From 5d35169e36b4fffc737ea015723e034c9efd7906 Mon Sep 17 00:00:00 2001
From: Alan Modra <amodra@gmail.com>
Date: Sun, 27 Jul 2003 09:05:08 +0000
Subject: [PATCH] * elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol):
Ensure no copy relocs on function descriptors.
(ELIMINATE_COPY_RELOCS): Expand comment. (ppc64_elf_special_sections):
Move. Don't include non-ppc64 sections. Do include ".toc1".
---
bfd/ChangeLog | 8 ++++++
bfd/elf64-ppc.c | 75 +++++++++++++++++++++++++------------------------
2 files changed, 46 insertions(+), 37 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index aabf428289c..23c0ad30b59 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2003-07-27 Alan Modra <amodra@bigpond.net.au>
+
+ * elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Ensure no copy relocs
+ on function descriptors.
+ (ELIMINATE_COPY_RELOCS): Expand comment.
+ (ppc64_elf_special_sections): Move. Don't include non-ppc64 sections.
+ Do include ".toc1".
+
2003-07-25 H.J. Lu <hongjiu.lu@intel.com>
* elf.c (_bfd_elf_new_section_hook): Set the default section
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 1e6d22df147..dda658de08c 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -2402,6 +2402,26 @@ ppc64_elf_merge_private_bfd_data (bfd *ibfd, bfd *obfd)
return TRUE;
}
+/* Add extra PPC sections. */
+
+static struct bfd_elf_special_section const ppc64_elf_special_sections[]=
+{
+ { ".sdata", 0, NULL, 0,
+ SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
+ { ".sbss", 0, NULL, 0,
+ SHT_NOBITS, SHF_ALLOC + SHF_WRITE },
+ { ".plt", 0, NULL, 0,
+ SHT_NOBITS, 0 },
+ { ".toc", 0, NULL, 0,
+ SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
+ { ".toc1", 0, NULL, 0,
+ SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
+ { ".tocbss", 0, NULL, 0,
+ SHT_NOBITS, SHF_ALLOC + SHF_WRITE },
+ { NULL, 0, NULL, 0,
+ 0, 0 }
+};
+
struct _ppc64_elf_section_data
{
struct bfd_elf_section_data elf;
@@ -2580,7 +2600,18 @@ struct plt_entry
/* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
copying dynamic variables from a shared lib into an app's dynbss
section, and instead use a dynamic relocation to point into the
- shared lib. */
+ shared lib. With code that gcc generates, it's vital that this be
+ enabled; In the PowerPC64 ABI, the address of a function is actually
+ the address of a function descriptor, which resides in the .opd
+ section. gcc uses the descriptor directly rather than going via the
+ GOT as some other ABI's do, which means that initialized function
+ pointers must reference the descriptor. Thus, a function pointer
+ initialized to the address of a function in a shared library will
+ either require a copy reloc, or a dynamic reloc. Using a copy reloc
+ redefines the function desctriptor symbol to point to the copy. This
+ presents a problem as a plt entry for that function is also
+ initialized from the function descriptor symbol and the copy reloc
+ may not be initialized first. */
#define ELIMINATE_COPY_RELOCS 1
/* Section name for stubs is the associated section name plus this
@@ -4500,9 +4531,6 @@ ppc64_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
return TRUE;
}
- /* This is a reference to a symbol defined by a dynamic object which
- is not a function. */
-
/* If we are creating a shared library, we must presume that the
only references to the symbol are via the global offset table.
For such cases we need not do anything here; the relocations will
@@ -4537,6 +4565,12 @@ ppc64_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
}
}
+ if (h->plt.plist != NULL)
+ return TRUE;
+
+ /* This is a reference to a symbol defined by a dynamic object which
+ is not a function. */
+
/* We must allocate the symbol in our .dynbss section, which will
become part of the .bss section of the executable. There will be
an entry for this symbol in the .dynsym section. The dynamic
@@ -8762,37 +8796,4 @@ ppc64_elf_finish_dynamic_sections (bfd *output_bfd,
return TRUE;
}
-/* Add extra PPC sections -- Note, for now, make .sbss2 and
- .PPC.EMB.sbss0 a normal section, and not a bss section so
- that the linker doesn't crater when trying to make more than
- 2 sections. */
-
-static struct bfd_elf_special_section const ppc64_elf_special_sections[]=
-{
- { ".tags", 0, NULL, 0,
- SHT_ORDERED, SHF_ALLOC },
- { ".sdata", 0, NULL, 0,
- SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
- { ".sbss", 0, NULL, 0,
- SHT_NOBITS, SHF_ALLOC + SHF_WRITE },
- { ".sdata2", 0, NULL, 0,
- SHT_PROGBITS, SHF_ALLOC },
- { ".sbss2", 0, NULL, 0,
- SHT_PROGBITS, SHF_ALLOC },
- { ".PPC.EMB.apuinfo", 0, NULL, 0,
- SHT_NOTE, 0 },
- { ".PPC.EMB.sdata0", 0, NULL, 0,
- SHT_PROGBITS, SHF_ALLOC },
- { ".PPC.EMB.sbss0", 0, NULL, 0,
- SHT_PROGBITS, SHF_ALLOC },
- { ".plt", 0, NULL, 0,
- SHT_NOBITS, 0 },
- { ".toc", 0, NULL, 0,
- SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
- { ".tocbss", 0, NULL, 0,
- SHT_NOBITS, SHF_ALLOC + SHF_WRITE },
- { NULL, 0, NULL, 0,
- 0, 0 }
-};
-
#include "elf64-target.h"