[PATCH] powerpc/vdso: Emit GNU & SysV hashes

From: Michael Ellerman
Date: Thu Aug 06 2015 - 23:06:25 EST


Andy Lutomirski says:

Some dynamic loaders may be slightly faster if a GNU hash is
available.

This is unlikely to have any measurable effect on the time it takes
to resolve vdso symbols (since there are so few of them). In some
contexts, it can be a win for a different reason: if every DSO has a
GNU hash section, then libc can avoid calculating SysV hashes at
all. Both musl and glibc appear to have this optimization.

Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
---
arch/powerpc/kernel/vdso32/Makefile | 2 +-
arch/powerpc/kernel/vdso64/Makefile | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile
index 53e6c9b979ec..6abffb7a8cd9 100644
--- a/arch/powerpc/kernel/vdso32/Makefile
+++ b/arch/powerpc/kernel/vdso32/Makefile
@@ -18,7 +18,7 @@ GCOV_PROFILE := n

ccflags-y := -shared -fno-common -fno-builtin
ccflags-y += -nostdlib -Wl,-soname=linux-vdso32.so.1 \
- $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
+ $(call cc-ldoption, -Wl$(comma)--hash-style=both)
asflags-y := -D__VDSO32__ -s

obj-y += vdso32_wrapper.o
diff --git a/arch/powerpc/kernel/vdso64/Makefile b/arch/powerpc/kernel/vdso64/Makefile
index effca9404b17..8c8f2ae43935 100644
--- a/arch/powerpc/kernel/vdso64/Makefile
+++ b/arch/powerpc/kernel/vdso64/Makefile
@@ -11,7 +11,7 @@ GCOV_PROFILE := n

ccflags-y := -shared -fno-common -fno-builtin
ccflags-y += -nostdlib -Wl,-soname=linux-vdso64.so.1 \
- $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
+ $(call cc-ldoption, -Wl$(comma)--hash-style=both)
asflags-y := -D__VDSO64__ -s

obj-y += vdso64_wrapper.o
--
2.1.4

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