[PATCH 0/2] modpost: skip section mismatch warnings on ELF local symbols by default

From: Paul Walmsley
Date: Sat Oct 20 2018 - 09:19:39 EST


modpost: skip section mismatch warnings on ELF local symbols by default

modpost, by default, reports section mismatch warnings on ELF local
symbols. This caused false positive warnings to be reported for a
local symbol name that would otherwise be elided by matching against a
name pattern. This was observed using a RISC-V toolchain that generates
section anchors.

To avoid this noise in the common case, this patch series disables
section mismatch warnings on ELF local symbols by default. It also
adds a modpost command line switch to re-enable these warnings, since
I wasn't able to convince myself that section mismatch warnings on ELF
local symbols were completely useless; just mostly useless :-)

I'm neither a modpost nor an ELF expert, so careful review of this
series is appreciated.

This modpost series can also be found at:

https://github.com/sifive/riscv-linux/tree/dev/paulw/modpost-elf-local-symbols-v4.19-rc7

The series was tested on a RISC-V build of the SiFive UART serial
driver, at:

https://github.com/sifive/riscv-linux/tree/dev/paulw/serial-v4.19-rc7

Paul Walmsley (2):
modpost: add switch to skip symbol exclusions likely to generate false
positives
modpost: skip ELF local symbols by default during section mismatch
check

scripts/mod/modpost.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)

Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Jim Wilson <jimw@xxxxxxxxxx>
Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Cc: Michal Marek <michal.lkml@xxxxxxxxxxx>
Cc: linux-kbuild@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

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2.19.1