[PATCH 4.9 31/59] perf probe powerpc: Ignore SyS symbols irrespective of endianness

Greg Kroah-Hartman
2018-10-08T18:39:24Z

From: Sandipan Das <sandipan@linux.ibm.com>

[ Upstream commit fa694160cca6dbba17c57dc7efec5f93feaf8795 ]

This makes sure that the SyS symbols are ignored for any powerpc system,
not just the big endian ones.

Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Fixes: fb6d59423115 ("perf probe ppc: Use the right prefix when ignoring SyS symbols on ppc")
Link: http://lkml.kernel.org/r/20180828090848.1914-1-sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/perf/arch/powerpc/util/sym-handling.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/tools/perf/arch/powerpc/util/sym-handling.c
+++ b/tools/perf/arch/powerpc/util/sym-handling.c
@@ -21,15 +21,16 @@ bool elf__needs_adjust_symbols(GElf_Ehdr

#endif

-#if !defined(_CALL_ELF) || _CALL_ELF != 2
int arch__choose_best_symbol(struct symbol *syma,
struct symbol *symb __maybe_unused)
{
char *sym = syma->name;

+#if !defined(_CALL_ELF) || _CALL_ELF != 2
/* Skip over any initial dot */
if (*sym == '.')
sym++;
+#endif

/* Avoid "SyS" kernel syscall aliases */
if (strlen(sym) >= 3 && !strncmp(sym, "SyS", 3))
@@ -40,6 +41,7 @@ int arch__choose_best_symbol(struct symb
return SYMBOL_A;
}

+#if !defined(_CALL_ELF) || _CALL_ELF != 2
/* Allow matching against dot variants */
int arch__compare_symbol_names(const char *namea, const char *nameb)
{