diff options
| -rw-r--r-- | arch/x86/include/asm/ptrace.h | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 4a040f0078f2..70c439f9071b 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -96,11 +96,13 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) } /* - * user_mode_vm(regs) determines whether a register set came from user mode. - * This is true if V8086 mode was enabled OR if the register set was from - * protected mode with RPL-3 CS value. This tricky test checks that with - * one comparison. Many places in the kernel can bypass this full check - * if they have already ruled out V8086 mode, so user_mode(regs) can be used. + * user_mode(regs) determines whether a register set came from user + * mode. On x86_32, this is true if V8086 mode was enabled OR if the + * register set was from protected mode with RPL-3 CS value. This + * tricky test checks that with one comparison. + * + * On x86_64, vm86 mode is mercifully nonexistent, and we don't need + * the extra check. */ static inline int user_mode(struct pt_regs *regs) { @@ -113,12 +115,7 @@ static inline int user_mode(struct pt_regs *regs) static inline int user_mode_vm(struct pt_regs *regs) { -#ifdef CONFIG_X86_32 - return ((regs->cs & SEGMENT_RPL_MASK) | (regs->flags & X86_VM_MASK)) >= - USER_RPL; -#else return user_mode(regs); -#endif } /* |