From: Nick Desaulniers <ndesaulniers@google.com>
To: miguel.ojeda.sandonis@gmail.com
Cc: sedat.dilek@gmail.com, will@kernel.org, jpoimboe@redhat.com,
naveen.n.rao@linux.vnet.ibm.com, davem@davemloft.net,
paul.burton@mips.com, clang-built-linux@googlegroups.com,
linux-kernel@vger.kernel.org,
Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH v3 11/14] include/asm-generic: prefer __section from compiler_attributes.h
Date: Wed, 28 Aug 2019 15:55:32 -0700 [thread overview]
Message-ID: <20190828225535.49592-12-ndesaulniers@google.com> (raw)
In-Reply-To: <20190828225535.49592-1-ndesaulniers@google.com>
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
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
include/asm-generic/error-injection.h | 2 +-
include/asm-generic/kprobes.h | 5 ++---
2 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/include/asm-generic/error-injection.h b/include/asm-generic/error-injection.h
index 95a159a4137f..a593a50b33e3 100644
--- a/include/asm-generic/error-injection.h
+++ b/include/asm-generic/error-injection.h
@@ -23,7 +23,7 @@ struct error_injection_entry {
*/
#define ALLOW_ERROR_INJECTION(fname, _etype) \
static struct error_injection_entry __used \
- __attribute__((__section__("_error_injection_whitelist"))) \
+ __section(_error_injection_whitelist) \
_eil_addr_##fname = { \
.addr = (unsigned long)fname, \
.etype = EI_ETYPE_##_etype, \
diff --git a/include/asm-generic/kprobes.h b/include/asm-generic/kprobes.h
index 4a982089c95c..20d69719270f 100644
--- a/include/asm-generic/kprobes.h
+++ b/include/asm-generic/kprobes.h
@@ -9,12 +9,11 @@
* by using this macro.
*/
# define __NOKPROBE_SYMBOL(fname) \
-static unsigned long __used \
- __attribute__((__section__("_kprobe_blacklist"))) \
+static unsigned long __used __section(_kprobe_blacklist) \
_kbl_addr_##fname = (unsigned long)fname;
# define NOKPROBE_SYMBOL(fname) __NOKPROBE_SYMBOL(fname)
/* Use this to forbid a kprobes attach on very low level functions */
-# define __kprobes __attribute__((__section__(".kprobes.text")))
+# define __kprobes __section(.kprobes.text)
# define nokprobe_inline __always_inline
#else
# define NOKPROBE_SYMBOL(fname)
--
2.23.0.187.g17f5b7556c-goog
next prev parent reply other threads:[~2019-08-28 22:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-28 22:55 [PATCH v3 00/14] treewide: prefer __section from compiler_attributes.h Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 01/14] s390/boot: fix section name escaping Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 02/14] include/linux/compiler.h: prefer __section from compiler_attributes.h Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 03/14] parisc: " Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 04/14] um: " Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 05/14] ia64: " Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 06/14] arm: " Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 07/14] mips: " Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 08/14] sparc: " Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 09/14] powerpc: prefer __section and __printf " Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 10/14] x86: prefer __section " Nick Desaulniers
2019-08-29 14:14 ` Miguel Ojeda
2019-08-29 14:22 ` Miguel Ojeda
2019-08-28 22:55 ` Nick Desaulniers [this message]
2019-08-28 22:55 ` [PATCH v3 12/14] include/linux: " Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 13/14] include/linux/compiler.h: remove unused KENTRY macro Nick Desaulniers
2019-08-28 22:55 ` [PATCH v3 14/14] compiler_attributes.h: add note about __section Nick Desaulniers
2019-08-29 20:24 ` [PATCH v3 00/14] treewide: prefer __section from compiler_attributes.h Miguel Ojeda
2019-08-29 20:37 ` Sedat Dilek
2019-08-29 20:47 ` Nick Desaulniers
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