diff options
| -rw-r--r-- | include/linux/ptrace.h | 7 | ||||
| -rw-r--r-- | kernel/ptrace.c | 35 | ||||
| -rw-r--r-- | kernel/signal.c | 39 |
3 files changed, 66 insertions, 15 deletions
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index e93ef1a54fc7..67ad3f152329 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -47,6 +47,11 @@ #define PTRACE_GETREGSET 0x4204 #define PTRACE_SETREGSET 0x4205 +#define PTRACE_SEIZE 0x4206 + +/* flags in @data for PTRACE_SEIZE */ +#define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */ + /* options set using PTRACE_SETOPTIONS */ #define PTRACE_O_TRACESYSGOOD 0x00000001 #define PTRACE_O_TRACEFORK 0x00000002 @@ -65,6 +70,7 @@ #define PTRACE_EVENT_EXEC 4 #define PTRACE_EVENT_VFORK_DONE 5 #define PTRACE_EVENT_EXIT 6 +#define PTRACE_EVENT_STOP 7 #include <asm/ptrace.h> @@ -77,6 +83,7 @@ * flags. When the a task is stopped the ptracer owns task->ptrace. */ +#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ #define PT_PTRACED 0x00000001 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ #define PT_TRACESYSGOOD 0x00000004 diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 45a8a4c5d8b2..dcf9f974198c 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -209,10 +209,28 @@ bool ptrace_may_access(struct task_struct *task, unsigned int mode) return !err; } -static int ptrace_attach(struct task_struct *task) +static int ptrace_attach(struct task_struct *task, long request, + unsigned long flags) { + bool seize = (request == PTRACE_SEIZE); int retval; + /* + * SEIZE will enable new ptrace behaviors which will be implemented + * gradually. SEIZE_DEVEL is used to prevent applications + * expecting full SEIZE behaviors trapping on kernel commits which + * are still in the process of implementing them. + * + * Only test programs for new ptrace behaviors being implemented + * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO. + * + * Once SEIZE behaviors are completely implemented, this flag and + * the following test will be removed. + */ + retval = -EIO; + if (seize && !(flags & PTRACE_SEIZE_DEVEL)) + goto out; + audit_ptrace(task); retval = -EPERM; @@ -244,11 +262,16 @@ static int ptrace_attach(struct task_struct *task) goto unlock_tasklist; task->ptrace = PT_PTRACED; + if (seize) + task->ptrace |= PT_SEIZED; if (task_ns_capable(task, CAP_SYS_PTRACE)) task->ptrace |= PT_PTRACE_CAP; __ptrace_link(task, current); - send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); + + /* SEIZE doesn't trap tracee on attach */ + if (!seize) + send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); spin_lock(&task->sighand->siglock); @@ -785,8 +808,8 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, goto out; } - if (request == PTRACE_ATTACH) { - ret = ptrace_attach(child); + if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { + ret = ptrace_attach(child, request, data); /* * Some architectures need to do book-keeping after * a ptrace attach. @@ -927,8 +950,8 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, goto out; } - if (request == PTRACE_ATTACH) { - ret = ptrace_attach(child); + if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { + ret = ptrace_attach(child, request, data); /* * Some architectures need to do book-keeping after * a ptrace attach. diff --git a/kernel/signal.c b/kernel/signal.c index b5f55ca1f43f..589292f38530 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1873,21 +1873,26 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) recalc_sigpending_tsk(current); } -void ptrace_notify(int exit_code) +static void ptrace_do_notify(int signr, int exit_code, int why) { siginfo_t info; - BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); - memset(&info, 0, sizeof info); - info.si_signo = SIGTRAP; + info.si_signo = signr; info.si_code = exit_code; info.si_pid = task_pid_vnr(current); info.si_uid = current_uid(); /* Let the debugger run. */ + ptrace_stop(exit_code, why, 1, &info); +} + +void ptrace_notify(int exit_code) +{ + BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); + spin_lock_irq(¤t->sighand->siglock); - ptrace_stop(exit_code, CLD_TRAPPED, 1, &info); + ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED); spin_unlock_irq(¤t->sighand->siglock); } @@ -2017,7 +2022,13 @@ static bool do_signal_stop(int signr) /** * do_jobctl_trap - take care of ptrace jobctl traps * - * It is currently used only to trap for group stop while ptraced. + * When PT_SEIZED, it's used for both group stop and explicit + * SEIZE/INTERRUPT traps. Both generate PTRACE_EVENT_STOP trap with + * accompanying siginfo. If stopped, lower eight bits of exit_code contain + * the stop signal; otherwise, %SIGTRAP. + * + * When !PT_SEIZED, it's used only for group stop trap with stop signal + * number as exit_code and no siginfo. * * CONTEXT: * Must be called with @current->sighand->siglock held, which may be @@ -2025,11 +2036,21 @@ static bool do_signal_stop(int signr) */ static void do_jobctl_trap(void) { + struct signal_struct *signal = current->signal; int signr = current->jobctl & JOBCTL_STOP_SIGMASK; - WARN_ON_ONCE(!signr); - ptrace_stop(signr, CLD_STOPPED, 0, NULL); - current->exit_code = 0; + if (current->ptrace & PT_SEIZED) { + if (!signal->group_stop_count && + !(signal->flags & SIGNAL_STOP_STOPPED)) + signr = SIGTRAP; + WARN_ON_ONCE(!signr); + ptrace_do_notify(signr, signr | (PTRACE_EVENT_STOP << 8), + CLD_STOPPED); + } else { + WARN_ON_ONCE(!signr); + ptrace_stop(signr, CLD_STOPPED, 0, NULL); + current->exit_code = 0; + } } static int ptrace_signal(int signr, siginfo_t *info, |