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charset="utf-8" Set up beauty_map, load it to BPF, in such format: if argument No.3 is a struct of size 32 bytes (of syscall number 114) beauty_map[114][2] =3D 32; if argument No.3 is a string (of syscall number 114) beauty_map[114][2] =3D 1; if argument No.3 is a buffer, its size is indicated by argument No.4 (of sy= scall number 114) beauty_map[114][2] =3D -4; /* -1 ~ -6, we'll read this buffer size in BPF = */ Add type_id member to syscall_arg_fmt because it is required by btf_dump. Add syscall_arg__scnprintf_buf() to pretty print augmented buffer. Use btf_dump API to pretty print augmented struct pointer. Add trace__init_pid_filter(), to set up pid_filter before running BPF program. This way, we don't accidentally collect augmented data from processes we don't care about. Signed-off-by: Howard Chu Acked-by: Ian Rogers --- tools/perf/builtin-trace.c | 254 ++++++++++++++++++++++++++++++++++++- 1 file changed, 250 insertions(+), 4 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 8af93a2f0bcd..cf52fda453e0 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -113,6 +113,7 @@ struct syscall_arg_fmt { bool show_zero; #ifdef HAVE_LIBBPF_SUPPORT const struct btf_type *type; + int type_id; #endif }; =20 @@ -851,6 +852,11 @@ static size_t syscall_arg__scnprintf_filename(char *bf= , size_t size, =20 #define SCA_FILENAME syscall_arg__scnprintf_filename =20 +static size_t syscall_arg__scnprintf_buf(char *bf, size_t size, + struct syscall_arg *arg); + +#define SCA_BUF syscall_arg__scnprintf_buf + static size_t syscall_arg__scnprintf_pipe_flags(char *bf, size_t size, struct syscall_arg *arg) { @@ -930,6 +936,24 @@ static void syscall_arg_fmt__cache_btf_enum(struct sys= call_arg_fmt *arg_fmt, str arg_fmt->type =3D btf__type_by_id(btf, id); } =20 +static int syscall_arg_fmt__cache_btf_struct(struct syscall_arg_fmt *arg_f= mt, struct btf *btf, char *type) +{ + /* this function is solely used in trace__bpf_sys_enter_beauty_map */ + int id; + + if (arg_fmt->type !=3D NULL) + return -1; + + id =3D btf__find_by_name(btf, type); + if (id < 0) + return -1; + + arg_fmt->type_id =3D id; /* used for dumping data later */ + arg_fmt->type =3D btf__type_by_id(btf, id); + + return 0; +} + static bool syscall_arg__strtoul_btf_enum(char *bf, size_t size, struct sy= scall_arg *arg, u64 *val) { const struct btf_type *bt =3D arg->fmt->type; @@ -991,8 +1015,56 @@ static size_t btf_enum_scnprintf(const struct btf_typ= e *type, struct btf *btf, c return 0; } =20 +#define DUMPSIZ 256 + +static void btf_dump_snprintf(void *ctx, const char *fmt, va_list args) +{ + char *s =3D ctx, new[DUMPSIZ]; + + vsnprintf(new, DUMPSIZ, fmt, args); + + if (strlen(s) + strlen(new) < DUMPSIZ) + strncat(s, new, DUMPSIZ); +} + +static size_t btf_dump__struct_scnprintf(const struct btf_type *type, stru= ct btf *btf, char *bf, size_t size, struct syscall_arg *arg, int type_id) +{ + char str[DUMPSIZ]; + int dump_size; + int consumed; + struct btf_dump *btf_dump; + struct augmented_arg *augmented_arg =3D arg->augmented.args; + LIBBPF_OPTS(btf_dump_opts, dump_opts); + LIBBPF_OPTS(btf_dump_type_data_opts, dump_data_opts); + + if (arg =3D=3D NULL || arg->augmented.args =3D=3D NULL) + return 0; + + memset(str, 0, sizeof(str)); + + dump_data_opts.compact =3D true; + dump_data_opts.skip_names =3D true; + + btf_dump =3D btf_dump__new(btf, btf_dump_snprintf, str, &dump_opts); + if (btf_dump =3D=3D NULL) + return 0; + + consumed =3D sizeof(*augmented_arg) + augmented_arg->size; + + dump_size =3D btf_dump__dump_type_data(btf_dump, type_id, arg->augmented.= args->value, type->size, &dump_data_opts); + if (dump_size =3D=3D 0) + return 0; + + arg->augmented.args =3D ((void *)arg->augmented.args) + consumed; + arg->augmented.size -=3D consumed; + + btf_dump__free(btf_dump); + + return scnprintf(bf, size, "%s", str); +} + static size_t trace__btf_scnprintf(struct trace *trace, struct syscall_arg= _fmt *arg_fmt, char *bf, - size_t size, int val, char *type) + size_t size, int val, struct syscall_arg *arg, char *type) { if (trace->btf =3D=3D NULL) return 0; @@ -1008,6 +1080,8 @@ static size_t trace__btf_scnprintf(struct trace *trac= e, struct syscall_arg_fmt * =20 if (btf_is_enum(arg_fmt->type)) return btf_enum_scnprintf(arg_fmt->type, trace->btf, bf, size, val); + else if (btf_is_struct(arg_fmt->type)) + return btf_dump__struct_scnprintf(arg_fmt->type, trace->btf, bf, size, a= rg, arg_fmt->type_id); =20 return 0; } @@ -1694,6 +1768,53 @@ static size_t syscall_arg__scnprintf_filename(char *= bf, size_t size, return 0; } =20 +#define MAX_CONTROL_CHAR 31 +#define MAX_ASCII 127 +#define MAX_BUF 32 + +static size_t syscall_arg__scnprintf_augmented_buf(struct syscall_arg *arg= , char *bf, size_t size) +{ + struct augmented_arg *augmented_arg =3D arg->augmented.args; + size_t printed =3D 0; + unsigned char *start =3D (unsigned char *)augmented_arg->value; + int i =3D 0, n =3D augmented_arg->size, consumed, digits; + char tmp[MAX_BUF * 4], tens[4]; + + memset(tmp, 0, sizeof(tmp)); + + for (int j =3D 0; j < n && i < (int)sizeof(tmp); ++j) { + /* print control characters(0~31 and 127), and characters bigger than 12= 7 in \ */ + if (start[j] <=3D MAX_CONTROL_CHAR || start[j] > MAX_ASCII) { + tmp[i++] =3D '\\'; + digits =3D scnprintf(tens, sizeof(tmp) - i, "%d", (int)start[j]); + if (digits + i <=3D (int)sizeof(tmp)) { + strncpy(tmp + i, tens, digits); + i +=3D digits; + } + } else { + tmp[i++] =3D start[j]; + } + } + + printed =3D scnprintf(bf, size, "\"%s\"", tmp); + + consumed =3D sizeof(*augmented_arg) + augmented_arg->size; + + arg->augmented.args =3D ((void *)arg->augmented.args) + consumed; + arg->augmented.size -=3D consumed; + + return printed; +} + +static size_t syscall_arg__scnprintf_buf(char *bf, size_t size, + struct syscall_arg *arg) +{ + if (arg->augmented.args) + return syscall_arg__scnprintf_augmented_buf(arg, bf, size); + + return 0; +} + static bool trace__filter_duration(struct trace *trace, double t) { return t < (trace->duration_filter * NSEC_PER_MSEC); @@ -1903,8 +2024,16 @@ syscall_arg_fmt__init_array(struct syscall_arg_fmt *= arg, struct tep_format_field =20 if (strcmp(field->type, "const char *") =3D=3D 0 && ((len >=3D 4 && strcmp(field->name + len - 4, "name") =3D=3D 0) || - strstr(field->name, "path") !=3D NULL)) + strstr(field->name, "path") || + strstr(field->name, "file") || + strstr(field->name, "root") || + strstr(field->name, "key") || + strstr(field->name, "special") || + strstr(field->name, "type") || + strstr(field->name, "description"))) arg->scnprintf =3D SCA_FILENAME; + else if (strstr(field->type, "char *") && strstr(field->name, "buf")) + arg->scnprintf =3D SCA_BUF; else if ((field->flags & TEP_FIELD_IS_POINTER) || strstr(field->name, "a= ddr")) arg->scnprintf =3D SCA_PTR; else if (strcmp(field->type, "pid_t") =3D=3D 0) @@ -2263,7 +2392,7 @@ static size_t syscall__scnprintf_args(struct syscall = *sc, char *bf, size_t size, printed +=3D scnprintf(bf + printed, size - printed, "%s: ", field->na= me); =20 btf_printed =3D trace__btf_scnprintf(trace, &sc->arg_fmt[arg.idx], bf += printed, - size - printed, val, field->type); + size - printed, val, &arg, field->type); if (btf_printed) { printed +=3D btf_printed; continue; @@ -2965,7 +3094,7 @@ static size_t trace__fprintf_tp_fields(struct trace *= trace, struct evsel *evsel, if (trace->show_arg_names) printed +=3D scnprintf(bf + printed, size - printed, "%s: ", field->nam= e); =20 - btf_printed =3D trace__btf_scnprintf(trace, arg, bf + printed, size - pr= inted, val, field->type); + btf_printed =3D trace__btf_scnprintf(trace, arg, bf + printed, size - pr= inted, val, NULL, field->type); if (btf_printed) { printed +=3D btf_printed; continue; @@ -3523,6 +3652,82 @@ static int trace__bpf_prog_sys_exit_fd(struct trace = *trace, int id) return sc ? bpf_program__fd(sc->bpf_prog.sys_exit) : bpf_program__fd(trac= e->skel->progs.syscall_unaugmented); } =20 +static int trace__bpf_sys_enter_beauty_map(struct trace *trace, int key, u= nsigned int *beauty_array) +{ + struct tep_format_field *field; + struct syscall *sc =3D trace__syscall_info(trace, NULL, key); + const struct btf_type *bt; + char *struct_offset, *tmp, name[32]; + bool augmented =3D false; + int i, cnt; + + if (sc =3D=3D NULL) + return -1; + + trace__load_vmlinux_btf(trace); + if (trace->btf =3D=3D NULL) + return -1; + + for (i =3D 0, field =3D sc->args; field; ++i, field =3D field->next) { + struct_offset =3D strstr(field->type, "struct "); + + if (field->flags & TEP_FIELD_IS_POINTER && struct_offset) { /* struct */ + struct_offset +=3D 7; + + /* for 'struct foo *', we only want 'foo' */ + for (tmp =3D struct_offset, cnt =3D 0; *tmp !=3D ' ' && *tmp !=3D '\0';= ++tmp, ++cnt) { + } + + strncpy(name, struct_offset, cnt); + name[cnt] =3D '\0'; + + if (syscall_arg_fmt__cache_btf_struct(&sc->arg_fmt[i], trace->btf, name= )) + continue; + + bt =3D sc->arg_fmt[i].type; + beauty_array[i] =3D bt->size; + augmented =3D true; + } else if (field->flags & TEP_FIELD_IS_POINTER && /* string */ + strcmp(field->type, "const char *") =3D=3D 0 && + (strstr(field->name, "name") || + strstr(field->name, "path") || + strstr(field->name, "file") || + strstr(field->name, "root") || + strstr(field->name, "key") || + strstr(field->name, "special") || + strstr(field->name, "type") || + strstr(field->name, "description"))) { + beauty_array[i] =3D 1; + augmented =3D true; + } else if (field->flags & TEP_FIELD_IS_POINTER && /* buffer */ + strstr(field->type, "char *") && + (strstr(field->name, "buf") || + strstr(field->name, "val") || + strstr(field->name, "msg"))) { + int j; + struct tep_format_field *field_tmp; + + /* find the size of the buffer */ + for (j =3D 0, field_tmp =3D sc->args; field_tmp; ++j, field_tmp =3D fie= ld_tmp->next) { + if (!(field_tmp->flags & TEP_FIELD_IS_POINTER) && /* only integers */ + (strstr(field_tmp->name, "count") || + strstr(field_tmp->name, "siz") || /* size, bufsiz */ + (strstr(field_tmp->name, "len") && strcmp(field_tmp->name, "filen= ame")))) { + /* filename's got 'len' in it, we don't want that */ + beauty_array[i] =3D -(j + 1); + augmented =3D true; + break; + } + } + } + } + + if (augmented) + return 0; + + return -1; +} + static struct bpf_program *trace__find_usable_bpf_prog_entry(struct trace = *trace, struct syscall *sc) { struct tep_format_field *field, *candidate_field; @@ -3627,7 +3832,9 @@ static int trace__init_syscalls_bpf_prog_array_maps(s= truct trace *trace) { int map_enter_fd =3D bpf_map__fd(trace->skel->maps.syscalls_sys_enter); int map_exit_fd =3D bpf_map__fd(trace->skel->maps.syscalls_sys_exit); + int beauty_map_fd =3D bpf_map__fd(trace->skel->maps.beauty_map_enter); int err =3D 0; + unsigned int beauty_array[6]; =20 for (int i =3D 0; i < trace->sctbl->syscalls.nr_entries; ++i) { int prog_fd, key =3D syscalltbl__id_at_idx(trace->sctbl, i); @@ -3646,6 +3853,15 @@ static int trace__init_syscalls_bpf_prog_array_maps(= struct trace *trace) err =3D bpf_map_update_elem(map_exit_fd, &key, &prog_fd, BPF_ANY); if (err) break; + + /* set up the size of struct pointer argument for beauty map */ + memset(beauty_array, 0, sizeof(beauty_array)); + err =3D trace__bpf_sys_enter_beauty_map(trace, key, (unsigned int *)beau= ty_array); + if (err) + continue; + err =3D bpf_map_update_elem(beauty_map_fd, &key, beauty_array, BPF_ANY); + if (err) + break; } =20 /* @@ -3714,6 +3930,33 @@ static int trace__init_syscalls_bpf_prog_array_maps(= struct trace *trace) =20 return err; } + +static void trace__init_pid_filter(struct trace *trace) +{ + int pid_filter_fd =3D bpf_map__fd(trace->skel->maps.pid_filter); + bool exists =3D true; + struct str_node *pos; + struct strlist *pid_slist =3D strlist__new(trace->opts.target.pid, NULL); + + trace->skel->bss->filter_pid =3D false; 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Wed, 31 Jul 2024 12:49:57 -0700 (PDT) Received: from localhost.localdomain ([120.229.49.244]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1fed7837e40sm124708615ad.0.2024.07.31.12.49.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Jul 2024 12:49:57 -0700 (PDT) From: Howard Chu To: acme@kernel.org Cc: adrian.hunter@intel.com, irogers@google.com, jolsa@kernel.org, kan.liang@linux.intel.com, namhyung@kernel.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v1 2/3] perf trace: Collect augmented data using BPF Date: Thu, 1 Aug 2024 03:49:38 +0800 Message-ID: <20240731194939.4760-3-howardchu95@gmail.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240731194939.4760-1-howardchu95@gmail.com> References: <20240731194939.4760-1-howardchu95@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add task filtering in BPF to avoid collecting useless data. I have to make the payload 6 times the size of augmented_arg, to pass the BPF verifier. Signed-off-by: Howard Chu Acked-by: Ian Rogers --- .../bpf_skel/augmented_raw_syscalls.bpf.c | 121 +++++++++++++++++- 1 file changed, 120 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c b/tools/= perf/util/bpf_skel/augmented_raw_syscalls.bpf.c index 0acbd74e8c76..e96a3ed46dca 100644 --- a/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c +++ b/tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c @@ -22,6 +22,10 @@ =20 #define MAX_CPUS 4096 =20 +#define MAX_BUF 32 /* maximum size of buffer augmentation */ + +volatile bool filter_pid; + /* bpf-output associated map */ struct __augmented_syscalls__ { __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); @@ -79,6 +83,13 @@ struct pids_filtered { __uint(max_entries, 64); } pids_filtered SEC(".maps"); =20 +struct pid_filter { + __uint(type, BPF_MAP_TYPE_HASH); + __type(key, pid_t); + __type(value, bool); + __uint(max_entries, 512); +} pid_filter SEC(".maps"); + /* * Desired design of maximum size and alignment (see RFC2553) */ @@ -124,6 +135,25 @@ struct augmented_args_tmp { __uint(max_entries, 1); } augmented_args_tmp SEC(".maps"); =20 +struct beauty_payload_enter { + struct syscall_enter_args args; + struct augmented_arg aug_args[6]; +}; + +struct beauty_map_enter { + __uint(type, BPF_MAP_TYPE_HASH); + __type(key, int); + __type(value, __u32[6]); + __uint(max_entries, 512); +} beauty_map_enter SEC(".maps"); + +struct beauty_payload_enter_map { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __type(key, int); + __type(value, struct beauty_payload_enter); + __uint(max_entries, 1); +} beauty_payload_enter_map SEC(".maps"); + static inline struct augmented_args_payload *augmented_args_payload(void) { int key =3D 0; @@ -136,6 +166,11 @@ static inline int augmented__output(void *ctx, struct = augmented_args_payload *ar return bpf_perf_event_output(ctx, &__augmented_syscalls__, BPF_F_CURRENT_= CPU, args, len); } =20 +static inline int augmented__beauty_output(void *ctx, void *data, int len) +{ + return bpf_perf_event_output(ctx, &__augmented_syscalls__, BPF_F_CURRENT_= CPU, data, len); +} + static inline unsigned int augmented_arg__read_str(struct augmented_arg *augmented_arg, = const void *arg, unsigned int arg_len) { @@ -176,6 +211,7 @@ int syscall_unaugmented(struct syscall_enter_args *args) * on from there, reading the first syscall arg as a string, i.e. open's * filename. */ + SEC("tp/syscalls/sys_enter_connect") int sys_enter_connect(struct syscall_enter_args *args) { @@ -372,6 +408,82 @@ static bool pid_filter__has(struct pids_filtered *pids= , pid_t pid) return bpf_map_lookup_elem(pids, &pid) !=3D NULL; } =20 +static inline bool not_in_filter(pid_t pid) +{ + return bpf_map_lookup_elem(&pid_filter, &pid) =3D=3D NULL; +} + +static int beauty_enter(void *ctx, struct syscall_enter_args *args) +{ + if (args =3D=3D NULL) + return 1; + + int zero =3D 0; + struct beauty_payload_enter *payload =3D bpf_map_lookup_elem(&beauty_payl= oad_enter_map, &zero); + unsigned int nr =3D (__u32)args->syscall_nr, + *m =3D bpf_map_lookup_elem(&beauty_map_enter, &nr); + + if (m =3D=3D NULL || payload =3D=3D NULL) + return 1; + + bool augment =3D false; + int size, err, index, written, output =3D 0, augsiz =3D sizeof(payload->a= ug_args[0].value); + void *arg, *arg_offset =3D (void *)&payload->aug_args; + + __builtin_memcpy(&payload->args, args, sizeof(struct syscall_enter_args)); + + for (int i =3D 0; i < 6; i++) { + size =3D m[i]; + arg =3D (void *)args->args[i]; + written =3D 0; + + if (size =3D=3D 0 || arg =3D=3D NULL) + continue; + + if (size =3D=3D 1) { /* string */ + size =3D bpf_probe_read_user_str(((struct augmented_arg *)arg_offset)->= value, augsiz, arg); + if (size < 0) + size =3D 0; + + /* these three lines can't be moved outside of this if block, sigh. */ + ((struct augmented_arg *)arg_offset)->size =3D size; + augment =3D true; + written =3D offsetof(struct augmented_arg, value) + size; + } else if (size > 0 && size <=3D augsiz) { /* struct */ + err =3D bpf_probe_read_user(((struct augmented_arg *)arg_offset)->value= , size, arg); + if (err) + continue; + + ((struct augmented_arg *)arg_offset)->size =3D size; + augment =3D true; + written =3D offsetof(struct augmented_arg, value) + size; + } else if (size < 0 && size >=3D -6) { /* buffer */ + index =3D -(size + 1); + size =3D args->args[index]; + + if (size > MAX_BUF) + size =3D MAX_BUF; + + if (size > 0) { + err =3D bpf_probe_read_user(((struct augmented_arg *)arg_offset)->valu= e, size, arg); + if (err) + continue; + + ((struct augmented_arg *)arg_offset)->size =3D size; + augment =3D true; + written =3D offsetof(struct augmented_arg, value) + size; + } + } + output +=3D written; + arg_offset +=3D written; + } + + if (!augment) + return 1; + + return augmented__beauty_output(ctx, payload, sizeof(struct syscall_enter= _args) + output); +} + SEC("tp/raw_syscalls/sys_enter") int sys_enter(struct syscall_enter_args *args) { @@ -389,6 +501,9 @@ int sys_enter(struct syscall_enter_args *args) if (pid_filter__has(&pids_filtered, getpid())) return 0; =20 + if (filter_pid && not_in_filter(getpid())) + return 0; + augmented_args =3D augmented_args_payload(); if (augmented_args =3D=3D NULL) return 1; @@ -400,7 +515,8 @@ int sys_enter(struct syscall_enter_args *args) * "!raw_syscalls:unaugmented" that will just return 1 to return the * unaugmented tracepoint payload. */ - bpf_tail_call(args, &syscalls_sys_enter, augmented_args->args.syscall_nr); + if (beauty_enter(args, &augmented_args->args)) + bpf_tail_call(args, &syscalls_sys_enter, augmented_args->args.syscall_nr= ); =20 // If not found on the PROG_ARRAY syscalls map, then we're filtering it: return 0; @@ -411,6 +527,9 @@ int sys_exit(struct syscall_exit_args *args) { struct syscall_exit_args exit_args; 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charset="utf-8" perf trace -p doesn't work on a syscall that's augmented(when it calls perf_event_output() in BPF). However, it does work when the syscall is unaugmented. Let's take open() as an example. open() is augmented in perf trace. Before: ``` perf $ perf trace -e open -p 3792392 ? ( ): ... [continued]: open()) = =3D -1 ENOENT (No such file or directory) ? ( ): ... [continued]: open()) = =3D -1 ENOENT (No such file or directory) ``` We can see there's no output. After: ``` perf $ perf trace -e open -p 3792392 0.000 ( 0.123 ms): a.out/3792392 open(filename: "DINGZHEN", flags: WRO= NLY) =3D -1 ENOENT (No such file or directory) 1000.398 ( 0.116 ms): a.out/3792392 open(filename: "DINGZHEN", flags: WRO= NLY) =3D -1 ENOENT (No such file or directory) ``` Reason: bpf_perf_event_output() will fail when you specify a pid in perf trace. When using perf trace -p 114, before perf_event_open(), we'll have PID =3D 114, and CPU =3D -1. This is bad for bpf-output event, because it doesn't accept output from BPF's perf_event_output(), making it fail. What is ideal is to make the PID =3D -1, everytime we need to open a bpf-output event. But PID =3D -1, and CPU =3D -1 is illegal. So we have to open bpf-output for every cpu, that is: PID =3D -1, CPU =3D 0 PID =3D -1, CPU =3D 1 PID =3D -1, CPU =3D 2 PID =3D -1, CPU =3D 3 ... This patch does just that. You can test it with this script: ``` #include #include int main() { int i1 =3D 1, i2 =3D 2, i3 =3D 3, i4 =3D 4; char s1[] =3D "DINGZHEN", s2[] =3D "XUEBAO"; while (1) { syscall(SYS_open, s1, i1, i2); sleep(1); } return 0; } ``` save, compile, run, get the pid ``` gcc open.c ./a.out # in a different window ps aux | grep a.out ``` perf trace ``` perf trace -p -e open ``` !!Note that perf trace is a little broken after this pid fix, so you can't do 'perf trace -e open ./a.out', please get pid by hand. Signed-off-by: Howard Chu Acked-by: Ian Rogers --- tools/perf/util/evlist.c | 14 +++++++++++++- tools/perf/util/evlist.h | 1 + tools/perf/util/evsel.c | 3 +++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 3a719edafc7a..d32f4f399ddd 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1063,7 +1063,7 @@ int evlist__create_maps(struct evlist *evlist, struct= target *target) if (!threads) return -1; =20 - if (target__uses_dummy_map(target)) + if (target__uses_dummy_map(target) && !evlist__has_bpf_output(evlist)) cpus =3D perf_cpu_map__new_any_cpu(); else cpus =3D perf_cpu_map__new(target->cpu_list); @@ -2556,3 +2556,15 @@ void evlist__uniquify_name(struct evlist *evlist) } } } + +bool evlist__has_bpf_output(struct evlist *evlist) +{ + struct evsel *evsel; + + evlist__for_each_entry(evlist, evsel) { + if (evsel__is_bpf_output(evsel)) + return true; + } + + return false; +} diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index cb91dc9117a2..09a6114daf8b 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -443,5 +443,6 @@ int evlist__scnprintf_evsels(struct evlist *evlist, siz= e_t size, char *bf); void evlist__check_mem_load_aux(struct evlist *evlist); void evlist__warn_user_requested_cpus(struct evlist *evlist, const char *c= pu_list); void evlist__uniquify_name(struct evlist *evlist); +bool evlist__has_bpf_output(struct evlist *evlist); =20 #endif /* __PERF_EVLIST_H */ diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index bc603193c477..0531efdf54e2 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2282,6 +2282,9 @@ static int evsel__open_cpu(struct evsel *evsel, struc= t perf_cpu_map *cpus, =20 test_attr__ready(); =20 + if (evsel__is_bpf_output(evsel)) + pid =3D -1; + /* Debug message used by test scripts */ pr_debug2_peo("sys_perf_event_open: pid %d cpu %d group_fd %d flags = %#lx", pid, perf_cpu_map__cpu(cpus, idx).cpu, group_fd, evsel->open_flags); --=20 2.45.2