[PATCH v3 5/7] perf probe/ppc64le: Fix ppc64 ABIv2 symbol decoding

From: Naveen N. Rao
Date: Tue Apr 28 2015 - 08:07:56 EST


From: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>

ppc64 ELF ABIv2 has a Global Entry Point (GEP) and a Local Entry Point
(LEP). For purposes of probing, we need the LEP - the offset to which is
encoded in st_other.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
---
Changes:
- No changes other than move to use __weak functions

tools/perf/arch/powerpc/util/sym-handling.c | 7 +++++++
tools/perf/util/symbol-elf.c | 4 ++++
tools/perf/util/symbol.h | 1 +
3 files changed, 12 insertions(+)

diff --git a/tools/perf/arch/powerpc/util/sym-handling.c b/tools/perf/arch/powerpc/util/sym-handling.c
index 2de2cc4..012a0f8 100644
--- a/tools/perf/arch/powerpc/util/sym-handling.c
+++ b/tools/perf/arch/powerpc/util/sym-handling.c
@@ -17,6 +17,13 @@ bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
ehdr.e_type == ET_REL ||
ehdr.e_type == ET_DYN;
}
+
+#if defined(_CALL_ELF) && _CALL_ELF == 2
+void arch__elf_sym_adjust(GElf_Sym *sym)
+{
+ sym->st_value += PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
+}
+#endif
#endif

#if !defined(_CALL_ELF) || _CALL_ELF != 2
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 7f5d237..9d526a5 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -776,6 +776,8 @@ static bool want_demangle(bool is_kernel_sym)
return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
}

+void __weak arch__elf_sym_adjust(GElf_Sym *sym __maybe_unused) { }
+
int dso__load_sym(struct dso *dso, struct map *map,
struct symsrc *syms_ss, struct symsrc *runtime_ss,
symbol_filter_t filter, int kmodule)
@@ -940,6 +942,8 @@ int dso__load_sym(struct dso *dso, struct map *map,
(sym.st_value & 1))
--sym.st_value;

+ arch__elf_sym_adjust(&sym);
+
if (dso->kernel || kmodule) {
char dso_name[PATH_MAX];

diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index bd50ba0..9096529 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -305,6 +305,7 @@ int setup_intlist(struct intlist **list, const char *list_str,

#ifdef HAVE_LIBELF_SUPPORT
bool elf__needs_adjust_symbols(GElf_Ehdr ehdr);
+void arch__elf_sym_adjust(GElf_Sym *sym);
#endif

#define SYMBOL_A 0
--
2.3.5

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