| From 2e885057b7f75035f0b85e02f737891482815a81 Mon Sep 17 00:00:00 2001 |
| From: David Daney <david.daney@cavium.com> |
| Date: Mon, 19 Dec 2011 17:42:42 -0800 |
| Subject: recordmcount: Fix handling of elf64 big-endian objects. |
| |
| 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; |
| } |
