For now, we disable the extended MMAP record support (MMAP2). We have identified cases where it would not report the correct mapping information, clone(VM_CLONE) but with separate pids. We will revisit the support once we find a solution for this case.
The patch changes the kernel to return EINVAL if attr->mmap2 is set. The patch also modifies the perf tool to use regular PERF_RECORD_MMAP for synthetic events and it also prevents the tool from requesting attr->mmap2 mode because the kernel would reject it. The support will be revisited once the kenrel interface is updated. In V2, we reduce the patch to the strict minimum. Signed-off-by: Stephane Eranian <[email protected]> --- kernel/events/core.c | 4 ++++ tools/perf/util/event.c | 30 +++++++++++++----------------- 2 files changed, 17 insertions(+), 17 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index c716385..5bd7fe4 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6773,6 +6773,10 @@ 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/util/event.c b/tools/perf/util/event.c index 9b393e7..63df031 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -187,7 +187,7 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool, return -1; } - event->header.type = PERF_RECORD_MMAP2; + event->header.type = PERF_RECORD_MMAP; /* * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c */ @@ -198,7 +198,6 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool, char prot[5]; char execname[PATH_MAX]; char anonstr[] = "//anon"; - unsigned int ino; size_t size; ssize_t n; @@ -209,13 +208,10 @@ static 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->mmap2.start, &event->mmap2.len, prot, - &event->mmap2.pgoff, &event->mmap2.maj, - &event->mmap2.min, - &ino, execname); - - event->mmap2.ino = (u64)ino; + n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %*x:%*x %*u %s\n", + &event->mmap.start, &event->mmap.len, prot, + &event->mmap.pgoff, + execname); if (n != 8) continue; @@ -227,15 +223,15 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool, strcpy(execname, anonstr); size = strlen(execname) + 1; - memcpy(event->mmap2.filename, execname, size); + memcpy(event->mmap.filename, execname, size); size = PERF_ALIGN(size, sizeof(u64)); - 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; + 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; if (process(tool, event, &synth_sample, machine) != 0) { rc = -1; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
