arm64: vdso32: Shuffle .ARM.exidx section above ELF_DETAILS

When building the 32-bit vDSO after commit 5c4fb60816ea ("arm64: vdso32:
add ARM.exidx* sections"), ld.lld 11 fails to link:

  ld.lld: error: could not allocate headers
  ld.lld: error: unable to place section .text at file offset [0x2A0, 0xBB1]; check your linker script for overflows
  ld.lld: error: unable to place section .comment at file offset [0xBB2, 0xC8A]; check your linker script for overflows
  ld.lld: error: unable to place section .symtab at file offset [0xC8C, 0xE0B]; check your linker script for overflows
  ld.lld: error: unable to place section .strtab at file offset [0xE0C, 0xF1C]; check your linker script for overflows
  ld.lld: error: unable to place section .shstrtab at file offset [0xF1D, 0xFAA]; check your linker script for overflows
  ld.lld: error: section .ARM.exidx file range overlaps with .hash
  >>> .ARM.exidx range is [0x90, 0xCF]
  >>> .hash range is [0xB4, 0xE3]

  ld.lld: error: section .hash file range overlaps with .ARM.attributes
  >>> .hash range is [0xB4, 0xE3]
  >>> .ARM.attributes range is [0xD0, 0x10B]

  ld.lld: error: section .ARM.attributes file range overlaps with .dynsym
  >>> .ARM.attributes range is [0xD0, 0x10B]
  >>> .dynsym range is [0xE4, 0x133]

  ld.lld: error: section .ARM.exidx virtual address range overlaps with .hash
  >>> .ARM.exidx range is [0x90, 0xCF]
  >>> .hash range is [0xB4, 0xE3]

  ld.lld: error: section .ARM.exidx load address range overlaps with .hash
  >>> .ARM.exidx range is [0x90, 0xCF]
  >>> .hash range is [0xB4, 0xE3]

This was fixed in ld.lld 12 with a change to match GNU ld's semantics of
placing non-SHF_ALLOC sections after SHF_ALLOC sections.

To workaround this issue, move the .ARM.exidx section before the
.comment, .symtab, .strtab, and .shstrtab sections (ELF_DETAILS) so that
those sections remain contiguous with the .ARM.attributes section.

Fixes: 5c4fb60816ea ("arm64: vdso32: add ARM.exidx* sections")
Link: https://github.com/llvm/llvm-project/commit/ec29538af2e0886a65f479d6a533956a1c478132
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20220630153121.1317045-2-nathan@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/kernel/vdso32/vdso.lds.S b/arch/arm64/kernel/vdso32/vdso.lds.S
index 6e67a65..c25bed8 100644 (file)
--- a/arch/arm64/kernel/vdso32/vdso.lds.S
+++ b/arch/arm64/kernel/vdso32/vdso.lds.S
@@ -56,8 +56,8 @@ SECTIONS
 
        .rel.dyn        : { *(.rel*) }
 
-       ELF_DETAILS
        .ARM.exidx : { *(.ARM.exidx*) }
+       ELF_DETAILS
        .ARM.attributes 0 : { *(.ARM.attributes) }
 
        /DISCARD/       : {