From b223564fe122cae9183e98c7598381f3b52ce763 Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Wed, 13 Nov 2024 09:21:21 +0900 Subject: [PATCH] perf probe: Replace unacceptable characters when generating event name Replace unacceptable characters with '_' when generating event name from the probing function name. This is not for a C program. For the a C program, it will continue to remove suffixes. Note that this language checking depends on the debuginfo. So without the debuginfo, perf probe will always replaces unacceptable characters with '_'. For example. $ ./perf probe -x cro3 -D \"cro3::cmd::servo::run_show\" p:probe_cro3/cro3_cmd_servo_run_show /work/cro3/target/x86_64-unknown-linux-gnu/debug/cro3:0x197530 $ ./perf probe -x /work/go/example/outyet/main -D 'main.(*Server).poll' p:probe_main/main_Server_poll /work/go/example/outyet/main:0x353040 Signed-off-by: Masami Hiramatsu Cc: Alexander Lobakin Cc: Dima Kogan Cc: Ian Rogers Cc: Ingo Molnar Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Przemek Kitszel Link: https://lore.kernel.org/r/173145728160.2747044.18089011235495186810.stgit@mhiramat.roam.corp.google.com [ Removed some extra tabs in the new struct fields ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 32 +++++++++++++++++++++++++------- tools/perf/util/probe-event.h | 1 + tools/perf/util/probe-finder.c | 15 +++++++++++++++ tools/perf/util/probe-finder.h | 5 +++++ 4 files changed, 46 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 6d51a4c98ad7..aa4a3aee677d 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -2775,7 +2775,7 @@ int show_perf_probe_events(struct strfilter *filter) static int get_new_event_name(char *buf, size_t len, const char *base, struct strlist *namelist, bool ret_event, - bool allow_suffix) + bool allow_suffix, bool not_C_symname) { int i, ret; char *p, *nbase; @@ -2786,10 +2786,24 @@ static int get_new_event_name(char *buf, size_t len, const char *base, if (!nbase) return -ENOMEM; - /* Cut off the dot suffixes (e.g. .const, .isra) and version suffixes */ - p = strpbrk(nbase, ".@"); - if (p && p != nbase) - *p = '\0'; + if (not_C_symname) { + /* Replace non-alnum with '_' */ + char *s, *d; + + s = d = nbase; + do { + if (*s && !isalnum(*s)) { + if (d != nbase && *(d - 1) != '_') + *d++ = '_'; + } else + *d++ = *s; + } while (*s++); + } else { + /* Cut off the dot suffixes (e.g. .const, .isra) and version suffixes */ + p = strpbrk(nbase, ".@"); + if (p && p != nbase) + *p = '\0'; + } /* Try no suffix number */ ret = e_snprintf(buf, len, "%s%s", nbase, ret_event ? "__return" : ""); @@ -2884,6 +2898,7 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev, bool allow_suffix) { const char *event, *group; + bool not_C_symname = true; char buf[MAX_EVENT_NAME_LEN]; int ret; @@ -2898,8 +2913,10 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev, (strncmp(pev->point.function, "0x", 2) != 0) && !strisglob(pev->point.function)) event = pev->point.function; - else + else { event = tev->point.realname; + not_C_symname = !is_known_C_lang(tev->lang); + } } if (pev->group && !pev->sdt) group = pev->group; @@ -2916,7 +2933,8 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev, /* Get an unused new event name */ ret = get_new_event_name(buf, sizeof(buf), event, namelist, - tev->point.retprobe, allow_suffix); + tev->point.retprobe, allow_suffix, + not_C_symname); if (ret < 0) return ret; diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index 61a5f4ff4e9c..71905ede0207 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -58,6 +58,7 @@ struct probe_trace_event { char *group; /* Group name */ struct probe_trace_point point; /* Trace point */ int nargs; /* Number of args */ + int lang; /* Dwarf language code */ bool uprobes; /* uprobes only */ struct probe_trace_arg *args; /* Arguments */ }; diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 7f2ee0cb43ca..1e769b68da37 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -35,6 +35,19 @@ /* Kprobe tracer basic type is up to u64 */ #define MAX_BASIC_TYPE_BITS 64 +bool is_known_C_lang(int lang) +{ + switch (lang) { + case DW_LANG_C89: + case DW_LANG_C: + case DW_LANG_C99: + case DW_LANG_C11: + return true; + default: + return false; + } +} + /* * Probe finder related functions */ @@ -1270,6 +1283,8 @@ static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf) goto end; } + tev->lang = dwarf_srclang(dwarf_diecu(sc_die, &pf->cu_die, NULL, NULL)); + pr_debug("Probe point found: %s+%lu\n", tev->point.symbol, tev->point.offset); diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h index be7b46ea2460..dcf6cc1e1cbe 100644 --- a/tools/perf/util/probe-finder.h +++ b/tools/perf/util/probe-finder.h @@ -26,6 +26,9 @@ static inline int is_c_varname(const char *name) #include "dwarf-aux.h" #include "debuginfo.h" +/* Check the language code is known C */ +bool is_known_C_lang(int lang); + /* Find probe_trace_events specified by perf_probe_event from debuginfo */ int debuginfo__find_trace_events(struct debuginfo *dbg, struct perf_probe_event *pev, @@ -103,6 +106,8 @@ struct line_finder { int found; }; +#else +#define is_known_C_lang(lang) (false) #endif /* HAVE_LIBDW_SUPPORT */ #endif /*_PROBE_FINDER_H */ -- 2.50.1