From 1a562c0d44974d3cf89c6cc5c34c708c08af420e Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 20 Feb 2024 19:41:51 -0800 Subject: tools subcmd: Add a no exec function call option Tools like perf fork tests in case they crash, but they don't want to exec a full binary. Add an option to call a function rather than do an exec. The child process exits with the result of the function call and is passed the struct of the run_command, things like container_of can then allow the child process function to determine additional arguments. Signed-off-by: Ian Rogers Cc: James Clark Cc: Justin Stitt Cc: Bill Wendling Cc: Nick Desaulniers Cc: Yang Jihong Cc: Nathan Chancellor Cc: Kan Liang Cc: Athira Jajeev Cc: llvm@lists.linux.dev Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240221034155.1500118-5-irogers@google.com --- tools/lib/subcmd/run-command.c | 2 ++ tools/lib/subcmd/run-command.h | 2 ++ 2 files changed, 4 insertions(+) (limited to 'tools/lib') diff --git a/tools/lib/subcmd/run-command.c b/tools/lib/subcmd/run-command.c index 5cdac2162532..d435eb42354b 100644 --- a/tools/lib/subcmd/run-command.c +++ b/tools/lib/subcmd/run-command.c @@ -122,6 +122,8 @@ int start_command(struct child_process *cmd) } if (cmd->preexec_cb) cmd->preexec_cb(); + if (cmd->no_exec_cmd) + exit(cmd->no_exec_cmd(cmd)); if (cmd->exec_cmd) { execv_cmd(cmd->argv); } else { diff --git a/tools/lib/subcmd/run-command.h b/tools/lib/subcmd/run-command.h index 17d969c6add3..d794138a797f 100644 --- a/tools/lib/subcmd/run-command.h +++ b/tools/lib/subcmd/run-command.h @@ -47,6 +47,8 @@ struct child_process { unsigned exec_cmd:1; /* if this is to be external sub-command */ unsigned stdout_to_stderr:1; void (*preexec_cb)(void); + /* If set, call function in child rather than doing an exec. */ + int (*no_exec_cmd)(struct child_process *process); }; int start_command(struct child_process *); -- cgit v1.2.3 From 1947b92464c3268381604bbe2ac977a3fd78192f Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Wed, 28 Feb 2024 23:07:57 -0800 Subject: libperf evlist: Avoid out-of-bounds access Parallel testing appears to show a race between allocating and setting evsel ids. As there is a bounds check on the xyarray it yields a segv like: ``` AddressSanitizer:DEADLYSIGNAL ================================================================= ==484408==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000010 ==484408==The signal is caused by a WRITE memory access. ==484408==Hint: address points to the zero page. #0 0x55cef5d4eff4 in perf_evlist__id_hash tools/lib/perf/evlist.c:256 #1 0x55cef5d4f132 in perf_evlist__id_add tools/lib/perf/evlist.c:274 #2 0x55cef5d4f545 in perf_evlist__id_add_fd tools/lib/perf/evlist.c:315 #3 0x55cef5a1923f in store_evsel_ids util/evsel.c:3130 #4 0x55cef5a19400 in evsel__store_ids util/evsel.c:3147 #5 0x55cef5888204 in __run_perf_stat tools/perf/builtin-stat.c:832 #6 0x55cef5888c06 in run_perf_stat tools/perf/builtin-stat.c:960 #7 0x55cef58932db in cmd_stat tools/perf/builtin-stat.c:2878 ... ``` Avoid this crash by early exiting the perf_evlist__id_add_fd and perf_evlist__id_add is the access is out-of-bounds. Signed-off-by: Ian Rogers Cc: Yang Jihong Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240229070757.796244-1-irogers@google.com --- tools/lib/perf/evlist.c | 18 ++++++++++++------ tools/lib/perf/include/internal/evlist.h | 4 ++-- 2 files changed, 14 insertions(+), 8 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c index 058e3ff10f9b..c6d67fc9e57e 100644 --- a/tools/lib/perf/evlist.c +++ b/tools/lib/perf/evlist.c @@ -248,10 +248,10 @@ u64 perf_evlist__read_format(struct perf_evlist *evlist) static void perf_evlist__id_hash(struct perf_evlist *evlist, struct perf_evsel *evsel, - int cpu, int thread, u64 id) + int cpu_map_idx, int thread, u64 id) { int hash; - struct perf_sample_id *sid = SID(evsel, cpu, thread); + struct perf_sample_id *sid = SID(evsel, cpu_map_idx, thread); sid->id = id; sid->evsel = evsel; @@ -269,21 +269,27 @@ void perf_evlist__reset_id_hash(struct perf_evlist *evlist) void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel, - int cpu, int thread, u64 id) + int cpu_map_idx, int thread, u64 id) { - perf_evlist__id_hash(evlist, evsel, cpu, thread, id); + if (!SID(evsel, cpu_map_idx, thread)) + return; + + perf_evlist__id_hash(evlist, evsel, cpu_map_idx, thread, id); evsel->id[evsel->ids++] = id; } int perf_evlist__id_add_fd(struct perf_evlist *evlist, struct perf_evsel *evsel, - int cpu, int thread, int fd) + int cpu_map_idx, int thread, int fd) { u64 read_data[4] = { 0, }; int id_idx = 1; /* The first entry is the counter value */ u64 id; int ret; + if (!SID(evsel, cpu_map_idx, thread)) + return -1; + ret = ioctl(fd, PERF_EVENT_IOC_ID, &id); if (!ret) goto add; @@ -312,7 +318,7 @@ int perf_evlist__id_add_fd(struct perf_evlist *evlist, id = read_data[id_idx]; add: - perf_evlist__id_add(evlist, evsel, cpu, thread, id); + perf_evlist__id_add(evlist, evsel, cpu_map_idx, thread, id); return 0; } diff --git a/tools/lib/perf/include/internal/evlist.h b/tools/lib/perf/include/internal/evlist.h index d86ffe8ed483..f43bdb9b6227 100644 --- a/tools/lib/perf/include/internal/evlist.h +++ b/tools/lib/perf/include/internal/evlist.h @@ -126,11 +126,11 @@ u64 perf_evlist__read_format(struct perf_evlist *evlist); void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel, - int cpu, int thread, u64 id); + int cpu_map_idx, int thread, u64 id); int perf_evlist__id_add_fd(struct perf_evlist *evlist, struct perf_evsel *evsel, - int cpu, int thread, int fd); + int cpu_map_idx, int thread, int fd); void perf_evlist__reset_id_hash(struct perf_evlist *evlist); -- cgit v1.2.3