lkml.org 
[lkml]   [2021]   [Jan]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v5 mips-next 0/9] MIPS: vmlinux.lds.S sections fixes & cleanup
From: Kees Cook <keescook@chromium.org>
Date: Mon, 11 Jan 2021 11:53:39 -0800

> On Sun, Jan 10, 2021 at 11:53:50AM +0000, Alexander Lobakin wrote:
>> This series hunts the problems discovered after manual enabling of
>> ARCH_WANT_LD_ORPHAN_WARN. Notably:
>> - adds the missing PAGE_ALIGNED_DATA() section affecting VDSO
>> placement (marked for stable);
>> - stops blind catching of orphan text sections with .text.*
>> directive;
>> - properly stops .eh_frame section generation.
>>
>> Compile and runtime tested on MIPS32R2 CPS board with no issues
>> using two different toolkits:
>> - Binutils 2.35.1, GCC 10.2.1 (with Alpine patches);
>> - LLVM stack: 11.0.0 and from latest Git snapshot.
>>
>> Since v4 [3]:
>> - new: drop redundant .text.cps-vec creation and blind inclusion
>> of orphan text sections via .text.* directive in vmlinux.lds.S;
>> - don't assert SIZEOF(.rel.dyn) as it's reported that it may be not
>> empty on certain machines and compilers (Thomas);
>> - align GOT table like it's done for ARM64;
>> - new: catch UBSAN's "unnamed data" sections in generic definitions
>> when building with LD_DEAD_CODE_DATA_ELIMINATION;
>> - collect Reviewed-bys (Kees, Nathan).
>
> Looks good; which tree will this land through?

linux-mips/mips-next I guess, since 7 of 9 patches are related only
to this architecture.
This might need Arnd's Acked-bys or Reviewed-by for the two that
refer include/asm-generic, let's see what Thomas think.

> -Kees
>
>>
>> Since v3 [2]:
>> - fix the third patch as GNU stack emits .rel.dyn into VDSO for
>> some reason if .cfi_sections is specified.
>>
>> Since v2 [1]:
>> - stop discarding .eh_frame and just prevent it from generating
>> (Kees);
>> - drop redundant sections assertions (Fangrui);
>> - place GOT table in .text instead of asserting as it's not empty
>> when building with LLVM (Nathan);
>> - catch compound literals in generic definitions when building with
>> LD_DEAD_CODE_DATA_ELIMINATION (Kees);
>> - collect two Reviewed-bys (Kees).
>>
>> Since v1 [0]:
>> - catch .got entries too as LLD may produce it (Nathan);
>> - check for unwanted sections to be zero-sized instead of
>> discarding (Fangrui).
>>
>> [0] https://lore.kernel.org/linux-mips/20210104121729.46981-1-alobakin@pm.me
>> [1] https://lore.kernel.org/linux-mips/20210106200713.31840-1-alobakin@pm.me
>> [2] https://lore.kernel.org/linux-mips/20210107115120.281008-1-alobakin@pm.me
>> [3] https://lore.kernel.org/linux-mips/20210107123331.354075-1-alobakin@pm.me
>>
>> Alexander Lobakin (9):
>> MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() section
>> MIPS: CPS: don't create redundant .text.cps-vec section
>> MIPS: vmlinux.lds.S: add ".gnu.attributes" to DISCARDS
>> MIPS: properly stop .eh_frame generation
>> MIPS: vmlinux.lds.S: explicitly catch .rel.dyn symbols
>> MIPS: vmlinux.lds.S: explicitly declare .got table
>> vmlinux.lds.h: catch compound literals into data and BSS
>> vmlinux.lds.h: catch UBSAN's "unnamed data" into data
>> MIPS: select ARCH_WANT_LD_ORPHAN_WARN
>>
>> arch/mips/Kconfig | 1 +
>> arch/mips/include/asm/asm.h | 18 ++++++++++++++++++
>> arch/mips/kernel/cps-vec.S | 1 -
>> arch/mips/kernel/vmlinux.lds.S | 11 +++++++++--
>> include/asm-generic/vmlinux.lds.h | 6 +++---
>> 5 files changed, 31 insertions(+), 6 deletions(-)
>>
>> --
>> 2.30.0
>>
>>
>
> --
> Kees Cook

Al

\
 
 \ /
  Last update: 2021-01-11 22:00    [W:0.065 / U:2.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site