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author | David Daney <david.daney@cavium.com> | 2011-12-19 17:42:42 -0800 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-25 17:24:50 -0800 |
commit | 9d3f99878bf33d36739bd772c7dafcb1f71387fb (patch) | |
tree | ccd3f136cda3744df4bd1d67ae3c1eef5c9de56e /scripts | |
parent | 15274414badc6ef0a893454e7102f3753f2c1ccd (diff) | |
download | lwn-9d3f99878bf33d36739bd772c7dafcb1f71387fb.tar.gz lwn-9d3f99878bf33d36739bd772c7dafcb1f71387fb.zip |
recordmcount: Fix handling of elf64 big-endian objects.
commit 2e885057b7f75035f0b85e02f737891482815a81 upstream.
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
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'scripts')
-rw-r--r-- | scripts/recordmcount.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h index f40a6af6bf40..54e35c1e5948 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; } |