Messages in this thread | | | From | Nick Desaulniers <> | Date | Mon, 12 Aug 2019 14:57:26 -0700 | Subject | Fwd: [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
| |