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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Yousong Zhou <yszhou4tech@gmail.com>,
	"Maciej W. Rozycki" <macro@linux-mips.org>,
	linux-mips@linux-mips.org, Ralf Baechle <ralf@linux-mips.org>,
	Amit Pundir <amit.pundir@linaro.org>
Subject: [PATCH 3.18 02/22] MIPS: UAPI: Ignore __arch_swab{16,32,64} when using MIPS16
Date: Thu, 13 Jul 2017 17:42:42 +0200	[thread overview]
Message-ID: <20170713153934.228855979@linuxfoundation.org> (raw)
In-Reply-To: <20170713153934.089183081@linuxfoundation.org>

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

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

From: Yousong Zhou <yszhou4tech@gmail.com>

commit 71a0a72456b48de972d7ed613b06a22a3aa9057f upstream.

Some GCC versions (e.g. 4.8.3) can incorrectly inline a function with
MIPS32 instructions into another function with MIPS16 code [1], causing
the assembler to genereate incorrect binary code or fail right away
complaining about unrecognized opcode.

In the case of __arch_swab{16,32}, when inlined by the compiler with
flags `-mips32r2 -mips16 -Os', the assembler can fail with the following
error.

    {standard input}:79: Error: unrecognized opcode `wsbh $2,$2'

For performance concerns and to workaround the issue already existing in
older compilers, just ignore these 2 functions when compiling with
mips16 enabled.

 [1] Inlining nomips16 function into mips16 function can result in
     undefined builtins, https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55777

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11241/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/uapi/asm/swab.h |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/arch/mips/include/uapi/asm/swab.h
+++ b/arch/mips/include/uapi/asm/swab.h
@@ -13,8 +13,9 @@
 
 #define __SWAB_64_THRU_32__
 
-#if (defined(__mips_isa_rev) && (__mips_isa_rev >= 2)) ||		\
-    defined(_MIPS_ARCH_LOONGSON3A)
+#if !defined(__mips16) &&					\
+	((defined(__mips_isa_rev) && (__mips_isa_rev >= 2)) ||	\
+	 defined(_MIPS_ARCH_LOONGSON3A))
 
 static inline __attribute_const__ __u16 __arch_swab16(__u16 x)
 {
@@ -65,5 +66,5 @@ static inline __attribute_const__ __u64
 }
 #define __arch_swab64 __arch_swab64
 #endif /* __mips64 */
-#endif /* MIPS R2 or newer or Loongson 3A */
+#endif /* (not __mips16) and (MIPS R2 or newer or Loongson 3A) */
 #endif /* _ASM_SWAB_H */

  parent reply	other threads:[~2017-07-13 15:58 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-13 15:42 [PATCH 3.18 00/22] 3.18.61-stable review Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 01/22] driver core: platform: fix race condition with driver_override Greg Kroah-Hartman
2017-07-13 15:42 ` Greg Kroah-Hartman [this message]
2017-07-13 15:42 ` [PATCH 3.18 04/22] bgmac: add check for oversized packets Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 06/22] usb: ehci-orion: fix probe for !GENERIC_PHY Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 07/22] tracing/kprobes: Allow to create probe with a module name starting with a digit Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 08/22] usb: dwc3: replace %p with %pK Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 09/22] USB: serial: cp210x: add ID for CEL EM3588 USB ZigBee stick Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 10/22] Add USB quirk for HVR-950q to avoid intermittent device resets Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 11/22] usb: usbip: set buffer pointers to NULL after free Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 12/22] usb: Fix typo in the definition of Endpoint[out]Request Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 14/22] pinctrl: sh-pfc: Update info pointer after SoC-specific init Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 17/22] KEYS: Fix an error code in request_master_key() Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 18/22] mqueue: fix a use-after-free in sys_mq_notify() Greg Kroah-Hartman
2017-07-13 15:42 ` [PATCH 3.18 19/22] md: fix super_offset endianness in super_1_rdev_size_change Greg Kroah-Hartman
2017-07-13 15:43 ` [PATCH 3.18 20/22] staging: vt6556: vnt_start Fix missing call to vnt_key_init_table Greg Kroah-Hartman
2017-07-13 15:43 ` [PATCH 3.18 21/22] staging: comedi: fix clean-up of comedi_class in comedi_init() Greg Kroah-Hartman
2017-07-13 15:43 ` [PATCH 3.18 22/22] [media] saa7134: fix warm Medion 7134 EEPROM read Greg Kroah-Hartman
2017-07-14  1:26 ` [PATCH 3.18 00/22] 3.18.61-stable review Guenter Roeck
2017-07-14  9:31   ` Greg Kroah-Hartman
2017-07-14 11:43     ` Amit Pundir

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