From c588d158124d5b60184fc612e551a19720720d68 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 13 Dec 2017 00:05:12 +0900 Subject: [PATCH] perf probe: Support escaped character in parser Support the special characters escaped by '\' in parser. This allows user to specify versions directly like below. ===== # ./perf probe -x /lib64/libc-2.25.so malloc_get_state\\@GLIBC_2.2.5 Added new event: probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc_get_state -aR sleep 1 ===== Or, you can use separators in source filename, e.g. ===== # ./perf probe -x /opt/test/a.out foo+bar.c:3 Semantic error :There is non-digit character in offset. Error: Command Parse Error. ===== Usually "+" in source file cause parser error, but ===== # ./perf probe -x /opt/test/a.out foo\\+bar.c:4 Added new event: probe_a:main (on @foo+bar.c:4 in /opt/test/a.out) You can now use it in all perf tools, such as: perf record -e probe_a:main -aR sleep 1 ===== escaped "\+" allows you to specify that. Signed-off-by: Masami Hiramatsu Reviewed-by: Thomas Richter Acked-by: Ravi Bangoria Cc: Paul Clarke Cc: bhargavb Cc: linux-rt-users@vger.kernel.org Link: http://lkml.kernel.org/r/151309111236.18107.5634753157435343410.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-probe.txt | 16 +++++++ tools/perf/util/probe-event.c | 58 +++++++++++++++---------- 2 files changed, 51 insertions(+), 23 deletions(-) diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt index f96382692f42..b6866a05edd2 100644 --- a/tools/perf/Documentation/perf-probe.txt +++ b/tools/perf/Documentation/perf-probe.txt @@ -182,6 +182,14 @@ Note that before using the SDT event, the target binary (on which SDT events are For details of the SDT, see below. https://sourceware.org/gdb/onlinedocs/gdb/Static-Probe-Points.html +ESCAPED CHARACTER +----------------- + +In the probe syntax, '=', '@', '+', ':' and ';' are treated as a special character. You can use a backslash ('\') to escape the special characters. +This is useful if you need to probe on a specific versioned symbols, like @GLIBC_... suffixes, or also you need to specify a source file which includes the special characters. +Note that usually single backslash is consumed by shell, so you might need to pass double backslash (\\) or wrapping with single quotes (\'AAA\@BBB'). +See EXAMPLES how it is used. + PROBE ARGUMENT -------------- Each probe argument follows below syntax. @@ -277,6 +285,14 @@ Add a USDT probe to a target process running in a different mount namespace ./perf probe --target-ns -x /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.121-0.b13.el7_3.x86_64/jre/lib/amd64/server/libjvm.so %sdt_hotspot:thread__sleep__end +Add a probe on specific versioned symbol by backslash escape + + ./perf probe -x /lib64/libc-2.25.so 'malloc_get_state\@GLIBC_2.2.5' + +Add a probe in a source file using special characters by backslash escape + + ./perf probe -x /opt/test/a.out 'foo\+bar.c:4' + SEE ALSO -------- diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 0d6c66d51939..e1dbc9821617 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -1325,27 +1325,30 @@ static int parse_perf_probe_event_name(char **arg, struct perf_probe_event *pev) { char *ptr; - ptr = strchr(*arg, ':'); + ptr = strpbrk_esc(*arg, ":"); if (ptr) { *ptr = '\0'; if (!pev->sdt && !is_c_func_name(*arg)) goto ng_name; - pev->group = strdup(*arg); + pev->group = strdup_esc(*arg); if (!pev->group) return -ENOMEM; *arg = ptr + 1; } else pev->group = NULL; - if (!pev->sdt && !is_c_func_name(*arg)) { + + pev->event = strdup_esc(*arg); + if (pev->event == NULL) + return -ENOMEM; + + if (!pev->sdt && !is_c_func_name(pev->event)) { + zfree(&pev->event); ng_name: + zfree(&pev->group); semantic_error("%s is bad for event name -it must " "follow C symbol-naming rule.\n", *arg); return -EINVAL; } - pev->event = strdup(*arg); - if (pev->event == NULL) - return -ENOMEM; - return 0; } @@ -1373,7 +1376,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev) arg++; } - ptr = strpbrk(arg, ";=@+%"); + ptr = strpbrk_esc(arg, ";=@+%"); if (pev->sdt) { if (ptr) { if (*ptr != '@') { @@ -1387,7 +1390,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev) pev->target = build_id_cache__origname(tmp); free(tmp); } else - pev->target = strdup(ptr + 1); + pev->target = strdup_esc(ptr + 1); if (!pev->target) return -ENOMEM; *ptr = '\0'; @@ -1421,13 +1424,14 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev) * * Otherwise, we consider arg to be a function specification. */ - if (!strpbrk(arg, "+@%") && (ptr = strpbrk(arg, ";:")) != NULL) { + if (!strpbrk_esc(arg, "+@%")) { + ptr = strpbrk_esc(arg, ";:"); /* This is a file spec if it includes a '.' before ; or : */ - if (memchr(arg, '.', ptr - arg)) + if (ptr && memchr(arg, '.', ptr - arg)) file_spec = true; } - ptr = strpbrk(arg, ";:+@%"); + ptr = strpbrk_esc(arg, ";:+@%"); if (ptr) { nc = *ptr; *ptr++ = '\0'; @@ -1436,7 +1440,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev) if (arg[0] == '\0') tmp = NULL; else { - tmp = strdup(arg); + tmp = strdup_esc(arg); if (tmp == NULL) return -ENOMEM; } @@ -1469,12 +1473,12 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev) arg = ptr; c = nc; if (c == ';') { /* Lazy pattern must be the last part */ - pp->lazy_line = strdup(arg); + pp->lazy_line = strdup(arg); /* let leave escapes */ if (pp->lazy_line == NULL) return -ENOMEM; break; } - ptr = strpbrk(arg, ";:+@%"); + ptr = strpbrk_esc(arg, ";:+@%"); if (ptr) { nc = *ptr; *ptr++ = '\0'; @@ -1501,7 +1505,7 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev) semantic_error("SRC@SRC is not allowed.\n"); return -EINVAL; } - pp->file = strdup(arg); + pp->file = strdup_esc(arg); if (pp->file == NULL) return -ENOMEM; break; @@ -2803,23 +2807,31 @@ static int find_probe_functions(struct map *map, char *name, struct rb_node *tmp; const char *norm, *ver; char *buf = NULL; + bool cut_version = true; if (map__load(map) < 0) return 0; + /* If user gives a version, don't cut off the version from symbols */ + if (strchr(name, '@')) + cut_version = false; + map__for_each_symbol(map, sym, tmp) { norm = arch__normalize_symbol_name(sym->name); if (!norm) continue; - /* We don't care about default symbol or not */ - ver = strchr(norm, '@'); - if (ver) { - buf = strndup(norm, ver - norm); - if (!buf) - return -ENOMEM; - norm = buf; + if (cut_version) { + /* We don't care about default symbol or not */ + ver = strchr(norm, '@'); + if (ver) { + buf = strndup(norm, ver - norm); + if (!buf) + return -ENOMEM; + norm = buf; + } } + if (strglobmatch(norm, name)) { found++; if (syms && found < probe_conf.max_probes) -- 2.34.1