This is a note to let you know that I've just added the patch titled
perf probe: Find versioned symbols from map
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: perf-probe-find-versioned-symbols-from-map.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Mon Apr 9 10:16:32 CEST 2018
From: Masami Hiramatsu mhiramat@kernel.org Date: Sat, 9 Dec 2017 01:28:12 +0900 Subject: perf probe: Find versioned symbols from map
From: Masami Hiramatsu mhiramat@kernel.org
[ Upstream commit 4b3a2716dd785fabb9f6ac80c1d53cb29a88169d ]
Commit d80406453ad4 ("perf symbols: Allow user probes on versioned symbols") allows user to find default versioned symbols (with "@@") in map. However, it did not enable normal versioned symbol (with "@") for perf-probe. E.g.
===== # ./perf probe -x /lib64/libc-2.25.so malloc_get_state Failed to find symbol malloc_get_state in /usr/lib64/libc-2.25.so Error: Failed to add events. =====
This solves above issue by improving perf-probe symbol search function, as below.
===== # ./perf probe -x /lib64/libc-2.25.so malloc_get_state Added new event: probe_libc:malloc_get_state (on malloc_get_state 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
# ./perf probe -l probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so) =====
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Reviewed-by: Thomas Richter tmricht@linux.vnet.ibm.com Acked-by: Ravi Bangoria ravi.bangoria@linux.vnet.ibm.com Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Paul Clarke pc@us.ibm.com Cc: bhargavb bhargavaramudu@gmail.com Cc: linux-rt-users@vger.kernel.org Link: http://lkml.kernel.org/r/151275049269.24652.1639103455496216255.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/perf/arch/powerpc/util/sym-handling.c | 8 ++++++++ tools/perf/util/probe-event.c | 20 ++++++++++++++++++-- tools/perf/util/symbol.c | 5 +++++ tools/perf/util/symbol.h | 1 + 4 files changed, 32 insertions(+), 2 deletions(-)
--- a/tools/perf/arch/powerpc/util/sym-handling.c +++ b/tools/perf/arch/powerpc/util/sym-handling.c @@ -64,6 +64,14 @@ int arch__compare_symbol_names_n(const c
return strncmp(namea, nameb, n); } + +const char *arch__normalize_symbol_name(const char *name) +{ + /* Skip over initial dot */ + if (name && *name == '.') + name++; + return name; +} #endif
#if defined(_CALL_ELF) && _CALL_ELF == 2 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -2792,16 +2792,32 @@ static int find_probe_functions(struct m int found = 0; struct symbol *sym; struct rb_node *tmp; + const char *norm, *ver; + char *buf = NULL;
if (map__load(map) < 0) return 0;
map__for_each_symbol(map, sym, tmp) { - if (strglobmatch(sym->name, name)) { + 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 (strglobmatch(norm, name)) { found++; if (syms && found < probe_conf.max_probes) syms[found - 1] = sym; } + if (buf) + zfree(&buf); }
return found; @@ -2847,7 +2863,7 @@ static int find_probe_trace_events_from_ * same name but different addresses, this lists all the symbols. */ num_matched_functions = find_probe_functions(map, pp->function, syms); - if (num_matched_functions == 0) { + if (num_matched_functions <= 0) { pr_err("Failed to find symbol %s in %s\n", pp->function, pev->target ? : "kernel"); ret = -ENOENT; --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -94,6 +94,11 @@ static int prefix_underscores_count(cons return tail - str; }
+const char * __weak arch__normalize_symbol_name(const char *name) +{ + return name; +} + int __weak arch__compare_symbol_names(const char *namea, const char *nameb) { return strcmp(namea, nameb); --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -349,6 +349,7 @@ bool elf__needs_adjust_symbols(GElf_Ehdr void arch__sym_update(struct symbol *s, GElf_Sym *sym); #endif
+const char *arch__normalize_symbol_name(const char *name); #define SYMBOL_A 0 #define SYMBOL_B 1
Patches currently in stable-queue which might be from mhiramat@kernel.org are
queue-4.15/perf-probe-find-versioned-symbols-from-map.patch queue-4.15/perf-probe-add-warning-message-if-there-is-unexpected-event-name.patch