[PATCH 11/15] x86/headers: Make sigcontext pointers bit independent

[Ingo Molnar <mingo@kernel.org>]

Before we can eliminate the duplication between 'struct sigcontext_32'
and 'struct sigcontext_ia32', make the 'fpstate' pointer field in
'struct sigcontext_32' bit independent.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/uapi/asm/sigcontext.h | 4 ++--
 arch/x86/kernel/signal.c               | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/uapi/asm/sigcontext.h b/arch/x86/include/uapi/asm/sigcontext.h
index 3591cef6d7d2..d0def259d545 100644
--- a/arch/x86/include/uapi/asm/sigcontext.h
+++ b/arch/x86/include/uapi/asm/sigcontext.h
@@ -218,7 +218,7 @@ struct sigcontext_32 {
 	 * of extended memory layout. See comments at the definition of
 	 * (struct _fpx_sw_bytes)
 	 */
-	void __user			*fpstate; /* Zero when no FPU/extended context */
+	__u32				fpstate; /* Zero when no FPU/extended context */
 	__u32				oldmask;
 	__u32				cr2;
 };
@@ -258,7 +258,7 @@ struct sigcontext_64 {
 	 * of extended memory layout. See comments at the definition of
 	 * (struct _fpx_sw_bytes)
 	 */
-	void __user			*fpstate; /* Zero when no FPU/extended context */
+	__u64				fpstate; /* Zero when no FPU/extended context */
 	__u64				reserved1[8];
 };
 
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 71820c42b6ce..373f87cbbdf5 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -63,6 +63,7 @@
 
 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
+	unsigned long buf_val;
 	void __user *buf;
 	unsigned int tmpflags;
 	unsigned int err = 0;
@@ -107,7 +108,8 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 		regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
 		regs->orig_ax = -1;		/* disable syscall checks */
 
-		get_user_ex(buf, &sc->fpstate);
+		get_user_ex(buf_val, &sc->fpstate);
+		buf = (void __user *)buf_val;
 	} get_user_catch(err);
 
 	err |= fpu__restore_sig(buf, config_enabled(CONFIG_X86_32));
-- 
2.1.4