixes: ef60777c9abd ("perf: Optimize the perf_output() path by removing IRQ-disables") Link: http://lkml.kernel.org/r/20190517115418.309516009@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-24perf/ring_buffer: Fix exposing a temporarily decreased data_headYabin Cui
In perf_output_put_handle(), an IRQ/NMI can happen in below location and write records to the same ring buffer: ... local_dec_and_test(&rb->nest) ... <-- an IRQ/NMI can happen here rb->user_page->data_head = head; ... In this case, a value A is written to data_head in the IRQ, then a value B is written to data_head after the IRQ. And A > B. As a result, data_head is temporarily decreased from A to B. And a reader may see data_head < data_tail if it read the buffer frequently enough, which creates unexpected behaviors. This can be fixed by moving dec(&rb->nest) to after updating data_head, which prevents the IRQ/NMI above from updating data_head. [ Split up by peterz. ] Signed-off-by: Yabin Cui <yabinc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: mark.rutland@arm.com Fixes: ef60777c9abd ("perf: Optimize the perf_output() path by removing IRQ-disables") Link: http://lkml.kernel.org/r/20190517115418.224478157@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-14mm/mmu_notifier: use correct mmu_notifier events for each invalidationJérôme Glisse
This updates each existing invalidation to use the correct mmu notifier event that represent what is happening to the CPU page table. See the patch which introduced the events to see the rational behind this. Link: http://lkml.kernel.org/r/20190326164747.24405-7-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Christian König <christian.koenig@amd.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14mm/mmu_notifier: contextual information for event triggering invalidationJérôme Glisse
CPU page table update can happens for many reasons, not only as a result of a syscall (munmap(), mprotect(), mremap(), madvise(), ...) but also as a result of kernel activities (memory compression, reclaim, migration, ...). Users of mmu notifier API track changes to the CPU page table and take specific action for them. While current API only provide range of virtual address affected by the change, not why the changes is happening. This patchset do the initial mechanical convertion of all the places that calls mmu_notifier_range_init to also provide the default MMU_NOTIFY_UNMAP event as well as the vma if it is know (most invalidation happens against a given vma). Passing down the vma allows the users of mmu notifier to inspect the new vma page protection. The MMU_NOTIFY_UNMAP is always the safe default as users of mmu notifier should assume that every for the range is going away when that event happens. A latter patch do convert mm call path to use a more appropriate events for each call. This is done as 2 patches so that no call site is forgotten especialy as it uses this following coccinelle patch: %<---------------------------------------------------------------------- @@ identifier I1, I2, I3, I4; @@ static inline void mmu_notifier_range_init(struct mmu_notifier_range *I1, +enum mmu_notifier_event event, +unsigned flags, +struct vm_area_struct *vma, struct mm_struct *I2, unsigned long I3, unsigned long I4) { ... } @@ @@ -#define mmu_notifier_range_init(range, mm, start, end) +#define mmu_notifier_range_init(range, event, flags, vma, mm, start, end) @@ expression E1, E3, E4; identifier I1; @@ <... mmu_notifier_range_init(E1, +MMU_NOTIFY_UNMAP, 0, I1, I1->vm_mm, E3, E4) ...> @@ expression E1, E2, E3, E4; identifier FN, VMA; @@ FN(..., struct vm_area_struct *VMA, ...) { <... mmu_notifier_range_init(E1, +MMU_NOTIFY_UNMAP, 0, VMA, E2, E3, E4) ...> } @@ expression E1, E2, E3, E4; identifier FN, VMA; @@ FN(...) { struct vm_area_struct *VMA; <... mmu_notifier_range_init(E1, +MMU_NOTIFY_UNMAP, 0, VMA, E2, E3, E4) ...> } @@ expression E1, E2, E3, E4; identifier FN; @@ FN(...) { <... mmu_notifier_range_init(E1, +MMU_NOTIFY_UNMAP, 0, NULL, E2, E3, E4) ...> } ---------------------------------------------------------------------->% Applied with: spatch --all-includes --sp-file mmu-notifier.spatch fs/proc/task_mmu.c --in-place spatch --sp-file mmu-notifier.spatch --dir kernel/events/ --in-place spatch --sp-file mmu-notifier.spatch --dir mm --in-place Link: http://lkml.kernel.org/r/20190326164747.24405-6-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Christian König <christian.koenig@amd.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-07Merge tag 'printk-for-5.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Allow state reset of printk_once() calls. - Prevent crashes when dereferencing invalid pointers in vsprintf(). Only the first byte is checked for simplicity. - Make vsprintf warnings consistent and inlined. - Treewide conversion of obsolete %pf, %pF to %ps, %pF printf modifiers. - Some clean up of vsprintf and test_printf code. * tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: lib/vsprintf: Make function pointer_string static vsprintf: Limit the length of inlined error messages vsprintf: Avoid confusion between invalid address and value vsprintf: Prevent crash when dereferencing invalid pointers vsprintf: Consolidate handling of unknown pointer specifiers vsprintf: Factor out %pO handler as kobject_string() vsprintf: Factor out %pV handler as va_format() vsprintf: Factor out %p[iI] handler as ip_addr_string() vsprintf: Do not check address of well-known strings vsprintf: Consistent %pK handling for kptr_restrict == 0 vsprintf: Shuffle restricted_pointer() printk: Tie printk_once / printk_deferred_once into .data.once for reset treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively lib/test_printf: Switch to bitmap_zalloc()
2019-05-06Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "The changes in here are: - text_poke() fixes and an extensive set of executability lockdowns, to (hopefully) eliminate the last residual circumstances under which we are using W|X mappings even temporarily on x86 kernels. This required a broad range of surgery in text patching facilities, module loading, trampoline handling and other bits. - tweak page fault messages to be more informative and more structured. - remove DISCONTIGMEM support on x86-32 and make SPARSEMEM the default. - reduce KASLR granularity on 5-level paging kernels from 512 GB to 1 GB. - misc other changes and updates" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/mm: Initialize PGD cache during mm initialization x86/alternatives: Add comment about module removal races x86/kprobes: Use vmalloc special flag x86/ftrace: Use vmalloc special flag bpf: Use vmalloc special flag modules: Use vmalloc special flag mm/vmalloc: Add flag for freeing of special permsissions mm/hibernation: Make hibernation handle unmapped pages x86/mm/cpa: Add set_direct_map_*() functions x86/alternatives: Remove the return value of text_poke_*() x86/jump-label: Remove support for custom text poker x86/modules: Avoid breaking W^X while loading modules x86/kprobes: Set instruction page as executable x86/ftrace: Set trampoline pages as executable x86/kgdb: Avoid redundant comparison of patched code x86/alternatives: Use temporary mm for text poking x86/alternatives: Initialize temporary mm for patching fork: Provide a function for copying init_mm uprobes: Initialize uprobes earlier x86/mm: Save debug registers when loading a temporary mm ...
2019-05-06Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "The main kernel changes were: - add support for Intel's "adaptive PEBS v4" - which embedds LBS data in PEBS records and can thus batch up and reduce the IRQ (NMI) rate significantly - reducing overhead and making call-graph profiling less intrusive. - add Intel CPU core and uncore support updates for Tremont, Icelake, - extend the x86 PMU constraints scheduler with 'constraint ranges' to better support Icelake hw constraints, - make x86 call-chain support work better with CONFIG_FRAME_POINTER=y - misc other changes Tooling changes: - updates to the main tools: 'perf record', 'perf trace', 'perf stat' - updated Intel and S/390 vendor events - libtraceevent updates - misc other updates and fixes" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits) perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER watchdog: Fix typo in comment perf/x86/intel: Add Tremont core PMU support perf/x86/intel/uncore: Add Intel Icelake uncore support perf/x86/msr: Add Icelake support perf/x86/intel/rapl: Add Icelake support perf/x86/intel/cstate: Add Icelake support perf/x86/intel: Add Icelake support perf/x86: Support constraint ranges perf/x86/lbr: Avoid reading the LBRs when adaptive PEBS handles them perf/x86/intel: Support adaptive PEBS v4 perf/x86/intel/ds: Extract code of event update in short period perf/x86/intel: Extract memory code PEBS parser for reuse perf/x86: Support outputting XMM registers perf/x86/intel: Force resched when TFA sysctl is modified perf/core: Add perf_pmu_resched() as global function perf/headers: Fix stale comment for struct perf_addr_filter perf/core: Make perf_swevent_init_cpu() static perf/x86: Add sanity checks to x86_schedule_events() perf/x86: Optimize x86_schedule_events() ...
2019-05-03perf/ring_buffer: Fix AUX software double bufferingAlexander Shishkin
This recent commit: 5768402fd9c6e87 ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically") overlooked the fact that the previous one page granularity of the AUX buffer provided an implicit double buffering capability to the PMU driver, which went away when the entire buffer became one high-order page. Always make the full-trace mode AUX allocation at least two-part to preserve the previous behavior and allow the implicit double buffering to continue. Reported-by: Ammy Yi <ammy.yi@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: adrian.hunter@intel.com Fixes: 5768402fd9c6e87 ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically") Link: http://lkml.kernel.org/r/20190503085536.24119-2-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>