lkml.org 
[lkml]   [2019]   [Aug]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectFwd: [PATCH 00/16] treewide: prefer __section from compiler_attributes.h
---------- Forwarded message ---------
From: Nick Desaulniers <ndesaulniers@google.com>
Date: Mon, Aug 12, 2019 at 2:53 PM
Subject: [PATCH 00/16] treewide: prefer __section from compiler_attributes.h
To: <akpm@linux-foundation.org>
Cc: <sedat.dilek@gmail.com>, <jpoimboe@redhat.com>, <yhs@fb.com>,
<miguel.ojeda.sandonis@gmail.com>,
<clang-built-linux@googlegroups.com>, Nick Desaulniers
<ndesaulniers@google.com>, Alexei Starovoitov <ast@kernel.org>, Daniel
Borkmann <daniel@iogearbox.net>, Martin KaFai Lau <kafai@fb.com>, Song
Liu <songliubraving@fb.com>, <netdev@vger.kernel.org>,
<bpf@vger.kernel.org>


GCC unescapes escaped string section names while Clang does not. Because
__section uses the `#` stringification operator for the section name, it
doesn't need to be escaped.

This fixes an Oops observed in distro's that use systemd and not
net.core.bpf_jit_enable=1, when their kernels are compiled with Clang.

Instead, we should:
1. Prefer __section(.section_name_no_quotes).
2. Only use __attribute__((__section(".section"))) when creating the
section name via C preprocessor (see the definition of __define_initcall
in arch/um/include/shared/init.h).

This antipattern was found with:
$ grep -e __section\(\" -e __section__\(\" -r

See the discussions in:
https://bugs.llvm.org/show_bug.cgi?id=42950
https://marc.info/?l=linux-netdev&m=156412960619946&w=2

Nick Desaulniers (16):
s390/boot: fix section name escaping
arc: prefer __section from compiler_attributes.h
parisc: prefer __section from compiler_attributes.h
um: prefer __section from compiler_attributes.h
sh: prefer __section from compiler_attributes.h
ia64: prefer __section from compiler_attributes.h
arm: prefer __section from compiler_attributes.h
mips: prefer __section from compiler_attributes.h
sparc: prefer __section from compiler_attributes.h
powerpc: prefer __section and __printf from compiler_attributes.h
x86: prefer __section from compiler_attributes.h
arm64: prefer __section from compiler_attributes.h
include/asm-generic: prefer __section from compiler_attributes.h
include/linux: prefer __section from compiler_attributes.h
include/linux/compiler.h: remove unused KENTRY macro
compiler_attributes.h: add note about __section

arch/arc/include/asm/linkage.h | 8 +++----
arch/arc/include/asm/mach_desc.h | 3 +--
arch/arm/include/asm/cache.h | 2 +-
arch/arm/include/asm/mach/arch.h | 4 ++--
arch/arm/include/asm/setup.h | 2 +-
arch/arm64/include/asm/cache.h | 2 +-
arch/arm64/kernel/smp_spin_table.c | 2 +-
arch/ia64/include/asm/cache.h | 2 +-
arch/mips/include/asm/cache.h | 2 +-
arch/parisc/include/asm/cache.h | 2 +-
arch/parisc/include/asm/ldcw.h | 2 +-
arch/powerpc/boot/main.c | 3 +--
arch/powerpc/boot/ps3.c | 6 ++----
arch/powerpc/include/asm/cache.h | 2 +-
arch/powerpc/kernel/btext.c | 2 +-
arch/s390/boot/startup.c | 2 +-
arch/sh/include/asm/cache.h | 2 +-
arch/sparc/include/asm/cache.h | 2 +-
arch/sparc/kernel/btext.c | 2 +-
arch/um/kernel/um_arch.c | 6 +++---
arch/x86/include/asm/cache.h | 2 +-
arch/x86/include/asm/intel-mid.h | 2 +-
arch/x86/include/asm/iommu_table.h | 5 ++---
arch/x86/include/asm/irqflags.h | 2 +-
arch/x86/include/asm/mem_encrypt.h | 2 +-
arch/x86/kernel/cpu/cpu.h | 3 +--
include/asm-generic/error-injection.h | 2 +-
include/asm-generic/kprobes.h | 5 ++---
include/linux/cache.h | 6 +++---
include/linux/compiler.h | 31 ++++-----------------------
include/linux/compiler_attributes.h | 10 +++++++++
include/linux/cpu.h | 2 +-
include/linux/export.h | 2 +-
include/linux/init_task.h | 4 ++--
include/linux/interrupt.h | 5 ++---
include/linux/sched/debug.h | 2 +-
include/linux/srcutree.h | 2 +-
37 files changed, 62 insertions(+), 83 deletions(-)

--
2.23.0.rc1.153.gdeed80330f-goog



--
Thanks,
~Nick Desaulniers

\
 
 \ /
  Last update: 2019-08-12 23:58    [W:0.374 / U:0.580 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site