Messages in this thread | | | Date | Fri, 06 Jan 2012 12:42:22 -0800 | From | David Daney <> | Subject | Re: [PATCH] recordmcount: Fix handling of elf64 big-endian objects. |
| |
On 12/19/2011 07:09 PM, Steven Rostedt wrote: > On Mon, 2011-12-19 at 17:42 -0800, David Daney wrote: >> From: David Daney<david.daney@cavium.com> >> >> 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. >> > > OUCH! > > This looks like something that needs to go to stable. Let me play with > this on my PPC64 tomorrow. >
Hi Steven,
Any more feedback on this patch? Should I look for it to appear in 3.3?
Thanks, David Daney
> Thanks! > > -- Steve > >> Signed-off-by: David Daney<david.daney@cavium.com> >> --- >> scripts/recordmcount.h | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h >> index f40a6af6..54e35c1 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; >> } > >
| |