diff options
Diffstat (limited to 'arch/x86/include/asm/ptrace.h')
| -rw-r--r-- | arch/x86/include/asm/ptrace.h | 45 |
1 files changed, 20 insertions, 25 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 86fc2bb82287..19507ffa5d28 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -31,13 +31,17 @@ struct pt_regs { #else /* __i386__ */ struct pt_regs { +/* + * C ABI says these regs are callee-preserved. They aren't saved on kernel entry + * unless syscall needs a complete, fully filled "struct pt_regs". + */ unsigned long r15; unsigned long r14; unsigned long r13; unsigned long r12; unsigned long bp; unsigned long bx; -/* arguments: non interrupts/non tracing syscalls only save up to here*/ +/* These regs are callee-clobbered. Always saved on kernel entry. */ unsigned long r11; unsigned long r10; unsigned long r9; @@ -47,9 +51,12 @@ struct pt_regs { unsigned long dx; unsigned long si; unsigned long di; +/* + * On syscall entry, this is syscall#. On CPU exception, this is error code. + * On hw interrupt, it's IRQ number: + */ unsigned long orig_ax; -/* end of arguments */ -/* cpu exception frame or undefined */ +/* Return frame for iretq */ unsigned long ip; unsigned long cs; unsigned long flags; @@ -89,11 +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) { @@ -104,16 +113,6 @@ static inline int user_mode(struct pt_regs *regs) #endif } -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 -} - static inline int v8086_mode(struct pt_regs *regs) { #ifdef CONFIG_X86_32 @@ -138,12 +137,8 @@ static inline bool user_64bit_mode(struct pt_regs *regs) #endif } -#define current_user_stack_pointer() this_cpu_read(old_rsp) -/* ia32 vs. x32 difference */ -#define compat_user_stack_pointer() \ - (test_thread_flag(TIF_IA32) \ - ? current_pt_regs()->sp \ - : this_cpu_read(old_rsp)) +#define current_user_stack_pointer() current_pt_regs()->sp +#define compat_user_stack_pointer() current_pt_regs()->sp #endif #ifdef CONFIG_X86_32 @@ -248,7 +243,7 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, */ #define arch_ptrace_stop_needed(code, info) \ ({ \ - set_thread_flag(TIF_NOTIFY_RESUME); \ + force_iret(); \ false; \ }) |