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powerpc/vdso: remove deprecated VDS64_HAS_DESCRIPTORS references
authorJoe Lawrence <joe.lawrence@redhat.com>
Mon, 24 Feb 2020 21:18:48 +0000 (16:18 -0500)
committerMichael Ellerman <mpe@ellerman.id.au>
Fri, 13 Mar 2020 10:13:06 +0000 (21:13 +1100)
commitffd3eaf178b0f616a071e510e289d937330b0b35
tree1c975cfa9fab8b025d93c9e9825f38a6db820429
parentcc6f0e39000900e5dd1448103a9571f0eccd7d4e
powerpc/vdso: remove deprecated VDS64_HAS_DESCRIPTORS references

The original 2005 patch that introduced the powerpc vdso, pre-git
("ppc64: Implement a vDSO and use it for signal trampoline") notes that:

  ... symbols exposed by the vDSO aren't "normal" function symbols, apps
  can't be expected to link against them directly, the vDSO's are both
  seen as if they were linked at 0 and the symbols just contain offsets
  to the various functions.  This is done on purpose to avoid a
  relocation step (ppc64 functions normally have descriptors with abs
  addresses in them).  When glibc uses those functions, it's expected to
  use it's own trampolines that know how to reach them.

Despite that explanation, there remains dead #ifdef
VDS64_HAS_DESCRIPTORS code-blocks that provide alternate function
definitions that setup function descriptors.

Since VDS64_HAS_DESCRIPTORS has been unused for all these years, we
might as well finally remove it from the codebase.

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200224211848.26087-1-joe.lawrence@redhat.com
arch/powerpc/include/asm/vdso.h
arch/powerpc/kernel/vdso.c