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Re: [PATCH] Fix localplt check for GNU_IFUNC
- From: Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Date: Tue, 25 Mar 2014 15:08:14 -0300
- Subject: Re: [PATCH] Fix localplt check for GNU_IFUNC
- Authentication-results: sourceware.org; auth=none
- References: <531B63DE dot 5090803 at linux dot vnet dot ibm dot com> <5329E65A dot 5010703 at redhat dot com> <5329F9F2 dot 6060900 at linux dot vnet dot ibm dot com> <20140321203357 dot 40883744AC at topped-with-meat dot com>
On 21-03-2014 17:33, Roland McGrath wrote:
> You need to double-check back to the oldest binutils version that we
> support for building libc (>=2.20) that had STT_GNU_IFUNC support (from
> NEWS looks like 2.20 itself did have it) to ensure that the script handles
> the output from the readelf in all the intervening binutils releases.
> If it's verified that the modified script works with all those versions of
> readelf, then it looks fine.
>
I just check against 2.20.1.20101209, 2.21.1.20110925, 2.22.0.20120801, 2.23.2.20130919,
and 2.24.0.20140325 'readelf -W -S -d -r' against a x86_64 and PowerPC64 build by generating
the jmprel files and all generate the same output for both archs.
I also check with wrong IFUNC usage code change on both archs to see if the script is now
capable to detect them:
* PowerPC64:
diff --git a/sysdeps/powerpc/powerpc64/power7/strncat.S b/sysdeps/powerpc/powerpc64/power7/strncat.S
index 1a1a95e..23861f6 100644
--- a/sysdeps/powerpc/powerpc64/power7/strncat.S
+++ b/sysdeps/powerpc/powerpc64/power7/strncat.S
@@ -69,7 +69,7 @@ EALIGN(STRNCAT, 4, 0)
beq cr0,L(done)
mr r31, r4 /* Save "s2" in r31 from r4. */
- bl STRLEN /* Call optimized strlen on s1; goto
+ bl strlen /* Call optimized strlen on s1; goto
end of s1. */
nop
cmpldi cr7, r29, 7 /* If s2 is <=7 process
* X86_64:
diff --git a/sysdeps/x86_64/multiarch/strcat-ssse3.S b/sysdeps/x86_64/multiarch/strcat-ssse3.S
index fde7b90..98fd69c 100644
--- a/sysdeps/x86_64/multiarch/strcat-ssse3.S
+++ b/sysdeps/x86_64/multiarch/strcat-ssse3.S
@@ -37,6 +37,8 @@ ENTRY (STRCAT)
/* Inline corresponding strlen file, temporary until new strcpy
implementation gets merged. */
+ call strstr
+
xor %eax, %eax
cmpb $0, (%rdi)
jz L(exit_tail0)
And both cases all readelf test correctly shows the wrong PLT cases. Ok to commit?