ARM: 6051/1: VFP: preserve the HW context when calling signal handlers
From: Imre Deak <imre.deak@nokia.com>
Signal handlers can use floating point, so prevent them to corrupt
the main thread's VFP context. So far there were two signal stack
frame formats defined based on the VFP implementation, but the user
struct used for ptrace covers all posibilities, so use it for the
signal stack too.
Introduce also a new user struct for VFP exception registers. In
this too fields not relevant to the current VFP architecture are
ignored.
Support to save / restore the exception registers was added by
Will Deacon.
Signed-off-by: Imre Deak <imre.deak@nokia.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/ucontext.h b/arch/arm/include/asm/ucontext.h
index bf65e9f..47f023a 100644
--- a/arch/arm/include/asm/ucontext.h
+++ b/arch/arm/include/asm/ucontext.h
@@ -59,23 +59,22 @@
#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 @@
#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. */