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Subject[PATCH] recordmcount: Fix handling of elf64 big-endian objects.
Date
From: David Daney <david.daney@cavium.com>

In ELF64, the sh_flags field is 64-bits wide. recordmcount was
erroneously treating it as a 32-bit wide field. For little endian
objects this works because the flags of interest (SHF_EXECINSTR)
reside in the lower 32 bits of the word, and you get the same result
with either a 32-bit or 64-bit read. Big endian objects on the
other hand do not work at all with this error.

The fix: Correctly treat sh_flags as 64-bits wide in elf64 objects.

The symptom I observed was that my
__start_mcount_loc..__stop_mcount_loc was empty even though ftrace
function tracing was enabled.

Signed-off-by: David Daney <david.daney@cavium.com>
---
scripts/recordmcount.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
index f40a6af6..54e35c1 100644
--- a/scripts/recordmcount.h
+++ b/scripts/recordmcount.h
@@ -462,7 +462,7 @@ __has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
succeed_file();
}
if (w(txthdr->sh_type) != SHT_PROGBITS ||
- !(w(txthdr->sh_flags) & SHF_EXECINSTR))
+ !(_w(txthdr->sh_flags) & SHF_EXECINSTR))
return NULL;
return txtname;
}
--
1.7.2.3


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