[v3,04/14] um: prefer __section from compiler_attributes.h

Message ID 20190828225535.49592-5-ndesaulniers@google.com
State New
Headers show
Series
  • treewide: prefer __section from compiler_attributes.h
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Commit Message

Nick Desaulniers Aug. 28, 2019, 10:55 p.m.
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.

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:
Link: https://bugs.llvm.org/show_bug.cgi?id=42950
Link: https://marc.info/?l=linux-netdev&m=156412960619946&w=2
Link: https://github.com/ClangBuiltLinux/linux/issues/619
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

---
 arch/um/kernel/um_arch.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

-- 
2.23.0.187.g17f5b7556c-goog

Patch

diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index a818ccef30ca..18e0287dd97e 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -52,9 +52,9 @@  struct cpuinfo_um boot_cpu_data = {
 	.ipi_pipe		= { -1, -1 }
 };
 
-union thread_union cpu0_irqstack
-	__attribute__((__section__(".data..init_irqstack"))) =
-		{ .thread_info = INIT_THREAD_INFO(init_task) };
+union thread_union cpu0_irqstack __section(.data..init_irqstack) = {
+	.thread_info = INIT_THREAD_INFO(init_task)
+};
 
 /* Changed in setup_arch, which is called in early boot */
 static char host_info[(__NEW_UTS_LEN + 1) * 5];