At this point, tracehooks aren't useful to mainline kernel and mostly just add an extra layer of obfuscation. Although they have comments, without actual in-kernel users, it is difficult to tell what are their assumptions and they're actually trying to achieve. To mainline kernel, they just aren't worth keeping around. This patch kills the following trivial tracehooks. * Ones testing whether task is ptraced. Replace with ->ptrace test. tracehook_expect_breakpoints() tracehook_consider_ignored_signal() tracehook_consider_fatal_signal() * ptrace_event() wrappers. Call directly. tracehook_report_exec() tracehook_report_exit() tracehook_report_vfork_done() * ptrace_release_task() wrapper. Call directly. tracehook_finish_release_task() * noop tracehook_prepare_release_task() tracehook_report_death() This doesn't introduce any behavior change.
Showing the changes to kernel/exit.c (1 of 7 files). Show all
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| @@ -169,7 +169,6 @@ void release_task(struct task_struct * p) · 168 unmodified lines | ||
| 169 | 169 | struct task_struct *leader; |
| 170 | 170 | int zap_leader; |
| 171 | 171 | repeat: |
| 172 | − tracehook_prepare_release_task(p); | |
| 173 | 172 | /* don't need to get the RCU readlock here - the process is dead and |
| 174 | 173 | * can't be modifying its own credentials. But shut RCU-lockdep up */ |
| 175 | 174 | rcu_read_lock(); |
| @@ -179,7 +178,7 @@ repeat: · 3 unmodified lines | ||
| 179 | 178 | proc_flush_task(p); |
| 180 | 179 | |
| 181 | 180 | write_lock_irq(&tasklist_lock); |
| 182 | − tracehook_finish_release_task(p); | |
| 181 | + ptrace_release_task(p); | |
| 183 | 182 | __exit_signal(p); |
| 184 | 183 | |
| 185 | 184 | /* |
| @@ -868,8 +867,6 @@ static void exit_notify(struct task_struct *tsk, int group_dead) · 682 unmodified lines | ||
| 868 | 867 | wake_up_process(tsk->signal->group_exit_task); |
| 869 | 868 | write_unlock_irq(&tasklist_lock); |
| 870 | 869 | |
| 871 | − tracehook_report_death(tsk, signal, cookie, group_dead); | |
| 872 | − | |
| 873 | 870 | /* If the process is dead, release it - nobody will wait for it */ |
| 874 | 871 | if (signal == DEATH_REAP) |
| 875 | 872 | release_task(tsk); |
| @@ -924,7 +921,7 @@ NORET_TYPE void do_exit(long code) · 48 unmodified lines | ||
| 924 | 921 | */ |
| 925 | 922 | set_fs(USER_DS); |
| 926 | 923 | |
| 927 | − tracehook_report_exit(&code); | |
| 924 | + ptrace_event(PTRACE_EVENT_EXIT, code); | |
| 928 | 925 | |
| 929 | 926 | validate_creds_for_do_exit(tsk); |
| 930 | 927 | |