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authorImre Deak <imre.deak@nokia.com>2010-04-11 15:58:27 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-04-14 11:11:30 +0100
commit82c6f5a5b3e91ef4d2fb8725de4b8cf7affd4d61 (patch)
tree1f077be392f88b7b8355960b882ffbfdc3e6bab6 /arch/arm/include
parent5c5cac63851f347d8308d69f1892c4af51d7c1a4 (diff)
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>
Diffstat (limited to 'arch/arm/include')
-rw-r--r--arch/arm/include/asm/ucontext.h23
-rw-r--r--arch/arm/include/asm/user.h12
2 files changed, 22 insertions, 13 deletions
diff --git a/arch/arm/include/asm/ucontext.h b/arch/arm/include/asm/ucontext.h
index bf65e9f4525..47f023aa849 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 df95e050f9d..05ac4b06876 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 */