[Qemu-devel] [PATCH] Fix missing symbols in .rela.plt sections

[Qemu-devel] [PATCH] Fix missing symbols in .rela.plt sections

[Loïc Minier]

[-- Attachment #1: Type: text/plain, Size: 2707 bytes --]

        Hi there,

 Static builds of qemu on x86-64 (and probably i386) fail with:
gcc -I/home/lool/git/savannah/qemu/slirp -Werror -m64 -Wold-style-definition -Wold-style-declaration -I. -I/home/lool/git/savannah/qemu -U_FORTIFY_SOURCE -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wall -Wundef -Wendif-labels -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing  -I/home/lool/git/savannah/qemu/fpu -I/home/lool/git/savannah/qemu/tcg -I/home/lool/git/savannah/qemu/tcg/x86_64  -I.. -I/home/lool/git/savannah/qemu/target-arm -DNEED_CPU_H -I/home/lool/git/savannah/qemu/linux-user -I/home/lool/git/savannah/qemu/linux-user/arm -O2 -g  -static -Wl,--warn-common -m64 -g  -Wl,-T../config-host.ld -Wl,-T,/home/lool/git/savannah/qemu/x86_64.ld  -o qemu-arm main.o syscall.o strace.o mmap.o signal.o thunk.o elfload.o linuxload.o uaccess.o gdbstub.o flatload.o gdbstub-xml.o nwfpe/fpa11.o nwfpe/fpa11_cpdo.o nwfpe/fpa11_cpdt.o nwfpe/fpa11_cprt.o nwfpe/fpopcode.o nwfpe/single_cpdo.o nwfpe/double_cpdo.o nwfpe/extended_cpdo.o arm-semi.o -Wl,--whole-archive ../libuser/libuser.a libqemu.a -Wl,--no-whole-archive -lrt -lpthread  -lm
/usr/lib/gcc/x86_64-linux-gnu/4.4.3/../../../../lib/libc.a(elf-init.o): In function `__libc_csu_irel':
(.text+0xd4): undefined reference to `__rela_iplt_end'
/usr/lib/gcc/x86_64-linux-gnu/4.4.3/../../../../lib/libc.a(elf-init.o): In function `__libc_csu_irel':
(.text+0xe5): undefined reference to `__rela_iplt_start'
/usr/lib/gcc/x86_64-linux-gnu/4.4.3/../../../../lib/libc.a(elf-init.o): In function `__libc_csu_irel':
(.text+0x100): undefined reference to `__rela_iplt_start'
/usr/lib/gcc/x86_64-linux-gnu/4.4.3/../../../../lib/libc.a(elf-init.o): In function `__libc_csu_irel':
(.text+0x10a): undefined reference to `__rela_iplt_start'
/usr/lib/gcc/x86_64-linux-gnu/4.4.3/../../../../lib/libc.a(elf-init.o): In function `__libc_csu_irel':
(.text+0x10f): undefined reference to `__rela_iplt_start'
/usr/lib/gcc/x86_64-linux-gnu/4.4.3/../../../../lib/libc.a(elf-init.o): In function `__libc_csu_irel':
(.text+0x114): undefined reference to `__rela_iplt_start'
collect2: ld returned 1 exit status

 This is due to changes in binutils + glibc, qemu's linker script need
 to be adjusted to include these symbols.  qemu's scripts weren't
 copying the .rela.iplt section at all, so I included this section and
 the __rela_iplt_start and __rela_iplt_end arount it.

 Tested by building qemu in static and shared mode for the
 arm-softmmu,i386-softmmu,x86_64-softmmu,arm-linux-user,i386-linux-user,x86_64-linux-user
 target-list; I also ran qemu for almost all combinations.

   Thanks,
-- 
Loïc Minier

[-- Attachment #2: 0001-Fix-missing-symbols-in-.rela.plt-sections.patch --]
[-- Type: text/x-diff, Size: 1882 bytes --]

>From ac0fe6dabaf05bf434e9c57d4f9b61d73f660e3c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Minier?= <lool@dooz.org>
Date: Sun, 17 Jan 2010 12:09:38 +0100
Subject: [PATCH] Fix missing symbols in .rela.plt sections
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fix .rela.plt sections in the output to not only include .rela.plt
sections from the input but also the .rela.iplt sections and to define
the hidden symbols __rela_iplt_start and __rela_iplt_end around
.rela.iplt as otherwise we get undefined references to these when
linking statically to a multilib libc.a.

Signed-off-by: Loïc Minier <lool@dooz.org>
---
 i386.ld   |    8 +++++++-
 x86_64.ld |    8 +++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/i386.ld b/i386.ld
index f2dafec..bb245a7 100644
--- a/i386.ld
+++ b/i386.ld
@@ -40,7 +40,13 @@ SECTIONS
   .rel.bss       : { *(.rel.bss)		}
   .rela.bss      : { *(.rela.bss)		}
   .rel.plt       : { *(.rel.plt)		}
-  .rela.plt      : { *(.rela.plt)		}
+  .rela.plt      :
+  {
+    *(.rela.plt)
+    PROVIDE_HIDDEN (__rela_iplt_start = .);
+    *(.rela.iplt)
+    PROVIDE_HIDDEN (__rela_iplt_end = .);
+  }
   .init          : { *(.init)	} =0x47ff041f
   .text      :
   {
diff --git a/x86_64.ld b/x86_64.ld
index 24ea77d..684d2d7 100644
--- a/x86_64.ld
+++ b/x86_64.ld
@@ -36,7 +36,13 @@ SECTIONS
   .rel.bss        : { *(.rel.bss .rel.bss.* .rel.gnu.linkonce.b.*) }
   .rela.bss       : { *(.rela.bss .rela.bss.* .rela.gnu.linkonce.b.*) }
   .rel.plt        : { *(.rel.plt) }
-  .rela.plt       : { *(.rela.plt) }
+  .rela.plt       :
+  {
+    *(.rela.plt)
+    PROVIDE_HIDDEN (__rela_iplt_start = .);
+    *(.rela.iplt)
+    PROVIDE_HIDDEN (__rela_iplt_end = .);
+  }
   .init           :
   {
     KEEP (*(.init))
-- 
1.6.5

Re: [Qemu-devel] [PATCH] Fix missing symbols in .rela.plt sections

[Loïc Minier]

[-- Attachment #1: Type: text/plain, Size: 438 bytes --]

On Sun, Jan 17, 2010, Loïc Minier wrote:
>  Static builds of qemu on x86-64 (and probably i386) fail

 After actually checking in an i386 Ubuntu lucid chroot, I found out
 that ld uses .rel.plt and .rel.iplt instead of .rela.plt and
 .rela.iplt.  I've applied the same fixes to the two .ld scripts and
 could build static flavors of qemu-linux-user on both with the updated
 patch in attachment.

     Thanks,
-- 
Loïc Minier

[-- Attachment #2: 0001-Fix-missing-symbols-in-.rel-.rela.plt-sections.patch --]
[-- Type: text/x-diff, Size: 2443 bytes --]

>From a3582e37351596119e947b0606021aedb19b6f61 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Minier?= <lool@dooz.org>
Date: Sun, 17 Jan 2010 12:09:38 +0100
Subject: [PATCH] Fix missing symbols in .rel/.rela.plt sections
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fix .rel.plt sections in the output to not only include .rel.plt
sections from the input but also the .rel.iplt sections and to define
the hidden symbols __rel_iplt_start and __rel_iplt_end around
.rel.iplt as otherwise we get undefined references to these when
linking statically to a multilib libc.a.  This fixes the static build
under i386.

Apply similar logic to rela.plt/.iplt and __rela_iplt/_plt_start/_end to
fix the static build under amd64.

Signed-off-by: Loïc Minier <lool@dooz.org>
---
 i386.ld   |   16 ++++++++++++++--
 x86_64.ld |   16 ++++++++++++++--
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/i386.ld b/i386.ld
index f2dafec..f8df7bf 100644
--- a/i386.ld
+++ b/i386.ld
@@ -39,8 +39,20 @@ SECTIONS
   .rela.fini     : { *(.rela.fini)	}
   .rel.bss       : { *(.rel.bss)		}
   .rela.bss      : { *(.rela.bss)		}
-  .rel.plt       : { *(.rel.plt)		}
-  .rela.plt      : { *(.rela.plt)		}
+  .rel.plt      :
+  {
+    *(.rel.plt)
+    PROVIDE_HIDDEN (__rel_iplt_start = .);
+    *(.rel.iplt)
+    PROVIDE_HIDDEN (__rel_iplt_end = .);
+  }
+  .rela.plt       :
+  {
+    *(.rela.plt)
+    PROVIDE_HIDDEN (__rela_iplt_start = .);
+    *(.rela.iplt)
+    PROVIDE_HIDDEN (__rela_iplt_end = .);
+  }
   .init          : { *(.init)	} =0x47ff041f
   .text      :
   {
diff --git a/x86_64.ld b/x86_64.ld
index 24ea77d..46d8d4d 100644
--- a/x86_64.ld
+++ b/x86_64.ld
@@ -35,8 +35,20 @@ SECTIONS
   .rela.got       : { *(.rela.got) }
   .rel.bss        : { *(.rel.bss .rel.bss.* .rel.gnu.linkonce.b.*) }
   .rela.bss       : { *(.rela.bss .rela.bss.* .rela.gnu.linkonce.b.*) }
-  .rel.plt        : { *(.rel.plt) }
-  .rela.plt       : { *(.rela.plt) }
+  .rel.plt      :
+  {
+    *(.rel.plt)
+    PROVIDE_HIDDEN (__rel_iplt_start = .);
+    *(.rel.iplt)
+    PROVIDE_HIDDEN (__rel_iplt_end = .);
+  }
+  .rela.plt       :
+  {
+    *(.rela.plt)
+    PROVIDE_HIDDEN (__rela_iplt_start = .);
+    *(.rela.iplt)
+    PROVIDE_HIDDEN (__rela_iplt_end = .);
+  }
   .init           :
   {
     KEEP (*(.init))
-- 
1.6.5