[PATCH 2/7] Revert "perf: Disable PERF_RECORD_MMAP2 support"

From: Don Zickus
Date: Mon May 19 2014 - 15:16:17 EST


This reverts commit 3090ffb5a2515990182f3f55b0688a7817325488.

Re-enable the mmap2 interface as we will have a user soon.

Since things have changed since perf disabled mmap2, small tweaks
to the revert had to be done:

o commit 9d4ecc88 forced (n!=8) to become (n<7)
o a new libunwind test needed updating to use mmap2 interface

Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>
---
v2: added a better changelog
fix a unwind test (thanks Jiri)
---
kernel/events/core.c | 4 ----
tools/perf/tests/dwarf-unwind.c | 2 +-
tools/perf/util/event.c | 36 +++++++++++++++++++-----------------
tools/perf/util/evsel.c | 1 +
4 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 0711cc9..c793cb0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6882,10 +6882,6 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
if (ret)
return -EFAULT;

- /* disabled for now */
- if (attr->mmap2)
- return -EINVAL;
-
if (attr->__reserved_1)
return -EINVAL;

diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c
index 108f0cd..96adb73 100644
--- a/tools/perf/tests/dwarf-unwind.c
+++ b/tools/perf/tests/dwarf-unwind.c
@@ -15,7 +15,7 @@ static int mmap_handler(struct perf_tool *tool __maybe_unused,
struct perf_sample *sample __maybe_unused,
struct machine *machine)
{
- return machine__process_mmap_event(machine, event, NULL);
+ return machine__process_mmap2_event(machine, event, NULL);
}

static int init_live_machine(struct machine *machine)
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 65795b8..5e7c722 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -178,13 +178,14 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
return -1;
}

- event->header.type = PERF_RECORD_MMAP;
+ event->header.type = PERF_RECORD_MMAP2;

while (1) {
char bf[BUFSIZ];
char prot[5];
char execname[PATH_MAX];
char anonstr[] = "//anon";
+ unsigned int ino;
size_t size;
ssize_t n;

@@ -195,14 +196,15 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
strcpy(execname, "");

/* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */
- n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %*x:%*x %*u %s\n",
- &event->mmap.start, &event->mmap.len, prot,
- &event->mmap.pgoff,
- execname);
- /*
- * Anon maps don't have the execname.
- */
- if (n < 4)
+ n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %x:%x %u %s\n",
+ &event->mmap2.start, &event->mmap2.len, prot,
+ &event->mmap2.pgoff, &event->mmap2.maj,
+ &event->mmap2.min,
+ &ino, execname);
+
+ event->mmap2.ino = (u64)ino;
+
+ if (n < 7)
continue;
/*
* Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
@@ -223,15 +225,15 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool,
strcpy(execname, anonstr);

size = strlen(execname) + 1;
- memcpy(event->mmap.filename, execname, size);
+ memcpy(event->mmap2.filename, execname, size);
size = PERF_ALIGN(size, sizeof(u64));
- event->mmap.len -= event->mmap.start;
- event->mmap.header.size = (sizeof(event->mmap) -
- (sizeof(event->mmap.filename) - size));
- memset(event->mmap.filename + size, 0, machine->id_hdr_size);
- event->mmap.header.size += machine->id_hdr_size;
- event->mmap.pid = tgid;
- event->mmap.tid = pid;
+ event->mmap2.len -= event->mmap.start;
+ event->mmap2.header.size = (sizeof(event->mmap2) -
+ (sizeof(event->mmap2.filename) - size));
+ memset(event->mmap2.filename + size, 0, machine->id_hdr_size);
+ event->mmap2.header.size += machine->id_hdr_size;
+ event->mmap2.pid = tgid;
+ event->mmap2.tid = pid;

if (process(tool, event, &synth_sample, machine) != 0) {
rc = -1;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 5c28d82..21154da 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -659,6 +659,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
perf_evsel__set_sample_bit(evsel, WEIGHT);

attr->mmap = track;
+ attr->mmap2 = track && !perf_missing_features.mmap2;
attr->comm = track;

if (opts->sample_transaction)
--
1.7.11.7

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