x86: ptrace: do not sign-extend orig_ax on write

The high 32 bits of orig_ax will be ignored when it matters,
so don't fiddle them when setting it.

Signed-off-by: Roland McGrath <roland@redhat.com>

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 8d7d5c9..52222fa 100644 (file)
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -325,16 +325,6 @@ static int putreg(struct task_struct *child,
                return set_flags(child, value);
 
 #ifdef CONFIG_X86_64
-       /*
-        * Orig_ax is really just a flag with small positive and
-        * negative values, so make sure to always sign-extend it
-        * from 32 bits so that it works correctly regardless of
-        * whether we come from a 32-bit environment or not.
-        */
-       case offsetof(struct user_regs_struct, orig_ax):
-               value = (long) (s32) value;
-               break;
-
        case offsetof(struct user_regs_struct,fs_base):
                if (value >= TASK_SIZE_OF(child))
                        return -EIO;
@@ -1121,17 +1111,10 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value)
        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.orig_eax):
-               /*
-                * Sign-extend the value so that orig_eax = -1
-                * causes (long)orig_ax < 0 tests to fire correctly.
-                */
-               regs->orig_ax = (long) (s32) value;
-               break;
-
        case offsetof(struct user32, regs.eflags):
                return set_flags(child, value);