x86: use generic register names in struct user_regs_struct

Switch struct user_regs_struct (defined in <asm/user.h>, which is no
longer exported to userspace) to using register names without e- or
r-prefixes for both 32 and 64 bit x86.  This is intended as a
preliminary step in unifying this code between architectures.

Also, be a bit more strict in truncating 32-bit "extended" segment
register values to 16 bits.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/process_32.c

@@ -523,6 +523,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 void dump_thread(struct pt_regs * regs, struct user * dump)
 {
 	int i;
+	u16 gs;
 
 /* changed the size calculations - should hopefully work better. lbt */
 	dump->magic = CMAGIC;
@@ -538,23 +539,23 @@ void dump_thread(struct pt_regs * regs, struct user * dump)
 	if (dump->start_stack < TASK_SIZE)
 		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
 
-	dump->regs.ebx = regs->bx;
-	dump->regs.ecx = regs->cx;
-	dump->regs.edx = regs->dx;
-	dump->regs.esi = regs->si;
-	dump->regs.edi = regs->di;
-	dump->regs.ebp = regs->bp;
-	dump->regs.eax = regs->ax;
-	dump->regs.ds = regs->ds;
-	dump->regs.es = regs->es;
-	dump->regs.fs = regs->fs;
-	savesegment(gs,dump->regs.gs);
-	dump->regs.orig_eax = regs->orig_ax;
-	dump->regs.eip = regs->ip;
-	dump->regs.cs = regs->cs;
-	dump->regs.eflags = regs->flags;
-	dump->regs.esp = regs->sp;
-	dump->regs.ss = regs->ss;
+	dump->regs.bx = regs->bx;
+	dump->regs.cx = regs->cx;
+	dump->regs.dx = regs->dx;
+	dump->regs.si = regs->si;
+	dump->regs.di = regs->di;
+	dump->regs.bp = regs->bp;
+	dump->regs.ax = regs->ax;
+	dump->regs.ds = (u16)regs->ds;
+	dump->regs.es = (u16)regs->es;
+	dump->regs.fs = (u16)regs->fs;
+	savesegment(gs,gs);
+	dump->regs.orig_ax = regs->orig_ax;
+	dump->regs.ip = regs->ip;
+	dump->regs.cs = (u16)regs->cs;
+	dump->regs.flags = regs->flags;
+	dump->regs.sp = regs->sp;
+	dump->regs.ss = (u16)regs->ss;
 
 	dump->u_fpvalid = dump_fpu (regs, &dump->i387);
 }

arch/x86/kernel/ptrace_64.c

@@ -108,7 +108,7 @@ static int putreg(struct task_struct *child,
 			if (child->thread.gs != value)
 				return do_arch_prctl(child, ARCH_SET_GS, value);
 			return 0;
-		case offsetof(struct user_regs_struct, eflags):
+		case offsetof(struct user_regs_struct,flags):
 			value &= FLAG_MASK;
 			/*
 			 * If the user value contains TF, mark that
@@ -164,7 +164,7 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno)
 			if (child->thread.gsindex != GS_TLS_SEL)
 				return 0;
 			return get_desc_base(&child->thread.tls_array[GS_TLS]);
-		case offsetof(struct user_regs_struct, eflags):
+		case offsetof(struct user_regs_struct, flags):
 			/*
 			 * If the debugger set TF, hide it from the readout.
 			 */

include/asm-x86/user_32.h

@@ -75,13 +75,23 @@ struct user_fxsr_struct {
  * doesn't use the extra segment registers)
  */
 struct user_regs_struct {
-	long ebx, ecx, edx, esi, edi, ebp, eax;
-	unsigned short ds, __ds, es, __es;
-	unsigned short fs, __fs, gs, __gs;
-	long orig_eax, eip;
-	unsigned short cs, __cs;
-	long eflags, esp;
-	unsigned short ss, __ss;
+	unsigned long	bx;
+	unsigned long	cx;
+	unsigned long	dx;
+	unsigned long	si;
+	unsigned long	di;
+	unsigned long	bp;
+	unsigned long	ax;
+	unsigned long	ds;
+	unsigned long	es;
+	unsigned long	fs;
+	unsigned long	gs;
+	unsigned long	orig_ax;
+	unsigned long	ip;
+	unsigned long	cs;
+	unsigned long	flags;
+	unsigned long	sp;
+	unsigned long	ss;
 };
 
 /* When the kernel dumps core, it starts by dumping the user struct -

include/asm-x86/user_64.h

@@ -40,13 +40,13 @@
  * and both the standard and SIMD floating point data can be accessed via
  * the new ptrace requests.  In either case, changes to the FPU environment
  * will be reflected in the task's state as expected.
- * 
+ *
  * x86-64 support by Andi Kleen.
  */
 
 /* This matches the 64bit FXSAVE format as defined by AMD. It is the same
    as the 32bit format defined by Intel, except that the selector:offset pairs for
-   data and eip are replaced with flat 64bit pointers. */ 
+   data and eip are replaced with flat 64bit pointers. */
 struct user_i387_struct {
 	unsigned short	cwd;
 	unsigned short	swd;
@@ -65,13 +65,34 @@ struct user_i387_struct {
  * Segment register layout in coredumps.
  */
 struct user_regs_struct {
-	unsigned long r15,r14,r13,r12,rbp,rbx,r11,r10;
-	unsigned long r9,r8,rax,rcx,rdx,rsi,rdi,orig_rax;
-	unsigned long rip,cs,eflags;
-	unsigned long rsp,ss;
-  	unsigned long fs_base, gs_base;
-	unsigned long ds,es,fs,gs; 
-}; 
+	unsigned long	r15;
+	unsigned long	r14;
+	unsigned long	r13;
+	unsigned long	r12;
+	unsigned long	bp;
+	unsigned long	bx;
+	unsigned long	r11;
+	unsigned long	r10;
+	unsigned long	r9;
+	unsigned long	r8;
+	unsigned long	ax;
+	unsigned long	cx;
+	unsigned long	dx;
+	unsigned long	si;
+	unsigned long	di;
+	unsigned long	orig_ax;
+	unsigned long	ip;
+	unsigned long	cs;
+	unsigned long	flags;
+	unsigned long	sp;
+	unsigned long	ss;
+	unsigned long	fs_base;
+	unsigned long	gs_base;
+	unsigned long	ds;
+	unsigned long	es;
+	unsigned long	fs;
+	unsigned long	gs;
+};
 
 /* When the kernel dumps core, it starts by dumping the user struct -
    this will be used by gdb to figure out where the data and stack segments
@@ -94,7 +115,7 @@ struct user{
 				   This is actually the bottom of the stack,
 				   the top of the stack is always found in the
 				   esp register.  */
-  long int signal;     		/* Signal that caused the core dump. */
+  long int signal;		/* Signal that caused the core dump. */
   int reserved;			/* No longer used */
   int pad1;
   struct user_pt_regs * u_ar0;	/* Used by gdb to help find the values for */