diff options
Diffstat (limited to 'arch/x86/kernel/ptrace.c')
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 151 |
1 files changed, 56 insertions, 95 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 77040b6070e1..e37dccce85db 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -1357,8 +1357,6 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) #endif } -#ifdef CONFIG_X86_32 - void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) { struct siginfo info; @@ -1377,89 +1375,10 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) force_sig_info(SIGTRAP, &info, tsk); } -/* notification of system call entry/exit - * - triggered by current->work.syscall_trace - */ -int do_syscall_trace(struct pt_regs *regs, int entryexit) -{ - int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU); - /* - * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall - * interception - */ - int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP); - int ret = 0; - - /* do the secure computing check first */ - if (!entryexit) - secure_computing(regs->orig_ax); - - if (unlikely(current->audit_context)) { - if (entryexit) - audit_syscall_exit(AUDITSC_RESULT(regs->ax), - regs->ax); - /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only - * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is - * not used, entry.S will call us only on syscall exit, not - * entry; so when TIF_SYSCALL_AUDIT is used we must avoid - * calling send_sigtrap() on syscall entry. - * - * Note that when PTRACE_SYSEMU_SINGLESTEP is used, - * is_singlestep is false, despite his name, so we will still do - * the correct thing. - */ - else if (is_singlestep) - goto out; - } - - if (!(current->ptrace & PT_PTRACED)) - goto out; - - /* If a process stops on the 1st tracepoint with SYSCALL_TRACE - * and then is resumed with SYSEMU_SINGLESTEP, it will come in - * here. We have to check this and return */ - if (is_sysemu && entryexit) - return 0; - - /* Fake a debug trap */ - if (is_singlestep) - send_sigtrap(current, regs, 0); - - if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu) - goto out; - - /* the 0x80 provides a way for the tracing parent to distinguish - between a syscall stop and SIGTRAP delivery */ - /* Note that the debugger could change the result of test_thread_flag!*/ - ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80:0)); - - /* - * this isn't the same as continuing with a signal, but it will do - * for normal use. strace only continues with a signal if the - * stopping signal is not SIGTRAP. -brl - */ - if (current->exit_code) { - send_sig(current->exit_code, current, 1); - current->exit_code = 0; - } - ret = is_sysemu; -out: - if (unlikely(current->audit_context) && !entryexit) - audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax, - regs->bx, regs->cx, regs->dx, regs->si); - if (ret == 0) - return 0; - - regs->orig_ax = -1; /* force skip of syscall restarting */ - if (unlikely(current->audit_context)) - audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax); - return 1; -} - -#else /* CONFIG_X86_64 */ - static void syscall_trace(struct pt_regs *regs) { + if (!(current->ptrace & PT_PTRACED)) + return; #if 0 printk("trace %s ip %lx sp %lx ax %d origrax %d caller %lx tiflags %x ptrace %x\n", @@ -1481,39 +1400,81 @@ static void syscall_trace(struct pt_regs *regs) } } -asmlinkage void syscall_trace_enter(struct pt_regs *regs) +#ifdef CONFIG_X86_32 +# define IS_IA32 1 +#elif defined CONFIG_IA32_EMULATION +# define IS_IA32 test_thread_flag(TIF_IA32) +#else +# define IS_IA32 0 +#endif + +/* + * We must return the syscall number to actually look up in the table. + * This can be -1L to skip running any syscall at all. + */ +asmregparm long syscall_trace_enter(struct pt_regs *regs) { + long ret = 0; + + /* + * If we stepped into a sysenter/syscall insn, it trapped in + * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP. + * If user-mode had set TF itself, then it's still clear from + * do_debug() and we need to set it again to restore the user + * state. If we entered on the slow path, TF was already set. + */ + if (test_thread_flag(TIF_SINGLESTEP)) + regs->flags |= X86_EFLAGS_TF; + /* do the secure computing check first */ secure_computing(regs->orig_ax); - if (test_thread_flag(TIF_SYSCALL_TRACE) - && (current->ptrace & PT_PTRACED)) + if (unlikely(test_thread_flag(TIF_SYSCALL_EMU))) + ret = -1L; + + if (ret || test_thread_flag(TIF_SYSCALL_TRACE)) syscall_trace(regs); if (unlikely(current->audit_context)) { - if (test_thread_flag(TIF_IA32)) { + if (IS_IA32) audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax, regs->bx, regs->cx, regs->dx, regs->si); - } else { +#ifdef CONFIG_X86_64 + else audit_syscall_entry(AUDIT_ARCH_X86_64, regs->orig_ax, regs->di, regs->si, regs->dx, regs->r10); - } +#endif } + + return ret ?: regs->orig_ax; } -asmlinkage void syscall_trace_leave(struct pt_regs *regs) +asmregparm void syscall_trace_leave(struct pt_regs *regs) { if (unlikely(current->audit_context)) audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax); - if ((test_thread_flag(TIF_SYSCALL_TRACE) - || test_thread_flag(TIF_SINGLESTEP)) - && (current->ptrace & PT_PTRACED)) + if (test_thread_flag(TIF_SYSCALL_TRACE)) syscall_trace(regs); -} -#endif /* CONFIG_X86_32 */ + /* + * If TIF_SYSCALL_EMU is set, we only get here because of + * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP). + * We already reported this syscall instruction in + * syscall_trace_enter(), so don't do any more now. + */ + if (unlikely(test_thread_flag(TIF_SYSCALL_EMU))) + return; + + /* + * If we are single-stepping, synthesize a trap to follow the + * system call instruction. + */ + if (test_thread_flag(TIF_SINGLESTEP) && + (current->ptrace & PT_PTRACED)) + send_sigtrap(current, regs, 0); +} |