If using the symbol table, symbol addresses are not being fixed up
properly, resulting in probes being placed at wrong addresses:
# perf probe do_fork
Added new event:
probe:do_fork (on do_fork)
You can now use it in all perf tools, such as:
perf record -e probe:do_fork -aR sleep 1
# cat /sys/kernel/debug/tracing/kprobe_events
p:probe/do_fork _text+635952
# printf "%x" 635952
9b430
# grep do_fork /boot/System.map
c0000000000ab430 T .do_fork
Fix by checking for ELF type ET_DYN used by ppc64 kernels.
Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
Reviewed-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ana...@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link:
http://lkml.kernel.org/r/41392bb856ef62d929995e0b61967689b7915207.1430217967.git.naveen.n....@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/arch/powerpc/Makefile | 1 +
tools/perf/arch/powerpc/util/sym-handling.c | 19 +++++++++++++++++++
tools/perf/util/symbol-elf.c | 8 ++++++--
tools/perf/util/symbol.h | 4 ++++
4 files changed, 30 insertions(+), 2 deletions(-)
create mode 100644 tools/perf/arch/powerpc/util/sym-handling.c
diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile
index 6f7782b..85d2306 100644
--- a/tools/perf/arch/powerpc/Makefile
+++ b/tools/perf/arch/powerpc/Makefile
@@ -4,3 +4,4 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/skip-callchain-idx.o
endif
LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/header.o
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/sym-handling.o
diff --git a/tools/perf/arch/powerpc/util/sym-handling.c
b/tools/perf/arch/powerpc/util/sym-handling.c
new file mode 100644
index 0000000..c9de001
--- /dev/null
+++ b/tools/perf/arch/powerpc/util/sym-handling.c
@@ -0,0 +1,19 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * Copyright (C) 2015 Naveen N. Rao, IBM Corporation
+ */
+
+#include "debug.h"
+#include "symbol.h"
+
+#ifdef HAVE_LIBELF_SUPPORT
+bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
+{
+ return ehdr.e_type == ET_EXEC ||
+ ehdr.e_type == ET_REL ||
+ ehdr.e_type == ET_DYN;
+}
+#endif
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 1e23a5b..ddb300b 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -563,6 +563,11 @@ void symsrc__destroy(struct symsrc *ss)
close(ss->fd);
}
+bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
+{
+ return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
+}
+
int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
enum dso_binary_type type)
{
@@ -628,8 +633,7 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const
char *name,
".gnu.prelink_undo",
NULL) != NULL);
} else {
- ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
- ehdr.e_type == ET_REL;
+ ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
}
ss->name = strdup(name);
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index eb2c19b..7335790 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -313,4 +313,8 @@ int compare_proc_modules(const char *from, const char *to);
int setup_list(struct strlist **list, const char *list_str,
const char *list_name);
+#ifdef HAVE_LIBELF_SUPPORT
+bool elf__needs_adjust_symbols(GElf_Ehdr ehdr);
+#endif
+
#endif /* __PERF_SYMBOL */
--
2.4.0
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