- 28 6月, 2011 8 次提交
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由 Oleg Nesterov 提交于
Change de_thread() to set old_leader->exit_signal = -1. This is good for the consistency, it is no longer the leader and all sub-threads have exit_signal = -1 set by copy_process(CLONE_THREAD). And this allows us to micro-optimize thread_group_leader(), it can simply check exit_signal >= 0. This also makes sense because we should move ->group_leader from task_struct to signal_struct. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Reviewed-by: NTejun Heo <tj@kernel.org>
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由 Oleg Nesterov 提交于
__ptrace_detach() and do_notify_parent() set task->exit_signal = -1 to mark the task dead. This is no longer needed, nobody checks exit_signal to detect the EXIT_DEAD task. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Reviewed-by: NTejun Heo <tj@kernel.org>
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由 Oleg Nesterov 提交于
Upadate the last user of task_detached(), wait_task_zombie(), to use thread_group_leader() and kill task_detached(). Signed-off-by: NOleg Nesterov <oleg@redhat.com> Reviewed-by: NTejun Heo <tj@kernel.org>
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由 Oleg Nesterov 提交于
Change reparent_leader() to check ->exit_state instead of ->exit_signal, this matches the similar EXIT_DEAD check in wait_consider_task() and allows us to cleanup the do_notify_parent/task_detached logic. task_detached() was really needed during reparenting before 9cd80bbb "do_wait() optimization: do not place sub-threads on ->children list" to filter out the sub-threads. After this change task_detached(p) can only be true if p is the dead group_leader and its parent ignores SIGCHLD, in this case the caller of do_notify_parent() is going to reap this task and it should set EXIT_DEAD. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Reviewed-by: NTejun Heo <tj@kernel.org>
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由 Oleg Nesterov 提交于
Change other callers of do_notify_parent() to check the value it returns, this makes the subsequent task_detached() unnecessary. Mark do_notify_parent() as __must_check. Use thread_group_leader() instead of !task_detached() to check if we need to notify the real parent in wait_task_zombie(). Remove the stale comment in release_task(). "just for sanity" is no longer true, we have to set EXIT_DEAD to avoid the races with do_wait(). Signed-off-by: NOleg Nesterov <oleg@redhat.com> Acked-by: NTejun Heo <tj@kernel.org>
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由 Oleg Nesterov 提交于
__ptrace_detach() relies on the current obscure behaviour of do_notify_parent(tsk) which changes tsk->exit_signal if this child should be silently reaped. That is why we check task_detached(), it is true if the task is sub-thread, or it is the group_leader but its exit_signal was changed by do_notify_parent(). This is confusing, change the code to rely on !thread_group_leader() or the value returned by do_notify_parent(). Signed-off-by: NOleg Nesterov <oleg@redhat.com> Acked-by: NTejun Heo <tj@kernel.org>
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由 Oleg Nesterov 提交于
Kill tracehook_notify_death(), reimplement the logic in its caller, exit_notify(). Also, change the exec_id's check to use thread_group_leader() instead of task_detached(), this is more clear. This logic only applies to the exiting leader, a sub-thread must never change its exit_signal. Note: when the traced group leader exits the exit_signal-or-SIGCHLD logic looks really strange: - we notify the tracer even if !thread_group_empty() but do_wait(WEXITED) can't work until all threads exit - if the tracer is real_parent, it is not clear why can't we use ->exit_signal event if !thread_group_empty() -v2: do not try to fix the 2nd oddity to avoid the subtle behavior change mixed with reorganization, suggested by Tejun. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Reviewed-by: NTejun Heo <tj@kernel.org>
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由 Oleg Nesterov 提交于
- change do_notify_parent() to return a boolean, true if the task should be reaped because its parent ignores SIGCHLD. - update the only caller which checks the returned value, exit_notify(). This temporary uglifies exit_notify() even more, will be cleanuped by the next change. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Acked-by: NTejun Heo <tj@kernel.org>
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- 23 6月, 2011 6 次提交
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由 Tejun Heo 提交于
tracehook.h is on the way out. Rename tracehook_tracer_task() to ptrace_parent() and move it from tracehook.h to ptrace.h. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: John Johansen <john.johansen@canonical.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
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 clone and exec related tracehooks. tracehook_prepare_clone() tracehook_finish_clone() tracehook_report_clone() tracehook_report_clone_complete() tracehook_unsafe_exec() The changes are mostly trivial - logic is moved to the caller and comments are merged and adjusted appropriately. The only exception is in check_unsafe_exec() where LSM_UNSAFE_PTRACE* are OR'd to bprm->unsafe instead of setting it, which produces the same result as the field is always zero on entry. It also tests p->ptrace instead of (p->ptrace & PT_PTRACED) for consistency, which also gives the same result. This doesn't introduce any behavior change. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
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. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
Move SIGTRAP on exec(2) logic from tracehook_report_exec() to ptrace_event(). This is part of changes to make ptrace_event() smarter and handle ptrace event related details in one place. This doesn't introduce any behavior change. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
This patch implements ptrace_event_enabled() which tests whether a given PTRACE_EVENT_* is enabled and use it to simplify ptrace_event() and tracehook_prepare_clone(). PT_EVENT_FLAG() macro is added which calculates PT_TRACE_* flag from PTRACE_EVENT_*. This is used to define PT_TRACE_* flags and by ptrace_event_enabled() to find the matching flag. This is used to make ptrace_event() and tracehook_prepare_clone() simpler. * ptrace_event() callers were responsible for providing mask to test whether the event was enabled. This patch implements ptrace_event_enabled() and make ptrace_event() drop @mask and determine whether the event is enabled from @event. Note that @event is constant and this conversion doesn't add runtime overhead. All conversions except tracehook_report_clone_complete() are trivial. tracehook_report_clone_complete() used to use 0 for @mask (always enabled) but now tests whether the specified event is enabled. This doesn't cause any behavior difference as it's guaranteed that the event specified by @trace is enabled. * tracehook_prepare_clone() now only determines which event is applicable and use ptrace_event_enabled() for enable test. This doesn't introduce any behavior change. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
task_ptrace(task) simply dereferences task->ptrace and isn't even used consistently only adding confusion. Kill it and directly access ->ptrace instead. This doesn't introduce any behavior change. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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- 17 6月, 2011 5 次提交
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由 Tejun Heo 提交于
The previous patch implemented async notification for ptrace but it only worked while trace is running. This patch introduces PTRACE_LISTEN which is suggested by Oleg Nestrov. It's allowed iff tracee is in STOP trap and puts tracee into quasi-running state - tracee never really runs but wait(2) and ptrace(2) consider it to be running. While ptracer is listening, tracee is allowed to re-enter STOP to notify an async event. Listening state is cleared on the first notification. Ptracer can also clear it by issuing INTERRUPT - tracee will re-trap into STOP with listening state cleared. This allows ptracer to monitor group stop state without running tracee - use INTERRUPT to put tracee into STOP trap, issue LISTEN and then wait(2) to wait for the next group stop event. When it happens, PTRACE_GETSIGINFO provides information to determine the current state. Test program follows. #define PTRACE_SEIZE 0x4206 #define PTRACE_INTERRUPT 0x4207 #define PTRACE_LISTEN 0x4208 #define PTRACE_SEIZE_DEVEL 0x80000000 static const struct timespec ts1s = { .tv_sec = 1 }; int main(int argc, char **argv) { pid_t tracee, tracer; int i; tracee = fork(); if (!tracee) while (1) pause(); tracer = fork(); if (!tracer) { siginfo_t si; ptrace(PTRACE_SEIZE, tracee, NULL, (void *)(unsigned long)PTRACE_SEIZE_DEVEL); ptrace(PTRACE_INTERRUPT, tracee, NULL, NULL); repeat: waitid(P_PID, tracee, NULL, WSTOPPED); ptrace(PTRACE_GETSIGINFO, tracee, NULL, &si); if (!si.si_code) { printf("tracer: SIG %d\n", si.si_signo); ptrace(PTRACE_CONT, tracee, NULL, (void *)(unsigned long)si.si_signo); goto repeat; } printf("tracer: stopped=%d signo=%d\n", si.si_signo != SIGTRAP, si.si_signo); if (si.si_signo != SIGTRAP) ptrace(PTRACE_LISTEN, tracee, NULL, NULL); else ptrace(PTRACE_CONT, tracee, NULL, NULL); goto repeat; } for (i = 0; i < 3; i++) { nanosleep(&ts1s, NULL); printf("mother: SIGSTOP\n"); kill(tracee, SIGSTOP); nanosleep(&ts1s, NULL); printf("mother: SIGCONT\n"); kill(tracee, SIGCONT); } nanosleep(&ts1s, NULL); kill(tracer, SIGKILL); kill(tracee, SIGKILL); return 0; } This is identical to the program to test TRAP_NOTIFY except that tracee is PTRACE_LISTEN'd instead of PTRACE_CONT'd when group stopped. This allows ptracer to monitor when group stop ends without running tracee. # ./test-listen tracer: stopped=0 signo=5 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 -v2: Moved JOBCTL_LISTENING check in wait_task_stopped() into task_stopped_code() as suggested by Oleg. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
Currently there's no way for ptracer to find out whether group stop finished other than polling with INTERRUPT - GETSIGINFO - CONT sequence. This patch implements group stop notification for ptracer using STOP traps. When group stop state of a seized tracee changes, JOBCTL_TRAP_NOTIFY is set, which schedules a STOP trap which is sticky - it isn't cleared by other traps and at least one STOP trap will happen eventually. STOP trap is synchronization point for event notification and the tracer can determine the current group stop state by looking at the signal number portion of exit code (si_status from waitid(2) or si_code from PTRACE_GETSIGINFO). Notifications are generated both on start and end of group stops but, because group stop participation always happens before STOP trap, this doesn't cause an extra trap while tracee is participating in group stop. The symmetry will be useful later. Note that this notification works iff tracee is not trapped. Currently there is no way to be notified of group stop state changes while tracee is trapped. This will be addressed by a later patch. An example program follows. #define PTRACE_SEIZE 0x4206 #define PTRACE_INTERRUPT 0x4207 #define PTRACE_SEIZE_DEVEL 0x80000000 static const struct timespec ts1s = { .tv_sec = 1 }; int main(int argc, char **argv) { pid_t tracee, tracer; int i; tracee = fork(); if (!tracee) while (1) pause(); tracer = fork(); if (!tracer) { siginfo_t si; ptrace(PTRACE_SEIZE, tracee, NULL, (void *)(unsigned long)PTRACE_SEIZE_DEVEL); ptrace(PTRACE_INTERRUPT, tracee, NULL, NULL); repeat: waitid(P_PID, tracee, NULL, WSTOPPED); ptrace(PTRACE_GETSIGINFO, tracee, NULL, &si); if (!si.si_code) { printf("tracer: SIG %d\n", si.si_signo); ptrace(PTRACE_CONT, tracee, NULL, (void *)(unsigned long)si.si_signo); goto repeat; } printf("tracer: stopped=%d signo=%d\n", si.si_signo != SIGTRAP, si.si_signo); ptrace(PTRACE_CONT, tracee, NULL, NULL); goto repeat; } for (i = 0; i < 3; i++) { nanosleep(&ts1s, NULL); printf("mother: SIGSTOP\n"); kill(tracee, SIGSTOP); nanosleep(&ts1s, NULL); printf("mother: SIGCONT\n"); kill(tracee, SIGCONT); } nanosleep(&ts1s, NULL); kill(tracer, SIGKILL); kill(tracee, SIGKILL); return 0; } In the above program, tracer keeps tracee running and gets notification of each group stop state changes. # ./test-notify tracer: stopped=0 signo=5 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
Currently, there's no way to trap a running ptracee short of sending a signal which has various side effects. This patch implements PTRACE_INTERRUPT which traps ptracee without any signal or job control related side effect. The implementation is almost trivial. It uses the group stop trap - SIGTRAP | PTRACE_EVENT_STOP << 8. A new trap flag JOBCTL_TRAP_INTERRUPT is added, which is set on PTRACE_INTERRUPT and cleared when any trap happens. As INTERRUPT should be useable regardless of the current state of tracee, task_is_traced() test in ptrace_check_attach() is skipped for INTERRUPT. PTRACE_INTERRUPT is available iff tracee is attached with PTRACE_SEIZE. Test program follows. #define PTRACE_SEIZE 0x4206 #define PTRACE_INTERRUPT 0x4207 #define PTRACE_SEIZE_DEVEL 0x80000000 static const struct timespec ts100ms = { .tv_nsec = 100000000 }; static const struct timespec ts1s = { .tv_sec = 1 }; static const struct timespec ts3s = { .tv_sec = 3 }; int main(int argc, char **argv) { pid_t tracee; tracee = fork(); if (tracee == 0) { nanosleep(&ts100ms, NULL); while (1) { printf("tracee: alive pid=%d\n", getpid()); nanosleep(&ts1s, NULL); } } if (argc > 1) kill(tracee, SIGSTOP); nanosleep(&ts100ms, NULL); ptrace(PTRACE_SEIZE, tracee, NULL, (void *)(unsigned long)PTRACE_SEIZE_DEVEL); if (argc > 1) { waitid(P_PID, tracee, NULL, WSTOPPED); ptrace(PTRACE_CONT, tracee, NULL, NULL); } nanosleep(&ts3s, NULL); printf("tracer: INTERRUPT and DETACH\n"); ptrace(PTRACE_INTERRUPT, tracee, NULL, NULL); waitid(P_PID, tracee, NULL, WSTOPPED); ptrace(PTRACE_DETACH, tracee, NULL, NULL); nanosleep(&ts3s, NULL); printf("tracer: exiting\n"); kill(tracee, SIGKILL); return 0; } When called without argument, tracee is seized from running state, interrupted and then detached back to running state. # ./test-interrupt tracee: alive pid=4546 tracee: alive pid=4546 tracee: alive pid=4546 tracer: INTERRUPT and DETACH tracee: alive pid=4546 tracee: alive pid=4546 tracee: alive pid=4546 tracer: exiting When called with argument, tracee is seized from stopped state, continued, interrupted and then detached back to stopped state. # ./test-interrupt 1 tracee: alive pid=4548 tracee: alive pid=4548 tracee: alive pid=4548 tracer: INTERRUPT and DETACH tracer: exiting Before PTRACE_INTERRUPT, once the tracee was running, there was no way to trap tracee and do PTRACE_DETACH without causing side effect. -v2: Updated to use task_set_jobctl_pending() so that it doesn't end up scheduling TRAP_STOP if child is dying which may make the child unkillable. Spotted by Oleg. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
PTRACE_ATTACH implicitly issues SIGSTOP on attach which has side effects on tracee signal and job control states. This patch implements a new ptrace request PTRACE_SEIZE which attaches a tracee without trapping it or affecting its signal and job control states. The usage is the same with PTRACE_ATTACH but it takes PTRACE_SEIZE_* flags in @data. Currently, the only defined flag is PTRACE_SEIZE_DEVEL which is a temporary flag to enable PTRACE_SEIZE. PTRACE_SEIZE will change ptrace behaviors outside of attach itself. The changes will be implemented gradually and the DEVEL flag is to prevent programs which expect full SEIZE behavior from using it before all the behavior modifications are complete while allowing unit testing. The flag will be removed once SEIZE behaviors are completely implemented. * PTRACE_SEIZE, unlike ATTACH, doesn't force tracee to trap. After attaching tracee continues to run unless a trap condition occurs. * PTRACE_SEIZE doesn't affect signal or group stop state. * If PTRACE_SEIZE'd, group stop uses PTRACE_EVENT_STOP trap which uses exit_code of (signr | PTRACE_EVENT_STOP << 8) where signr is one of the stopping signals if group stop is in effect or SIGTRAP otherwise, and returns usual trap siginfo on PTRACE_GETSIGINFO instead of NULL. Seizing sets PT_SEIZED in ->ptrace of the tracee. This flag will be used to determine whether new SEIZE behaviors should be enabled. Test program follows. #define PTRACE_SEIZE 0x4206 #define PTRACE_SEIZE_DEVEL 0x80000000 static const struct timespec ts100ms = { .tv_nsec = 100000000 }; static const struct timespec ts1s = { .tv_sec = 1 }; static const struct timespec ts3s = { .tv_sec = 3 }; int main(int argc, char **argv) { pid_t tracee; tracee = fork(); if (tracee == 0) { nanosleep(&ts100ms, NULL); while (1) { printf("tracee: alive\n"); nanosleep(&ts1s, NULL); } } if (argc > 1) kill(tracee, SIGSTOP); nanosleep(&ts100ms, NULL); ptrace(PTRACE_SEIZE, tracee, NULL, (void *)(unsigned long)PTRACE_SEIZE_DEVEL); if (argc > 1) { waitid(P_PID, tracee, NULL, WSTOPPED); ptrace(PTRACE_CONT, tracee, NULL, NULL); } nanosleep(&ts3s, NULL); printf("tracer: exiting\n"); return 0; } When the above program is called w/o argument, tracee is seized while running and remains running. When tracer exits, tracee continues to run and print out messages. # ./test-seize-simple tracee: alive tracee: alive tracee: alive tracer: exiting tracee: alive tracee: alive When called with an argument, tracee is seized from stopped state and continued, and returns to stopped state when tracer exits. # ./test-seize tracee: alive tracee: alive tracee: alive tracer: exiting # ps -el|grep test-seize 1 T 0 4720 1 0 80 0 - 941 signal ttyS0 00:00:00 test-seize -v2: SEIZE doesn't schedule TRAP_STOP and leaves tracee running as Jan suggested. -v3: PTRACE_EVENT_STOP traps now report group stop state by signr. If group stop is in effect the stop signal number is returned as part of exit_code; otherwise, SIGTRAP. This was suggested by Denys and Oleg. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Oleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
do_signal_stop() implemented both normal group stop and trap for group stop while ptraced. This approach has been enough but scheduled changes require trap mechanism which can be used in more generic manner and using group stop trap for generic trap site simplifies both userland visible interface and implementation. This patch adds a new jobctl flag - JOBCTL_TRAP_STOP. When set, it triggers a trap site, which behaves like group stop trap, in get_signal_to_deliver() after checking for pending signals. While ptraced, do_signal_stop() doesn't stop itself. It initiates group stop if requested and schedules JOBCTL_TRAP_STOP and returns. The caller - get_signal_to_deliver() - is responsible for checking whether TRAP_STOP is pending afterwards and handling it. ptrace_attach() is updated to use JOBCTL_TRAP_STOP instead of JOBCTL_STOP_PENDING and __ptrace_unlink() to clear all pending trap bits and TRAPPING so that TRAP_STOP and future trap bits don't linger after detach. While at it, add proper function comment to do_signal_stop() and make it return bool. -v2: __ptrace_unlink() updated to clear JOBCTL_TRAP_MASK and TRAPPING instead of JOBCTL_PENDING_MASK. This avoids accidentally clearing JOBCTL_STOP_CONSUME. Spotted by Oleg. -v3: do_signal_stop() updated to return %false without dropping siglock while ptraced and TRAP_STOP check moved inside for(;;) loop after group stop participation. This avoids unnecessary relocking and also will help avoiding unnecessary traps by consuming group stop before handling pending traps. -v4: Jobctl trap handling moved into a separate function - do_jobctl_trap(). Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
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- 05 6月, 2011 9 次提交
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由 Tejun Heo 提交于
Remove the following three noop tracehooks in signals.c. * tracehook_force_sigpending() * tracehook_get_signal() * tracehook_finish_jctl() The code area is about to be updated and these hooks don't do anything other than obfuscating the logic. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
ptracer->signal->wait_chldexit was used to wait for TRAPPING; however, ->wait_chldexit was already complicated with waker-side filtering without adding TRAPPING wait on top of it. Also, it unnecessarily made TRAPPING clearing depend on the current ptrace relationship - if the ptracee is detached, wakeup is lost. There is no reason to use signal->wait_chldexit here. We're just waiting for JOBCTL_TRAPPING bit to clear and given the relatively infrequent use of ptrace, bit_waitqueue can serve it perfectly. This patch makes JOBCTL_TRAPPING wait use bit_waitqueue instead of signal->wait_chldexit. -v2: Use JOBCTL_*_BIT macros instead of ilog2() as suggested by Linus. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
task->jobctl currently hosts JOBCTL_STOP_PENDING and will host TRAP pending bits too. Setting pending conditions on a dying task may make the task unkillable. Currently, each setting site is responsible for checking for the condition but with to-be-added job control traps this becomes too fragile. This patch adds task_set_jobctl_pending() which should be used when setting task->jobctl bits to schedule a stop or trap. The function performs the followings to ease setting pending bits. * Sanity checks. * If fatal signal is pending or PF_EXITING is set, no bit is set. * STOP_SIGMASK is automatically cleared if new value is being set. do_signal_stop() and ptrace_attach() are updated to use task_set_jobctl_pending() instead of setting STOP_PENDING explicitly. The surrounding structures around setting are changed to fit task_set_jobctl_pending() better but there should be no userland visible behavior difference. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
JOBCTL_TRAPPING indicates that ptracer is waiting for tracee to (re)transit into TRACED. task_clear_jobctl_pending() must be called when either tracee enters TRACED or the transition is cancelled for some reason. The former is achieved by explicitly calling task_clear_jobctl_pending() in ptrace_stop() and the latter by calling it at the end of do_signal_stop(). Calling task_clear_jobctl_trapping() at the end of do_signal_stop() limits the scope TRAPPING can be used and is fragile in that seemingly unrelated changes to tracee's control flow can lead to stuck TRAPPING. We already have task_clear_jobctl_pending() calls on those cancelling events to clear JOBCTL_STOP_PENDING. Cancellations can be handled by making those call sites use JOBCTL_PENDING_MASK instead and updating task_clear_jobctl_pending() such that task_clear_jobctl_trapping() is called automatically if no stop/trap is pending. This patch makes the above changes and removes the fallback task_clear_jobctl_trapping() call from do_signal_stop(). Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
This patch introduces JOBCTL_PENDING_MASK and replaces task_clear_jobctl_stop_pending() with task_clear_jobctl_pending() which takes an extra @mask argument. JOBCTL_PENDING_MASK is currently equal to JOBCTL_STOP_PENDING but future patches will add more bits. recalc_sigpending_tsk() is updated to use JOBCTL_PENDING_MASK instead. task_clear_jobctl_pending() takes @mask which in subset of JOBCTL_PENDING_MASK and clears the relevant jobctl bits. If JOBCTL_STOP_PENDING is set, other STOP bits are cleared together. All task_clear_jobctl_stop_pending() users are updated to call task_clear_jobctl_pending() with JOBCTL_STOP_PENDING which is functionally identical to task_clear_jobctl_stop_pending(). This patch doesn't cause any functional change. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
In ptrace_stop(), after arch hook is done, the task state and jobctl bits are updated while holding siglock. The ordering requirement there is that TASK_TRACED is set before JOBCTL_TRAPPING is cleared to prevent ptracer waiting on TRAPPING doesn't end up waking up TRACED is actually set and sees TASK_RUNNING in wait(2). Move set_current_state(TASK_TRACED) to the top of the block and reorganize comments. This makes the ordering more obvious (TASK_TRACED before other updates) and helps future updates to group stop participation. This patch doesn't cause any functional change. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
PTRACE_INTERRUPT is going to be added which should also skip task_is_traced() check in ptrace_check_attach(). Rename @kill to @ignore_state and make it bool. Add function comment while at it. This patch doesn't introduce any behavior difference. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
signal->group_stop currently hosts mostly group stop related flags; however, it's gonna be used for wider purposes and the GROUP_STOP_ flag prefix becomes confusing. Rename signal->group_stop to signal->jobctl and rename all GROUP_STOP_* flags to JOBCTL_*. Bit position macros JOBCTL_*_BIT are defined and JOBCTL_* flags are defined in terms of them to allow using bitops later. While at it, reassign JOBCTL_TRAPPING to bit 22 to better accomodate future additions. This doesn't cause any functional change. -v2: JOBCTL_*_BIT macros added as suggested by Linus. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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由 Tejun Heo 提交于
Remove local variable wait_trap which determines whether to wait for !TRAPPING or not and simply wait for it if attach was successful. -v2: Oleg pointed out wait should happen iff attach was successful. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: NOleg Nesterov <oleg@redhat.com>
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- 04 6月, 2011 12 次提交
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6由 Linus Torvalds 提交于
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6: [SCSI] Fix oops caused by queue refcounting failure
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6由 Linus Torvalds 提交于
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (40 commits) tg3: Fix tg3_skb_error_unmap() net: tracepoint of net_dev_xmit sees freed skb and causes panic drivers/net/can/flexcan.c: add missing clk_put net: dm9000: Get the chip in a known good state before enabling interrupts drivers/net/davinci_emac.c: add missing clk_put af-packet: Add flag to distinguish VID 0 from no-vlan. caif: Fix race when conditionally taking rtnl lock usbnet/cdc_ncm: add missing .reset_resume hook vlan: fix typo in vlan_dev_hard_start_xmit() net/ipv4: Check for mistakenly passed in non-IPv4 address iwl4965: correctly validate temperature value bluetooth l2cap: fix locking in l2cap_global_chan_by_psm ath9k: fix two more bugs in tx power cfg80211: don't drop p2p probe responses Revert "net: fix section mismatches" drivers/net/usb/catc.c: Fix potential deadlock in catc_ctrl_run() sctp: stop pending timers and purge queues when peer restart asoc drivers/net: ks8842 Fix crash on received packet when in PIO mode. ip_options_compile: properly handle unaligned pointer iwlagn: fix incorrect PCI subsystem id for 6150 devices ...
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git://git.kernel.dk/linux-block由 Linus Torvalds 提交于
* 'for-linus' of git://git.kernel.dk/linux-block: block: Use hlist_entry() for io_context.cic_list.first cfq-iosched: Remove bogus check in queue_fail path xen/blkback: potential null dereference in error handling xen/blkback: don't call vbd_size() if bd_disk is NULL block: blkdev_get() should access ->bd_disk only after success CFQ: Fix typo and remove unnecessary semicolon block: remove unwanted semicolons Revert "block: Remove extra discard_alignment from hd_struct." nbd: adjust 'max_part' according to part_shift nbd: limit module parameters to a sane value nbd: pass MSG_* flags to kernel_recvmsg() block: improve the bio_add_page() and bio_add_pc_page() descriptions
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git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin由 Linus Torvalds 提交于
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin: Blackfin: strncpy: fix handling of zero lengths
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git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile由 Linus Torvalds 提交于
* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: asm-generic/unistd.h: support sendmmsg syscall tile: enable CONFIG_BUGVERBOSE
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git://git.infradead.org/ubifs-2.6由 Linus Torvalds 提交于
* 'linux-next' of git://git.infradead.org/ubifs-2.6: UBIFS: fix-up free space earlier UBIFS: intialize LPT earlier UBIFS: assert no fixup when writing a node UBIFS: fix clean znode counter corruption in error cases UBIFS: fix memory leak on error path UBIFS: fix shrinker object count reports UBIFS: fix recovery broken by the previous recovery fix UBIFS: amend ubifs_recover_leb interface UBIFS: introduce a "grouped" journal head flag UBIFS: supress false error messages
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-ktest由 Linus Torvalds 提交于
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-ktest: ktest: Ignore unset values of the minconfig in config_bisect ktest: Fix result of rebooting the kernel ktest: Fix off-by-one in config bisect result
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由 Linus Torvalds 提交于
Merge branch 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6 * 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: ARM: mach-shmobile: add DMAC clock definitions on SH7372 ARM: arch-shmobile: support SDHI card detection on mackerel, using a GPIO sh_mobile_meram: MERAM platform data for LCDC
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git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6由 Linus Torvalds 提交于
* 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: dmaengine: shdma: fix a regression: initialise DMA channels for memcpy dmaengine: shdma: Fix up fallout from runtime PM changes. Revert "clocksource: sh_cmt: Runtime PM support" Revert "clocksource: sh_tmu: Runtime PM support" sh: Fix up asm-generic/ptrace.h fallout. sh64: Move from P1SEG to CAC_ADDR for consistent sync. sh64: asm/pgtable.h needs asm/mmu.h sh: asm/tlb.h needs linux/swap.h sh: mark DMA slave ID 0 as invalid sh: Update shmin to reflect PIO dependency. sh: arch/sh/kernel/process_32.c needs linux/prefetch.h. sh: add MMCIF runtime PM support on ecovec sh: switch ap325rxa to dynamically manage the platform camera
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由 Linus Torvalds 提交于
This reverts commit ed0bd233. Since we reverted the TTY API change, we should revert the ASoC update to it too. Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Liam Girdwood <lrg@ti.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Linus Torvalds 提交于
This reverts commit b1c43f82. It was broken in so many ways, and results in random odd pty issues. It re-introduced the buggy schedule_work() in flush_to_ldisc() that can cause endless work-loops (see commit a5660b41: "tty: fix endless work loop when the buffer fills up"). It also used an "unsigned int" return value fo the ->receive_buf() function, but then made multiple functions return a negative error code, and didn't actually check for the error in the caller. And it didn't actually work at all. BenH bisected down odd tty behavior to it: "It looks like the patch is causing some major malfunctions of the X server for me, possibly related to PTYs. For example, cat'ing a large file in a gnome terminal hangs the kernel for -minutes- in a loop of what looks like flush_to_ldisc/workqueue code, (some ftrace data in the quoted bits further down). ... Some more data: It -looks- like what happens is that the flush_to_ldisc work queue entry constantly re-queues itself (because the PTY is full ?) and the workqueue thread will basically loop forver calling it without ever scheduling, thus starving the consumer process that could have emptied the PTY." which is pretty much exactly the problem we fixed in a5660b41. Milton Miller pointed out the 'unsigned int' issue. Reported-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Reported-by: NMilton Miller <miltonm@bga.com> Cc: Stefan Bigler <stefan.bigler@keymile.com> Cc: Toby Gray <toby.gray@realvnc.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 John W. Linville 提交于
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 into for-davem
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