x86: x86 ia32 ptrace getreg/putreg merge

This reimplements the 64-bit IA32-emulation register access
functions in arch/x86/kernel/ptrace.c, where they can share
some guts with the native access functions directly.

These functions are not used yet, but this paves the way to move
IA32 ptrace support into this file to share its local functions.

[akpm@linuxfoundation.org: Build fix]
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/ptrace.c

@@ -215,14 +215,14 @@ static int set_segment_reg(struct task_struct *task,
 #ifdef CONFIG_IA32_EMULATION
 		if (test_tsk_thread_flag(task, TIF_IA32))
 			task_pt_regs(task)->cs = value;
-		break;
 #endif
+		break;
 	case offsetof(struct user_regs_struct,ss):
 #ifdef CONFIG_IA32_EMULATION
 		if (test_tsk_thread_flag(task, TIF_IA32))
 			task_pt_regs(task)->ss = value;
-		break;
 #endif
+		break;
 	}
 
 	return 0;
@@ -634,6 +634,132 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 	return ret;
 }
 
+#ifdef CONFIG_IA32_EMULATION
+
+#include <asm/user32.h>
+
+#define R32(l,q)							\
+	case offsetof(struct user32, regs.l):				\
+		regs->q = value; break
+
+#define SEG32(rs)							\
+	case offsetof(struct user32, regs.rs):				\
+		return set_segment_reg(child,				\
+				       offsetof(struct user_regs_struct, rs), \
+				       value);				\
+		break
+
+static int putreg32(struct task_struct *child, unsigned regno, u32 value)
+{
+	struct pt_regs *regs = task_pt_regs(child);
+
+	switch (regno) {
+
+	SEG32(cs);
+	SEG32(ds);
+	SEG32(es);
+	SEG32(fs);
+	SEG32(gs);
+	SEG32(ss);
+
+	R32(ebx, bx);
+	R32(ecx, cx);
+	R32(edx, dx);
+	R32(edi, di);
+	R32(esi, si);
+	R32(ebp, bp);
+	R32(eax, ax);
+	R32(orig_eax, orig_ax);
+	R32(eip, ip);
+	R32(esp, sp);
+
+	case offsetof(struct user32, regs.eflags):
+		return set_flags(child, value);
+
+	case offsetof(struct user32, u_debugreg[0]) ...
+		offsetof(struct user32, u_debugreg[7]):
+		regno -= offsetof(struct user32, u_debugreg[0]);
+		return ptrace_set_debugreg(child, regno / 4, value);
+
+	default:
+		if (regno > sizeof(struct user32) || (regno & 3))
+			return -EIO;
+
+		/*
+		 * Other dummy fields in the virtual user structure
+		 * are ignored
+		 */
+		break;
+	}
+	return 0;
+}
+
+#undef R32
+#undef SEG32
+
+#define R32(l,q)							\
+	case offsetof(struct user32, regs.l):				\
+		*val = regs->q; break
+
+#define SEG32(rs)							\
+	case offsetof(struct user32, regs.rs):				\
+		*val = get_segment_reg(child,				\
+				       offsetof(struct user_regs_struct, rs)); \
+		break
+
+static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
+{
+	struct pt_regs *regs = task_pt_regs(child);
+
+	switch (regno) {
+
+	SEG32(ds);
+	SEG32(es);
+	SEG32(fs);
+	SEG32(gs);
+
+	R32(cs, cs);
+	R32(ss, ss);
+	R32(ebx, bx);
+	R32(ecx, cx);
+	R32(edx, dx);
+	R32(edi, di);
+	R32(esi, si);
+	R32(ebp, bp);
+	R32(eax, ax);
+	R32(orig_eax, orig_ax);
+	R32(eip, ip);
+	R32(esp, sp);
+
+	case offsetof(struct user32, regs.eflags):
+		*val = get_flags(child);
+		break;
+
+	case offsetof(struct user32, u_debugreg[0]) ...
+		offsetof(struct user32, u_debugreg[7]):
+		regno -= offsetof(struct user32, u_debugreg[0]);
+		*val = ptrace_get_debugreg(child, regno / 4);
+		break;
+
+	default:
+		if (regno > sizeof(struct user32) || (regno & 3))
+			return -EIO;
+
+		/*
+		 * Other dummy fields in the virtual user structure
+		 * are ignored
+		 */
+		*val = 0;
+		break;
+	}
+	return 0;
+}
+
+#undef R32
+#undef SEG32
+
+#endif	/* CONFIG_IA32_EMULATION */
+
 #ifdef CONFIG_X86_32
 
 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)