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From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, "Arnd Bergmann" <arnd@arndb.de>,
	linux-mips@linux-mips.org, "Ralf Baechle" <ralf@linux-mips.org>,
	"Paul Burton" <paul.burton@imgtec.com>
Subject: [PATCH 3.16 05/19] MIPS: save/disable MSA in lose_fpu
Date: Sat, 01 Apr 2017 14:17:50 +0100	[thread overview]
Message-ID: <lsq.1491052670.178507888@decadent.org.uk> (raw)
In-Reply-To: <lsq.1491052670.319419763@decadent.org.uk>

3.16.43-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Paul Burton <paul.burton@imgtec.com>

commit 33c771ba5c5d067f85a5a6c4b11047219b5b8f4e upstream.

The kernel depends upon MSA never being enabled when the FPU is not, a
condition which is currently violated in a few places (whilst saving
sigcontext, following mips_cpu_save). Catch all the problem cases by
disabling MSA in lose_fpu, after saving context if necessary.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7302/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 arch/mips/include/asm/fpu.h | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

--- a/arch/mips/include/asm/fpu.h
+++ b/arch/mips/include/asm/fpu.h
@@ -21,6 +21,7 @@
 #include <asm/hazards.h>
 #include <asm/processor.h>
 #include <asm/current.h>
+#include <asm/msa.h>
 
 #ifdef CONFIG_MIPS_MT_FPAFF
 #include <asm/mips_mt.h>
@@ -141,13 +142,21 @@ static inline int own_fpu(int restore)
 static inline void lose_fpu(int save)
 {
 	preempt_disable();
-	if (is_fpu_owner()) {
+	if (is_msa_enabled()) {
+		if (save) {
+			save_msa(current);
+			asm volatile("cfc1 %0, $31"
+				: "=r"(current->thread.fpu.fcr31));
+		}
+		disable_msa();
+		clear_thread_flag(TIF_USEDMSA);
+	} else if (is_fpu_owner()) {
 		if (save)
 			_save_fp(current);
-		KSTK_STATUS(current) &= ~ST0_CU1;
-		clear_thread_flag(TIF_USEDFPU);
 		__disable_fpu();
 	}
+	KSTK_STATUS(current) &= ~ST0_CU1;
+	clear_thread_flag(TIF_USEDFPU);
 	preempt_enable();
 }
 

  parent reply	other threads:[~2017-04-01 13:17 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-01 13:17 [PATCH 3.16 00/19] 3.16.43-rc1 review Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 13/19] MIPS: ralink: Cosmetic change to prom_init() Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 17/19] vfs: Commit to never having exectuables on proc and sysfs Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 19/19] keys: Guard against null match function in keyring_search_aux() Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 10/19] fs/nfs: fix new compiler warning about boolean in switch Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 01/19] fs: namespace: suppress 'may be used uninitialized' warnings Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 15/19] HID: hid-input: Add parentheses to quell gcc warning Ben Hutchings
2017-04-01 13:17 ` Ben Hutchings [this message]
2017-04-01 13:17 ` [PATCH 3.16 09/19] crypto: improve gcc optimization flags for serpent and wp512 Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 11/19] mmc: sunxi: avoid invalid pointer calculation Ben Hutchings
2017-04-01 18:45   ` David Lanzendörfer
2017-04-01 19:53     ` Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 07/19] MIPS: Fix build with binutils 2.24.51+ Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 06/19] MIPS: init upper 64b of vector registers when MSA is first used Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 04/19] MIPS: preserve scalar FP CSR when switching vector context Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 03/19] MIPS: save/restore MSACSR register on context switch Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 14/19] MIPS: Zero variable read by get_user / __get_user in case of an error Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 12/19] serial: samsung: Use %pa to print 'resource_size_t' type Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 16/19] netlink: remove mmapped netlink support Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 08/19] atm: iphase: fix misleading indention Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 02/19] blk: rq_data_dir() should not return a boolean Ben Hutchings
2017-04-01 13:17 ` [PATCH 3.16 18/19] aio: mark AIO pseudo-fs noexec Ben Hutchings
2017-04-01 17:43 ` [PATCH 3.16 00/19] 3.16.43-rc1 review Guenter Roeck
2017-04-01 22:40   ` Ben Hutchings
2017-04-02  2:21     ` Guenter Roeck
2017-04-02  2:48     ` Ben Hutchings
2017-04-02  3:04 ` [PATCH 3.16 00/26] 3.16.43-rc2 review Ben Hutchings
2017-04-02  3:04   ` [PATCH 3.16 21/26] MIPS: mipsregs.h: Add write_32bit_cp1_register() Ben Hutchings
2017-04-02  3:04   ` [PATCH 3.16 20/26] MIPS: allow msa.h to be included in assembly files Ben Hutchings
2017-04-02  3:04   ` [PATCH 3.16 26/26] MIPS: wrap cfcmsa & ctcmsa accesses for toolchains with MSA support Ben Hutchings
2017-04-02  3:04   ` [PATCH 3.16 23/26] MIPS: Push .set mips64r* into the functions needing it Ben Hutchings
2017-04-02  3:04   ` [PATCH 3.16 25/26] MIPS: remove MSA macro recursion Ben Hutchings
2017-04-02  3:04   ` [PATCH 3.16 24/26] MIPS: assume at as source/dest of MSA copy/insert instructions Ben Hutchings
2017-04-02  3:04   ` [PATCH 3.16 22/26] MIPS: traps: Fix inline asm ctc1 missing .set hardfloat Ben Hutchings
2017-04-02  3:15   ` [PATCH 3.16 00/26] 3.16.43-rc2 review Ben Hutchings

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