Merge branch '4.1-fp' into mips-for-linux-next

[linux-drm-fsl-dcu.git] / arch / mips / kernel / ptrace.c

diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 6d1e3f8005f79dc2506012249c7e87462322c5a1..d544e774eea6b1b6e0f811099290600b1fc5b534 100644 (file)
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -47,6 +47,26 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/syscalls.h>
 
+static void init_fp_ctx(struct task_struct *target)
+{
+       /* If FP has been used then the target already has context */
+       if (tsk_used_math(target))
+               return;
+
+       /* Begin with data registers set to all 1s... */
+       memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));
+
+       /* ...and FCSR zeroed */
+       target->thread.fpu.fcr31 = 0;
+
+       /*
+        * Record that the target has "used" math, such that the context
+        * just initialised, and any modifications made by the caller,
+        * aren't discarded.
+        */
+       set_stopped_child_used_math(target);
+}
+
 /*
  * Called by kernel/ptrace.c when detaching..
  *
@@ -146,6 +166,7 @@ int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
        if (!access_ok(VERIFY_READ, data, 33 * 8))
                return -EIO;
 
+       init_fp_ctx(child);
        fregs = get_fpu_regs(child);
 
        for (i = 0; i < 32; i++) {
@@ -445,6 +466,8 @@ static int fpr_set(struct task_struct *target,
 
        /* XXX fcr31  */
 
+       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,
@@ -666,12 +689,7 @@ long arch_ptrace(struct task_struct *child, long request,
                case FPR_BASE ... FPR_BASE + 31: {
                        union fpureg *fregs = get_fpu_regs(child);
 
-                       if (!tsk_used_math(child)) {
-                               /* FP not yet used  */
-                               memset(&child->thread.fpu, ~0,
-                                      sizeof(child->thread.fpu));
-                               child->thread.fpu.fcr31 = 0;
-                       }
+                       init_fp_ctx(child);
 #ifdef CONFIG_32BIT
                        if (test_thread_flag(TIF_32BIT_FPREGS)) {
                                /*