[50/90] recordmcount: Fix handling of elf64 big-endian objects.
From: Greg KH <gregkh@suse.de>
Date: 2012-01-23 23:49:04
Also in:
lkml
3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Daney <redacted> 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 <redacted> 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; }