| | Date | Mon, 23 Jan 2012 18:34:53 -0800 | | From | Greg KH <> | | Subject | [073/129] recordmcount: Fix handling of elf64 big-endian objects. |
| |
3.2-stable review patch. If anyone has any objections, please let me know.
------------------ Content-Length: 1330 Lines: 39 From: David Daney <david.daney@cavium.com>
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>
--- scripts/recordmcount.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/scripts/recordmcount.h +++ b/scripts/recordmcount.h @@ -462,7 +462,7 @@ __has_rel_mcount(Elf_Shdr const *const r 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; }
|