1 files changed, 10 insertions, 0 deletions

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index f41fdc98efb1..8f64abe699fd 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -323,6 +323,16 @@ 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;