1 files changed, 122 insertions, 25 deletions

diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index efbd8df8b665..0b23b1ad99e6 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -419,63 +419,160 @@ static int gpr64_set(struct task_struct *target,
 
 #endif /* CONFIG_64BIT */
 
+/*
+ * Copy the floating-point context to the supplied NT_PRFPREG buffer,
+ * !CONFIG_CPU_HAS_MSA variant.  FP context's general register slots
+ * correspond 1:1 to buffer slots.  Only general registers are copied.
+ */
+static int fpr_get_fpa(struct task_struct *target,
+		       unsigned int *pos, unsigned int *count,
+		       void **kbuf, void __user **ubuf)
+{
+	return user_regset_copyout(pos, count, kbuf, ubuf,
+				   &target->thread.fpu,
+				   0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
+}
+
+/*
+ * Copy the floating-point context to the supplied NT_PRFPREG buffer,
+ * CONFIG_CPU_HAS_MSA variant.  Only lower 64 bits of FP context's
+ * general register slots are copied to buffer slots.  Only general
+ * registers are copied.
+ */
+static int fpr_get_msa(struct task_struct *target,
+		       unsigned int *pos, unsigned int *count,
+		       void **kbuf, void __user **ubuf)
+{
+	unsigned int i;
+	u64 fpr_val;
+	int err;
+
+	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
+	for (i = 0; i < NUM_FPU_REGS; i++) {
+		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
+		err = user_regset_copyout(pos, count, kbuf, ubuf,
+					  &fpr_val, i * sizeof(elf_fpreg_t),
+					  (i + 1) * sizeof(elf_fpreg_t));
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+/*
+ * Copy the floating-point context to the supplied NT_PRFPREG buffer.
+ * Choose the appropriate helper for general registers, and then copy
+ * the FCSR register separately.
+ */
 static int fpr_get(struct task_struct *target,
 		   const struct user_regset *regset,
 		   unsigned int pos, unsigned int count,
 		   void *kbuf, void __user *ubuf)
 {
-	unsigned i;
+	const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
 	int err;
-	u64 fpr_val;
 
-	/* XXX fcr31  */
+	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
+		err = fpr_get_fpa(target, &pos, &count, &kbuf, &ubuf);
+	else
+		err = fpr_get_msa(target, &pos, &count, &kbuf, &ubuf);
+	if (err)
+		return err;
 
-	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
-		return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					   &target->thread.fpu,
-					   0, sizeof(elf_fpregset_t));
+	err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  &target->thread.fpu.fcr31,
+				  fcr31_pos, fcr31_pos + sizeof(u32));
 
-	for (i = 0; i < NUM_FPU_REGS; i++) {
-		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
-		err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &fpr_val, i * sizeof(elf_fpreg_t),
-					  (i + 1) * sizeof(elf_fpreg_t));
+	return err;
+}
+
+/*
+ * Copy the supplied NT_PRFPREG buffer to the floating-point context,
+ * !CONFIG_CPU_HAS_MSA variant.   Buffer slots correspond 1:1 to FP
+ * context's general register slots.  Only general registers are copied.
+ */
+static int fpr_set_fpa(struct task_struct *target,
+		       unsigned int *pos, unsigned int *count,
+		       const void **kbuf, const void __user **ubuf)
+{
+	return user_regset_copyin(pos, count, kbuf, ubuf,
+				  &target->thread.fpu,
+				  0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
+}
+
+/*
+ * Copy the supplied NT_PRFPREG buffer to the floating-point context,
+ * CONFIG_CPU_HAS_MSA variant.  Buffer slots are copied to lower 64
+ * bits only of FP context's general register slots.  Only general
+ * registers are copied.
+ */
+static int fpr_set_msa(struct task_struct *target,
+		       unsigned int *pos, unsigned int *count,
+		       const void **kbuf, const void __user **ubuf)
+{
+	unsigned int i;
+	u64 fpr_val;
+	int err;
+
+	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
+	for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) {
+		err = user_regset_copyin(pos, count, kbuf, ubuf,
+					 &fpr_val, i * sizeof(elf_fpreg_t),
+					 (i + 1) * sizeof(elf_fpreg_t));
 		if (err)
 			return err;
+		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
 	}
 
 	return 0;
 }
 
+/*
+ * Copy the supplied NT_PRFPREG buffer to the floating-point context.
+ * Choose the appropriate helper for general registers, and then copy
+ * the FCSR register separately.
+ *
+ * We optimize for the case where `count % sizeof(elf_fpreg_t) == 0',
+ * which is supposed to have been guaranteed by the kernel before
+ * calling us, e.g. in `ptrace_regset'.  We enforce that requirement,
+ * so that we can safely avoid preinitializing temporaries for
+ * partial register writes.
+ */
 static int fpr_set(struct task_struct *target,
 		   const struct user_regset *regset,
 		   unsigned int pos, unsigned int count,
 		   const void *kbuf, const void __user *ubuf)
 {
-	unsigned i;
+	const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
+	u32 fcr31;
 	int err;
-	u64 fpr_val;
 
-	/* XXX fcr31  */
+	BUG_ON(count % sizeof(elf_fpreg_t));
+
+	if (pos + count > sizeof(elf_fpregset_t))
+		return -EIO;
 
 	init_fp_ctx(target);
 
-	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
-		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-					  &target->thread.fpu,
-					  0, sizeof(elf_fpregset_t));
+	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
+		err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf);
+	else
+		err = fpr_set_msa(target, &pos, &count, &kbuf, &ubuf);
+	if (err)
+		return err;
 
-	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
-	for (i = 0; i < NUM_FPU_REGS && count >= sizeof(elf_fpreg_t); i++) {
+	if (count > 0) {
 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-					 &fpr_val, i * sizeof(elf_fpreg_t),
-					 (i + 1) * sizeof(elf_fpreg_t));
+					 &fcr31,
+					 fcr31_pos, fcr31_pos + sizeof(u32));
 		if (err)
 			return err;
-		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
+
+		ptrace_setfcr31(target, fcr31);
 	}
 
-	return 0;
+	return err;
 }
 
 enum mips_regset {