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* perf jit: Generate .eh_frame/.eh_frame_hdr in DSOStefano Sanfilippo2016-10-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the jit_buf_desc contains unwinding information, it is emitted as eh_frame unwinding sections in the DSOs generated by perf inject. The unwinding information is required to unwind of JITed code which do not maintain the frame pointer register during function calls. It can be emitted by V8 / Chromium when the --perf_prof_unwinding_info is passed to V8. The eh_frame and eh_frame_hdr sections are emitted immediately after the .text. The .eh_frame is aligned at a 8-byte boundary, and .eh_frame_hdr at a 4-byte one. Since size of the .eh_frame is required to be a multiple of the word size, which means there will never be additional padding between it and the .eh_frame_hdr on machines where the word size is 4 or 8 bytes. However, additional padding might be inserted between .text and .eh_frame to reach the correct alignment, which will always be 8 bytes, also on 32bit machines. The reasoning behind this choice is that 4 extra bytes of padding worst case are not a large cost for the advantage of removing word-size dependent offset calculations when emitting the jitdump. Signed-off-by: Stefano Sanfilippo <ssanfilippo@chromium.org> Signed-off-by: Ross McIlroy <rmcilroy@chromium.org> Reviewed-by: Stephane Eranian <eranian@google.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1476356383-30100-8-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf jit: Enable jitdump support without dwarfMaciej Debski2016-10-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | This patch modifies the build dependencies on the jitdump support in perf. As it stands jitdump was wrongfully made dependent 100% on using DWARF. However, the dwarf dependency, only exist if generating the source line table in genelf_debug.c. The rest of the support does not need DWARF. This patch removes the dependency on DWARF for the entire jitdump support. It keeps it only for the genelf_debug.c support. Signed-off-by: Maciej Debski <maciejd@google.com> Reviewed-by: Stephane Eranian <eranian@google.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1476356383-30100-3-git-send-email-eranian@google.com Fixes: e12b202f8fb9 ("perf jitdump: Build only on supported archs") [ Make it build only if NO_LIBELF isn't defined, as jitdump.o will only be built in that case ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf jit: genelf makes assumptions about endianAnton Blanchard2016-03-301-14/+10
| | | | | | | | | | | | | | | | | | | | | Commit 9b07e27f88b9 ("perf inject: Add jitdump mmap injection support") incorrectly assumed that PowerPC is big endian only. Simplify things by consolidating the define of GEN_ELF_ENDIAN and checking for __BYTE_ORDER == __BIG_ENDIAN. The PowerPC checks were also incorrect, they do not match what gcc emits. We should first look for __powerpc64__, then __powerpc__. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Carl Love <cel@us.ibm.com> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Fixes: 9b07e27f88b9 ("perf inject: Add jitdump mmap injection support") Link: http://lkml.kernel.org/r/20160329175944.33a211cc@kryten Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Remove needless 'extern' from function prototypesArnaldo Carvalho de Melo2016-03-231-5/+3
| | | | | | | | | Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-w246stf7ponfamclsai6b9zo@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf jit: add source line info supportStephane Eranian2016-02-051-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds source line information support to perf for jitted code. The source line info must be emitted by the runtime, such as JVMTI. Perf injects extract the source line info from the jitdump file and adds the corresponding .debug_lines section in the ELF image generated for each jitted function. The source line enables matching any address in the profile with a source file and line number. The improvement is visible in perf annotate with the source code displayed alongside the assembly code. The dwarf code leverages the support from OProfile which is also released under GPLv2. Copyright 2007 OProfile authors. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Carl Love <cel@us.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John McCutchan <johnmccutchan@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sonny Rao <sonnyrao@chromium.org> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1448874143-7269-5-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf inject: Add jitdump mmap injection supportStephane Eranian2016-02-051-0/+63
This patch adds a --jit/-j option to perf inject. This options injects MMAP records into the perf.data file to cover the jitted code mmaps. It also emits ELF images for each function in the jidump file. Those images are created where the jitdump file is. The MMAP records point to that location as well. Typical flow: $ perf record -k mono -- java -agentpath:libpjvmti.so java_class $ perf inject --jit -i perf.data -o perf.data.jitted $ perf report -i perf.data.jitted Note that jitdump.h support is not limited to Java, it works with any jitted environment modified to emit the jitdump file format, include those where code can be jitted multiple times and moved around. The jitdump.h format is adapted from the Oprofile project. The genelf.c (ELF binary generation) depends on MD5 hash encoding for the buildid. To enable this, libssl-dev must be installed. If not, then genelf.c defaults to using urandom to generate the buildid, which is not ideal. The Makefile auto-detects the presence on libssl-dev. This version mmaps the jitdump file to create a marker MMAP record in the perf.data file. The marker is used to detect jitdump and cause perf inject to inject the jitted mmaps and generate ELF images for jitted functions. In V8, the following fixes and changes were made among other things: - the jidump header format include a new flags field to be used to carry information about the configuration of the runtime agent. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - Fix mmap pgoff: MMAP event pgoff must be the offset within the ELF file at which the code resides. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - Fix ELF virtual addresses: perf tools expect the ELF virtual addresses of dynamic objects to match the file offset. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - JIT MMAP injection does not obey finished_round semantics. JIT MMAP injection injects all MMAP events in one go, so it does not obey finished_round semantics, so drop the finished_round events from the output perf.data file. Contributed by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Carl Love <cel@us.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John McCutchan <johnmccutchan@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sonny Rao <sonnyrao@chromium.org> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1448874143-7269-3-git-send-email-eranian@google.com [ Moved inject.build_ids ordering bits to a separate patch, fixed the NO_LIBELF=1 build ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>