diff options
Diffstat (limited to 'arch/x86/entry/common.c')
| -rw-r--r-- | arch/x86/entry/common.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index d5eee851071c..08a945d7915e 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -394,8 +394,20 @@ __visible long do_fast_syscall_32(struct pt_regs *regs) * WARNING: We are in CONTEXT_USER and RCU isn't paying attention! */ local_irq_enable(); - if (get_user(*(u32 *)®s->cx, - (u32 __user __force *)(unsigned long)(u32)regs->sp)) { + if ( +#ifdef CONFIG_X86_64 + /* + * Micro-optimization: the pointer we're following is explicitly + * 32 bits, so it can't be out of range. + */ + __get_user(*(u32 *)®s->cx, + (u32 __user __force *)(unsigned long)(u32)regs->sp) +#else + get_user(*(u32 *)®s->cx, + (u32 __user __force *)(unsigned long)(u32)regs->sp) +#endif + ) { + /* User code screwed up. */ local_irq_disable(); regs->ax = -EFAULT; |