3 files changed, 111 insertions, 17 deletions

diff --git a/arch/arm/include/asm/ucontext.h b/arch/arm/include/asm/ucontext.h
index bf65e9f4525d..47f023aa8495 100644
--- a/arch/arm/include/asm/ucontext.h
+++ b/arch/arm/include/asm/ucontext.h
@@ -59,23 +59,22 @@ struct iwmmxt_sigframe {
 #endif /* CONFIG_IWMMXT */
 
 #ifdef CONFIG_VFP
-#if __LINUX_ARM_ARCH__ < 6
-/* For ARM pre-v6, we use fstmiax and fldmiax.  This adds one extra
- * word after the registers, and a word of padding at the end for
- * alignment.  */
 #define VFP_MAGIC               0x56465001
-#define VFP_STORAGE_SIZE        152
-#else
-#define VFP_MAGIC               0x56465002
-#define VFP_STORAGE_SIZE        144
-#endif
 
 struct vfp_sigframe
 {
         unsigned long           magic;
         unsigned long           size;
-        union vfp_state         storage;
-};
+        struct user_vfp         ufp;
+        struct user_vfp_exc     ufp_exc;
+} __attribute__((__aligned__(8)));
+
+/*
+ *  8 byte for magic and size, 264 byte for ufp, 12 bytes for ufp_exc,
+ *  4 bytes padding.
+ */
+#define VFP_STORAGE_SIZE        sizeof(struct vfp_sigframe)
+
 #endif /* CONFIG_VFP */
 
 /*
@@ -91,7 +90,7 @@ struct aux_sigframe {
 #ifdef CONFIG_IWMMXT
         struct iwmmxt_sigframe  iwmmxt;
 #endif
-#if 0 && defined CONFIG_VFP /* Not yet saved.  */
+#ifdef CONFIG_VFP
         struct vfp_sigframe     vfp;
 #endif
         /* Something that isn't a valid magic number for any coprocessor.  */
diff --git a/arch/arm/include/asm/user.h b/arch/arm/include/asm/user.h
index df95e050f9dd..05ac4b06876a 100644
--- a/arch/arm/include/asm/user.h
+++ b/arch/arm/include/asm/user.h
@@ -83,11 +83,21 @@ struct user{
 
 /*
  * User specific VFP registers. If only VFPv2 is present, registers 16 to 31
- * are ignored by the ptrace system call.
+ * are ignored by the ptrace system call and the signal handler.
  */
 struct user_vfp {
         unsigned long long fpregs[32];
         unsigned long fpscr;
 };
 
+/*
+ * VFP exception registers exposed to user space during signal delivery.
+ * Fields not relavant to the current VFP architecture are ignored.
+ */
+struct user_vfp_exc {
+        unsigned long   fpexc;
+        unsigned long   fpinst;
+        unsigned long   fpinst2;
+};
+
 #endif /* _ARM_USER_H */
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index e7714f367eb8..907d5a620bca 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -18,6 +18,7 @@
 #include <asm/cacheflush.h>
 #include <asm/ucontext.h>
 #include <asm/unistd.h>
+#include <asm/vfp.h>
 
 #include "ptrace.h"
 #include "signal.h"
@@ -175,6 +176,90 @@ static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
 
 #endif
 
+#ifdef CONFIG_VFP
+
+static int preserve_vfp_context(struct vfp_sigframe __user *frame)
+{
+        struct thread_info *thread = current_thread_info();
+        struct vfp_hard_struct *h = &thread->vfpstate.hard;
+        const unsigned long magic = VFP_MAGIC;
+        const unsigned long size = VFP_STORAGE_SIZE;
+        int err = 0;
+
+        vfp_sync_hwstate(thread);
+        __put_user_error(magic, &frame->magic, err);
+        __put_user_error(size, &frame->size, err);
+
+        /*
+         * Copy the floating point registers. There can be unused
+         * registers see asm/hwcap.h for details.
+         */
+        err |= __copy_to_user(&frame->ufp.fpregs, &h->fpregs,
+                              sizeof(h->fpregs));
+        /*
+         * Copy the status and control register.
+         */
+        __put_user_error(h->fpscr, &frame->ufp.fpscr, err);
+
+        /*
+         * Copy the exception registers.
+         */
+        __put_user_error(h->fpexc, &frame->ufp_exc.fpexc, err);
+        __put_user_error(h->fpinst, &frame->ufp_exc.fpinst, err);
+        __put_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err);
+
+        return err ? -EFAULT : 0;
+}
+
+static int restore_vfp_context(struct vfp_sigframe __user *frame)
+{
+        struct thread_info *thread = current_thread_info();
+        struct vfp_hard_struct *h = &thread->vfpstate.hard;
+        unsigned long magic;
+        unsigned long size;
+        unsigned long fpexc;
+        int err = 0;
+
+        __get_user_error(magic, &frame->magic, err);
+        __get_user_error(size, &frame->size, err);
+
+        if (err)
+                return -EFAULT;
+        if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
+                return -EINVAL;
+
+        /*
+         * Copy the floating point registers. There can be unused
+         * registers see asm/hwcap.h for details.
+         */
+        err |= __copy_from_user(&h->fpregs, &frame->ufp.fpregs,
+                                sizeof(h->fpregs));
+        /*
+         * Copy the status and control register.
+         */
+        __get_user_error(h->fpscr, &frame->ufp.fpscr, err);
+
+        /*
+         * Sanitise and restore the exception registers.
+         */
+        __get_user_error(fpexc, &frame->ufp_exc.fpexc, err);
+        /* Ensure the VFP is enabled. */
+        fpexc |= FPEXC_EN;
+        /* Ensure FPINST2 is invalid and the exception flag is cleared. */
+        fpexc &= ~(FPEXC_EX | FPEXC_FP2V);
+        h->fpexc = fpexc;
+
+        __get_user_error(h->fpinst, &frame->ufp_exc.fpinst, err);
+        __get_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err);
+
+        if (!err)
+                vfp_flush_hwstate(thread);
+
+        return err ? -EFAULT : 0;
+}
+
+#endif
+
 /*
  * Do a signal return; undo the signal stack.  These are aligned to 64-bit.
  */
@@ -233,8 +318,8 @@ static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
                 err |= restore_iwmmxt_context(&aux->iwmmxt);
 #endif
 #ifdef CONFIG_VFP
-//      if (err == 0)
-//              err |= vfp_restore_state(&sf->aux.vfp);
+        if (err == 0)
+                err |= restore_vfp_context(&aux->vfp);
 #endif
 
         return err;
@@ -348,8 +433,8 @@ setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
                 err |= preserve_iwmmxt_context(&aux->iwmmxt);
 #endif
 #ifdef CONFIG_VFP
-//      if (err == 0)
-//              err |= vfp_save_state(&sf->aux.vfp);
+        if (err == 0)
+                err |= preserve_vfp_context(&aux->vfp);
 #endif
         __put_user_error(0, &aux->end_magic, err);