Messages in this thread Patch in this message | | | Date | Sun, 31 Jul 2022 09:49:23 -0700 | Subject | [PATCH] perf symbol: Fail to read phdr workaround | From | Ian Rogers <> |
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The perf jvmti agent doesn't create program headers, in this case fallback on section headers as happened previously.
Fixes: 882528d2e776 ("perf symbol: Skip symbols if SHF_ALLOC flag is not set") Signed-off-by: Ian Rogers <irogers@google.com> --- 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 b3be5b1d9dbb..75bec32d4f57 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1305,16 +1305,29 @@ dso__load_sym_internal(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); -- 2.37.1.455.g008518b4e5-goog
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