[PATCH v3 1/6] perf symbols: Fix broken ELF_C_READ_MMAP fallback guard

[Alireza Haghdoost via B4 Relay <devnull+haghdoost.uber.com@kernel.org>]

From: Alireza Haghdoost <haghdoost@uber.com>

Commit 22dd1ac91a77 ("tools: Remove feature-libelf-mmap feature
detection") replaced perf's compile-time feature test with an #ifdef on
ELF_C_READ_MMAP. ELF_C_READ_MMAP is an Elf_Cmd enumerator rather than a
preprocessor macro, so the condition is always false and perf silently
uses ELF_C_READ.

Perf already requires a sufficiently recent elfutils version that
provides ELF_C_READ_MMAP. Use the enumerator directly instead of
restoring a feature probe or retaining an unreachable fallback.

Fixes: 22dd1ac91a77 ("tools: Remove feature-libelf-mmap feature detection")
Signed-off-by: Alireza Haghdoost <haghdoost@uber.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/symbol.h | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index d0bac824c79c..46b1649c64fc 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -57,15 +57,7 @@ static inline bool is_livepatch_symbol(const char *str)
 	return strstarts(str, KLP_SYM_PREFIX);
 }
 
-/*
- * libelf 0.8.x and earlier do not support ELF_C_READ_MMAP;
- * for newer versions we can use mmap to reduce memory usage:
- */
-#ifdef ELF_C_READ_MMAP
-# define PERF_ELF_C_READ_MMAP ELF_C_READ_MMAP
-#else
-# define PERF_ELF_C_READ_MMAP ELF_C_READ
-#endif
+#define PERF_ELF_C_READ_MMAP ELF_C_READ_MMAP
 
 #ifdef HAVE_LIBELF_SUPPORT
 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,

-- 
Git-157)