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authorPaul Burton <paul.burton@imgtec.com>2013-11-22 13:12:07 +0000
committerRalf Baechle <ralf@linux-mips.org>2014-01-13 23:40:56 +0100
commit597ce1723e0fa0bdbe2ae4c94f18da6e29b92635 (patch)
tree21f67268915b8457dd305c6bcf7ac905772fd0ee /arch/mips/kernel
parent56a22d21bf9744315f56b2bbd6416170f27b7765 (diff)
downloadop-kernel-dev-597ce1723e0fa0bdbe2ae4c94f18da6e29b92635.zip
op-kernel-dev-597ce1723e0fa0bdbe2ae4c94f18da6e29b92635.tar.gz
MIPS: Support for 64-bit FP with O32 binaries
CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs do. In order to preserve backwards compatibility a 64-bit FPU will act like a 32-bit FPU (by accessing doubles from the least significant 32 bits of an even-odd pair of FP registers) when the Status.FR bit is zero, again just like a mips64 CPU. The standard O32 ABI is defined expecting a 32-bit FPU, however recent toolchains support use of a 64-bit FPU from an O32 MIPS32 executable. When an ELF executable is built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF header. With this patch the kernel will check the EF_MIPS_FP64 flag when executing an O32 binary, and set Status.FR accordingly. The addition of O32 64-bit FP support lessens the opportunity for optimisation in the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is introduced to allow this support to be disabled for those that don't require it. Inspired by an earlier patch by Leonid Yegoshin, but implemented more cleanly & correctly. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Paul Burton <paul.burton@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/6154/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r--arch/mips/kernel/binfmt_elfo32.c14
-rw-r--r--arch/mips/kernel/cpu-probe.c2
-rw-r--r--arch/mips/kernel/process.c3
-rw-r--r--arch/mips/kernel/ptrace.c60
-rw-r--r--arch/mips/kernel/ptrace32.c53
-rw-r--r--arch/mips/kernel/r4k_fpu.S74
-rw-r--r--arch/mips/kernel/r4k_switch.S45
-rw-r--r--arch/mips/kernel/signal.c10
-rw-r--r--arch/mips/kernel/signal32.c10
-rw-r--r--arch/mips/kernel/traps.c10
10 files changed, 209 insertions, 72 deletions
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index 202e581..7faf5f2 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -28,6 +28,18 @@ typedef double elf_fpreg_t;
typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
/*
+ * In order to be sure that we don't attempt to execute an O32 binary which
+ * requires 64 bit FP (FR=1) on a system which does not support it we refuse
+ * to execute any binary which has bits specified by the following macro set
+ * in its ELF header flags.
+ */
+#ifdef CONFIG_MIPS_O32_FP64_SUPPORT
+# define __MIPS_O32_FP64_MUST_BE_ZERO 0
+#else
+# define __MIPS_O32_FP64_MUST_BE_ZERO EF_MIPS_FP64
+#endif
+
+/*
* This is used to ensure we don't load something for the wrong architecture.
*/
#define elf_check_arch(hdr) \
@@ -44,6 +56,8 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
if (((__h->e_flags & EF_MIPS_ABI) != 0) && \
((__h->e_flags & EF_MIPS_ABI) != EF_MIPS_ABI_O32)) \
__res = 0; \
+ if (__h->e_flags & __MIPS_O32_FP64_MUST_BE_ZERO) \
+ __res = 0; \
\
__res; \
})
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index c814287..e2b2d20 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -112,7 +112,7 @@ static inline unsigned long cpu_get_fpu_id(void)
unsigned long tmp, fpu_id;
tmp = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
fpu_id = read_32bit_cp1_register(CP1_REVISION);
write_c0_status(tmp);
return fpu_id;
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index ddc7610..747a6cf 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -60,9 +60,6 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
/* New thread loses kernel privileges. */
status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK);
-#ifdef CONFIG_64BIT
- status |= test_thread_flag(TIF_32BIT_REGS) ? 0 : ST0_FR;
-#endif
status |= KU_USER;
regs->cp0_status = status;
clear_used_math();
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index b52e1d2..7da9b76 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -137,13 +137,13 @@ int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
write_c0_status(flags);
}
@@ -408,6 +408,7 @@ long arch_ptrace(struct task_struct *child, long request,
/* Read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
struct pt_regs *regs;
+ fpureg_t *fregs;
unsigned long tmp = 0;
regs = task_pt_regs(child);
@@ -418,26 +419,28 @@ long arch_ptrace(struct task_struct *child, long request,
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
- if (tsk_used_math(child)) {
- fpureg_t *fregs = get_fpu_regs(child);
+ if (!tsk_used_math(child)) {
+ /* FP not yet used */
+ tmp = -1;
+ break;
+ }
+ fregs = get_fpu_regs(child);
#ifdef CONFIG_32BIT
+ if (test_thread_flag(TIF_32BIT_FPREGS)) {
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers - unless we're using r2k_switch.S.
*/
if (addr & 1)
- tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
+ tmp = fregs[(addr & ~1) - 32] >> 32;
else
- tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
-#endif
-#ifdef CONFIG_64BIT
- tmp = fregs[addr - FPR_BASE];
-#endif
- } else {
- tmp = -1; /* FP not yet used */
+ tmp = fregs[addr - 32];
+ break;
}
+#endif
+ tmp = fregs[addr - FPR_BASE];
break;
case PC:
tmp = regs->cp0_epc;
@@ -483,13 +486,13 @@ long arch_ptrace(struct task_struct *child, long request,
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
}
@@ -554,22 +557,25 @@ long arch_ptrace(struct task_struct *child, long request,
child->thread.fpu.fcr31 = 0;
}
#ifdef CONFIG_32BIT
- /*
- * The odd registers are actually the high order bits
- * of the values stored in the even registers - unless
- * we're using r2k_switch.S.
- */
- if (addr & 1) {
- fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
- fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
- } else {
- fregs[addr - FPR_BASE] &= ~0xffffffffLL;
- fregs[addr - FPR_BASE] |= data;
+ if (test_thread_flag(TIF_32BIT_FPREGS)) {
+ /*
+ * The odd registers are actually the high
+ * order bits of the values stored in the even
+ * registers - unless we're using r2k_switch.S.
+ */
+ if (addr & 1) {
+ fregs[(addr & ~1) - FPR_BASE] &=
+ 0xffffffff;
+ fregs[(addr & ~1) - FPR_BASE] |=
+ ((u64)data) << 32;
+ } else {
+ fregs[addr - FPR_BASE] &= ~0xffffffffLL;
+ fregs[addr - FPR_BASE] |= data;
+ }
+ break;
}
#endif
-#ifdef CONFIG_64BIT
fregs[addr - FPR_BASE] = data;
-#endif
break;
}
case PC:
diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c
index 9486055..b8aa2dd 100644
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -80,6 +80,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
/* Read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
struct pt_regs *regs;
+ fpureg_t *fregs;
unsigned int tmp;
regs = task_pt_regs(child);
@@ -90,21 +91,25 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
- if (tsk_used_math(child)) {
- fpureg_t *fregs = get_fpu_regs(child);
-
+ if (!tsk_used_math(child)) {
+ /* FP not yet used */
+ tmp = -1;
+ break;
+ }
+ fregs = get_fpu_regs(child);
+ if (test_thread_flag(TIF_32BIT_FPREGS)) {
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers - unless we're using r2k_switch.S.
*/
if (addr & 1)
- tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
+ tmp = fregs[(addr & ~1) - 32] >> 32;
else
- tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
- } else {
- tmp = -1; /* FP not yet used */
+ tmp = fregs[addr - 32];
+ break;
}
+ tmp = fregs[addr - FPR_BASE];
break;
case PC:
tmp = regs->cp0_epc;
@@ -147,13 +152,13 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
}
@@ -236,20 +241,24 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
sizeof(child->thread.fpu));
child->thread.fpu.fcr31 = 0;
}
- /*
- * The odd registers are actually the high order bits
- * of the values stored in the even registers - unless
- * we're using r2k_switch.S.
- */
- if (addr & 1) {
- fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
- fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
- } else {
- fregs[addr - FPR_BASE] &= ~0xffffffffLL;
- /* Must cast, lest sign extension fill upper
- bits! */
- fregs[addr - FPR_BASE] |= (unsigned int)data;
+ if (test_thread_flag(TIF_32BIT_FPREGS)) {
+ /*
+ * The odd registers are actually the high
+ * order bits of the values stored in the even
+ * registers - unless we're using r2k_switch.S.
+ */
+ if (addr & 1) {
+ fregs[(addr & ~1) - FPR_BASE] &=
+ 0xffffffff;
+ fregs[(addr & ~1) - FPR_BASE] |=
+ ((u64)data) << 32;
+ } else {
+ fregs[addr - FPR_BASE] &= ~0xffffffffLL;
+ fregs[addr - FPR_BASE] |= data;
+ }
+ break;
}
+ fregs[addr - FPR_BASE] = data;
break;
}
case PC:
diff --git a/arch/mips/kernel/r4k_fpu.S b/arch/mips/kernel/r4k_fpu.S
index 55ffe14..253b2fb 100644
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -35,7 +35,15 @@
LEAF(_save_fp_context)
cfc1 t1, fcr31
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) || defined(CONFIG_MIPS32_R2)
+ .set push
+#ifdef CONFIG_MIPS32_R2
+ .set mips64r2
+ mfc0 t0, CP0_STATUS
+ sll t0, t0, 5
+ bgez t0, 1f # skip storing odd if FR=0
+ nop
+#endif
/* Store the 16 odd double precision registers */
EX sdc1 $f1, SC_FPREGS+8(a0)
EX sdc1 $f3, SC_FPREGS+24(a0)
@@ -53,6 +61,7 @@ LEAF(_save_fp_context)
EX sdc1 $f27, SC_FPREGS+216(a0)
EX sdc1 $f29, SC_FPREGS+232(a0)
EX sdc1 $f31, SC_FPREGS+248(a0)
+1: .set pop
#endif
/* Store the 16 even double precision registers */
@@ -82,7 +91,31 @@ LEAF(_save_fp_context)
LEAF(_save_fp_context32)
cfc1 t1, fcr31
- EX sdc1 $f0, SC32_FPREGS+0(a0)
+ mfc0 t0, CP0_STATUS
+ sll t0, t0, 5
+ bgez t0, 1f # skip storing odd if FR=0
+ nop
+
+ /* Store the 16 odd double precision registers */
+ EX sdc1 $f1, SC32_FPREGS+8(a0)
+ EX sdc1 $f3, SC32_FPREGS+24(a0)
+ EX sdc1 $f5, SC32_FPREGS+40(a0)
+ EX sdc1 $f7, SC32_FPREGS+56(a0)
+ EX sdc1 $f9, SC32_FPREGS+72(a0)
+ EX sdc1 $f11, SC32_FPREGS+88(a0)
+ EX sdc1 $f13, SC32_FPREGS+104(a0)
+ EX sdc1 $f15, SC32_FPREGS+120(a0)
+ EX sdc1 $f17, SC32_FPREGS+136(a0)
+ EX sdc1 $f19, SC32_FPREGS+152(a0)
+ EX sdc1 $f21, SC32_FPREGS+168(a0)
+ EX sdc1 $f23, SC32_FPREGS+184(a0)
+ EX sdc1 $f25, SC32_FPREGS+200(a0)
+ EX sdc1 $f27, SC32_FPREGS+216(a0)
+ EX sdc1 $f29, SC32_FPREGS+232(a0)
+ EX sdc1 $f31, SC32_FPREGS+248(a0)
+
+ /* Store the 16 even double precision registers */
+1: EX sdc1 $f0, SC32_FPREGS+0(a0)
EX sdc1 $f2, SC32_FPREGS+16(a0)
EX sdc1 $f4, SC32_FPREGS+32(a0)
EX sdc1 $f6, SC32_FPREGS+48(a0)
@@ -114,7 +147,16 @@ LEAF(_save_fp_context32)
*/
LEAF(_restore_fp_context)
EX lw t0, SC_FPC_CSR(a0)
-#ifdef CONFIG_64BIT
+
+#if defined(CONFIG_64BIT) || defined(CONFIG_MIPS32_R2)
+ .set push
+#ifdef CONFIG_MIPS32_R2
+ .set mips64r2
+ mfc0 t0, CP0_STATUS
+ sll t0, t0, 5
+ bgez t0, 1f # skip loading odd if FR=0
+ nop
+#endif
EX ldc1 $f1, SC_FPREGS+8(a0)
EX ldc1 $f3, SC_FPREGS+24(a0)
EX ldc1 $f5, SC_FPREGS+40(a0)
@@ -131,6 +173,7 @@ LEAF(_restore_fp_context)
EX ldc1 $f27, SC_FPREGS+216(a0)
EX ldc1 $f29, SC_FPREGS+232(a0)
EX ldc1 $f31, SC_FPREGS+248(a0)
+1: .set pop
#endif
EX ldc1 $f0, SC_FPREGS+0(a0)
EX ldc1 $f2, SC_FPREGS+16(a0)
@@ -157,7 +200,30 @@ LEAF(_restore_fp_context)
LEAF(_restore_fp_context32)
/* Restore an o32 sigcontext. */
EX lw t0, SC32_FPC_CSR(a0)
- EX ldc1 $f0, SC32_FPREGS+0(a0)
+
+ mfc0 t0, CP0_STATUS
+ sll t0, t0, 5
+ bgez t0, 1f # skip loading odd if FR=0
+ nop
+
+ EX ldc1 $f1, SC32_FPREGS+8(a0)
+ EX ldc1 $f3, SC32_FPREGS+24(a0)
+ EX ldc1 $f5, SC32_FPREGS+40(a0)
+ EX ldc1 $f7, SC32_FPREGS+56(a0)
+ EX ldc1 $f9, SC32_FPREGS+72(a0)
+ EX ldc1 $f11, SC32_FPREGS+88(a0)
+ EX ldc1 $f13, SC32_FPREGS+104(a0)
+ EX ldc1 $f15, SC32_FPREGS+120(a0)
+ EX ldc1 $f17, SC32_FPREGS+136(a0)
+ EX ldc1 $f19, SC32_FPREGS+152(a0)
+ EX ldc1 $f21, SC32_FPREGS+168(a0)
+ EX ldc1 $f23, SC32_FPREGS+184(a0)
+ EX ldc1 $f25, SC32_FPREGS+200(a0)
+ EX ldc1 $f27, SC32_FPREGS+216(a0)
+ EX ldc1 $f29, SC32_FPREGS+232(a0)
+ EX ldc1 $f31, SC32_FPREGS+248(a0)
+
+1: EX ldc1 $f0, SC32_FPREGS+0(a0)
EX ldc1 $f2, SC32_FPREGS+16(a0)
EX ldc1 $f4, SC32_FPREGS+32(a0)
EX ldc1 $f6, SC32_FPREGS+48(a0)
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index 078de5ea..cc78dd9 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -123,7 +123,7 @@
* Save a thread's fp context.
*/
LEAF(_save_fp)
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
mfc0 t0, CP0_STATUS
#endif
fpu_save_double a0 t0 t1 # clobbers t1
@@ -134,7 +134,7 @@ LEAF(_save_fp)
* Restore a thread's fp context.
*/
LEAF(_restore_fp)
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
mfc0 t0, CP0_STATUS
#endif
fpu_restore_double a0 t0 t1 # clobbers t1
@@ -228,6 +228,47 @@ LEAF(_init_fpu)
mtc1 t1, $f29
mtc1 t1, $f30
mtc1 t1, $f31
+
+#ifdef CONFIG_CPU_MIPS32_R2
+ .set push
+ .set mips64r2
+ sll t0, t0, 5 # is Status.FR set?
+ bgez t0, 1f # no: skip setting upper 32b
+
+ mthc1 t1, $f0
+ mthc1 t1, $f1
+ mthc1 t1, $f2
+ mthc1 t1, $f3
+ mthc1 t1, $f4
+ mthc1 t1, $f5
+ mthc1 t1, $f6
+ mthc1 t1, $f7
+ mthc1 t1, $f8
+ mthc1 t1, $f9
+ mthc1 t1, $f10
+ mthc1 t1, $f11
+ mthc1 t1, $f12
+ mthc1 t1, $f13
+ mthc1 t1, $f14
+ mthc1 t1, $f15
+ mthc1 t1, $f16
+ mthc1 t1, $f17
+ mthc1 t1, $f18
+ mthc1 t1, $f19
+ mthc1 t1, $f20
+ mthc1 t1, $f21
+ mthc1 t1, $f22
+ mthc1 t1, $f23
+ mthc1 t1, $f24
+ mthc1 t1, $f25
+ mthc1 t1, $f26
+ mthc1 t1, $f27
+ mthc1 t1, $f28
+ mthc1 t1, $f29
+ mthc1 t1, $f30
+ mthc1 t1, $f31
+1: .set pop
+#endif /* CONFIG_CPU_MIPS32_R2 */
#else
.set mips3
dmtc1 t1, $f0
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2f285ab..5199563 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -71,8 +71,9 @@ static int protected_save_fp_context(struct sigcontext __user *sc)
int err;
while (1) {
lock_fpu_owner();
- own_fpu_inatomic(1);
- err = save_fp_context(sc); /* this might fail */
+ err = own_fpu_inatomic(1);
+ if (!err)
+ err = save_fp_context(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
@@ -91,8 +92,9 @@ static int protected_restore_fp_context(struct sigcontext __user *sc)
int err, tmp __maybe_unused;
while (1) {
lock_fpu_owner();
- own_fpu_inatomic(0);
- err = restore_fp_context(sc); /* this might fail */
+ err = own_fpu_inatomic(0);
+ if (!err)
+ err = restore_fp_context(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index 1905a41..3d60f77 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -85,8 +85,9 @@ static int protected_save_fp_context32(struct sigcontext32 __user *sc)
int err;
while (1) {
lock_fpu_owner();
- own_fpu_inatomic(1);
- err = save_fp_context32(sc); /* this might fail */
+ err = own_fpu_inatomic(1);
+ if (!err)
+ err = save_fp_context32(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
@@ -105,8 +106,9 @@ static int protected_restore_fp_context32(struct sigcontext32 __user *sc)
int err, tmp __maybe_unused;
while (1) {
lock_fpu_owner();
- own_fpu_inatomic(0);
- err = restore_fp_context32(sc); /* this might fail */
+ err = own_fpu_inatomic(0);
+ if (!err)
+ err = restore_fp_context32(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index f9c8746..f40f688 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1080,7 +1080,7 @@ asmlinkage void do_cpu(struct pt_regs *regs)
unsigned long old_epc, old31;
unsigned int opcode;
unsigned int cpid;
- int status;
+ int status, err;
unsigned long __maybe_unused flags;
prev_state = exception_enter();
@@ -1153,19 +1153,19 @@ asmlinkage void do_cpu(struct pt_regs *regs)
case 1:
if (used_math()) /* Using the FPU again. */
- own_fpu(1);
+ err = own_fpu(1);
else { /* First time FPU user. */
- init_fpu();
+ err = init_fpu();
set_used_math();
}
- if (!raw_cpu_has_fpu) {
+ if (!raw_cpu_has_fpu || err) {
int sig;
void __user *fault_addr = NULL;
sig = fpu_emulator_cop1Handler(regs,
&current->thread.fpu,
0, &fault_addr);
- if (!process_fpemu_return(sig, fault_addr))
+ if (!process_fpemu_return(sig, fault_addr) && !err)
mt_ase_fp_affinity();
}
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