diff options
| -rw-r--r-- | arch/x86/include/asm/ptrace.h | 17 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 6 |
3 files changed, 4 insertions, 21 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index d20bae2..19507ff 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -113,23 +113,6 @@ static inline int user_mode(struct pt_regs *regs) #endif } -/* - * This is the fastest way to check whether regs come from user space. - * It is unsafe if regs might come from vm86 mode, though -- in vm86 - * mode, all bits of CS and SS are completely under the user's control. - * The CPU considers vm86 mode to be CPL 3 regardless of CS and SS. - * - * Do NOT use this function unless you have already ruled out the - * possibility that regs came from vm86 mode. - * - * We check for RPL != 0 instead of RPL == 3 because we don't use rings - * 1 or 2 and this is more efficient. - */ -static inline int user_mode_ignore_vm86(struct pt_regs *regs) -{ - return (regs->cs & SEGMENT_RPL_MASK) != 0; -} - static inline int v8086_mode(struct pt_regs *regs) { #ifdef CONFIG_X86_32 diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 56f7e60..e2888a3 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -2159,7 +2159,7 @@ static unsigned long code_segment_base(struct pt_regs *regs) if (regs->flags & X86_VM_MASK) return 0x10 * regs->cs; - if (user_mode_ignore_vm86(regs) && regs->cs != __USER_CS) + if (user_mode(regs) && regs->cs != __USER_CS) return get_segment_base(regs->cs); #else if (user_mode(regs) && !user_64bit_mode(regs) && diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index c8eb469..6751c5c 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -207,7 +207,7 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, return -1; } - if (!user_mode_ignore_vm86(regs)) { + if (!user_mode(regs)) { if (!fixup_exception(regs)) { tsk->thread.error_code = error_code; tsk->thread.trap_nr = trapnr; @@ -468,7 +468,7 @@ do_general_protection(struct pt_regs *regs, long error_code) } tsk = current; - if (!user_mode_ignore_vm86(regs)) { + if (!user_mode(regs)) { if (fixup_exception(regs)) goto exit; @@ -685,7 +685,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) * We already checked v86 mode above, so we can check for kernel mode * by just checking the CPL of CS. */ - if ((dr6 & DR_STEP) && !user_mode_ignore_vm86(regs)) { + if ((dr6 & DR_STEP) && !user_mode(regs)) { tsk->thread.debugreg6 &= ~DR_STEP; set_tsk_thread_flag(tsk, TIF_SINGLESTEP); regs->flags &= ~X86_EFLAGS_TF; |
