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

Pull perf update from Ingo Molnar:
 "Lots of changes in this cycle as well, with hundreds of commits from
  over 30 contributors.  Most of the activity was on the tooling side.

  Higher level changes:

   - New 'perf kvm' analysis tool, from Xiao Guangrong.

   - New 'perf trace' system-wide tracing tool

   - uprobes fixes + cleanups from Oleg Nesterov.

   - Lots of patches to make perf build on Android out of box, from
     Irina Tirdea

   - Extend ftrace function tracing utility to be more dynamic for its
     users.  It allows for data passing to the callback functions, as
     well as reading regs as if a breakpoint were to trigger at function
     entry.

     The main goal of this patch series was to allow kprobes to use
     ftrace as an optimized probe point when a probe is placed on an
     ftrace nop.  With lots of help from Masami Hiramatsu, and going
     through lots of iterations, we finally came up with a good
     solution.

   - Add cpumask for uncore pmu, use it in 'stat', from Yan, Zheng.

   - Various tracing updates from Steve Rostedt

   - Clean up and improve 'perf sched' performance by elliminating lots
     of needless calls to libtraceevent.

   - Event group parsing support, from Jiri Olsa

   - UI/gtk refactorings and improvements from Namhyung Kim

   - Add support for non-tracepoint events in perf script python, from
     Feng Tang

   - Add --symbols to 'script', similar to the one in 'report', from
     Feng Tang.

  Infrastructure enhancements and fixes:

   - Convert the trace builtins to use the growing evsel/evlist
     tracepoint infrastructure, removing several open coded constructs
     like switch like series of strcmp to dispatch events, etc.
     Basically what had already been showcased in 'perf sched'.

   - Add evsel constructor for tracepoints, that uses libtraceevent just
     to parse the /format events file, use it in a new 'perf test' to
     make sure the libtraceevent format parsing regressions can be more
     readily caught.

   - Some strange errors were happening in some builds, but not on the
     next, reported by several people, problem was some parser related
     files, generated during the build, didn't had proper make deps, fix
     from Eric Sandeen.

   - Introduce struct and cache information about the environment where
     a perf.data file was captured, from Namhyung Kim.

   - Fix handling of unresolved samples when --symbols is used in
     'report', from Feng Tang.

   - Add union member access support to 'probe', from Hyeoncheol Lee.

   - Fixups to die() removal, from Namhyung Kim.

   - Render fixes for the TUI, from Namhyung Kim.

   - Don't enable annotation in non symbolic view, from Namhyung Kim.

   - Fix pipe mode in 'report', from Namhyung Kim.

   - Move related stats code from stat to util/, will be used by the
     'stat' kvm tool, from Xiao Guangrong.

   - Remove die()/exit() calls from several tools.

   - Resolve vdso callchains, from Jiri Olsa

   - Don't pass const char pointers to basename, so that we can
     unconditionally use libgen.h and thus avoid ifdef BIONIC lines,
     from David Ahern

   - Refactor hist formatting so that it can be reused with the GTK
     browser, From Namhyung Kim

   - Fix build for another rbtree.c change, from Adrian Hunter.

   - Make 'perf diff' command work with evsel hists, from Jiri Olsa.

   - Use the only field_sep var that is set up: symbol_conf.field_sep,
     fix from Jiri Olsa.

   - .gitignore compiled python binaries, from Namhyung Kim.

   - Get rid of die() in more libtraceevent places, from Namhyung Kim.

   - Rename libtraceevent 'private' struct member to 'priv' so that it
     works in C++, from Steven Rostedt

   - Remove lots of exit()/die() calls from tools so that the main perf
     exit routine can take place, from David Ahern

   - Fix x86 build on x86-64, from David Ahern.

   - {int,str,rb}list fixes from Suzuki K Poulose

   - perf.data header fixes from Namhyung Kim

   - Allow user to indicate objdump path, needed in cross environments,
     from Maciek Borzecki

   - Fix hardware cache event name generation, fix from Jiri Olsa

   - Add round trip test for sw, hw and cache event names, catching the
     problem Jiri fixed, after Jiri's patch, the test passes
     successfully.

   - Clean target should do clean for lib/traceevent too, fix from David
     Ahern

   - Check the right variable for allocation failure, fix from Namhyung
     Kim

   - Set up evsel->tp_format regardless of evsel->name being set
     already, fix from Namhyung Kim

   - Oprofile fixes from Robert Richter.

   - Remove perf_event_attr needless version inflation, from Jiri Olsa

   - Introduce libtraceevent strerror like error reporting facility,
     from Namhyung Kim

   - Add pmu mappings to perf.data header and use event names from cmd
     line, from Robert Richter

   - Fix include order for bison/flex-generated C files, from Ben
     Hutchings

   - Build fixes and documentation corrections from David Ahern

   - Assorted cleanups from Robert Richter

   - Let O= makes handle relative paths, from Steven Rostedt

   - perf script python fixes, from Feng Tang.

   - Initial bash completion support, from Frederic Weisbecker

   - Allow building without libelf, from Namhyung Kim.

   - Support DWARF CFI based unwind to have callchains when %bp based
     unwinding is not possible, from Jiri Olsa.

   - Symbol resolution fixes, while fixing support PPC64 files with an
     .opt ELF section was the end goal, several fixes for code that
     handles all architectures and cleanups are included, from Cody
     Schafer.

   - Assorted fixes for Documentation and build in 32 bit, from Robert
     Richter

   - Cache the libtraceevent event_format associated to each evsel
     early, so that we avoid relookups, i.e.  calling pevent_find_event
     repeatedly when processing tracepoint events.

     [ This is to reduce the surface contact with libtraceevents and
        make clear what is that the perf tools needs from that lib: so
        far parsing the common and per event fields.  ]

   - Don't stop the build if the audit libraries are not installed, fix
     from Namhyung Kim.

   - Fix bfd.h/libbfd detection with recent binutils, from Markus
     Trippelsdorf.

   - Improve warning message when libunwind devel packages not present,
     from Jiri Olsa"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (282 commits)
  perf trace: Add aliases for some syscalls
  perf probe: Print an enum type variable in "enum variable-name" format when showing accessible variables
  perf tools: Check libaudit availability for perf-trace builtin
  perf hists: Add missing period_* fields when collapsing a hist entry
  perf trace: New tool
  perf evsel: Export the event_format constructor
  perf evsel: Introduce rawptr() method
  perf tools: Use perf_evsel__newtp in the event parser
  perf evsel: The tracepoint constructor should store sys:name
  perf evlist: Introduce set_filter() method
  perf evlist: Renane set_filters method to apply_filters
  perf test: Add test to check we correctly parse and match syscall open parms
  perf evsel: Handle endianity in intval method
  perf evsel: Know if byte swap is needed
  perf tools: Allow handling a NULL cpu_map as meaning "all cpus"
  perf evsel: Improve tracepoint constructor setup
  tools lib traceevent: Fix error path on pevent_parse_event
  perf test: Fix build failure
  trace: Move trace event enable from fs_initcall to core_initcall
  tracing: Add an option for disabling markers
  ...

1 files changed, 176 insertions, 71 deletions

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index c62b8546cc90..098f396aa409 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -561,9 +561,9 @@ static __kprobes void kprobe_optimizer(struct work_struct *work)
 {
         LIST_HEAD(free_list);
 
+        mutex_lock(&kprobe_mutex);
         /* Lock modules while optimizing kprobes */
         mutex_lock(&module_mutex);
-        mutex_lock(&kprobe_mutex);
 
         /*
          * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed)
@@ -586,8 +586,8 @@ static __kprobes void kprobe_optimizer(struct work_struct *work)
         /* Step 4: Free cleaned kprobes after quiesence period */
         do_free_cleaned_kprobes(&free_list);
 
-        mutex_unlock(&kprobe_mutex);
         mutex_unlock(&module_mutex);
+        mutex_unlock(&kprobe_mutex);
 
         /* Step 5: Kick optimizer again if needed */
         if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list))
@@ -759,20 +759,32 @@ static __kprobes void try_to_optimize_kprobe(struct kprobe *p)
         struct kprobe *ap;
         struct optimized_kprobe *op;
 
+        /* Impossible to optimize ftrace-based kprobe */
+        if (kprobe_ftrace(p))
+                return;
+
+        /* For preparing optimization, jump_label_text_reserved() is called */
+        jump_label_lock();
+        mutex_lock(&text_mutex);
+
         ap = alloc_aggr_kprobe(p);
         if (!ap)
-                return;
+                goto out;
 
         op = container_of(ap, struct optimized_kprobe, kp);
         if (!arch_prepared_optinsn(&op->optinsn)) {
                 /* If failed to setup optimizing, fallback to kprobe */
                 arch_remove_optimized_kprobe(op);
                 kfree(op);
-                return;
+                goto out;
         }
 
         init_aggr_kprobe(ap, p);
-        optimize_kprobe(ap);
+        optimize_kprobe(ap);    /* This just kicks optimizer thread */
+
+out:
+        mutex_unlock(&text_mutex);
+        jump_label_unlock();
 }
 
 #ifdef CONFIG_SYSCTL
@@ -907,9 +919,64 @@ static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
 }
 #endif /* CONFIG_OPTPROBES */
 
+#ifdef KPROBES_CAN_USE_FTRACE
+static struct ftrace_ops kprobe_ftrace_ops __read_mostly = {
+        .func = kprobe_ftrace_handler,
+        .flags = FTRACE_OPS_FL_SAVE_REGS,
+};
+static int kprobe_ftrace_enabled;
+
+/* Must ensure p->addr is really on ftrace */
+static int __kprobes prepare_kprobe(struct kprobe *p)
+{
+        if (!kprobe_ftrace(p))
+                return arch_prepare_kprobe(p);
+
+        return arch_prepare_kprobe_ftrace(p);
+}
+
+/* Caller must lock kprobe_mutex */
+static void __kprobes arm_kprobe_ftrace(struct kprobe *p)
+{
+        int ret;
+
+        ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
+                                   (unsigned long)p->addr, 0, 0);
+        WARN(ret < 0, "Failed to arm kprobe-ftrace at %p (%d)\n", p->addr, ret);
+        kprobe_ftrace_enabled++;
+        if (kprobe_ftrace_enabled == 1) {
+                ret = register_ftrace_function(&kprobe_ftrace_ops);
+                WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret);
+        }
+}
+
+/* Caller must lock kprobe_mutex */
+static void __kprobes disarm_kprobe_ftrace(struct kprobe *p)
+{
+        int ret;
+
+        kprobe_ftrace_enabled--;
+        if (kprobe_ftrace_enabled == 0) {
+                ret = unregister_ftrace_function(&kprobe_ftrace_ops);
+                WARN(ret < 0, "Failed to init kprobe-ftrace (%d)\n", ret);
+        }
+        ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
+                           (unsigned long)p->addr, 1, 0);
+        WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret);
+}
+#else   /* !KPROBES_CAN_USE_FTRACE */
+#define prepare_kprobe(p)       arch_prepare_kprobe(p)
+#define arm_kprobe_ftrace(p)    do {} while (0)
+#define disarm_kprobe_ftrace(p) do {} while (0)
+#endif
+
 /* Arm a kprobe with text_mutex */
 static void __kprobes arm_kprobe(struct kprobe *kp)
 {
+        if (unlikely(kprobe_ftrace(kp))) {
+                arm_kprobe_ftrace(kp);
+                return;
+        }
         /*
          * Here, since __arm_kprobe() doesn't use stop_machine(),
          * this doesn't cause deadlock on text_mutex. So, we don't
@@ -921,11 +988,15 @@ static void __kprobes arm_kprobe(struct kprobe *kp)
 }
 
 /* Disarm a kprobe with text_mutex */
-static void __kprobes disarm_kprobe(struct kprobe *kp)
+static void __kprobes disarm_kprobe(struct kprobe *kp, bool reopt)
 {
+        if (unlikely(kprobe_ftrace(kp))) {
+                disarm_kprobe_ftrace(kp);
+                return;
+        }
         /* Ditto */
         mutex_lock(&text_mutex);
-        __disarm_kprobe(kp, true);
+        __disarm_kprobe(kp, reopt);
         mutex_unlock(&text_mutex);
 }
 
@@ -1144,12 +1215,6 @@ static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p)
         if (p->post_handler && !ap->post_handler)
                 ap->post_handler = aggr_post_handler;
 
-        if (kprobe_disabled(ap) && !kprobe_disabled(p)) {
-                ap->flags &= ~KPROBE_FLAG_DISABLED;
-                if (!kprobes_all_disarmed)
-                        /* Arm the breakpoint again. */
-                        __arm_kprobe(ap);
-        }
         return 0;
 }
 
@@ -1189,11 +1254,22 @@ static int __kprobes register_aggr_kprobe(struct kprobe *orig_p,
         int ret = 0;
         struct kprobe *ap = orig_p;
 
+        /* For preparing optimization, jump_label_text_reserved() is called */
+        jump_label_lock();
+        /*
+         * Get online CPUs to avoid text_mutex deadlock.with stop machine,
+         * which is invoked by unoptimize_kprobe() in add_new_kprobe()
+         */
+        get_online_cpus();
+        mutex_lock(&text_mutex);
+
         if (!kprobe_aggrprobe(orig_p)) {
                 /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */
                 ap = alloc_aggr_kprobe(orig_p);
-                if (!ap)
-                        return -ENOMEM;
+                if (!ap) {
+                        ret = -ENOMEM;
+                        goto out;
+                }
                 init_aggr_kprobe(ap, orig_p);
         } else if (kprobe_unused(ap))
                 /* This probe is going to die. Rescue it */
@@ -1213,7 +1289,7 @@ static int __kprobes register_aggr_kprobe(struct kprobe *orig_p,
                          * free aggr_probe. It will be used next time, or
                          * freed by unregister_kprobe.
                          */
-                        return ret;
+                        goto out;
 
                 /* Prepare optimized instructions if possible. */
                 prepare_optimized_kprobe(ap);
@@ -1228,7 +1304,20 @@ static int __kprobes register_aggr_kprobe(struct kprobe *orig_p,
 
         /* Copy ap's insn slot to p */
         copy_kprobe(ap, p);
-        return add_new_kprobe(ap, p);
+        ret = add_new_kprobe(ap, p);
+
+out:
+        mutex_unlock(&text_mutex);
+        put_online_cpus();
+        jump_label_unlock();
+
+        if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) {
+                ap->flags &= ~KPROBE_FLAG_DISABLED;
+                if (!kprobes_all_disarmed)
+                        /* Arm the breakpoint again. */
+                        arm_kprobe(ap);
+        }
+        return ret;
 }
 
 static int __kprobes in_kprobes_functions(unsigned long addr)
@@ -1313,71 +1402,96 @@ static inline int check_kprobe_rereg(struct kprobe *p)
         return ret;
 }
 
-int __kprobes register_kprobe(struct kprobe *p)
+static __kprobes int check_kprobe_address_safe(struct kprobe *p,
+                                               struct module **probed_mod)
 {
         int ret = 0;
-        struct kprobe *old_p;
-        struct module *probed_mod;
-        kprobe_opcode_t *addr;
-
-        addr = kprobe_addr(p);
-        if (IS_ERR(addr))
-                return PTR_ERR(addr);
-        p->addr = addr;
+        unsigned long ftrace_addr;
 
-        ret = check_kprobe_rereg(p);
-        if (ret)
-                return ret;
+        /*
+         * If the address is located on a ftrace nop, set the
+         * breakpoint to the following instruction.
+         */
+        ftrace_addr = ftrace_location((unsigned long)p->addr);
+        if (ftrace_addr) {
+#ifdef KPROBES_CAN_USE_FTRACE
+                /* Given address is not on the instruction boundary */
+                if ((unsigned long)p->addr != ftrace_addr)
+                        return -EILSEQ;
+                p->flags |= KPROBE_FLAG_FTRACE;
+#else   /* !KPROBES_CAN_USE_FTRACE */
+                return -EINVAL;
+#endif
+        }
 
         jump_label_lock();
         preempt_disable();
+
+        /* Ensure it is not in reserved area nor out of text */
         if (!kernel_text_address((unsigned long) p->addr) ||
             in_kprobes_functions((unsigned long) p->addr) ||
-            ftrace_text_reserved(p->addr, p->addr) ||
             jump_label_text_reserved(p->addr, p->addr)) {
                 ret = -EINVAL;
-                goto cannot_probe;
+                goto out;
         }
 
-        /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */
-        p->flags &= KPROBE_FLAG_DISABLED;
-
-        /*
-         * Check if are we probing a module.
-         */
-        probed_mod = __module_text_address((unsigned long) p->addr);
-        if (probed_mod) {
-                /* Return -ENOENT if fail. */
-                ret = -ENOENT;
+        /* Check if are we probing a module */
+        *probed_mod = __module_text_address((unsigned long) p->addr);
+        if (*probed_mod) {
                 /*
                  * We must hold a refcount of the probed module while updating
                  * its code to prohibit unexpected unloading.
                  */
-                if (unlikely(!try_module_get(probed_mod)))
-                        goto cannot_probe;
+                if (unlikely(!try_module_get(*probed_mod))) {
+                        ret = -ENOENT;
+                        goto out;
+                }
 
                 /*
                  * If the module freed .init.text, we couldn't insert
                  * kprobes in there.
                  */
-                if (within_module_init((unsigned long)p->addr, probed_mod) &&
-                    probed_mod->state != MODULE_STATE_COMING) {
-                        module_put(probed_mod);
-                        goto cannot_probe;
+                if (within_module_init((unsigned long)p->addr, *probed_mod) &&
+                    (*probed_mod)->state != MODULE_STATE_COMING) {
+                        module_put(*probed_mod);
+                        *probed_mod = NULL;
+                        ret = -ENOENT;
                 }
-                /* ret will be updated by following code */
         }
+out:
         preempt_enable();
         jump_label_unlock();
 
+        return ret;
+}
+
+int __kprobes register_kprobe(struct kprobe *p)
+{
+        int ret;
+        struct kprobe *old_p;
+        struct module *probed_mod;
+        kprobe_opcode_t *addr;
+
+        /* Adjust probe address from symbol */
+        addr = kprobe_addr(p);
+        if (IS_ERR(addr))
+                return PTR_ERR(addr);
+        p->addr = addr;
+
+        ret = check_kprobe_rereg(p);
+        if (ret)
+                return ret;
+
+        /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */
+        p->flags &= KPROBE_FLAG_DISABLED;
         p->nmissed = 0;
         INIT_LIST_HEAD(&p->list);
-        mutex_lock(&kprobe_mutex);
 
-        jump_label_lock(); /* needed to call jump_label_text_reserved() */
+        ret = check_kprobe_address_safe(p, &probed_mod);
+        if (ret)
+                return ret;
 
-        get_online_cpus();      /* For avoiding text_mutex deadlock. */
-        mutex_lock(&text_mutex);
+        mutex_lock(&kprobe_mutex);
 
         old_p = get_kprobe(p->addr);
         if (old_p) {
@@ -1386,7 +1500,9 @@ int __kprobes register_kprobe(struct kprobe *p)
                 goto out;
         }
 
-        ret = arch_prepare_kprobe(p);
+        mutex_lock(&text_mutex);        /* Avoiding text modification */
+        ret = prepare_kprobe(p);
+        mutex_unlock(&text_mutex);
         if (ret)
                 goto out;
 
@@ -1395,26 +1511,18 @@ int __kprobes register_kprobe(struct kprobe *p)
                        &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]);
 
         if (!kprobes_all_disarmed && !kprobe_disabled(p))
-                __arm_kprobe(p);
+                arm_kprobe(p);
 
         /* Try to optimize kprobe */
         try_to_optimize_kprobe(p);
 
 out:
-        mutex_unlock(&text_mutex);
-        put_online_cpus();
-        jump_label_unlock();
         mutex_unlock(&kprobe_mutex);
 
         if (probed_mod)
                 module_put(probed_mod);
 
         return ret;
-
-cannot_probe:
-        preempt_enable();
-        jump_label_unlock();
-        return ret;
 }
 EXPORT_SYMBOL_GPL(register_kprobe);
 
@@ -1451,7 +1559,7 @@ static struct kprobe *__kprobes __disable_kprobe(struct kprobe *p)
 
                 /* Try to disarm and disable this/parent probe */
                 if (p == orig_p || aggr_kprobe_disabled(orig_p)) {
-                        disarm_kprobe(orig_p);
+                        disarm_kprobe(orig_p, true);
                         orig_p->flags |= KPROBE_FLAG_DISABLED;
                 }
         }
@@ -2049,10 +2157,11 @@ static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p,
 
         if (!pp)
                 pp = p;
-        seq_printf(pi, "%s%s%s\n",
+        seq_printf(pi, "%s%s%s%s\n",
                 (kprobe_gone(p) ? "[GONE]" : ""),
                 ((kprobe_disabled(p) && !kprobe_gone(p)) ?  "[DISABLED]" : ""),
-                (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""));
+                (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""),
+                (kprobe_ftrace(pp) ? "[FTRACE]" : ""));
 }
 
 static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos)
@@ -2131,14 +2240,12 @@ static void __kprobes arm_all_kprobes(void)
                 goto already_enabled;
 
         /* Arming kprobes doesn't optimize kprobe itself */
-        mutex_lock(&text_mutex);
         for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
                 head = &kprobe_table[i];
                 hlist_for_each_entry_rcu(p, node, head, hlist)
                         if (!kprobe_disabled(p))
-                                __arm_kprobe(p);
+                                arm_kprobe(p);
         }
-        mutex_unlock(&text_mutex);
 
         kprobes_all_disarmed = false;
         printk(KERN_INFO "Kprobes globally enabled\n");
@@ -2166,15 +2273,13 @@ static void __kprobes disarm_all_kprobes(void)
         kprobes_all_disarmed = true;
         printk(KERN_INFO "Kprobes globally disabled\n");
 
-        mutex_lock(&text_mutex);
         for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
                 head = &kprobe_table[i];
                 hlist_for_each_entry_rcu(p, node, head, hlist) {
                         if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p))
-                                __disarm_kprobe(p, false);
+                                disarm_kprobe(p, false);
                 }
         }
-        mutex_unlock(&text_mutex);
         mutex_unlock(&kprobe_mutex);
 
         /* Wait for disarming all kprobes by optimizer */