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| author | Alan Modra <amodra@gmail.com> | 2017-06-14 10:47:25 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2017-06-14 10:47:25 +0930 |
| commit | 0572433b5beb636de1a49ec6b4fdab830c38cdc5 (patch) | |
| tree | 718b3b7cd3011961b409a8233dfac4f2b0c6c487 /elf/elf.h | |
| parent | d5b411854f0a3135c931921dfa8a33af395acfd3 (diff) | |
| download | glibc-0572433b5beb636de1a49ec6b4fdab830c38cdc5.tar.gz glibc-0572433b5beb636de1a49ec6b4fdab830c38cdc5.tar.xz glibc-0572433b5beb636de1a49ec6b4fdab830c38cdc5.zip | |
PowerPC64 ELFv2 PPC64_OPT_LOCALENTRY
ELFv2 functions with localentry:0 are those with a single entry point, ie. global entry == local entry, that have no requirement on r2 or r12 and guarantee r2 is unchanged on return. Such an external function can be called via the PLT without saving r2 or restoring it on return, avoiding a common load-hit-store for small functions. This patch implements the ld.so changes necessary for this optimization. ld.so needs to check that an optimized plt call sequence is in fact calling a function implemented with localentry:0, end emit a fatal error otherwise. The elf/testobj6.c change is to stop "error while loading shared libraries: expected localentry:0 `preload'" when running elf/preloadtest, which we'd get otherwise. * elf/elf.h (PPC64_OPT_LOCALENTRY): Define. * sysdeps/alpha/dl-machine.h (elf_machine_fixup_plt): Add refsym and sym parameters. Adjust callers. * sysdeps/aarch64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/arm/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/generic/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/hppa/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/i386/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/ia64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/m68k/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/microblaze/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/mips/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/nios2/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/s390/s390-32/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/s390/s390-64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/sh/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/sparc/sparc32/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/sparc/sparc64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/tile/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/x86_64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/powerpc/powerpc64/dl-machine.c (_dl_error_localentry): New. (_dl_reloc_overflow): Increase buffser size. Formatting. * sysdeps/powerpc/powerpc64/dl-machine.h (ppc64_local_entry_offset): Delete reloc param, add refsym and sym. Check optimized plt call stubs for localentry:0 functions. Adjust callers. (elf_machine_fixup_plt, elf_machine_plt_conflict): Add refsym and sym parameters. Adjust callers. (_dl_reloc_overflow): Move attribute. (_dl_error_localentry): Declare. * elf/dl-runtime.c (_dl_fixup): Save original sym. Pass refsym and sym to elf_machine_fixup_plt. * elf/testobj6.c (preload): Call printf.
Diffstat (limited to 'elf/elf.h')
| -rw-r--r-- | elf/elf.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/elf/elf.h b/elf/elf.h index fff893d433..3900b4c9f0 100644 --- a/elf/elf.h +++ b/elf/elf.h @@ -2544,9 +2544,10 @@ enum #define DT_PPC64_OPT (DT_LOPROC + 3) #define DT_PPC64_NUM 4 -/* PowerPC64 specific values for the DT_PPC64_OPT Dyn entry. */ +/* PowerPC64 specific bits in the DT_PPC64_OPT Dyn entry. */ #define PPC64_OPT_TLS 1 #define PPC64_OPT_MULTI_TOC 2 +#define PPC64_OPT_LOCALENTRY 4 /* PowerPC64 specific values for the Elf64_Sym st_other field. */ #define STO_PPC64_LOCAL_BIT 5 |