perf tools: Allow using PERF_RECORD_MMAP2 to synthesize the kernel map

Allow using PERF_RECORD_MMAP2 to synthesize the kernel map so that we
can use PERF_RECORD_MMAP2 to encode the kernel build id in the following
csets.

It's enabled by a new symbol_conf.buildid_mmap2 bool field, which will
be switchable in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201214105457.543111-9-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/symbol_conf.h b/tools/perf/util/symbol_conf.h
index b916afb..b18f9c8 100644 (file)
--- a/tools/perf/util/symbol_conf.h
+++ b/tools/perf/util/symbol_conf.h
@@ -42,7 +42,8 @@ struct symbol_conf {
                        report_block,
                        report_individual_block,
                        inline_name,
-                       disable_add2line_warn;
+                       disable_add2line_warn,
+                       buildid_mmap2;
        const char      *vmlinux_name,
                        *kallsyms_name,
                        *source_prefix,

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index 2947e3f..746f35b 100644 (file)
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -991,11 +991,12 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
                                                perf_event__handler_t process,
                                                struct machine *machine)
 {
-       size_t size;
+       union perf_event *event;
+       size_t size = symbol_conf.buildid_mmap2 ?
+                       sizeof(event->mmap2) : sizeof(event->mmap);
        struct map *map = machine__kernel_map(machine);
        struct kmap *kmap;
        int err;
-       union perf_event *event;
 
        if (map == NULL)
                return -1;
@@ -1009,7 +1010,7 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
         * available use this, and after it is use this as a fallback for older
         * kernels.
         */
-       event = zalloc((sizeof(event->mmap) + machine->id_hdr_size));
+       event = zalloc(size + machine->id_hdr_size);
        if (event == NULL) {
                pr_debug("Not enough memory synthesizing mmap event "
                         "for kernel modules\n");
@@ -1026,16 +1027,29 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
                event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
        }
 
-       size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
-                       "%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
-       size = PERF_ALIGN(size, sizeof(u64));
-       event->mmap.header.type = PERF_RECORD_MMAP;
-       event->mmap.header.size = (sizeof(event->mmap) -
-                       (sizeof(event->mmap.filename) - size) + machine->id_hdr_size);
-       event->mmap.pgoff = kmap->ref_reloc_sym->addr;
-       event->mmap.start = map->start;
-       event->mmap.len   = map->end - event->mmap.start;
-       event->mmap.pid   = machine->pid;
+       if (symbol_conf.buildid_mmap2) {
+               size = snprintf(event->mmap2.filename, sizeof(event->mmap2.filename),
+                               "%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
+               size = PERF_ALIGN(size, sizeof(u64));
+               event->mmap2.header.type = PERF_RECORD_MMAP2;
+               event->mmap2.header.size = (sizeof(event->mmap2) -
+                               (sizeof(event->mmap2.filename) - size) + machine->id_hdr_size);
+               event->mmap2.pgoff = kmap->ref_reloc_sym->addr;
+               event->mmap2.start = map->start;
+               event->mmap2.len   = map->end - event->mmap.start;
+               event->mmap2.pid   = machine->pid;
+       } else {
+               size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
+                               "%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
+               size = PERF_ALIGN(size, sizeof(u64));
+               event->mmap.header.type = PERF_RECORD_MMAP;
+               event->mmap.header.size = (sizeof(event->mmap) -
+                               (sizeof(event->mmap.filename) - size) + machine->id_hdr_size);
+               event->mmap.pgoff = kmap->ref_reloc_sym->addr;
+               event->mmap.start = map->start;
+               event->mmap.len   = map->end - event->mmap.start;
+               event->mmap.pid   = machine->pid;
+       }
 
        err = perf_tool__process_synth_event(tool, event, machine, process);
        free(event);