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Subject[PATCH 3.15 14/66] Revert "MIPS: Save/restore MSA context around signals"
Date
3.15-stable review patch.  If anyone has any objections, please let me know.

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

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

commit 16f77de82f2d2f628306dab9bc4799df0d28a199 upstream.

This reverts commit eec43a224cf1 "MIPS: Save/restore MSA context around
signals" and the MSA parts of ca750649e08c "MIPS: kernel: signal:
Prevent save/restore FPU context in user memory" (the restore path of
which appears incorrect anyway...).

The reverted patch took care not to break compatibility with userland
users of struct sigcontext, but inadvertantly changed the offset of the
uc_sigmask field of struct ucontext. Thus Linux v3.15 breaks the
userland ABI. The MSA context will need to be saved via some other
opt-in mechanism, but for now revert the change to reduce the fallout.

This will have minimal impact upon use of MSA since the only supported
CPU which includes it (the P5600) is 32-bit and therefore requires that
the experimental CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option be selected
before the kernel will set FR=1 for a task, a requirement for MSA use.
Thus the users of MSA are limited to known small groups of people & this
patch won't be breaking any previously working MSA-using userland
outside of experimental settings.

[ralf@linux-mips.org: Fixed rejects.]

Reported-by: Joseph S. Myers <joseph@codesourcery.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7107/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/mips/include/asm/sigcontext.h | 2
arch/mips/include/uapi/asm/sigcontext.h | 8 -
arch/mips/kernel/asm-offsets.c | 3
arch/mips/kernel/r4k_fpu.S | 213 --------------------------------
arch/mips/kernel/signal.c | 79 +----------
arch/mips/kernel/signal32.c | 74 +----------
6 files changed, 16 insertions(+), 363 deletions(-)

--- a/arch/mips/include/asm/sigcontext.h
+++ b/arch/mips/include/asm/sigcontext.h
@@ -32,8 +32,6 @@ struct sigcontext32 {
__u32 sc_lo2;
__u32 sc_hi3;
__u32 sc_lo3;
- __u64 sc_msaregs[32]; /* Most significant 64 bits */
- __u32 sc_msa_csr;
};
#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 || _MIPS_SIM == _MIPS_SIM_NABI32 */
#endif /* _ASM_SIGCONTEXT_H */
--- a/arch/mips/include/uapi/asm/sigcontext.h
+++ b/arch/mips/include/uapi/asm/sigcontext.h
@@ -12,10 +12,6 @@
#include <linux/types.h>
#include <asm/sgidefs.h>

-/* Bits which may be set in sc_used_math */
-#define USEDMATH_FP (1 << 0)
-#define USEDMATH_MSA (1 << 1)
-
#if _MIPS_SIM == _MIPS_SIM_ABI32

/*
@@ -41,8 +37,6 @@ struct sigcontext {
unsigned long sc_lo2;
unsigned long sc_hi3;
unsigned long sc_lo3;
- unsigned long long sc_msaregs[32]; /* Most significant 64 bits */
- unsigned long sc_msa_csr;
};

#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
@@ -76,8 +70,6 @@ struct sigcontext {
__u32 sc_used_math;
__u32 sc_dsp;
__u32 sc_reserved;
- __u64 sc_msaregs[32];
- __u32 sc_msa_csr;
};


--- a/arch/mips/kernel/asm-offsets.c
+++ b/arch/mips/kernel/asm-offsets.c
@@ -295,7 +295,6 @@ void output_sc_defines(void)
OFFSET(SC_LO2, sigcontext, sc_lo2);
OFFSET(SC_HI3, sigcontext, sc_hi3);
OFFSET(SC_LO3, sigcontext, sc_lo3);
- OFFSET(SC_MSAREGS, sigcontext, sc_msaregs);
BLANK();
}
#endif
@@ -310,7 +309,6 @@ void output_sc_defines(void)
OFFSET(SC_MDLO, sigcontext, sc_mdlo);
OFFSET(SC_PC, sigcontext, sc_pc);
OFFSET(SC_FPC_CSR, sigcontext, sc_fpc_csr);
- OFFSET(SC_MSAREGS, sigcontext, sc_msaregs);
BLANK();
}
#endif
@@ -322,7 +320,6 @@ void output_sc32_defines(void)
OFFSET(SC32_FPREGS, sigcontext32, sc_fpregs);
OFFSET(SC32_FPC_CSR, sigcontext32, sc_fpc_csr);
OFFSET(SC32_FPC_EIR, sigcontext32, sc_fpc_eir);
- OFFSET(SC32_MSAREGS, sigcontext32, sc_msaregs);
BLANK();
}
#endif
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -13,7 +13,6 @@
* Copyright (C) 1999, 2001 Silicon Graphics, Inc.
*/
#include <asm/asm.h>
-#include <asm/asmmacro.h>
#include <asm/errno.h>
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
@@ -246,218 +245,6 @@ LEAF(_restore_fp_context32)
END(_restore_fp_context32)
#endif

-#ifdef CONFIG_CPU_HAS_MSA
-
- .macro save_sc_msareg wr, off, sc, tmp
-#ifdef CONFIG_64BIT
- copy_u_d \tmp, \wr, 1
- EX sd \tmp, (\off+(\wr*8))(\sc)
-#elif defined(CONFIG_CPU_LITTLE_ENDIAN)
- copy_u_w \tmp, \wr, 2
- EX sw \tmp, (\off+(\wr*8)+0)(\sc)
- copy_u_w \tmp, \wr, 3
- EX sw \tmp, (\off+(\wr*8)+4)(\sc)
-#else /* CONFIG_CPU_BIG_ENDIAN */
- copy_u_w \tmp, \wr, 2
- EX sw \tmp, (\off+(\wr*8)+4)(\sc)
- copy_u_w \tmp, \wr, 3
- EX sw \tmp, (\off+(\wr*8)+0)(\sc)
-#endif
- .endm
-
-/*
- * int _save_msa_context(struct sigcontext *sc)
- *
- * Save the upper 64 bits of each vector register along with the MSA_CSR
- * register into sc. Returns zero on success, else non-zero.
- */
-LEAF(_save_msa_context)
- save_sc_msareg 0, SC_MSAREGS, a0, t0
- save_sc_msareg 1, SC_MSAREGS, a0, t0
- save_sc_msareg 2, SC_MSAREGS, a0, t0
- save_sc_msareg 3, SC_MSAREGS, a0, t0
- save_sc_msareg 4, SC_MSAREGS, a0, t0
- save_sc_msareg 5, SC_MSAREGS, a0, t0
- save_sc_msareg 6, SC_MSAREGS, a0, t0
- save_sc_msareg 7, SC_MSAREGS, a0, t0
- save_sc_msareg 8, SC_MSAREGS, a0, t0
- save_sc_msareg 9, SC_MSAREGS, a0, t0
- save_sc_msareg 10, SC_MSAREGS, a0, t0
- save_sc_msareg 11, SC_MSAREGS, a0, t0
- save_sc_msareg 12, SC_MSAREGS, a0, t0
- save_sc_msareg 13, SC_MSAREGS, a0, t0
- save_sc_msareg 14, SC_MSAREGS, a0, t0
- save_sc_msareg 15, SC_MSAREGS, a0, t0
- save_sc_msareg 16, SC_MSAREGS, a0, t0
- save_sc_msareg 17, SC_MSAREGS, a0, t0
- save_sc_msareg 18, SC_MSAREGS, a0, t0
- save_sc_msareg 19, SC_MSAREGS, a0, t0
- save_sc_msareg 20, SC_MSAREGS, a0, t0
- save_sc_msareg 21, SC_MSAREGS, a0, t0
- save_sc_msareg 22, SC_MSAREGS, a0, t0
- save_sc_msareg 23, SC_MSAREGS, a0, t0
- save_sc_msareg 24, SC_MSAREGS, a0, t0
- save_sc_msareg 25, SC_MSAREGS, a0, t0
- save_sc_msareg 26, SC_MSAREGS, a0, t0
- save_sc_msareg 27, SC_MSAREGS, a0, t0
- save_sc_msareg 28, SC_MSAREGS, a0, t0
- save_sc_msareg 29, SC_MSAREGS, a0, t0
- save_sc_msareg 30, SC_MSAREGS, a0, t0
- save_sc_msareg 31, SC_MSAREGS, a0, t0
- jr ra
- li v0, 0
- END(_save_msa_context)
-
-#ifdef CONFIG_MIPS32_COMPAT
-
-/*
- * int _save_msa_context32(struct sigcontext32 *sc)
- *
- * Save the upper 64 bits of each vector register along with the MSA_CSR
- * register into sc. Returns zero on success, else non-zero.
- */
-LEAF(_save_msa_context32)
- save_sc_msareg 0, SC32_MSAREGS, a0, t0
- save_sc_msareg 1, SC32_MSAREGS, a0, t0
- save_sc_msareg 2, SC32_MSAREGS, a0, t0
- save_sc_msareg 3, SC32_MSAREGS, a0, t0
- save_sc_msareg 4, SC32_MSAREGS, a0, t0
- save_sc_msareg 5, SC32_MSAREGS, a0, t0
- save_sc_msareg 6, SC32_MSAREGS, a0, t0
- save_sc_msareg 7, SC32_MSAREGS, a0, t0
- save_sc_msareg 8, SC32_MSAREGS, a0, t0
- save_sc_msareg 9, SC32_MSAREGS, a0, t0
- save_sc_msareg 10, SC32_MSAREGS, a0, t0
- save_sc_msareg 11, SC32_MSAREGS, a0, t0
- save_sc_msareg 12, SC32_MSAREGS, a0, t0
- save_sc_msareg 13, SC32_MSAREGS, a0, t0
- save_sc_msareg 14, SC32_MSAREGS, a0, t0
- save_sc_msareg 15, SC32_MSAREGS, a0, t0
- save_sc_msareg 16, SC32_MSAREGS, a0, t0
- save_sc_msareg 17, SC32_MSAREGS, a0, t0
- save_sc_msareg 18, SC32_MSAREGS, a0, t0
- save_sc_msareg 19, SC32_MSAREGS, a0, t0
- save_sc_msareg 20, SC32_MSAREGS, a0, t0
- save_sc_msareg 21, SC32_MSAREGS, a0, t0
- save_sc_msareg 22, SC32_MSAREGS, a0, t0
- save_sc_msareg 23, SC32_MSAREGS, a0, t0
- save_sc_msareg 24, SC32_MSAREGS, a0, t0
- save_sc_msareg 25, SC32_MSAREGS, a0, t0
- save_sc_msareg 26, SC32_MSAREGS, a0, t0
- save_sc_msareg 27, SC32_MSAREGS, a0, t0
- save_sc_msareg 28, SC32_MSAREGS, a0, t0
- save_sc_msareg 29, SC32_MSAREGS, a0, t0
- save_sc_msareg 30, SC32_MSAREGS, a0, t0
- save_sc_msareg 31, SC32_MSAREGS, a0, t0
- jr ra
- li v0, 0
- END(_save_msa_context32)
-
-#endif /* CONFIG_MIPS32_COMPAT */
-
- .macro restore_sc_msareg wr, off, sc, tmp
-#ifdef CONFIG_64BIT
- EX ld \tmp, (\off+(\wr*8))(\sc)
- insert_d \wr, 1, \tmp
-#elif defined(CONFIG_CPU_LITTLE_ENDIAN)
- EX lw \tmp, (\off+(\wr*8)+0)(\sc)
- insert_w \wr, 2, \tmp
- EX lw \tmp, (\off+(\wr*8)+4)(\sc)
- insert_w \wr, 3, \tmp
-#else /* CONFIG_CPU_BIG_ENDIAN */
- EX lw \tmp, (\off+(\wr*8)+4)(\sc)
- insert_w \wr, 2, \tmp
- EX lw \tmp, (\off+(\wr*8)+0)(\sc)
- insert_w \wr, 3, \tmp
-#endif
- .endm
-
-/*
- * int _restore_msa_context(struct sigcontext *sc)
- */
-LEAF(_restore_msa_context)
- restore_sc_msareg 0, SC_MSAREGS, a0, t0
- restore_sc_msareg 1, SC_MSAREGS, a0, t0
- restore_sc_msareg 2, SC_MSAREGS, a0, t0
- restore_sc_msareg 3, SC_MSAREGS, a0, t0
- restore_sc_msareg 4, SC_MSAREGS, a0, t0
- restore_sc_msareg 5, SC_MSAREGS, a0, t0
- restore_sc_msareg 6, SC_MSAREGS, a0, t0
- restore_sc_msareg 7, SC_MSAREGS, a0, t0
- restore_sc_msareg 8, SC_MSAREGS, a0, t0
- restore_sc_msareg 9, SC_MSAREGS, a0, t0
- restore_sc_msareg 10, SC_MSAREGS, a0, t0
- restore_sc_msareg 11, SC_MSAREGS, a0, t0
- restore_sc_msareg 12, SC_MSAREGS, a0, t0
- restore_sc_msareg 13, SC_MSAREGS, a0, t0
- restore_sc_msareg 14, SC_MSAREGS, a0, t0
- restore_sc_msareg 15, SC_MSAREGS, a0, t0
- restore_sc_msareg 16, SC_MSAREGS, a0, t0
- restore_sc_msareg 17, SC_MSAREGS, a0, t0
- restore_sc_msareg 18, SC_MSAREGS, a0, t0
- restore_sc_msareg 19, SC_MSAREGS, a0, t0
- restore_sc_msareg 20, SC_MSAREGS, a0, t0
- restore_sc_msareg 21, SC_MSAREGS, a0, t0
- restore_sc_msareg 22, SC_MSAREGS, a0, t0
- restore_sc_msareg 23, SC_MSAREGS, a0, t0
- restore_sc_msareg 24, SC_MSAREGS, a0, t0
- restore_sc_msareg 25, SC_MSAREGS, a0, t0
- restore_sc_msareg 26, SC_MSAREGS, a0, t0
- restore_sc_msareg 27, SC_MSAREGS, a0, t0
- restore_sc_msareg 28, SC_MSAREGS, a0, t0
- restore_sc_msareg 29, SC_MSAREGS, a0, t0
- restore_sc_msareg 30, SC_MSAREGS, a0, t0
- restore_sc_msareg 31, SC_MSAREGS, a0, t0
- jr ra
- li v0, 0
- END(_restore_msa_context)
-
-#ifdef CONFIG_MIPS32_COMPAT
-
-/*
- * int _restore_msa_context32(struct sigcontext32 *sc)
- */
-LEAF(_restore_msa_context32)
- restore_sc_msareg 0, SC32_MSAREGS, a0, t0
- restore_sc_msareg 1, SC32_MSAREGS, a0, t0
- restore_sc_msareg 2, SC32_MSAREGS, a0, t0
- restore_sc_msareg 3, SC32_MSAREGS, a0, t0
- restore_sc_msareg 4, SC32_MSAREGS, a0, t0
- restore_sc_msareg 5, SC32_MSAREGS, a0, t0
- restore_sc_msareg 6, SC32_MSAREGS, a0, t0
- restore_sc_msareg 7, SC32_MSAREGS, a0, t0
- restore_sc_msareg 8, SC32_MSAREGS, a0, t0
- restore_sc_msareg 9, SC32_MSAREGS, a0, t0
- restore_sc_msareg 10, SC32_MSAREGS, a0, t0
- restore_sc_msareg 11, SC32_MSAREGS, a0, t0
- restore_sc_msareg 12, SC32_MSAREGS, a0, t0
- restore_sc_msareg 13, SC32_MSAREGS, a0, t0
- restore_sc_msareg 14, SC32_MSAREGS, a0, t0
- restore_sc_msareg 15, SC32_MSAREGS, a0, t0
- restore_sc_msareg 16, SC32_MSAREGS, a0, t0
- restore_sc_msareg 17, SC32_MSAREGS, a0, t0
- restore_sc_msareg 18, SC32_MSAREGS, a0, t0
- restore_sc_msareg 19, SC32_MSAREGS, a0, t0
- restore_sc_msareg 20, SC32_MSAREGS, a0, t0
- restore_sc_msareg 21, SC32_MSAREGS, a0, t0
- restore_sc_msareg 22, SC32_MSAREGS, a0, t0
- restore_sc_msareg 23, SC32_MSAREGS, a0, t0
- restore_sc_msareg 24, SC32_MSAREGS, a0, t0
- restore_sc_msareg 25, SC32_MSAREGS, a0, t0
- restore_sc_msareg 26, SC32_MSAREGS, a0, t0
- restore_sc_msareg 27, SC32_MSAREGS, a0, t0
- restore_sc_msareg 28, SC32_MSAREGS, a0, t0
- restore_sc_msareg 29, SC32_MSAREGS, a0, t0
- restore_sc_msareg 30, SC32_MSAREGS, a0, t0
- restore_sc_msareg 31, SC32_MSAREGS, a0, t0
- jr ra
- li v0, 0
- END(_restore_msa_context32)
-
-#endif /* CONFIG_MIPS32_COMPAT */
-
-#endif /* CONFIG_CPU_HAS_MSA */
-
.set reorder

.type fault@function
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -31,7 +31,6 @@
#include <linux/bitops.h>
#include <asm/cacheflush.h>
#include <asm/fpu.h>
-#include <asm/msa.h>
#include <asm/sim.h>
#include <asm/ucontext.h>
#include <asm/cpu-features.h>
@@ -48,9 +47,6 @@ static int (*restore_fp_context)(struct
extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);

-extern asmlinkage int _save_msa_context(struct sigcontext __user *sc);
-extern asmlinkage int _restore_msa_context(struct sigcontext __user *sc);
-
struct sigframe {
u32 sf_ass[4]; /* argument save space for o32 */
u32 sf_pad[2]; /* Was: signal trampoline */
@@ -100,60 +96,20 @@ static int copy_fp_from_sigcontext(struc
}

/*
- * These functions will save only the upper 64 bits of the vector registers,
- * since the lower 64 bits have already been saved as the scalar FP context.
- */
-static int copy_msa_to_sigcontext(struct sigcontext __user *sc)
-{
- int i;
- int err = 0;
-
- for (i = 0; i < NUM_FPU_REGS; i++) {
- err |=
- __put_user(get_fpr64(&current->thread.fpu.fpr[i], 1),
- &sc->sc_msaregs[i]);
- }
- err |= __put_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
-
- return err;
-}
-
-static int copy_msa_from_sigcontext(struct sigcontext __user *sc)
-{
- int i;
- int err = 0;
- u64 val;
-
- for (i = 0; i < NUM_FPU_REGS; i++) {
- err |= __get_user(val, &sc->sc_msaregs[i]);
- set_fpr64(&current->thread.fpu.fpr[i], 1, val);
- }
- err |= __get_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
-
- return err;
-}
-
-/*
* Helper routines
*/
-static int protected_save_fp_context(struct sigcontext __user *sc,
- unsigned used_math)
+static int protected_save_fp_context(struct sigcontext __user *sc)
{
int err;
- bool save_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
#ifndef CONFIG_EVA
while (1) {
lock_fpu_owner();
if (is_fpu_owner()) {
err = save_fp_context(sc);
- if (save_msa && !err)
- err = _save_msa_context(sc);
unlock_fpu_owner();
} else {
unlock_fpu_owner();
err = copy_fp_to_sigcontext(sc);
- if (save_msa && !err)
- err = copy_msa_to_sigcontext(sc);
}
if (likely(!err))
break;
@@ -169,38 +125,24 @@ static int protected_save_fp_context(str
* EVA does not have FPU EVA instructions so saving fpu context directly
* does not work.
*/
- disable_msa();
lose_fpu(1);
err = save_fp_context(sc); /* this might fail */
- if (save_msa && !err)
- err = copy_msa_to_sigcontext(sc);
#endif
return err;
}

-static int protected_restore_fp_context(struct sigcontext __user *sc,
- unsigned used_math)
+static int protected_restore_fp_context(struct sigcontext __user *sc)
{
int err, tmp __maybe_unused;
- bool restore_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
#ifndef CONFIG_EVA
while (1) {
lock_fpu_owner();
if (is_fpu_owner()) {
err = restore_fp_context(sc);
- if (restore_msa && !err) {
- enable_msa();
- err = _restore_msa_context(sc);
- } else {
- /* signal handler may have used MSA */
- disable_msa();
- }
unlock_fpu_owner();
} else {
unlock_fpu_owner();
err = copy_fp_from_sigcontext(sc);
- if (!err && (used_math & USEDMATH_MSA))
- err = copy_msa_from_sigcontext(sc);
}
if (likely(!err))
break;
@@ -216,11 +158,8 @@ static int protected_restore_fp_context(
* EVA does not have FPU EVA instructions so restoring fpu context
* directly does not work.
*/
- enable_msa();
lose_fpu(0);
err = restore_fp_context(sc); /* this might fail */
- if (restore_msa && !err)
- err = copy_msa_from_sigcontext(sc);
#endif
return err;
}
@@ -252,8 +191,7 @@ int setup_sigcontext(struct pt_regs *reg
err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
}

- used_math = used_math() ? USEDMATH_FP : 0;
- used_math |= thread_msa_context_live() ? USEDMATH_MSA : 0;
+ used_math = !!used_math();
err |= __put_user(used_math, &sc->sc_used_math);

if (used_math) {
@@ -261,7 +199,7 @@ int setup_sigcontext(struct pt_regs *reg
* Save FPU state to signal context. Signal handler
* will "inherit" current FPU state.
*/
- err |= protected_save_fp_context(sc, used_math);
+ err |= protected_save_fp_context(sc);
}
return err;
}
@@ -286,14 +224,14 @@ int fpcsr_pending(unsigned int __user *f
}

static int
-check_and_restore_fp_context(struct sigcontext __user *sc, unsigned used_math)
+check_and_restore_fp_context(struct sigcontext __user *sc)
{
int err, sig;

err = sig = fpcsr_pending(&sc->sc_fpc_csr);
if (err > 0)
err = 0;
- err |= protected_restore_fp_context(sc, used_math);
+ err |= protected_restore_fp_context(sc);
return err ?: sig;
}

@@ -333,10 +271,9 @@ int restore_sigcontext(struct pt_regs *r
if (used_math) {
/* restore fpu context if we have used it before */
if (!err)
- err = check_and_restore_fp_context(sc, used_math);
+ err = check_and_restore_fp_context(sc);
} else {
- /* signal handler may have used FPU or MSA. Disable them. */
- disable_msa();
+ /* signal handler may have used FPU. Give it up. */
lose_fpu(0);
}

--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -30,7 +30,6 @@
#include <asm/sim.h>
#include <asm/ucontext.h>
#include <asm/fpu.h>
-#include <asm/msa.h>
#include <asm/war.h>
#include <asm/vdso.h>
#include <asm/dsp.h>
@@ -43,9 +42,6 @@ static int (*restore_fp_context32)(struc
extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);

-extern asmlinkage int _save_msa_context32(struct sigcontext32 __user *sc);
-extern asmlinkage int _restore_msa_context32(struct sigcontext32 __user *sc);
-
/*
* Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
*/
@@ -115,59 +111,19 @@ static int copy_fp_from_sigcontext32(str
}

/*
- * These functions will save only the upper 64 bits of the vector registers,
- * since the lower 64 bits have already been saved as the scalar FP context.
- */
-static int copy_msa_to_sigcontext32(struct sigcontext32 __user *sc)
-{
- int i;
- int err = 0;
-
- for (i = 0; i < NUM_FPU_REGS; i++) {
- err |=
- __put_user(get_fpr64(&current->thread.fpu.fpr[i], 1),
- &sc->sc_msaregs[i]);
- }
- err |= __put_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
-
- return err;
-}
-
-static int copy_msa_from_sigcontext32(struct sigcontext32 __user *sc)
-{
- int i;
- int err = 0;
- u64 val;
-
- for (i = 0; i < NUM_FPU_REGS; i++) {
- err |= __get_user(val, &sc->sc_msaregs[i]);
- set_fpr64(&current->thread.fpu.fpr[i], 1, val);
- }
- err |= __get_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);
-
- return err;
-}
-
-/*
* sigcontext handlers
*/
-static int protected_save_fp_context32(struct sigcontext32 __user *sc,
- unsigned used_math)
+static int protected_save_fp_context32(struct sigcontext32 __user *sc)
{
int err;
- bool save_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
while (1) {
lock_fpu_owner();
if (is_fpu_owner()) {
err = save_fp_context32(sc);
- if (save_msa && !err)
- err = _save_msa_context32(sc);
unlock_fpu_owner();
} else {
unlock_fpu_owner();
err = copy_fp_to_sigcontext32(sc);
- if (save_msa && !err)
- err = copy_msa_to_sigcontext32(sc);
}
if (likely(!err))
break;
@@ -181,28 +137,17 @@ static int protected_save_fp_context32(s
return err;
}

-static int protected_restore_fp_context32(struct sigcontext32 __user *sc,
- unsigned used_math)
+static int protected_restore_fp_context32(struct sigcontext32 __user *sc)
{
int err, tmp __maybe_unused;
- bool restore_msa = cpu_has_msa && (used_math & USEDMATH_MSA);
while (1) {
lock_fpu_owner();
if (is_fpu_owner()) {
err = restore_fp_context32(sc);
- if (restore_msa && !err) {
- enable_msa();
- err = _restore_msa_context32(sc);
- } else {
- /* signal handler may have used MSA */
- disable_msa();
- }
unlock_fpu_owner();
} else {
unlock_fpu_owner();
err = copy_fp_from_sigcontext32(sc);
- if (restore_msa && !err)
- err = copy_msa_from_sigcontext32(sc);
}
if (likely(!err))
break;
@@ -241,8 +186,7 @@ static int setup_sigcontext32(struct pt_
err |= __put_user(mflo3(), &sc->sc_lo3);
}

- used_math = used_math() ? USEDMATH_FP : 0;
- used_math |= thread_msa_context_live() ? USEDMATH_MSA : 0;
+ used_math = !!used_math();
err |= __put_user(used_math, &sc->sc_used_math);

if (used_math) {
@@ -250,21 +194,20 @@ static int setup_sigcontext32(struct pt_
* Save FPU state to signal context. Signal handler
* will "inherit" current FPU state.
*/
- err |= protected_save_fp_context32(sc, used_math);
+ err |= protected_save_fp_context32(sc);
}
return err;
}

static int
-check_and_restore_fp_context32(struct sigcontext32 __user *sc,
- unsigned used_math)
+check_and_restore_fp_context32(struct sigcontext32 __user *sc)
{
int err, sig;

err = sig = fpcsr_pending(&sc->sc_fpc_csr);
if (err > 0)
err = 0;
- err |= protected_restore_fp_context32(sc, used_math);
+ err |= protected_restore_fp_context32(sc);
return err ?: sig;
}

@@ -301,10 +244,9 @@ static int restore_sigcontext32(struct p
if (used_math) {
/* restore fpu context if we have used it before */
if (!err)
- err = check_and_restore_fp_context32(sc, used_math);
+ err = check_and_restore_fp_context32(sc);
} else {
- /* signal handler may have used FPU or MSA. Disable them. */
- disable_msa();
+ /* signal handler may have used FPU. Give it up. */
lose_fpu(0);
}




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