x86 ptrace: fix PTRACE_GETFPXREGS error

ptrace has always returned only -EIO for all failures to access
registers.  The user_regset calls are allowed to return a more
meaningful variety of errors.  The REGSET_XFP calls use -ENODEV
for !cpu_has_fxsr hardware.  Make ptrace return the traditional
-EIO instead of the error code from the user_regset call.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 4 insertions, 4 deletions

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 95e80e5033c3..eb9ddd8efb82 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -162,7 +162,7 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
         int ret;
 
         if (!cpu_has_fxsr)
-                return -EIO;
+                return -ENODEV;
 
         ret = init_fpu(target);
         if (ret)
@@ -179,7 +179,7 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
         int ret;
 
         if (!cpu_has_fxsr)
-                return -EIO;
+                return -ENODEV;
 
         ret = init_fpu(target);
         if (ret)
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index a7835f282936..77040b6070e1 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -943,13 +943,13 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                 return copy_regset_to_user(child, &user_x86_32_view,
                                            REGSET_XFP,
                                            0, sizeof(struct user_fxsr_struct),
-                                           datap);
+                                           datap) ? -EIO : 0;
 
         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
                 return copy_regset_from_user(child, &user_x86_32_view,
                                              REGSET_XFP,
                                              0, sizeof(struct user_fxsr_struct),
-                                             datap);
+                                             datap) ? -EIO : 0;
 #endif
 
 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION