x86, xsave: remove the redundant access_ok() in setup_rt_frame()

[~andy/linux] / arch / x86 / kernel / signal_64.c

diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index ddf6123a55c89ab6ea0ab0550bf830bdb90c8349..6c581698ab56887292596e56729dc200b6f750f8 100644 (file)
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -192,7 +192,7 @@ get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size)
                        sp = current->sas_ss_sp + current->sas_ss_size;
        }
 
-       return (void __user *)round_down(sp - size, 16);
+       return (void __user *)round_down(sp - size, 64);
 }
 
 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
@@ -208,9 +208,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                frame = (void __user *)round_down(
                        (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
 
-               if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
-                       goto give_sigsegv;
-
                if (save_i387_xstate(fp) < 0)
                        err |= -1; 
        } else
@@ -226,7 +223,10 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
        }
                
        /* Create the ucontext.  */
-       err |= __put_user(0, &frame->uc.uc_flags);
+       if (cpu_has_xsave)
+               err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
+       else
+               err |= __put_user(0, &frame->uc.uc_flags);
        err |= __put_user(0, &frame->uc.uc_link);
        err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
        err |= __put_user(sas_ss_flags(regs->sp),