All of lore.kernel.org
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	"H. Peter Anvin" <hpa@zytor.com>, Joe Perches <joe@perches.com>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Juergen Gross <jgross@suse.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	acme@redhat.com, akataria@vmware.com, akpm@linux-foundation.org,
	andrea.parri@amarulasolutions.com, ard.biesheuvel@linaro.org,
	aryabinin@virtuozzo.com, astrachan@google.com,
	boris.ostrovsky@oracle.com, brijesh.singh@amd.com,
	caoj.fnst@cn.fujitsu.com, geert@linux-m68k.org,
	ghackmann@google.com, jan.kiszka@siemens.com,
	jarkko.sakkinen@linux.intel.com, jpoimboe@redhat.com,
	keescook@google.com, kirill.shutemov@linux.intel.com,
	kstewart@linuxfoundation.org, linux-efi@vger.kernel.org,
	linux-kbuild@vger.kernel.org, manojgupta@google.com,
	mawilcox@microsoft.com, michal.lkml@markovi.net,
	mjg59@google.com, mka@chromium.org, pombredanne@nexb.com,
	rientjes@google.com, rostedt@goodmis.org, sedat.dilek@gmail.com,
	thomas.lendacky@amd.com, tstellar@redhat.com, tweek@google.com,
	virtualization@lists.linux-foundation.org, will.deacon@arm.com,
	yamada.masahiro@socionext.com, Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 4.4 04/31] compiler-gcc.h: Add __attribute__((gnu_inline)) to all inline declarations
Date: Fri, 20 Jul 2018 14:13:34 +0200	[thread overview]
Message-ID: <20180720121340.315434780@linuxfoundation.org> (raw)
In-Reply-To: <20180720121340.158484922@linuxfoundation.org>

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nick Desaulniers <ndesaulniers@google.com>

commit d03db2bc26f0e4a6849ad649a09c9c73fccdc656 upstream.

Functions marked extern inline do not emit an externally visible
function when the gnu89 C standard is used. Some KBUILD Makefiles
overwrite KBUILD_CFLAGS. This is an issue for GCC 5.1+ users as without
an explicit C standard specified, the default is gnu11. Since c99, the
semantics of extern inline have changed such that an externally visible
function is always emitted. This can lead to multiple definition errors
of extern inline functions at link time of compilation units whose build
files have removed an explicit C standard compiler flag for users of GCC
5.1+ or Clang.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@redhat.com
Cc: akataria@vmware.com
Cc: akpm@linux-foundation.org
Cc: andrea.parri@amarulasolutions.com
Cc: ard.biesheuvel@linaro.org
Cc: aryabinin@virtuozzo.com
Cc: astrachan@google.com
Cc: boris.ostrovsky@oracle.com
Cc: brijesh.singh@amd.com
Cc: caoj.fnst@cn.fujitsu.com
Cc: geert@linux-m68k.org
Cc: ghackmann@google.com
Cc: gregkh@linuxfoundation.org
Cc: jan.kiszka@siemens.com
Cc: jarkko.sakkinen@linux.intel.com
Cc: jpoimboe@redhat.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: kstewart@linuxfoundation.org
Cc: linux-efi@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Cc: manojgupta@google.com
Cc: mawilcox@microsoft.com
Cc: michal.lkml@markovi.net
Cc: mjg59@google.com
Cc: mka@chromium.org
Cc: pombredanne@nexb.com
Cc: rientjes@google.com
Cc: rostedt@goodmis.org
Cc: sedat.dilek@gmail.com
Cc: thomas.lendacky@amd.com
Cc: tstellar@redhat.com
Cc: tweek@google.com
Cc: virtualization@lists.linux-foundation.org
Cc: will.deacon@arm.com
Cc: yamada.masahiro@socionext.com
Link: http://lkml.kernel.org/r/20180621162324.36656-2-ndesaulniers@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 include/linux/compiler-gcc.h |   29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -65,25 +65,40 @@
 #endif
 
 /*
+ * Feature detection for gnu_inline (gnu89 extern inline semantics). Either
+ * __GNUC_STDC_INLINE__ is defined (not using gnu89 extern inline semantics,
+ * and we opt in to the gnu89 semantics), or __GNUC_STDC_INLINE__ is not
+ * defined so the gnu89 semantics are the default.
+ */
+#ifdef __GNUC_STDC_INLINE__
+# define __gnu_inline	__attribute__((gnu_inline))
+#else
+# define __gnu_inline
+#endif
+
+/*
  * Force always-inline if the user requests it so via the .config,
  * or if gcc is too old.
  * GCC does not warn about unused static inline functions for
  * -Wunused-function.  This turns out to avoid the need for complex #ifdef
  * directives.  Suppress the warning in clang as well by using "unused"
  * function attribute, which is redundant but not harmful for gcc.
+ * Prefer gnu_inline, so that extern inline functions do not emit an
+ * externally visible function. This makes extern inline behave as per gnu89
+ * semantics rather than c99. This prevents multiple symbol definition errors
+ * of extern inline functions at link time.
+ * A lot of inline functions can cause havoc with function tracing.
  */
 #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) ||		\
     !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
-#define inline inline		__attribute__((always_inline,unused)) notrace
-#define __inline__ __inline__	__attribute__((always_inline,unused)) notrace
-#define __inline __inline	__attribute__((always_inline,unused)) notrace
+#define inline \
+	inline __attribute__((always_inline, unused)) notrace __gnu_inline
 #else
-/* A lot of inline functions can cause havoc with function tracing */
-#define inline inline		__attribute__((unused)) notrace
-#define __inline__ __inline__	__attribute__((unused)) notrace
-#define __inline __inline	__attribute__((unused)) notrace
+#define inline inline		__attribute__((unused)) notrace __gnu_inline
 #endif
 
+#define __inline__ inline
+#define __inline inline
 #define __always_inline	inline __attribute__((always_inline))
 #define  noinline	__attribute__((noinline))
 



WARNING: multiple messages have this Message-ID
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: andrea.parri@amarulasolutions.com, kstewart@linuxfoundation.org,
	linux-efi@vger.kernel.org, brijesh.singh@amd.com,
	Peter Zijlstra <peterz@infradead.org>,
	jan.kiszka@siemens.com, will.deacon@arm.com,
	jarkko.sakkinen@linux.intel.com,
	virtualization@lists.linux-foundation.org,
	yamada.masahiro@socionext.com, manojgupta@google.com,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	tweek@google.com, mawilcox@microsoft.com, akataria@vmware.com,
	ghackmann@google.com, Ingo Molnar <mingo@kernel.org>,
	mjg59@google.com, mka@chromium.org, geert@linux-m68k.org,
	rientjes@google.com, aryabinin@virtuozzo.com,
	thomas.lendacky@amd.com, Arnd Bergmann <arnd@arndb.de>,
	linux-kbuild@vger.kernel.org, pombredanne@nexb.com,
	rostedt@goodmis.org, acme@redhat.com, caoj.fnst@cn.fujitsu.com,
	jpoimboe@redhat.com, sedat.dilek@gmail.com,
	boris.ostrovsky@oracle.com, Juergen
Subject: [PATCH 4.4 04/31] compiler-gcc.h: Add __attribute__((gnu_inline)) to all inline declarations
Date: Fri, 20 Jul 2018 14:13:34 +0200	[thread overview]
Message-ID: <20180720121340.315434780@linuxfoundation.org> (raw)
In-Reply-To: <20180720121340.158484922@linuxfoundation.org>

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nick Desaulniers <ndesaulniers@google.com>

commit d03db2bc26f0e4a6849ad649a09c9c73fccdc656 upstream.

Functions marked extern inline do not emit an externally visible
function when the gnu89 C standard is used. Some KBUILD Makefiles
overwrite KBUILD_CFLAGS. This is an issue for GCC 5.1+ users as without
an explicit C standard specified, the default is gnu11. Since c99, the
semantics of extern inline have changed such that an externally visible
function is always emitted. This can lead to multiple definition errors
of extern inline functions at link time of compilation units whose build
files have removed an explicit C standard compiler flag for users of GCC
5.1+ or Clang.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@redhat.com
Cc: akataria@vmware.com
Cc: akpm@linux-foundation.org
Cc: andrea.parri@amarulasolutions.com
Cc: ard.biesheuvel@linaro.org
Cc: aryabinin@virtuozzo.com
Cc: astrachan@google.com
Cc: boris.ostrovsky@oracle.com
Cc: brijesh.singh@amd.com
Cc: caoj.fnst@cn.fujitsu.com
Cc: geert@linux-m68k.org
Cc: ghackmann@google.com
Cc: gregkh@linuxfoundation.org
Cc: jan.kiszka@siemens.com
Cc: jarkko.sakkinen@linux.intel.com
Cc: jpoimboe@redhat.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: kstewart@linuxfoundation.org
Cc: linux-efi@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Cc: manojgupta@google.com
Cc: mawilcox@microsoft.com
Cc: michal.lkml@markovi.net
Cc: mjg59@google.com
Cc: mka@chromium.org
Cc: pombredanne@nexb.com
Cc: rientjes@google.com
Cc: rostedt@goodmis.org
Cc: sedat.dilek@gmail.com
Cc: thomas.lendacky@amd.com
Cc: tstellar@redhat.com
Cc: tweek@google.com
Cc: virtualization@lists.linux-foundation.org
Cc: will.deacon@arm.com
Cc: yamada.masahiro@socionext.com
Link: http://lkml.kernel.org/r/20180621162324.36656-2-ndesaulniers@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 include/linux/compiler-gcc.h |   29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -65,25 +65,40 @@
 #endif
 
 /*
+ * Feature detection for gnu_inline (gnu89 extern inline semantics). Either
+ * __GNUC_STDC_INLINE__ is defined (not using gnu89 extern inline semantics,
+ * and we opt in to the gnu89 semantics), or __GNUC_STDC_INLINE__ is not
+ * defined so the gnu89 semantics are the default.
+ */
+#ifdef __GNUC_STDC_INLINE__
+# define __gnu_inline	__attribute__((gnu_inline))
+#else
+# define __gnu_inline
+#endif
+
+/*
  * Force always-inline if the user requests it so via the .config,
  * or if gcc is too old.
  * GCC does not warn about unused static inline functions for
  * -Wunused-function.  This turns out to avoid the need for complex #ifdef
  * directives.  Suppress the warning in clang as well by using "unused"
  * function attribute, which is redundant but not harmful for gcc.
+ * Prefer gnu_inline, so that extern inline functions do not emit an
+ * externally visible function. This makes extern inline behave as per gnu89
+ * semantics rather than c99. This prevents multiple symbol definition errors
+ * of extern inline functions at link time.
+ * A lot of inline functions can cause havoc with function tracing.
  */
 #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) ||		\
     !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
-#define inline inline		__attribute__((always_inline,unused)) notrace
-#define __inline__ __inline__	__attribute__((always_inline,unused)) notrace
-#define __inline __inline	__attribute__((always_inline,unused)) notrace
+#define inline \
+	inline __attribute__((always_inline, unused)) notrace __gnu_inline
 #else
-/* A lot of inline functions can cause havoc with function tracing */
-#define inline inline		__attribute__((unused)) notrace
-#define __inline__ __inline__	__attribute__((unused)) notrace
-#define __inline __inline	__attribute__((unused)) notrace
+#define inline inline		__attribute__((unused)) notrace __gnu_inline
 #endif
 
+#define __inline__ inline
+#define __inline inline
 #define __always_inline	inline __attribute__((always_inline))
 #define  noinline	__attribute__((noinline))

  parent reply	other threads:[~2018-07-20 12:27 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-20 12:13 [PATCH 4.4 00/31] 4.4.143-stable review Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 01/31] compiler, clang: suppress warning for unused static inline functions Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 02/31] compiler, clang: properly override inline for clang Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 03/31] compiler, clang: always inline when CONFIG_OPTIMIZE_INLINING is disabled Greg Kroah-Hartman
2018-07-20 12:13 ` Greg Kroah-Hartman [this message]
2018-07-20 12:13   ` [PATCH 4.4 04/31] compiler-gcc.h: Add __attribute__((gnu_inline)) to all inline declarations Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 05/31] x86/asm: Add _ASM_ARG* constants for argument registers to <asm/asm.h> Greg Kroah-Hartman
2018-07-20 12:13 ` Greg Kroah-Hartman
2018-07-20 12:13   ` Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 06/31] Revert "sit: reload iphdr in ipip6_rcv" Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 07/31] ocfs2: subsystem.su_mutex is required while accessing the item->ci_parent Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 08/31] bcm63xx_enet: correct clock usage Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 09/31] bcm63xx_enet: do not write to random DMA channel on BCM6345 Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 10/31] crypto: crypto4xx - remove bad list_del Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 11/31] crypto: crypto4xx - fix crypto4xx_build_pdr, crypto4xx_build_sdr leak Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 12/31] atm: zatm: Fix potential Spectre v1 Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 13/31] net: dccp: avoid crash in ccid3_hc_rx_send_feedback() Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 14/31] net: dccp: switch rx_tstamp_last_feedback to monotonic clock Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 15/31] net/mlx5: Fix incorrect raw command length parsing Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 16/31] net: sungem: fix rx checksum support Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 17/31] qed: Limit msix vectors in kdump kernel to the minimum required count Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 18/31] r8152: napi hangup fix after disconnect Greg Kroah-Hartman
2018-07-20 12:13   ` [4.4,18/31] " Greg Kroah-Hartman
2018-08-24 16:38   ` [PATCH 4.4 18/31] " Ben Hutchings
2018-08-24 16:38     ` [4.4,18/31] " Ben Hutchings
2018-08-25  7:43     ` [PATCH 4.4 18/31] " Jiri Slaby
2018-08-25  7:43       ` [4.4,18/31] " Jiri Slaby
2018-09-12 18:54       ` [PATCH 4.4 18/31] " Ben Hutchings
2018-09-12 18:54         ` [4.4,18/31] " Ben Hutchings
2018-07-20 12:13 ` [PATCH 4.4 19/31] tcp: fix Fast Open key endianness Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 21/31] vhost_net: validate sock before trying to put its fd Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 22/31] net_sched: blackhole: tell upper qdisc about dropped packets Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 23/31] net/mlx5: Fix command interface race in polling mode Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 24/31] net: cxgb3_main: fix potential Spectre v1 Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 25/31] rtlwifi: rtl8821ae: fix firmware is not ready to run Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 26/31] MIPS: Call dump_stack() from show_regs() Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 27/31] MIPS: Use async IPIs for arch_trigger_cpumask_backtrace() Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 28/31] netfilter: ebtables: reject non-bridge targets Greg Kroah-Hartman
2018-07-20 12:13 ` [PATCH 4.4 29/31] KEYS: DNS: fix parsing multiple options Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.4 30/31] rds: avoid unenecessary cong_update in loop transport Greg Kroah-Hartman
2018-07-20 12:14 ` [PATCH 4.4 31/31] net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL Greg Kroah-Hartman
2018-07-20 13:34 ` [PATCH 4.4 00/31] 4.4.143-stable review Nathan Chancellor
2018-07-21  7:38 ` Naresh Kamboju
2018-07-21 13:39 ` Guenter Roeck

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180720121340.315434780@linuxfoundation.org \
    --to=gregkh@linuxfoundation.org \
    --cc=acme@redhat.com \
    --cc=akataria@vmware.com \
    --cc=akpm@linux-foundation.org \
    --cc=andrea.parri@amarulasolutions.com \
    --cc=ard.biesheuvel@linaro.org \
    --cc=arnd@arndb.de \
    --cc=aryabinin@virtuozzo.com \
    --cc=astrachan@google.com \
    --cc=boris.ostrovsky@oracle.com \
    --cc=brijesh.singh@amd.com \
    --cc=caoj.fnst@cn.fujitsu.com \
    --cc=geert@linux-m68k.org \
    --cc=ghackmann@google.com \
    --cc=hpa@zytor.com \
    --cc=jan.kiszka@siemens.com \
    --cc=jarkko.sakkinen@linux.intel.com \
    --cc=jgross@suse.com \
    --cc=joe@perches.com \
    --cc=jpoimboe@redhat.com \
    --cc=keescook@google.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=kstewart@linuxfoundation.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=manojgupta@google.com \
    --cc=mawilcox@microsoft.com \
    --cc=michal.lkml@markovi.net \
    --cc=mingo@kernel.org \
    --cc=mjg59@google.com \
    --cc=mka@chromium.org \
    --cc=ndesaulniers@google.com \
    --cc=peterz@infradead.org \
    --cc=pombredanne@nexb.com \
    --cc=rientjes@google.com \
    --cc=rostedt@goodmis.org \
    --cc=sedat.dilek@gmail.com \
    --cc=stable@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=thomas.lendacky@amd.com \
    --cc=torvalds@linux-foundation.org \
    --cc=tstellar@redhat.com \
    --cc=tweek@google.com \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=will.deacon@arm.com \
    --cc=yamada.masahiro@socionext.com \
    --subject='Re: [PATCH 4.4 04/31] compiler-gcc.h: Add __attribute__((gnu_inline)) to all inline declarations' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.