| Petr Machata | 9282254 | 2012-03-28 00:31:14 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * This file is part of ltrace. |
| 3 | * Copyright (C) 2011,2012 Petr Machata, Red Hat Inc. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License as |
| 7 | * published by the Free Software Foundation; either version 2 of the |
| 8 | * License, or (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA |
| 18 | * 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #ifndef _LTRACE_LINUX_TRACE_H_ |
| 22 | #define _LTRACE_LINUX_TRACE_H_ |
| 23 | |
| 24 | /* This publishes some Linux-specific data structures used for process |
| 25 | * handling. */ |
| 26 | |
| 27 | /** |
| 28 | * This is used for bookkeeping related to PIDs that the event |
| 29 | * handlers work with. |
| 30 | */ |
| 31 | struct pid_task { |
| 32 | pid_t pid; /* This may be 0 for tasks that exited |
| 33 | * mid-handling. */ |
| 34 | int sigstopped : 1; |
| 35 | int got_event : 1; |
| 36 | int delivered : 1; |
| 37 | int vforked : 1; |
| 38 | int sysret : 1; |
| 39 | }; |
| 40 | |
| 41 | struct pid_set { |
| 42 | struct pid_task *tasks; |
| 43 | size_t count; |
| 44 | size_t alloc; |
| 45 | }; |
| 46 | |
| 47 | /** |
| 48 | * Breakpoint re-enablement. When we hit a breakpoint, we must |
| 49 | * disable it, single-step, and re-enable it. That single-step can be |
| 50 | * done only by one task in a task group, while others are stopped, |
| 51 | * otherwise the processes would race for who sees the breakpoint |
| 52 | * disabled and who doesn't. The following is to keep track of it |
| 53 | * all. |
| 54 | */ |
| 55 | struct process_stopping_handler |
| 56 | { |
| 57 | struct event_handler super; |
| 58 | |
| 59 | /* The task that is doing the re-enablement. */ |
| 60 | Process *task_enabling_breakpoint; |
| 61 | |
| 62 | /* The pointer being re-enabled. */ |
| 63 | struct breakpoint *breakpoint_being_enabled; |
| 64 | |
| 65 | /* Artificial atomic skip breakpoint, if any needed. */ |
| 66 | void *atomic_skip_bp_addr; |
| 67 | |
| 68 | /* When all tasks are stopped, this callback gets called. */ |
| 69 | void (*on_all_stopped)(struct process_stopping_handler *); |
| 70 | |
| 71 | enum { |
| 72 | /* We are waiting for everyone to land in t/T. */ |
| 73 | psh_stopping = 0, |
| 74 | |
| 75 | /* We are doing the PTRACE_SINGLESTEP. */ |
| 76 | psh_singlestep, |
| 77 | |
| 78 | /* We are waiting for all the SIGSTOPs to arrive so |
| 79 | * that we can sink them. */ |
| 80 | psh_sinking, |
| 81 | |
| 82 | /* This is for tracking the ugly workaround. */ |
| 83 | psh_ugly_workaround, |
| 84 | } state; |
| 85 | |
| 86 | int exiting; |
| 87 | |
| 88 | struct pid_set pids; |
| 89 | }; |
| 90 | |
| 91 | /* Allocate a process stopping handler, initialize it and install it. |
| 92 | * Return 0 on success or a negative value on failure. */ |
| 93 | int process_install_stopping_handler |
| 94 | (struct Process *proc, struct breakpoint *sbp, |
| 95 | void (*cb)(struct process_stopping_handler *)); |
| 96 | |
| 97 | #endif /* _LTRACE_LINUX_TRACE_H_ */ |