This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
PATCH: Properly mark 64-bit .eh_frame section on x86 as type unwind
- From: Rainer Orth <ro at CeBiTec dot Uni-Bielefeld dot DE>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Anthony Green <green at redhat dot com>, java-patches at gcc dot gnu dot org
- Date: Wed, 24 Feb 2010 15:09:25 +0100
- Subject: PATCH: Properly mark 64-bit .eh_frame section on x86 as type unwind
Several 64-bit libffi tests were failing on Solaris 11/x86:
Running target unix/-m64
FAIL: libffi.special/unwindtest.cc execution test
FAIL: libffi.special/unwindtest_ffi_call.cc execution test
Ultimately, the problem turned out to be due to libffi.so (and, as a
consequence, libgcj.so) having two .eh_frame sections:
$ elfdump -c -N.eh_frame libffi.so
Section Header[2]: sh_name: .eh_frame
sh_addr: 0x250 sh_flags: [ SHF_ALLOC ]
sh_size: 0x834 sh_type: [ SHT_AMD64_UNWIND ]
sh_offset: 0x250 sh_entsize: 0
sh_link: 0 sh_info: 0
sh_addralign: 0x8
Section Header[19]: sh_name: .eh_frame
sh_addr: 0x6d18 sh_flags: [ SHF_ALLOC ]
sh_size: 0x70 sh_type: [ SHT_PROGBITS ]
sh_offset: 0x6d18 sh_entsize: 0
sh_link: 0 sh_info: 0
sh_addralign: 0x8
This happens because the Sun ld doesn't merge sections with different
flags or types, and the .eh_frame section in src/x86/unix64.S is marked
@progbits instead of the correct @unwind.
Changing this caused the testcases above to pass, as well as several
libjava testcases that were affected, too.
The patch is trivial and works with both Sun as and gas 2.19, but I'd
first like to get confirmation that it works on the other x86_64
platforms (amd64-*-freebsd*, amd64-*-openbsd*, x86_64-*-darwin*,
x86_64-*-cygwin*, x86_64-*-mingw*), too, without needing some autoconf
test. I'm not sure which of those uses gas (which should work) and
which doesn't (probably darwin).
Ok for mainline?
Rainer
--
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University
2010-02-14 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
* src/x86/unix64.S (.eh_frame): Mark as @unwind.
diff -r 8ef90ce89af5 -r 489f27ea21f7 libffi/src/x86/unix64.S
--- a/libffi/src/x86/unix64.S Mon Feb 15 00:08:49 2010 +0100
+++ b/libffi/src/x86/unix64.S Mon Feb 15 09:04:35 2010 +0100
@@ -324,7 +324,7 @@
.LUW9:
.size ffi_closure_unix64,.-ffi_closure_unix64
- .section .eh_frame,"a",@progbits
+ .section .eh_frame,"a",@unwind
.Lframe1:
.long .LECIE1-.LSCIE1 /* CIE Length */
.LSCIE1: