6.10-stable review patch. If anyone has any objections, please let me know.
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From: Athira Rajeev atrajeev@linux.vnet.ibm.com
[ Upstream commit b0979f008f1352a44cd3c8877e3eb8a1e3e1c6f3 ]
Perf test for perf probe of function from different CU fails as below:
./perf test -vv "test perf probe of function from different CU" 116: test perf probe of function from different CU: --- start --- test child forked, pid 2679 Failed to find symbol foo in /tmp/perf-uprobe-different-cu-sh.Msa7iy89bx/testfile Error: Failed to add events. --- Cleaning up --- "foo" does not hit any event. Error: Failed to delete events. ---- end(-1) ---- 116: test perf probe of function from different CU : FAILED!
The test does below to probe function "foo" :
# gcc -g -Og -flto -c /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile-foo.c -o /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile-foo.o # gcc -g -Og -c /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile-main.c -o /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile-main.o # gcc -g -Og -o /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile-foo.o /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile-main.o
# ./perf probe -x /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile foo Failed to find symbol foo in /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7/testfile Error: Failed to add events.
Perf probe fails to find symbol foo in the executable placed in /tmp/perf-uprobe-different-cu-sh.XniNxNEVT7
Simple reproduce:
# mktemp -d /tmp/perf-checkXXXXXXXXXX /tmp/perf-checkcWpuLRQI8j
# gcc -g -o test test.c # cp test /tmp/perf-checkcWpuLRQI8j/ # nm /tmp/perf-checkcWpuLRQI8j/test | grep foo 00000000100006bc T foo
# ./perf probe -x /tmp/perf-checkcWpuLRQI8j/test foo Failed to find symbol foo in /tmp/perf-checkcWpuLRQI8j/test Error: Failed to add events.
But it works with any files like /tmp/perf/test. Only for patterns with "/tmp/perf-", this fails.
Further debugging, commit 80d496be89ed ("perf report: Add support for profiling JIT generated code") added support for profiling JIT generated code. This patch handles dso's of form "/tmp/perf-$PID.map" .
The check used "if (strncmp(self->name, "/tmp/perf-", 10) == 0)" to match "/tmp/perf-$PID.map". With this commit, any dso in /tmp/perf- folder will be considered separately for processing (not only JIT created map files ). Fix this by changing the string pattern to check for "/tmp/perf-%d.map". Add a helper function is_perf_pid_map_name to do this check. In "struct dso", dso->long_name holds the long name of the dso file. Since the /tmp/perf-$PID.map check uses the complete name, use dso___long_name for the string name.
With the fix, # ./perf test "test perf probe of function from different CU" 117: test perf probe of function from different CU : Ok
Fixes: 56cbeacf1435 ("perf probe: Add test for regression introduced by switch to die_get_decl_file()") Signed-off-by: Athira Rajeev atrajeev@linux.vnet.ibm.com Reviewed-by: Chaitanya S Prakash chaitanyas.prakash@arm.com Reviewed-by: Adrian Hunter adrian.hunter@intel.com Cc: akanksha@linux.ibm.com Cc: kjain@linux.ibm.com Cc: maddy@linux.ibm.com Cc: disgoel@linux.vnet.ibm.com Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Namhyung Kim namhyung@kernel.org Link: https://lore.kernel.org/r/20240623064850.83720-1-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/dso.c | 12 ++++++++++++ tools/perf/util/dso.h | 4 ++++ tools/perf/util/symbol.c | 3 ++- 3 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index dde706b71da7b..2340c4f6d0c24 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -1652,3 +1652,15 @@ int dso__strerror_load(struct dso *dso, char *buf, size_t buflen) scnprintf(buf, buflen, "%s", dso_load__error_str[idx]); return 0; } + +bool perf_pid_map_tid(const char *dso_name, int *tid) +{ + return sscanf(dso_name, "/tmp/perf-%d.map", tid) == 1; +} + +bool is_perf_pid_map_name(const char *dso_name) +{ + int tid; + + return perf_pid_map_tid(dso_name, &tid); +} diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h index df2c98402af3e..d72f3b8c37f6a 100644 --- a/tools/perf/util/dso.h +++ b/tools/perf/util/dso.h @@ -809,4 +809,8 @@ void reset_fd_limit(void); u64 dso__find_global_type(struct dso *dso, u64 addr); u64 dso__findnew_global_type(struct dso *dso, u64 addr, u64 offset);
+/* Check if dso name is of format "/tmp/perf-%d.map" */ +bool perf_pid_map_tid(const char *dso_name, int *tid); +bool is_perf_pid_map_name(const char *dso_name); + #endif /* __PERF_DSO */ diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 9e5940b5bc591..aee0a4cfb3836 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1799,7 +1799,8 @@ int dso__load(struct dso *dso, struct map *map) const char *map_path = dso__long_name(dso);
mutex_lock(dso__lock(dso)); - perfmap = strncmp(dso__name(dso), "/tmp/perf-", 10) == 0; + perfmap = is_perf_pid_map_name(map_path); + if (perfmap) { if (dso__nsinfo(dso) && (dso__find_perf_map(newmapname, sizeof(newmapname),