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    Subject[PATCH 2/2] powerpc/vdso32: link vdso64 with linker
    From
    Rather than invoke the compiler as the driver, use the linker. That way
    we can check --orphan-handling=warn support correctly, as cc-ldoption
    was removed in
    commit 055efab3120b ("kbuild: drop support for cc-ldoption").

    Requires dropping the .got section. I couldn't find how it was used in
    the vdso32.

    Fixes: commit f2af201002a8 ("powerpc/build: vdso linker warning for orphan sections")
    Link: https://lore.kernel.org/lkml/CAKwvOdnn3wxYdJomvnveyD_njwRku3fABWT_bS92duihhywLJQ@mail.gmail.com/
    Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
    ---
    Not sure removing .got is a good idea or not. Otherwise I observe the
    following link error:
    powerpc-linux-gnu-ld: warning: orphan section `.got' from `arch/powerpc/kernel/vdso32/sigtramp.o' being placed in section `.got'
    powerpc-linux-gnu-ld: _GLOBAL_OFFSET_TABLE_ not defined in linker created .got
    powerpc-linux-gnu-ld: final link failed: bad value

    sigtramp.c doesn't mention anything from the GOT AFAICT, and doesn't
    look like it contains relocations that do, so I'm not sure where
    references to _GLOBAL_OFFSET_TABLE_ are coming from.

    arch/powerpc/kernel/vdso32/Makefile | 7 +++++--
    arch/powerpc/kernel/vdso32/vdso32.lds.S | 3 ++-
    2 files changed, 7 insertions(+), 3 deletions(-)

    diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile
    index 87ab1152d5ce..611a5951945a 100644
    --- a/arch/powerpc/kernel/vdso32/Makefile
    +++ b/arch/powerpc/kernel/vdso32/Makefile
    @@ -27,6 +27,9 @@ UBSAN_SANITIZE := n
    ccflags-y := -shared -fno-common -fno-builtin -nostdlib \
    -Wl,-soname=linux-vdso32.so.1 -Wl,--hash-style=both
    asflags-y := -D__VDSO32__ -s
    +ldflags-y := -shared -soname linux-vdso32.so.1 \
    + $(call ld-option, --eh-frame-hdr) \
    + $(call ld-option, --orphan-handling=warn) -T

    obj-y += vdso32_wrapper.o
    extra-y += vdso32.lds
    @@ -49,8 +52,8 @@ $(obj-vdso32): %.o: %.S FORCE
    $(call if_changed_dep,vdso32as)

    # actual build commands
    -quiet_cmd_vdso32ld = VDSO32L $@
    - cmd_vdso32ld = $(VDSOCC) $(c_flags) $(CC32FLAGS) -o $@ $(call cc-ldoption, -Wl$(comma)--orphan-handling=warn) -Wl,-T$(filter %.lds,$^) $(filter %.o,$^)
    +quiet_cmd_vdso32ld = LD $@
    + cmd_vdso32ld = $(cmd_ld)
    quiet_cmd_vdso32as = VDSO32A $@
    cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) -c -o $@ $<

    diff --git a/arch/powerpc/kernel/vdso32/vdso32.lds.S b/arch/powerpc/kernel/vdso32/vdso32.lds.S
    index 4c985467a668..0ccdebad18b8 100644
    --- a/arch/powerpc/kernel/vdso32/vdso32.lds.S
    +++ b/arch/powerpc/kernel/vdso32/vdso32.lds.S
    @@ -61,7 +61,6 @@ SECTIONS
    .fixup : { *(.fixup) }

    .dynamic : { *(.dynamic) } :text :dynamic
    - .got : { *(.got) } :text
    .plt : { *(.plt) }

    _end = .;
    @@ -108,7 +107,9 @@ SECTIONS
    .debug_varnames 0 : { *(.debug_varnames) }

    /DISCARD/ : {
    + *(.got)
    *(.note.GNU-stack)
    + *(.branch_lt)
    *(.data .data.* .gnu.linkonce.d.* .sdata*)
    *(.bss .sbss .dynbss .dynsbss)
    *(.glink .iplt .plt .rela*)
    --
    2.28.0.402.g5ffc5be6b7-goog
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