[PATCH v3 0/3] modversions: Fix CRC mangling under CONFIG_RELOCATABLE=y

Ard Biesheuvel ard.biesheuvel at linaro.org
Thu Oct 27 09:27:08 PDT 2016

This series is a followup to the single patch 'modversions: treat symbol
CRCs as 32 bit quantities on 64 bit archs', of which two versions have
been sent out so far [0][1]

As pointed out by Michael, GNU ld behaves a bit differently between arm64
and PowerPC64, and where the former gets rid of all runtime relocations
related to CRCs, the latter is not as easily convinced.

Patch #1 fixes the issue where CRCs are corrupted by the runtime relocation
routines for 32-bit PowerPC, for which the original fix was effectively
reverted by commit 0e0ed6406e61 ("powerpc/modules: Module CRC relocation fix
causes perf issues")

Patch #2 adds handling of R_PPC64_ADDR32 relocations against the NULL .dynsym
symbol entry to the PPC64 runtime relocation routines, so it is prepared to
deal with CRCs being emitted as 32-bit quantities.

Patch #3 is the original patch from the v1 and v2 submissions.

Changes since v2:
- added #1 and #2
- updated #3 to deal with CRC entries being emitted from assembler
- added Rusty's ack (#3)

Branch can be found here:

[0] http://marc.info/?l=linux-kernel&m=147652300207369&w=2
[1] http://marc.info/?l=linux-kernel&m=147695629614409&w=2

Ard Biesheuvel (3):
  powerpc/reloc32: fix corrupted modversion CRCs
  powerpc/reloc64: add support for 32-bit CRC pseudo-symbols
  modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

 arch/powerpc/include/asm/module.h |  4 --
 arch/powerpc/kernel/module_64.c   |  8 ----
 arch/powerpc/kernel/reloc_32.S    | 36 +++++++++++++--
 arch/powerpc/kernel/reloc_64.S    | 22 +++++++--
 arch/powerpc/relocs_check.sh      |  3 +-
 include/asm-generic/export.h      |  7 +--
 include/linux/export.h            |  8 ++++
 include/linux/module.h            | 14 +++---
 kernel/module.c                   | 47 +++++++-------------
 9 files changed, 85 insertions(+), 64 deletions(-)


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