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

Pull perf updates from Ingo Molnar:
 "Features:

   - Add "uretprobes" - an optimization to uprobes, like kretprobes are
     an optimization to kprobes.  "perf probe -x file sym%return" now
     works like kretprobes.  By Oleg Nesterov.

   - Introduce per core aggregation in 'perf stat', from Stephane
     Eranian.

   - Add memory profiling via PEBS, from Stephane Eranian.

   - Event group view for 'annotate' in --stdio, --tui and --gtk, from
     Namhyung Kim.

   - Add support for AMD NB and L2I "uncore" counters, by Jacob Shin.

   - Add Ivy Bridge-EP uncore support, by Zheng Yan

   - IBM zEnterprise EC12 oprofile support patchlet from Robert Richter.

   - Add perf test entries for checking breakpoint overflow signal
     handler issues, from Jiri Olsa.

   - Add perf test entry for for checking number of EXIT events, from
     Namhyung Kim.

   - Add perf test entries for checking --cpu in record and stat, from
     Jiri Olsa.

   - Introduce perf stat --repeat forever, from Frederik Deweerdt.

   - Add --no-demangle to report/top, from Namhyung Kim.

   - PowerPC fixes plus a couple of cleanups/optimizations in uprobes
     and trace_uprobes, by Oleg Nesterov.

  Various fixes and refactorings:

   - Fix dependency of the python binding wrt libtraceevent, from
     Naohiro Aota.

   - Simplify some perf_evlist methods and to allow 'stat' to share code
     with 'record' and 'trace', by Arnaldo Carvalho de Melo.

   - Remove dead code in related to libtraceevent integration, from
     Namhyung Kim.

   - Revert "perf sched: Handle PERF_RECORD_EXIT events" to get 'perf
     sched lat' back working, by Arnaldo Carvalho de Melo

   - We don't use Newt anymore, just plain libslang, by Arnaldo Carvalho
     de Melo.

   - Kill a bunch of die() calls, from Namhyung Kim.

   - Fix build on non-glibc systems due to libio.h absence, from Cody P
     Schafer.

   - Remove some perf_session and tracing dead code, from David Ahern.

   - Honor parallel jobs, fix from Borislav Petkov

   - Introduce tools/lib/lk library, initially just removing duplication
     among tools/perf and tools/vm.  from Borislav Petkov

  ... and many more I missed to list, see the shortlog and git log for
  more details."

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (136 commits)
  perf/x86/intel/P4: Robistify P4 PMU types
  perf/x86/amd: Fix AMD NB and L2I "uncore" support
  perf/x86/amd: Remove old-style NB counter support from perf_event_amd.c
  perf/x86: Check all MSRs before passing hw check
  perf/x86/amd: Add support for AMD NB and L2I "uncore" counters
  perf/x86/intel: Add Ivy Bridge-EP uncore support
  perf/x86/intel: Fix SNB-EP CBO and PCU uncore PMU filter management
  perf/x86: Avoid kfree() in CPU_{STARTING,DYING}
  uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is empty
  uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()
  uprobes/tracing: Change create_trace_uprobe() to support uretprobes
  uprobes/tracing: Make seq_printf() code uretprobe-friendly
  uprobes/tracing: Make register_uprobe_event() paths uretprobe-friendly
  uprobes/tracing: Make uprobe_{trace,perf}_print() uretprobe-friendly
  uprobes/tracing: Introduce is_ret_probe() and uretprobe_dispatcher()
  uprobes/tracing: Introduce uprobe_{trace,perf}_print() helpers
  uprobes/tracing: Generalize struct uprobe_trace_entry_head
  uprobes/tracing: Kill the pointless local_save_flags/preempt_count calls
  uprobes/tracing: Kill the pointless seq_print_ip_sym() call
  uprobes/tracing: Kill the pointless task_pt_regs() calls
  ...

1 files changed, 7 insertions, 78 deletions

diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
index b76edf2f833..71c9c2511ee 100644
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c
@@ -36,7 +36,7 @@
 #include <sys/statfs.h>
 #include "../../include/uapi/linux/magic.h"
 #include "../../include/uapi/linux/kernel-page-flags.h"
-
+#include <lk/debugfs.h>
 
 #ifndef MAX_PATH
 # define MAX_PATH 256
@@ -178,7 +178,7 @@ static int		kpageflags_fd;
 static int		opt_hwpoison;
 static int		opt_unpoison;
 
-static char		hwpoison_debug_fs[MAX_PATH+1];
+static char		*hwpoison_debug_fs;
 static int		hwpoison_inject_fd;
 static int		hwpoison_forget_fd;
 
@@ -458,81 +458,6 @@ static uint64_t kpageflags_flags(uint64_t flags)
 	return flags;
 }
 
-/* verify that a mountpoint is actually a debugfs instance */
-static int debugfs_valid_mountpoint(const char *debugfs)
-{
-	struct statfs st_fs;
-
-	if (statfs(debugfs, &st_fs) < 0)
-		return -ENOENT;
-	else if (st_fs.f_type != (long) DEBUGFS_MAGIC)
-		return -ENOENT;
-
-	return 0;
-}
-
-/* find the path to the mounted debugfs */
-static const char *debugfs_find_mountpoint(void)
-{
-	const char *const *ptr;
-	char type[100];
-	FILE *fp;
-
-	ptr = debugfs_known_mountpoints;
-	while (*ptr) {
-		if (debugfs_valid_mountpoint(*ptr) == 0) {
-			strcpy(hwpoison_debug_fs, *ptr);
-			return hwpoison_debug_fs;
-		}
-		ptr++;
-	}
-
-	/* give up and parse /proc/mounts */
-	fp = fopen("/proc/mounts", "r");
-	if (fp == NULL)
-		perror("Can't open /proc/mounts for read");
-
-	while (fscanf(fp, "%*s %"
-		      STR(MAX_PATH)
-		      "s %99s %*s %*d %*d\n",
-		      hwpoison_debug_fs, type) == 2) {
-		if (strcmp(type, "debugfs") == 0)
-			break;
-	}
-	fclose(fp);
-
-	if (strcmp(type, "debugfs") != 0)
-		return NULL;
-
-	return hwpoison_debug_fs;
-}
-
-/* mount the debugfs somewhere if it's not mounted */
-
-static void debugfs_mount(void)
-{
-	const char *const *ptr;
-
-	/* see if it's already mounted */
-	if (debugfs_find_mountpoint())
-		return;
-
-	ptr = debugfs_known_mountpoints;
-	while (*ptr) {
-		if (mount(NULL, *ptr, "debugfs", 0, NULL) == 0) {
-			/* save the mountpoint */
-			strcpy(hwpoison_debug_fs, *ptr);
-			break;
-		}
-		ptr++;
-	}
-
-	if (*ptr == NULL) {
-		perror("mount debugfs");
-		exit(EXIT_FAILURE);
-	}
-}
-
 /*
  * page actions
  */
@@ -541,7 +466,11 @@ static void prepare_hwpoison_fd(void)
 {
 	char buf[MAX_PATH + 1];
 
-	debugfs_mount();
+	hwpoison_debug_fs = debugfs_mount(NULL);
+	if (!hwpoison_debug_fs) {
+		perror("mount debugfs");
+		exit(EXIT_FAILURE);
+	}
 
 	if (opt_hwpoison && !hwpoison_inject_fd) {
 		snprintf(buf, MAX_PATH, "%s/hwpoison/corrupt-pfn",