File perf-map-no-need-to-adjust-the-long-name-of-modules.patch of Package perf
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1
From: Arnaldo Carvalho de Melo <acme@redhat.com>2
Date: Thu, 14 Nov 2019 10:46:45 -03003
Subject: perf map: No need to adjust the long name of modules4
Git-commit: f068435d9bb2d825d59e3c101bc579f09315ee015
Patch-mainline: v5.5-rc16
References: git-fixes7
8
At some point in the past we needed to make sure we would get the long9
name of modules and not just what we get from /proc/modules, but that10
need, as described in the cset that introduced the adjustment function:11
12
Fixes: c03d5184f0e9 ("perf machine: Adjust dso->long_name for offline module")13
14
Without using the buildid-cache:15
16
# lsmod | grep trusted17
# insmod trusted.ko18
# lsmod | grep trusted19
trusted 24576 020
# strace -e open,openat perf probe -m ./trusted.ko key_seal |& grep trusted21
openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 422
openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 723
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 324
openat(AT_FDCWD, "/root/.debug/root/trusted.ko/dd3d355d567394d540f527e093e0f64b95879584/probes", O_RDWR|O_CREAT, 0644) = 325
openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)26
openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)27
openat(AT_FDCWD, "/root/.debug/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)28
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 329
openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)30
openat(AT_FDCWD, ".debug/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)31
openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)32
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 333
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 334
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 435
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 336
probe:key_seal (on key_seal in trusted)37
# perf probe -l38
probe:key_seal (on key_seal in trusted)39
#40
41
No attempt at opening '[trusted]'.42
43
Now using the build-id cache:44
45
# rmmod trusted46
# perf buildid-cache --add ./trusted.ko47
# insmod trusted.ko48
# strace -e open,openat perf probe -m ./trusted.ko key_seal |& grep trusted49
openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 450
openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 751
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 352
openat(AT_FDCWD, "/root/.debug/root/trusted.ko/dd3d355d567394d540f527e093e0f64b95879584/probes", O_RDWR|O_CREAT, 0644) = 353
openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)54
openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)55
openat(AT_FDCWD, "/root/.debug/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)56
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 357
openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)58
openat(AT_FDCWD, ".debug/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)59
openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)60
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 361
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 362
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 463
openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 364
#65
66
Again, no attempt at reading '[trusted]'.67
68
Finally, adding a probe to that function and then using:69
70
[root@quaco ~]# perf trace -e probe_perf:*/max-stack=16/ --max-events=271
0.000 perf/13456 probe_perf:dso__adjust_kmod_long_name(__probe_ip: 5492263)72
dso__adjust_kmod_long_name (/home/acme/bin/perf)73
machine__process_kernel_mmap_event (/home/acme/bin/perf)74
machine__process_mmap_event (/home/acme/bin/perf)75
perf_event__process_mmap (/home/acme/bin/perf)76
machines__deliver_event (/home/acme/bin/perf)77
perf_session__deliver_event (/home/acme/bin/perf)78
perf_session__process_event (/home/acme/bin/perf)79
process_simple (/home/acme/bin/perf)80
reader__process_events (/home/acme/bin/perf)81
__perf_session__process_events (/home/acme/bin/perf)82
perf_session__process_events (/home/acme/bin/perf)83
process_buildids (/home/acme/bin/perf)84
record__finish_output (/home/acme/bin/perf)85
__cmd_record (/home/acme/bin/perf)86
cmd_record (/home/acme/bin/perf)87
run_builtin (/home/acme/bin/perf)88
0.055 perf/13456 probe_perf:dso__adjust_kmod_long_name(__probe_ip: 5492263)89
dso__adjust_kmod_long_name (/home/acme/bin/perf)90
machine__process_kernel_mmap_event (/home/acme/bin/perf)91
machine__process_mmap_event (/home/acme/bin/perf)92
perf_event__process_mmap (/home/acme/bin/perf)93
machines__deliver_event (/home/acme/bin/perf)94
perf_session__deliver_event (/home/acme/bin/perf)95
perf_session__process_event (/home/acme/bin/perf)96
process_simple (/home/acme/bin/perf)97
reader__process_events (/home/acme/bin/perf)98
__perf_session__process_events (/home/acme/bin/perf)99
perf_session__process_events (/home/acme/bin/perf)100
process_buildids (/home/acme/bin/perf)101
record__finish_output (/home/acme/bin/perf)102
__cmd_record (/home/acme/bin/perf)103
cmd_record (/home/acme/bin/perf)104
run_builtin (/home/acme/bin/perf)105
#106
107
This was the only path I could find using the perf tools that reach at this108
function, then as of november/2019, if we put a probe in the line where the109
actuall setting of the dso->long_name is done:110
111
# perf trace -e probe_perf:*112
^C[root@quaco ~]113
# perf stat -e probe_perf:* -I 2000114
2.000404265 0 probe_perf:dso__adjust_kmod_long_name115
4.001142200 0 probe_perf:dso__adjust_kmod_long_name116
6.001704120 0 probe_perf:dso__adjust_kmod_long_name117
8.002398316 0 probe_perf:dso__adjust_kmod_long_name118
10.002984010 0 probe_perf:dso__adjust_kmod_long_name119
12.003597851 0 probe_perf:dso__adjust_kmod_long_name120
14.004113303 0 probe_perf:dso__adjust_kmod_long_name121
16.004582773 0 probe_perf:dso__adjust_kmod_long_name122
18.005176373 0 probe_perf:dso__adjust_kmod_long_name123
20.005801605 0 probe_perf:dso__adjust_kmod_long_name124
22.006467540 0 probe_perf:dso__adjust_kmod_long_name125
^C 23.683261941 0 probe_perf:dso__adjust_kmod_long_name126
127
#128
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Its not being used at all.130
131
To further test this I used kvm.ko as the offline module, i.e. removed132
if from the buildid-cache by nuking it completely (rm -rf ~/.debug) and133
moved it from the normal kernel distro path, removed the modules, stoped134
the kvm guest, and then installed it manually, etc.135
136
# rmmod kvm-intel137
# rmmod kvm138
# lsmod | grep kvm139
# modprobe kvm-intel140
modprobe: ERROR: ctx=0x55d3b1722260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory141
modprobe: ERROR: ctx=0x55d3b1722260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory142
modprobe: ERROR: could not insert 'kvm_intel': Unknown symbol in module, or unknown parameter (see dmesg)143
# insmod ./kvm.ko144
# modprobe kvm-intel145
modprobe: ERROR: ctx=0x562f34026260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory146
modprobe: ERROR: ctx=0x562f34026260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory147
# lsmod | grep kvm148
kvm_intel 299008 0149
kvm 765952 1 kvm_intel150
irqbypass 16384 1 kvm151
#152
# perf probe -x ~/bin/perf machine__findnew_module_map:12 mname=m.name:string filename=filename:string 'dso_long_name=map->dso->long_name:string' 'dso_name=map->dso->name:string'153
# perf probe -l154
probe_perf:machine__findnew_module_map (on machine__findnew_module_map:12@util/machine.c in /home/acme/bin/perf with mname filename dso_long_name dso_name)155
# perf record156
^C[ perf record: Woken up 2 times to write data ]157
[ perf record: Captured and wrote 3.416 MB perf.data (33956 samples) ]158
# perf trace -e probe_perf:machine*159
<SNIP>160
6.322 perf/23099 probe_perf:machine__findnew_module_map(__probe_ip: 5492493, mname: "[salsa20_generic]", filename: "/lib/modules/5.3.8-200.fc30.x86_64/kernel/crypto/salsa20_generic.ko.xz", dso_long_name: "/lib/modules/5.3.8-200.fc30.x86_64/kernel/crypto/salsa20_generic.ko.xz", dso_name: "[salsa20_generic]")161
6.375 perf/23099 probe_perf:machine__findnew_module_map(__probe_ip: 5492493, mname: "[kvm]", filename: "[kvm]", dso_long_name: "[kvm]", dso_name: "[kvm]")162
<SNIP>163
164
The filename doesn't come with the path, no point in trying to set the dso->long_name.165
166
[root@quaco ~]# strace -e open,openat perf probe -m ./kvm.ko kvm_apic_local_deliver |& egrep 'open.*kvm'167
openat(AT_FDCWD, "/sys/module/kvm_intel/notes/.note.gnu.build-id", O_RDONLY) = 4168
openat(AT_FDCWD, "/sys/module/kvm/notes/.note.gnu.build-id", O_RDONLY) = 4169
openat(AT_FDCWD, "/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 7170
openat(AT_FDCWD, "/sys/module/kvm_intel/notes/.note.gnu.build-id", O_RDONLY) = 8171
openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3172
openat(AT_FDCWD, "/root/.debug/root/kvm.ko/5955f426cb93f03f30f3e876814be2db80ab0b55/probes", O_RDWR|O_CREAT, 0644) = 3173
openat(AT_FDCWD, "/usr/lib/debug/root/kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)174
openat(AT_FDCWD, "/usr/lib/debug/root/kvm.ko", O_RDONLY) = -1 ENOENT (No such file or directory)175
openat(AT_FDCWD, "/root/.debug/kvm.ko", O_RDONLY) = -1 ENOENT (No such file or directory)176
openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3177
openat(AT_FDCWD, "kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)178
openat(AT_FDCWD, ".debug/kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)179
openat(AT_FDCWD, "kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)180
openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3181
openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3182
openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 4183
openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3184
[root@quaco ~]#185
186
Cc: Adrian Hunter <adrian.hunter@intel.com>187
Cc: Andi Kleen <ak@linux.intel.com>188
Cc: Jiri Olsa <jolsa@kernel.org>189
Cc: Namhyung Kim <namhyung@kernel.org>190
Cc: Wang Nan <wangnan0@huawei.com>191
Link: https://lkml.kernel.org/n/tip-jlfew3lyb24d58egrp0o72o2@git.kernel.org192
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>193
Signed-off-by: Tony Jones <tonyj@suse.de>194
---195
tools/perf/util/machine.c | 27 +--------------------------196
1 file changed, 1 insertion(+), 26 deletions(-)197
198
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c199
index 6a0f5c25ce3e..6804c8247782 100644200
--- a/tools/perf/util/machine.c201
+++ b/tools/perf/util/machine.c202
203
return machine__process_ksymbol_register(machine, event, sample);204
}205
206
-static void dso__adjust_kmod_long_name(struct dso *dso, const char *filename)207
-{208
- const char *dup_filename;209
-210
- if (!filename || !dso || !dso->long_name)211
- return;212
- if (dso->long_name[0] != '[')213
- return;214
- if (!strchr(filename, '/'))215
- return;216
-217
- dup_filename = strdup(filename);218
- if (!dup_filename)219
- return;220
-221
- dso__set_long_name(dso, dup_filename, true);222
-}223
-224
struct map *machine__findnew_module_map(struct machine *machine, u64 start,225
const char *filename)226
{227
228
return NULL;229
230
map = map_groups__find_by_name(&machine->kmaps, m.name);231
- if (map) {232
- /*233
- * If the map's dso is an offline module, give dso__load()234
- * a chance to find the file path of that module by fixing235
- * long_name.236
- */237
- dso__adjust_kmod_long_name(map->dso, filename);238
+ if (map)239
goto out;240
- }241
242
dso = machine__findnew_module_dso(machine, &m, filename);243
if (dso == NULL)244
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