From: Ian Rogers irogers@google.com
[ Upstream commit 6d518ac7be6223811ab947897273b1bbef846180 ]
The perf jvmti agent doesn't create program headers, in this case fallback on section headers as happened previously.
Committer notes:
To test this, from a public post by Ian:
1) download a Java workload dacapo-9.12-MR1-bach.jar from https://sourceforge.net/projects/dacapobench/
2) build perf such as "make -C tools/perf O=/tmp/perf NO_LIBBFD=1" it should detect Java and create /tmp/perf/libperf-jvmti.so
3) run perf with the jvmti agent:
perf record -k 1 java -agentpath:/tmp/perf/libperf-jvmti.so -jar dacapo-9.12-MR1-bach.jar -n 10 fop
4) run perf inject:
perf inject -i perf.data -o perf-injected.data -j
5) run perf report
perf report -i perf-injected.data | grep org.apache.fop
With this patch reverted I see lots of symbols like:
0.00% java jitted-388040-4656.so [.] org.apache.fop.fo.FObj.bind(org.apache.fop.fo.PropertyList)
With the patch (2d86612aacb7805f ("perf symbol: Correct address for bss symbols")) I see lots of:
dso__load_sym_internal: failed to find program header for symbol: Lorg/apache/fop/fo/FObj;bind(Lorg/apache/fop/fo/PropertyList;)V st_value: 0x40
Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols") Reviewed-by: Leo Yan leo.yan@linaro.org Signed-off-by: Ian Rogers irogers@google.com Tested-by: Leo Yan leo.yan@linaro.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Jiri Olsa jolsa@kernel.org Cc: Leo Yan leo.yan@linaro.org Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Stephane Eranian eranian@google.com Link: http://lore.kernel.org/lkml/20220731164923.691193-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/symbol-elf.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 1cab29d45bfb..d8d79a9ec775 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1249,16 +1249,29 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
if (elf_read_program_header(syms_ss->elf, (u64)sym.st_value, &phdr)) { - pr_warning("%s: failed to find program header for " + pr_debug4("%s: failed to find program header for " "symbol: %s st_value: %#" PRIx64 "\n", __func__, elf_name, (u64)sym.st_value); - continue; + pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " + "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", + __func__, (u64)sym.st_value, (u64)shdr.sh_addr, + (u64)shdr.sh_offset); + /* + * Fail to find program header, let's rollback + * to use shdr.sh_addr and shdr.sh_offset to + * calibrate symbol's file address, though this + * is not necessary for normal C ELF file, we + * still need to handle java JIT symbols in this + * case. + */ + sym.st_value -= shdr.sh_addr - shdr.sh_offset; + } else { + pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " + "p_vaddr: %#" PRIx64 " p_offset: %#" PRIx64 "\n", + __func__, (u64)sym.st_value, (u64)phdr.p_vaddr, + (u64)phdr.p_offset); + sym.st_value -= phdr.p_vaddr - phdr.p_offset; } - pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " - "p_vaddr: %#" PRIx64 " p_offset: %#" PRIx64 "\n", - __func__, (u64)sym.st_value, (u64)phdr.p_vaddr, - (u64)phdr.p_offset); - sym.st_value -= phdr.p_vaddr - phdr.p_offset; }
demangled = demangle_sym(dso, kmodule, elf_name);