linux-dev/tools/perf/jvmti, branch master

perf tools: Fix various typos in comments

2021-03-23T20:13:43Z

Fix ~124 single-word typos and a few spelling errors in the perf tooling code, accumulated over the years. Signed-off-by: Ingo Molnar Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20210321113734.GA248990@gmail.com Link: http://lore.kernel.org/lkml/20210323160915.GA61903@gmail.com Signed-off-by: Arnaldo Carvalho de Melo

perf jvmti: Remove redundant jitdump line table entries

2020-05-29T19:51:38Z

For each PC/BCI pair in the JVMTI compiler inlining record table, the jitdump plugin emits debug line table entries for every source line in the method preceding that BCI. Instead only emit one source line per PC/BCI pair. Reported by Ian Rogers. This reduces the .dump size for SPECjbb from ~230MB to ~40MB. Signed-off-by: Nick Gasson Acked-by: Ian Rogers Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200528054049.13662-1-nick.gasson@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf jvmti: Do not report error when missing debug information

2020-05-28T13:03:28Z

If the Java sources are compiled with -g:none to disable debug information the perf JVMTI plugin reports a lot of errors like: java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION Instead if GetLineNumberTable returns JVMTI_ERROR_ABSENT_INFORMATION simply skip emitting line number information for that method. Unlike the previous patch these errors don't affect the jitdump generation, they just generate a lot of noise. Similarly for native methods which also don't have line tables. Signed-off-by: Nick Gasson Reviewed-by: Ian Rogers Tested-by: Ian Rogers Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20200427061520.24905-3-nick.gasson@arm.com [ Moved || operator to the end of the line, not at the start of 2nd if condition ] Signed-off-by: Arnaldo Carvalho de Melo

perf jvmti: Fix jitdump for methods without debug info

2020-05-28T13:03:28Z

If a Java class is compiled with -g:none to omit debug information, the JVMTI plugin won't write jitdump entries for any method in this class and prints a lot of errors like: java: GetSourceFileName failed with JVMTI_ERROR_ABSENT_INFORMATION The call to GetSourceFileName is used to derive the file name `fn`, but this value is not actually used since commit ca58d7e64bdf ("perf jvmti: Generate correct debug information for inlined code") which moved the file name lookup into fill_source_filenames(). So the call to GetSourceFileName and related code can be safely removed. Signed-off-by: Nick Gasson Reviewed-by: Ian Rogers Tested-by: Ian Rogers Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20200427061520.24905-2-nick.gasson@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf jvmti: Link against tools/lib/ctype.h to have weak strlcpy()

2019-10-15T14:47:38Z

The build of file libperf-jvmti.so succeeds but the resulting object fails to load: # ~/linux/tools/perf/perf record -k mono -- java \ -XX:+PreserveFramePointer \ -agentpath:/root/linux/tools/perf/libperf-jvmti.so \ hog 100000 123450 Error occurred during initialization of VM Could not find agent library /root/linux/tools/perf/libperf-jvmti.so in absolute path, with error: /root/linux/tools/perf/libperf-jvmti.so: undefined symbol: _ctype Add the missing _ctype symbol into the build script. Fixes: 79743bc927f6 ("perf jvmti: Link against tools/lib/string.o to have weak strlcpy()") Signed-off-by: Thomas Richter Cc: Heiko Carstens Cc: Vasily Gorbik Link: http://lore.kernel.org/lkml/20191008093841.59387-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf jvmti: Link against tools/lib/string.o to have weak strlcpy()

2019-09-20T12:18:45Z

That is needed in systems such some S/390 distros. $ readelf -s /tmp/build/perf/jvmti/jvmti-in.o | grep strlcpy 452: 0000000000002990 125 FUNC WEAK DEFAULT 119 strlcpy $ Thanks to Jiri Olsa for fixing up my initial stab at this, I forgot how Makefiles are picky about spaces versus tabs. Reported-by: Thomas Richter Cc: Adrian Hunter Cc: Andreas Krebbel Cc: Jiri Olsa Cc: Namhyung Kim Cc: Sergey Melnikov Link: https://lkml.kernel.org/n/tip-x8vg9sffgb2t1tzqmhkrulh7@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools build: Check if gettid() is available before providing helper

2019-06-17T18:57:19Z

Laura reported that the perf build failed in fedora when we got a glibc that provides gettid(), which I reproduced using fedora rawhide with the glibc-devel-2.29.9000-26.fc31.x86_64 package. Add a feature check to avoid providing a gettid() helper in such systems. On a fedora rawhide system with this patch applied we now get: [root@7a5f55352234 perf]# grep gettid /tmp/build/perf/FEATURE-DUMP feature-gettid=1 [root@7a5f55352234 perf]# cat /tmp/build/perf/feature/test-gettid.make.output [root@7a5f55352234 perf]# ldd /tmp/build/perf/feature/test-gettid.bin linux-vdso.so.1 (0x00007ffc6b1f6000) libc.so.6 => /lib64/libc.so.6 (0x00007f04e0a74000) /lib64/ld-linux-x86-64.so.2 (0x00007f04e0c47000) [root@7a5f55352234 perf]# nm /tmp/build/perf/feature/test-gettid.bin | grep -w gettid U gettid@@GLIBC_2.30 [root@7a5f55352234 perf]# While on a fedora:29 system: [acme@quaco perf]$ grep gettid /tmp/build/perf/FEATURE-DUMP feature-gettid=0 [acme@quaco perf]$ cat /tmp/build/perf/feature/test-gettid.make.output test-gettid.c: In function ‘main’: test-gettid.c:8:9: error: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Werror=implicit-function-declaration] return gettid(); ^~~~~~ getgid cc1: all warnings being treated as errors [acme@quaco perf]$ Reported-by: Laura Abbott Tested-by: Laura Abbott Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Florian Weimer Cc: Namhyung Kim Cc: Stephane Eranian Link: https://lkml.kernel.org/n/tip-yfy3ch53agmklwu9o7rlgf9c@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf jvmti: Address gcc string overflow warning for strncpy()

2019-06-05T12:51:26Z

We are getting false positive gcc warning when we compile with gcc9 (9.1.1): CC jvmti/libjvmti.o In file included from /usr/include/string.h:494, from jvmti/libjvmti.c:5: In function ‘strncpy’, inlined from ‘copy_class_filename.constprop’ at jvmti/libjvmti.c:166:3: /usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound depends on the length of the source argument [-Werror=stringop-overflow=] 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ jvmti/libjvmti.c: In function ‘copy_class_filename.constprop’: jvmti/libjvmti.c:165:26: note: length computed here 165 | size_t file_name_len = strlen(file_name); | ^~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors As per Arnaldo's suggestion use strlcpy(), which does the same thing and keeps gcc silent. Suggested-by: Arnaldo Carvalho de Melo Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Ben Gainey Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/20190531131321.GB1281@krava Signed-off-by: Arnaldo Carvalho de Melo

perf jvmti: Separate jvmti cmlr check

2018-11-22T01:39:58Z

The Compiled Method Load Record (cmlr) is JDK specific interface to access JVM stack info. This makes the jvmti agent code not compile under another jdk, which does not support that. Separating jvmti cmlr check into special feature check, and adding HAVE_JVMTI_CMLR macro to indicate that. Mark cmlr code in jvmti/libjvmti.c with HAVE_JVMTI_CMLR, so we can compile it on system without cmlr support. This change makes the jvmti compile with java-1.8.0-ibm package. It's without the line numbers support, but the rest works. Adding NO_JVMTI_CMLR compile variable for testing. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Ben Gainey Cc: Gustavo Luiz Duarte Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/20181121154341.21521-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix undefined symbol scnprintf in libperf-jvmti.so

2018-11-05T19:28:00Z

Currently jvmti agent can not be used because function scnprintf is not present in the agent libperf-jvmti.so. As a result the JVM when using such agent to record JITed code profiling information will fail on looking up scnprintf: java: symbol lookup error: lib/libperf-jvmti.so: undefined symbol: scnprintf This commit fixes that by reverting to the use of snprintf, that can be looked up, instead of scnprintf, adding a proper check for the returned value in order to print a better error message when the jitdump file pathname is too long. Checking the returned value also helps to comply with some recent gcc versions, like gcc8, which will fail due to truncated writing checks related to the -Werror=format-truncation= flag. Signed-off-by: Gustavo Romero Acked-by: Jiri Olsa LPU-Reference: 1541117601-18937-2-git-send-email-gromero@linux.vnet.ibm.com Link: https://lkml.kernel.org/n/tip-mvpxxxy7wnzaj74cq75muw3f@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo