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recordmcount: Fix handling of elf64 big-endian objects.

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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.

Link: http://lkml.kernel.org/r/1324345362-12230-1-git-send-email-ddaney.cavm@gmail.com

Cc: stable@kernel.org # 3.0+
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
David Daney 2011-12-19 17:42:42 -08:00 committed by Steven Rostedt
parent 805a6af8db
commit 2e885057b7
1 changed files with 1 additions and 1 deletions
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2
scripts/recordmcount.h
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@ -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;
}