Like the kernel text, the location of x86_64 KPTI entry trampolines must be recorded in the perf.data file. Like the kernel, synthesize a mmap event for that, and add processing for it.
Signed-off-by: Adrian Hunter <[email protected]> --- tools/perf/util/event.c | 90 +++++++++++++++++++++++++++++++++++++++++++++-- tools/perf/util/machine.c | 28 +++++++++++++++ 2 files changed, 115 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index aafa9878465f..d810ff8488b1 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -888,9 +888,80 @@ int kallsyms__get_function_start(const char *kallsyms_filename, return 0; } -int perf_event__synthesize_kernel_mmap(struct perf_tool *tool, - perf_event__handler_t process, - struct machine *machine) +#if defined(__x86_64__) + +static int perf_event__synthesize_special_kmaps(struct perf_tool *tool, + perf_event__handler_t process, + struct machine *machine) +{ + int rc = 0; + struct map *pos; + struct map_groups *kmaps = &machine->kmaps; + struct maps *maps = &kmaps->maps; + union perf_event *event = zalloc(sizeof(event->mmap) + + machine->id_hdr_size); + + if (!event) { + pr_debug("Not enough memory synthesizing mmap event " + "for special kernel maps\n"); + return -1; + } + + for (pos = maps__first(maps); pos; pos = map__next(pos)) { + struct kmap *kmap; + size_t size; + + if (!__map__is_special_kernel_map(pos)) + continue; + + kmap = map__kmap(pos); + + size = sizeof(event->mmap) - sizeof(event->mmap.filename) + + PERF_ALIGN(strlen(kmap->name) + 1, sizeof(u64)) + + machine->id_hdr_size; + + memset(event, 0, size); + + event->mmap.header.type = PERF_RECORD_MMAP; + + /* + * kernel uses 0 for user space maps, see kernel/perf_event.c + * __perf_event_mmap + */ + if (machine__is_host(machine)) + event->header.misc = PERF_RECORD_MISC_KERNEL; + else + event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL; + + event->mmap.header.size = size; + + event->mmap.start = pos->start; + event->mmap.len = pos->end - pos->start; + event->mmap.pgoff = pos->pgoff; + event->mmap.pid = machine->pid; + + strlcpy(event->mmap.filename, kmap->name, PATH_MAX); + + if (perf_tool__process_synth_event(tool, event, machine, + process) != 0) { + rc = -1; + break; + } + } + + free(event); + return rc; +} + +#else + +#define perf_event__synthesize_special_kmaps(t, p, m) 0 + +#endif + +static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, + perf_event__handler_t process, + struct machine *machine) { size_t size; struct map *map = machine__kernel_map(machine); @@ -943,6 +1014,19 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool, return err; } +int perf_event__synthesize_kernel_mmap(struct perf_tool *tool, + perf_event__handler_t process, + struct machine *machine) +{ + int err; + + err = __perf_event__synthesize_kernel_mmap(tool, process, machine); + if (err < 0) + return err; + + return perf_event__synthesize_special_kmaps(tool, process, machine); +} + int perf_event__synthesize_thread_map2(struct perf_tool *tool, struct thread_map *threads, perf_event__handler_t process, diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index aa6bb493fcfa..aa938f92d6d1 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1493,6 +1493,32 @@ static bool machine__uses_kcore(struct machine *machine) return false; } +static bool perf_event__is_special_kernel_mmap(struct machine *machine, + union perf_event *event) +{ + return machine__is(machine, "x86_64") && + is_entry_trampoline(event->mmap.filename); +} + +static int machine__process_special_kernel_map(struct machine *machine, + union perf_event *event) +{ + struct map *kernel_map = machine__kernel_map(machine); + struct dso *kernel = kernel_map ? kernel_map->dso : NULL; + struct special_kernal_map sm = { + .start = event->mmap.start, + .end = event->mmap.start + event->mmap.len, + .pgoff = event->mmap.pgoff, + }; + + if (kernel == NULL) + return -1; + + strlcpy(sm.name, event->mmap.filename, KMAP_NAME_LEN); + + return machine__create_special_kernel_map(machine, kernel, &sm); +} + static int machine__process_kernel_mmap_event(struct machine *machine, union perf_event *event) { @@ -1596,6 +1622,8 @@ static int machine__process_kernel_mmap_event(struct machine *machine, */ dso__load(kernel, machine__kernel_map(machine)); } + } else if (perf_event__is_special_kernel_mmap(machine, event)) { + return machine__process_special_kernel_map(machine, event); } return 0; out_problem: -- 1.9.1
