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Diffstat (limited to 'arch/s390/kernel/process.c')
-rw-r--r--arch/s390/kernel/process.c32
1 files changed, 15 insertions, 17 deletions
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index f2dac9f0799d..b63787156a19 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -87,31 +87,29 @@ void arch_release_task_struct(struct task_struct *tsk)
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
+ size_t fpu_regs_size;
+
*dst = *src;
- /* Set up a new floating-point register save area */
- dst->thread.fpu.fpc = 0;
- dst->thread.fpu.flags = 0; /* Always start with VX disabled */
- dst->thread.fpu.fprs = kzalloc(sizeof(freg_t) * __NUM_FPRS,
- GFP_KERNEL|__GFP_REPEAT);
- if (!dst->thread.fpu.fprs)
+ /*
+ * If the vector extension is available, it is enabled for all tasks,
+ * and, thus, the FPU register save area must be allocated accordingly.
+ */
+ fpu_regs_size = MACHINE_HAS_VX ? sizeof(__vector128) * __NUM_VXRS
+ : sizeof(freg_t) * __NUM_FPRS;
+ dst->thread.fpu.regs = kzalloc(fpu_regs_size, GFP_KERNEL|__GFP_REPEAT);
+ if (!dst->thread.fpu.regs)
return -ENOMEM;
/*
* Save the floating-point or vector register state of the current
- * task. The state is not saved for early kernel threads, for example,
- * the init_task, which do not have an allocated save area.
- * The CIF_FPU flag is set in any case to lazy clear or restore a saved
- * state when switching to a different task or returning to user space.
+ * task and set the CIF_FPU flag to lazy restore the FPU register
+ * state when returning to user space.
*/
save_fpu_regs();
dst->thread.fpu.fpc = current->thread.fpu.fpc;
- if (is_vx_task(current))
- convert_vx_to_fp(dst->thread.fpu.fprs,
- current->thread.fpu.vxrs);
- else
- memcpy(dst->thread.fpu.fprs, current->thread.fpu.fprs,
- sizeof(freg_t) * __NUM_FPRS);
+ memcpy(dst->thread.fpu.regs, current->thread.fpu.regs, fpu_regs_size);
+
return 0;
}
@@ -199,7 +197,7 @@ int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
save_fpu_regs();
fpregs->fpc = current->thread.fpu.fpc;
fpregs->pad = 0;
- if (is_vx_task(current))
+ if (MACHINE_HAS_VX)
convert_vx_to_fp((freg_t *)&fpregs->fprs,
current->thread.fpu.vxrs);
else