Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf changes from Ingo Molnar:
 "Core kernel changes:

   - One of the more interesting features in this cycle is the ability
     to attach eBPF programs (user-defined, sandboxed bytecode executed
     by the kernel) to kprobes.

     This allows user-defined instrumentation on a live kernel image
     that can never crash, hang or interfere with the kernel negatively.
     (Right now it's limited to root-only, but in the future we might
     allow unprivileged use as well.)

     (Alexei Starovoitov)

   - Another non-trivial feature is per event clockid support: this
     allows, amongst other things, the selection of different clock
     sources for event timestamps traced via perf.

     This feature is sought by people who'd like to merge perf generated
     events with external events that were measured with different
     clocks:

       - cluster wide profiling

       - for system wide tracing with user-space events,

       - JIT profiling events

     etc.  Matching perf tooling support is added as well, available via
     the -k, --clockid <clockid> parameter to perf record et al.

     (Peter Zijlstra)

  Hardware enablement kernel changes:

   - x86 Intel Processor Trace (PT) support: which is a hardware tracer
     on steroids, available on Broadwell CPUs.

     The hardware trace stream is directly output into the user-space
     ring-buffer, using the 'AUX' data format extension that was added
     to the perf core to support hardware constraints such as the
     necessity to have the tracing buffer physically contiguous.

     This patch-set was developed for two years and this is the result.
     A simple way to make use of this is to use BTS tracing, the PT
     driver emulates BTS output - available via the 'intel_bts' PMU.
     More explicit PT specific tooling support is in the works as well -
     will probably be ready by 4.2.

     (Alexander Shishkin, Peter Zijlstra)

   - x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
     feature of Intel Xeon CPUs that allows the measurement and
     allocation/partitioning of caches to individual workloads.

     These kernel changes expose the measurement side as a new PMU
     driver, which exposes various QoS related PMU events.  (The
     partitioning change is work in progress and is planned to be merged
     as a cgroup extension.)

     (Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
     Waskiewicz Jr)

   - x86 Intel Haswell LBR call stack support: this is a new Haswell
     feature that allows the hardware recording of call chains, plus
     tooling support.  To activate this feature you have to enable it
     via the new 'lbr' call-graph recording option:

        perf record --call-graph lbr
        perf report

     or:

        perf top --call-graph lbr

     This hardware feature is a lot faster than stack walk or dwarf
     based unwinding, but has some limitations:

       - It reuses the current LBR facility, so LBR call stack and
         branch record can not be enabled at the same time.

       - It is only available for user-space callchains.

     (Yan, Zheng)

   - x86 Intel Broadwell CPU support and various event constraints and
     event table fixes for earlier models.

     (Andi Kleen)

   - x86 Intel HT CPUs event scheduling workarounds.  This is a complex
     CPU bug affecting the SNB,IVB,HSW families that results in counter
     value corruption.  The mitigation code is automatically enabled and
     is transparent.

     (Maria Dimakopoulou, Stephane Eranian)

  The perf tooling side had a ton of changes in this cycle as well, so
  I'm only able to list the user visible changes here, in addition to
  the tooling changes outlined above:

  User visible changes affecting all tools:

      - Improve support of compressed kernel modules (Jiri Olsa)
      - Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
      - Bash completion for subcommands (Yunlong Song)
      - Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
      - Support missing -f to override perf.data file ownership. (Yunlong Song)
      - Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)

  User visible changes in individual tools:

    'perf data':

        New tool for converting perf.data to other formats, initially
        for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
        Sebastian Siewior)

    'perf diff':

        Add --kallsyms option (David Ahern)

    'perf list':

        Allow listing events with 'tracepoint' prefix (Yunlong Song)

        Sort the output of the command (Yunlong Song)

    'perf kmem':

        Respect -i option (Jiri Olsa)

        Print big numbers using thousands' group (Namhyung Kim)

        Allow -v option (Namhyung Kim)

        Fix alignment of slab result table (Namhyung Kim)

    'perf probe':

        Support multiple probes on different binaries on the same command line (Masami Hiramatsu)

        Support unnamed union/structure members data collection. (Masami Hiramatsu)

        Check kprobes blacklist when adding new events. (Masami Hiramatsu)

    'perf record':

        Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)

        Support recording running/enabled time (Andi Kleen)

    'perf sched':

        Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)

    'perf report' and 'perf top':

        Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)

        Indicate which callchain entries are annotated in the
        TUI hists browser (Arnaldo Carvalho de Melo)

        Add pid/tid filtering to 'report' and 'script' commands (David Ahern)

        Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
        cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
        events (Arnaldo Carvalho de Melo)

    'perf stat':

        Report unsupported events properly (Suzuki K. Poulose)

        Output running time and run/enabled ratio in CSV mode (Andi Kleen)

    'perf trace':

        Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)

        Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)

        Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)

        Dump stack on segfaults (Arnaldo Carvalho de Melo)

        No need to explicitely enable evsels for workload started from perf, let it
        be enabled via perf_event_attr.enable_on_exec, removing some events that take
        place in the 'perf trace' before a workload is really started by it.
        (Arnaldo Carvalho de Melo)

        Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)

  There's also been a ton of infrastructure work done, such as the
  split-out of perf's build system into tools/build/ and other changes -
  see the shortlog and changelog for details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
  perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
  perf evlist: Fix type for references to data_head/tail
  perf probe: Check the orphaned -x option
  perf probe: Support multiple probes on different binaries
  perf buildid-list: Fix segfault when show DSOs with hits
  perf tools: Fix cross-endian analysis
  perf tools: Fix error path to do closedir() when synthesizing threads
  perf tools: Fix synthesizing fork_event.ppid for non-main thread
  perf tools: Add 'I' event modifier for exclude_idle bit
  perf report: Don't call map__kmap if map is NULL.
  perf tests: Fix attr tests
  perf probe: Fix ARM 32 building error
  perf tools: Merge all perf_event_attr print functions
  perf record: Add clockid parameter
  perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
  perf sched replay: Support using -f to override perf.data file ownership
  perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
  perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
  perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
  perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
  ...

5 files changed, 245 insertions, 6 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index fedbdd7d5d1e..3b9a48ae153a 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -432,6 +432,14 @@ config UPROBE_EVENT
           This option is required if you plan to use perf-probe subcommand
           of perf tools on user space applications.
 
+config BPF_EVENTS
+        depends on BPF_SYSCALL
+        depends on KPROBE_EVENT
+        bool
+        default y
+        help
+          This allows the user to attach BPF programs to kprobe events.
+
 config PROBE_EVENTS
         def_bool n
 
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 98f26588255e..9b1044e936a6 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_EVENT_TRACING) += trace_event_perf.o
 endif
 obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
 obj-$(CONFIG_EVENT_TRACING) += trace_events_trigger.o
+obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o
 obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o
 obj-$(CONFIG_TRACEPOINTS) += power-traces.o
 ifeq ($(CONFIG_PM),y)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
new file mode 100644
index 000000000000..2d56ce501632
--- /dev/null
+++ b/kernel/trace/bpf_trace.c
@@ -0,0 +1,222 @@
+/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/uaccess.h>
+#include <linux/ctype.h>
+#include "trace.h"
+
+static DEFINE_PER_CPU(int, bpf_prog_active);
+
+/**
+ * trace_call_bpf - invoke BPF program
+ * @prog: BPF program
+ * @ctx: opaque context pointer
+ *
+ * kprobe handlers execute BPF programs via this helper.
+ * Can be used from static tracepoints in the future.
+ *
+ * Return: BPF programs always return an integer which is interpreted by
+ * kprobe handler as:
+ * 0 - return from kprobe (event is filtered out)
+ * 1 - store kprobe event into ring buffer
+ * Other values are reserved and currently alias to 1
+ */
+unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx)
+{
+        unsigned int ret;
+
+        if (in_nmi()) /* not supported yet */
+                return 1;
+
+        preempt_disable();
+
+        if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
+                /*
+                 * since some bpf program is already running on this cpu,
+                 * don't call into another bpf program (same or different)
+                 * and don't send kprobe event into ring-buffer,
+                 * so return zero here
+                 */
+                ret = 0;
+                goto out;
+        }
+
+        rcu_read_lock();
+        ret = BPF_PROG_RUN(prog, ctx);
+        rcu_read_unlock();
+
+ out:
+        __this_cpu_dec(bpf_prog_active);
+        preempt_enable();
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(trace_call_bpf);
+
+static u64 bpf_probe_read(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+        void *dst = (void *) (long) r1;
+        int size = (int) r2;
+        void *unsafe_ptr = (void *) (long) r3;
+
+        return probe_kernel_read(dst, unsafe_ptr, size);
+}
+
+static const struct bpf_func_proto bpf_probe_read_proto = {
+        .func           = bpf_probe_read,
+        .gpl_only       = true,
+        .ret_type       = RET_INTEGER,
+        .arg1_type      = ARG_PTR_TO_STACK,
+        .arg2_type      = ARG_CONST_STACK_SIZE,
+        .arg3_type      = ARG_ANYTHING,
+};
+
+static u64 bpf_ktime_get_ns(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+        /* NMI safe access to clock monotonic */
+        return ktime_get_mono_fast_ns();
+}
+
+static const struct bpf_func_proto bpf_ktime_get_ns_proto = {
+        .func           = bpf_ktime_get_ns,
+        .gpl_only       = true,
+        .ret_type       = RET_INTEGER,
+};
+
+/*
+ * limited trace_printk()
+ * only %d %u %x %ld %lu %lx %lld %llu %llx %p conversion specifiers allowed
+ */
+static u64 bpf_trace_printk(u64 r1, u64 fmt_size, u64 r3, u64 r4, u64 r5)
+{
+        char *fmt = (char *) (long) r1;
+        int mod[3] = {};
+        int fmt_cnt = 0;
+        int i;
+
+        /*
+         * bpf_check()->check_func_arg()->check_stack_boundary()
+         * guarantees that fmt points to bpf program stack,
+         * fmt_size bytes of it were initialized and fmt_size > 0
+         */
+        if (fmt[--fmt_size] != 0)
+                return -EINVAL;
+
+        /* check format string for allowed specifiers */
+        for (i = 0; i < fmt_size; i++) {
+                if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
+                        return -EINVAL;
+
+                if (fmt[i] != '%')
+                        continue;
+
+                if (fmt_cnt >= 3)
+                        return -EINVAL;
+
+                /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
+                i++;
+                if (fmt[i] == 'l') {
+                        mod[fmt_cnt]++;
+                        i++;
+                } else if (fmt[i] == 'p') {
+                        mod[fmt_cnt]++;
+                        i++;
+                        if (!isspace(fmt[i]) && !ispunct(fmt[i]) && fmt[i] != 0)
+                                return -EINVAL;
+                        fmt_cnt++;
+                        continue;
+                }
+
+                if (fmt[i] == 'l') {
+                        mod[fmt_cnt]++;
+                        i++;
+                }
+
+                if (fmt[i] != 'd' && fmt[i] != 'u' && fmt[i] != 'x')
+                        return -EINVAL;
+                fmt_cnt++;
+        }
+
+        return __trace_printk(1/* fake ip will not be printed */, fmt,
+                              mod[0] == 2 ? r3 : mod[0] == 1 ? (long) r3 : (u32) r3,
+                              mod[1] == 2 ? r4 : mod[1] == 1 ? (long) r4 : (u32) r4,
+                              mod[2] == 2 ? r5 : mod[2] == 1 ? (long) r5 : (u32) r5);
+}
+
+static const struct bpf_func_proto bpf_trace_printk_proto = {
+        .func           = bpf_trace_printk,
+        .gpl_only       = true,
+        .ret_type       = RET_INTEGER,
+        .arg1_type      = ARG_PTR_TO_STACK,
+        .arg2_type      = ARG_CONST_STACK_SIZE,
+};
+
+static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func_id)
+{
+        switch (func_id) {
+        case BPF_FUNC_map_lookup_elem:
+                return &bpf_map_lookup_elem_proto;
+        case BPF_FUNC_map_update_elem:
+                return &bpf_map_update_elem_proto;
+        case BPF_FUNC_map_delete_elem:
+                return &bpf_map_delete_elem_proto;
+        case BPF_FUNC_probe_read:
+                return &bpf_probe_read_proto;
+        case BPF_FUNC_ktime_get_ns:
+                return &bpf_ktime_get_ns_proto;
+
+        case BPF_FUNC_trace_printk:
+                /*
+                 * this program might be calling bpf_trace_printk,
+                 * so allocate per-cpu printk buffers
+                 */
+                trace_printk_init_buffers();
+
+                return &bpf_trace_printk_proto;
+        default:
+                return NULL;
+        }
+}
+
+/* bpf+kprobe programs can access fields of 'struct pt_regs' */
+static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type)
+{
+        /* check bounds */
+        if (off < 0 || off >= sizeof(struct pt_regs))
+                return false;
+
+        /* only read is allowed */
+        if (type != BPF_READ)
+                return false;
+
+        /* disallow misaligned access */
+        if (off % size != 0)
+                return false;
+
+        return true;
+}
+
+static struct bpf_verifier_ops kprobe_prog_ops = {
+        .get_func_proto  = kprobe_prog_func_proto,
+        .is_valid_access = kprobe_prog_is_valid_access,
+};
+
+static struct bpf_prog_type_list kprobe_tl = {
+        .ops    = &kprobe_prog_ops,
+        .type   = BPF_PROG_TYPE_KPROBE,
+};
+
+static int __init register_kprobe_prog_ops(void)
+{
+        bpf_register_prog_type(&kprobe_tl);
+        return 0;
+}
+late_initcall(register_kprobe_prog_ops);
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 9ba3f43f580e..d0ce590f06e1 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1135,11 +1135,15 @@ static void
 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
 {
         struct ftrace_event_call *call = &tk->tp.call;
+        struct bpf_prog *prog = call->prog;
         struct kprobe_trace_entry_head *entry;
         struct hlist_head *head;
         int size, __size, dsize;
         int rctx;
 
+        if (prog && !trace_call_bpf(prog, regs))
+                return;
+
         head = this_cpu_ptr(call->perf_events);
         if (hlist_empty(head))
                 return;
@@ -1166,11 +1170,15 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
                     struct pt_regs *regs)
 {
         struct ftrace_event_call *call = &tk->tp.call;
+        struct bpf_prog *prog = call->prog;
         struct kretprobe_trace_entry_head *entry;
         struct hlist_head *head;
         int size, __size, dsize;
         int rctx;
 
+        if (prog && !trace_call_bpf(prog, regs))
+                return;
+
         head = this_cpu_ptr(call->perf_events);
         if (hlist_empty(head))
                 return;
@@ -1287,7 +1295,7 @@ static int register_kprobe_event(struct trace_kprobe *tk)
                 kfree(call->print_fmt);
                 return -ENODEV;
         }
-        call->flags = 0;
+        call->flags = TRACE_EVENT_FL_KPROBE;
         call->class->reg = kprobe_register;
         call->data = tk;
         ret = trace_add_event_call(call);
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 74865465e0b7..d60fe62ec4fa 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1006,7 +1006,7 @@ __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
                 return true;
 
         list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
-                if (event->hw.tp_target->mm == mm)
+                if (event->hw.target->mm == mm)
                         return true;
         }
 
@@ -1016,7 +1016,7 @@ __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
 static inline bool
 uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
 {
-        return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm);
+        return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
 }
 
 static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
@@ -1024,10 +1024,10 @@ static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
         bool done;
 
         write_lock(&tu->filter.rwlock);
-        if (event->hw.tp_target) {
+        if (event->hw.target) {
                 list_del(&event->hw.tp_list);
                 done = tu->filter.nr_systemwide ||
-                        (event->hw.tp_target->flags & PF_EXITING) ||
+                        (event->hw.target->flags & PF_EXITING) ||
                         uprobe_filter_event(tu, event);
         } else {
                 tu->filter.nr_systemwide--;
@@ -1047,7 +1047,7 @@ static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
         int err;
 
         write_lock(&tu->filter.rwlock);
-        if (event->hw.tp_target) {
+        if (event->hw.target) {
                 /*
                  * event->parent != NULL means copy_process(), we can avoid
                  * uprobe_apply(). current->mm must be probed and we can rely