From 1227dd773d8d4e3983b4b751f9ffa0f41402fb7c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 24 Apr 2012 02:44:49 -0400 Subject: TIF_NOTIFY_RESUME is defined on all targets now Signed-off-by: Al Viro --- include/linux/tracehook.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/tracehook.h') diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 51bd91d911c3..8a2a3fc9bd05 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -153,7 +153,6 @@ static inline void tracehook_signal_handler(int sig, siginfo_t *info, ptrace_notify(SIGTRAP); } -#ifdef TIF_NOTIFY_RESUME /** * set_notify_resume - cause tracehook_notify_resume() to be called * @task: task that will call tracehook_notify_resume() @@ -185,6 +184,5 @@ static inline void set_notify_resume(struct task_struct *task) static inline void tracehook_notify_resume(struct pt_regs *regs) { } -#endif /* TIF_NOTIFY_RESUME */ #endif /* */ -- cgit v1.3-8-gc7d7 From a42c6ded827dbd396d2efde7530620be029a72d1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 23 May 2012 14:44:37 -0400 Subject: move key_repace_session_keyring() into tracehook_notify_resume() Signed-off-by: Al Viro --- arch/alpha/kernel/signal.c | 2 -- arch/arm/kernel/signal.c | 2 -- arch/avr32/kernel/signal.c | 2 -- arch/blackfin/kernel/signal.c | 2 -- arch/c6x/kernel/signal.c | 2 -- arch/cris/kernel/ptrace.c | 2 -- arch/frv/kernel/signal.c | 2 -- arch/h8300/kernel/signal.c | 2 -- arch/hexagon/kernel/signal.c | 2 -- arch/ia64/kernel/process.c | 2 -- arch/m32r/kernel/signal.c | 2 -- arch/m68k/kernel/signal.c | 5 +---- arch/microblaze/kernel/signal.c | 5 +---- arch/mips/kernel/signal.c | 2 -- arch/mn10300/kernel/signal.c | 2 -- arch/openrisc/kernel/signal.c | 2 -- arch/parisc/kernel/signal.c | 2 -- arch/powerpc/kernel/signal.c | 2 -- arch/s390/kernel/signal.c | 2 -- arch/score/kernel/signal.c | 2 -- arch/sh/kernel/signal_32.c | 2 -- arch/sh/kernel/signal_64.c | 2 -- arch/sparc/kernel/signal_32.c | 2 -- arch/sparc/kernel/signal_64.c | 2 -- arch/tile/kernel/process.c | 2 -- arch/um/kernel/process.c | 5 +---- arch/unicore32/kernel/signal.c | 2 -- arch/x86/kernel/signal.c | 2 -- arch/xtensa/kernel/signal.c | 5 +---- include/linux/tracehook.h | 2 ++ 30 files changed, 6 insertions(+), 66 deletions(-) (limited to 'include/linux/tracehook.h') diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c index 10ab2d74ecbb..f6db3032ddf0 100644 --- a/arch/alpha/kernel/signal.c +++ b/arch/alpha/kernel/signal.c @@ -590,7 +590,5 @@ do_notify_resume(struct pt_regs *regs, struct switch_stack *sw, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 4e5fdd9bd9e3..ec640412aed0 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -728,7 +728,5 @@ do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) if (thread_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c index ae386c304bee..e7595ef74f51 100644 --- a/arch/avr32/kernel/signal.c +++ b/arch/avr32/kernel/signal.c @@ -321,7 +321,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti) if (ti->flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c index e5bbc1a5edc2..fc9ecce8b6ce 100644 --- a/arch/blackfin/kernel/signal.c +++ b/arch/blackfin/kernel/signal.c @@ -336,8 +336,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs) if (test_thread_flag(TIF_NOTIFY_RESUME)) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/c6x/kernel/signal.c b/arch/c6x/kernel/signal.c index cf37478c1169..9493f0bbf0a6 100644 --- a/arch/c6x/kernel/signal.c +++ b/arch/c6x/kernel/signal.c @@ -364,7 +364,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags, if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/cris/kernel/ptrace.c b/arch/cris/kernel/ptrace.c index d114ad3da9b1..58d44ee1a71f 100644 --- a/arch/cris/kernel/ptrace.c +++ b/arch/cris/kernel/ptrace.c @@ -40,7 +40,5 @@ void do_notify_resume(int canrestart, struct pt_regs *regs, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/frv/kernel/signal.c b/arch/frv/kernel/signal.c index 8cf5dca01758..595bf1e5a5dc 100644 --- a/arch/frv/kernel/signal.c +++ b/arch/frv/kernel/signal.c @@ -562,8 +562,6 @@ asmlinkage void do_notify_resume(__u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(__frame); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } /* end do_notify_resume() */ diff --git a/arch/h8300/kernel/signal.c b/arch/h8300/kernel/signal.c index d4b0555d2904..e58992ad789e 100644 --- a/arch/h8300/kernel/signal.c +++ b/arch/h8300/kernel/signal.c @@ -513,7 +513,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/hexagon/kernel/signal.c b/arch/hexagon/kernel/signal.c index 434866eb0f1c..21a3018cb9bf 100644 --- a/arch/hexagon/kernel/signal.c +++ b/arch/hexagon/kernel/signal.c @@ -273,8 +273,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 5e0e86ddb12f..dd6fc1449741 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -199,8 +199,6 @@ do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall) if (test_thread_flag(TIF_NOTIFY_RESUME)) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(&scr->pt); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } /* copy user rbs to kernel rbs */ diff --git a/arch/m32r/kernel/signal.c b/arch/m32r/kernel/signal.c index f54d96993ea1..64804f1f5141 100644 --- a/arch/m32r/kernel/signal.c +++ b/arch/m32r/kernel/signal.c @@ -383,8 +383,6 @@ void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } clear_thread_flag(TIF_IRET); diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c index d9f3d1900eed..973eec60cad4 100644 --- a/arch/m68k/kernel/signal.c +++ b/arch/m68k/kernel/signal.c @@ -1193,9 +1193,6 @@ void do_notify_resume(struct pt_regs *regs) if (test_thread_flag(TIF_SIGPENDING)) do_signal(regs); - if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) { + if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); - } } diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c index 7f4c7bef1642..5d796e32786e 100644 --- a/arch/microblaze/kernel/signal.c +++ b/arch/microblaze/kernel/signal.c @@ -401,9 +401,6 @@ void do_notify_resume(struct pt_regs *regs, int in_syscall) if (test_thread_flag(TIF_SIGPENDING)) do_signal(regs, in_syscall); - if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) { + if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); - } } diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index 17f6ee30ad0d..8a6e6d116ab0 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -636,8 +636,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/mn10300/kernel/signal.c b/arch/mn10300/kernel/signal.c index 890cf91767cc..b8b6aa1a6837 100644 --- a/arch/mn10300/kernel/signal.c +++ b/arch/mn10300/kernel/signal.c @@ -554,7 +554,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(current_frame()); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c index e970743251ae..9ae611522953 100644 --- a/arch/openrisc/kernel/signal.c +++ b/arch/openrisc/kernel/signal.c @@ -376,7 +376,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs) if (current_thread_info()->flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c index 4b9cb0d546d1..e7a7cd3e1120 100644 --- a/arch/parisc/kernel/signal.c +++ b/arch/parisc/kernel/signal.c @@ -638,7 +638,5 @@ void do_notify_resume(struct pt_regs *regs, long in_syscall) if (test_thread_flag(TIF_NOTIFY_RESUME)) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c index 651c5963662b..bfc3ec1382fb 100644 --- a/arch/powerpc/kernel/signal.c +++ b/arch/powerpc/kernel/signal.c @@ -193,8 +193,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c index f626232e216c..42a6e8b47f06 100644 --- a/arch/s390/kernel/signal.c +++ b/arch/s390/kernel/signal.c @@ -494,6 +494,4 @@ void do_notify_resume(struct pt_regs *regs) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } diff --git a/arch/score/kernel/signal.c b/arch/score/kernel/signal.c index d4a49011c48a..302838d3acf6 100644 --- a/arch/score/kernel/signal.c +++ b/arch/score/kernel/signal.c @@ -356,7 +356,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c index cb4172c8af7d..9d7bfd66f189 100644 --- a/arch/sh/kernel/signal_32.c +++ b/arch/sh/kernel/signal_32.c @@ -626,7 +626,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/sh/kernel/signal_64.c b/arch/sh/kernel/signal_64.c index b589a354c069..aa6428430842 100644 --- a/arch/sh/kernel/signal_64.c +++ b/arch/sh/kernel/signal_64.c @@ -685,7 +685,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c index 2b7e849f7c65..6b42e8622d12 100644 --- a/arch/sparc/kernel/signal_32.c +++ b/arch/sparc/kernel/signal_32.c @@ -590,8 +590,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c index eafaab486b2d..c82cf1cc3965 100644 --- a/arch/sparc/kernel/signal_64.c +++ b/arch/sparc/kernel/signal_64.c @@ -607,8 +607,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c index f572c19c4082..32817ab6062a 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -569,8 +569,6 @@ int do_work_pending(struct pt_regs *regs, u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); return 1; } if (thread_info_flags & _TIF_SINGLESTEP) { diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 3a2235e0abc3..ccb9a9d283f1 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -117,11 +117,8 @@ void interrupt_end(void) schedule(); if (test_thread_flag(TIF_SIGPENDING)) do_signal(); - if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) { + if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) tracehook_notify_resume(¤t->thread.regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); - } } void exit_thread(void) diff --git a/arch/unicore32/kernel/signal.c b/arch/unicore32/kernel/signal.c index 7754df6ef7d4..28782ad47b93 100644 --- a/arch/unicore32/kernel/signal.c +++ b/arch/unicore32/kernel/signal.c @@ -464,8 +464,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, if (thread_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } } diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index b68ccadd2ff4..9363b58b967c 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -821,8 +821,6 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); } if (thread_info_flags & _TIF_USER_RETURN_NOTIFY) fire_user_return_notifiers(); diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index c5e4ec0598d2..ea7e17778a75 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -548,9 +548,6 @@ void do_notify_resume(struct pt_regs *regs) if (test_thread_flag(TIF_SIGPENDING)) do_signal(regs); - if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) { + if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) tracehook_notify_resume(regs); - if (current->replacement_session_keyring) - key_replace_session_keyring(); - } } diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 8a2a3fc9bd05..b9ca903bb553 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -183,6 +183,8 @@ static inline void set_notify_resume(struct task_struct *task) */ static inline void tracehook_notify_resume(struct pt_regs *regs) { + if (current->replacement_session_keyring) + key_replace_session_keyring(); } #endif /* */ -- cgit v1.3-8-gc7d7 From e73f8959af0439d114847eab5a8a5ce48f1217c4 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 11 May 2012 10:59:07 +1000 Subject: task_work_add: generic process-context callbacks Provide a simple mechanism that allows running code in the (nonatomic) context of the arbitrary task. The caller does task_work_add(task, task_work) and this task executes task_work->func() either from do_notify_resume() or from do_exit(). The callback can rely on PF_EXITING to detect the latter case. "struct task_work" can be embedded in another struct, still it has "void *data" to handle the most common/simple case. This allows us to kill the ->replacement_session_keyring hack, and potentially this can have more users. Performance-wise, this adds 2 "unlikely(!hlist_empty())" checks into tracehook_notify_resume() and do_exit(). But at the same time we can remove the "replacement_session_keyring != NULL" checks from arch/*/signal.c and exit_creds(). Note: task_work_add/task_work_run abuses ->pi_lock. This is only because this lock is already used by lookup_pi_state() to synchronize with do_exit() setting PF_EXITING. Fortunately the scope of this lock in task_work.c is really tiny, and the code is unlikely anyway. Signed-off-by: Oleg Nesterov Acked-by: David Howells Cc: Thomas Gleixner Cc: Richard Kuo Cc: Linus Torvalds Cc: Alexander Gordeev Cc: Chris Zankel Cc: David Smith Cc: "Frank Ch. Eigler" Cc: Geert Uytterhoeven Cc: Larry Woodman Cc: Peter Zijlstra Cc: Tejun Heo Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- include/linux/sched.h | 2 ++ include/linux/task_work.h | 33 +++++++++++++++++++ include/linux/tracehook.h | 11 +++++++ kernel/Makefile | 2 +- kernel/exit.c | 5 ++- kernel/fork.c | 1 + kernel/task_work.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 136 insertions(+), 2 deletions(-) create mode 100644 include/linux/task_work.h create mode 100644 kernel/task_work.c (limited to 'include/linux/tracehook.h') diff --git a/include/linux/sched.h b/include/linux/sched.h index 5ea8baea9387..7930131abc1a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1400,6 +1400,8 @@ struct task_struct { int (*notifier)(void *priv); void *notifier_data; sigset_t *notifier_mask; + struct hlist_head task_works; + struct audit_context *audit_context; #ifdef CONFIG_AUDITSYSCALL uid_t loginuid; diff --git a/include/linux/task_work.h b/include/linux/task_work.h new file mode 100644 index 000000000000..294d5d5e90b1 --- /dev/null +++ b/include/linux/task_work.h @@ -0,0 +1,33 @@ +#ifndef _LINUX_TASK_WORK_H +#define _LINUX_TASK_WORK_H + +#include +#include + +struct task_work; +typedef void (*task_work_func_t)(struct task_work *); + +struct task_work { + struct hlist_node hlist; + task_work_func_t func; + void *data; +}; + +static inline void +init_task_work(struct task_work *twork, task_work_func_t func, void *data) +{ + twork->func = func; + twork->data = data; +} + +int task_work_add(struct task_struct *task, struct task_work *twork, bool); +struct task_work *task_work_cancel(struct task_struct *, task_work_func_t); +void task_work_run(void); + +static inline void exit_task_work(struct task_struct *task) +{ + if (unlikely(!hlist_empty(&task->task_works))) + task_work_run(); +} + +#endif /* _LINUX_TASK_WORK_H */ diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index b9ca903bb553..b2dd0917ca0d 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -49,6 +49,7 @@ #include #include #include +#include struct linux_binprm; /* @@ -164,8 +165,10 @@ static inline void tracehook_signal_handler(int sig, siginfo_t *info, */ static inline void set_notify_resume(struct task_struct *task) { +#ifdef TIF_NOTIFY_RESUME if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME)) kick_process(task); +#endif } /** @@ -185,6 +188,14 @@ static inline void tracehook_notify_resume(struct pt_regs *regs) { if (current->replacement_session_keyring) key_replace_session_keyring(); + /* + * The caller just cleared TIF_NOTIFY_RESUME. This barrier + * pairs with task_work_add()->set_notify_resume() after + * hlist_add_head(task->task_works); + */ + smp_mb__after_clear_bit(); + if (unlikely(!hlist_empty(¤t->task_works))) + task_work_run(); } #endif /* */ diff --git a/kernel/Makefile b/kernel/Makefile index 6c07f30fa9b7..bf1034008aca 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -5,7 +5,7 @@ obj-y = fork.o exec_domain.o panic.o printk.o \ cpu.o exit.o itimer.o time.o softirq.o resource.o \ sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \ - signal.o sys.o kmod.o workqueue.o pid.o \ + signal.o sys.o kmod.o workqueue.o pid.o task_work.o \ rcupdate.o extable.o params.o posix-timers.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ diff --git a/kernel/exit.c b/kernel/exit.c index 910a0716e17a..3d93325e0b1a 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -946,11 +946,14 @@ void do_exit(long code) exit_signals(tsk); /* sets PF_EXITING */ /* * tsk->flags are checked in the futex code to protect against - * an exiting task cleaning up the robust pi futexes. + * an exiting task cleaning up the robust pi futexes, and in + * task_work_add() to avoid the race with exit_task_work(). */ smp_mb(); raw_spin_unlock_wait(&tsk->pi_lock); + exit_task_work(tsk); + exit_irq_thread(); if (unlikely(in_atomic())) diff --git a/kernel/fork.c b/kernel/fork.c index 05c813dc9ecc..a46db217a589 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1411,6 +1411,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, */ p->group_leader = p; INIT_LIST_HEAD(&p->thread_group); + INIT_HLIST_HEAD(&p->task_works); /* Now that the task is set up, run cgroup callbacks if * necessary. We need to run them before the task is visible diff --git a/kernel/task_work.c b/kernel/task_work.c new file mode 100644 index 000000000000..82d1c794066d --- /dev/null +++ b/kernel/task_work.c @@ -0,0 +1,84 @@ +#include +#include +#include + +int +task_work_add(struct task_struct *task, struct task_work *twork, bool notify) +{ + unsigned long flags; + int err = -ESRCH; + +#ifndef TIF_NOTIFY_RESUME + if (notify) + return -ENOTSUPP; +#endif + /* + * We must not insert the new work if the task has already passed + * exit_task_work(). We rely on do_exit()->raw_spin_unlock_wait() + * and check PF_EXITING under pi_lock. + */ + raw_spin_lock_irqsave(&task->pi_lock, flags); + if (likely(!(task->flags & PF_EXITING))) { + hlist_add_head(&twork->hlist, &task->task_works); + err = 0; + } + raw_spin_unlock_irqrestore(&task->pi_lock, flags); + + /* test_and_set_bit() implies mb(), see tracehook_notify_resume(). */ + if (likely(!err) && notify) + set_notify_resume(task); + return err; +} + +struct task_work * +task_work_cancel(struct task_struct *task, task_work_func_t func) +{ + unsigned long flags; + struct task_work *twork; + struct hlist_node *pos; + + raw_spin_lock_irqsave(&task->pi_lock, flags); + hlist_for_each_entry(twork, pos, &task->task_works, hlist) { + if (twork->func == func) { + hlist_del(&twork->hlist); + goto found; + } + } + twork = NULL; + found: + raw_spin_unlock_irqrestore(&task->pi_lock, flags); + + return twork; +} + +void task_work_run(void) +{ + struct task_struct *task = current; + struct hlist_head task_works; + struct hlist_node *pos; + + raw_spin_lock_irq(&task->pi_lock); + hlist_move_list(&task->task_works, &task_works); + raw_spin_unlock_irq(&task->pi_lock); + + if (unlikely(hlist_empty(&task_works))) + return; + /* + * We use hlist to save the space in task_struct, but we want fifo. + * Find the last entry, the list should be short, then process them + * in reverse order. + */ + for (pos = task_works.first; pos->next; pos = pos->next) + ; + + for (;;) { + struct hlist_node **pprev = pos->pprev; + struct task_work *twork = container_of(pos, struct task_work, + hlist); + twork->func(twork); + + if (pprev == &task_works.first) + break; + pos = container_of(pprev, struct hlist_node, next); + } +} -- cgit v1.3-8-gc7d7 From dea649b8ac1861107c5d91e1a71121434fc64193 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 11 May 2012 10:59:09 +1000 Subject: keys: kill the dummy key_replace_session_keyring() After the previouse change key_replace_session_keyring() becomes a nop. Remove the dummy definition in key.h and update the callers in arch/*/kernel/signal.c. Signed-off-by: Oleg Nesterov Acked-by: David Howells Cc: Thomas Gleixner Cc: Richard Kuo Cc: Linus Torvalds Cc: Alexander Gordeev Cc: Chris Zankel Cc: David Smith Cc: "Frank Ch. Eigler" Cc: Geert Uytterhoeven Cc: Larry Woodman Cc: Peter Zijlstra Cc: Tejun Heo Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- include/linux/key.h | 2 -- include/linux/tracehook.h | 2 -- 2 files changed, 4 deletions(-) (limited to 'include/linux/tracehook.h') diff --git a/include/linux/key.h b/include/linux/key.h index 2a0ee11584e9..4cd22ed627ef 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -33,8 +33,6 @@ typedef uint32_t key_perm_t; struct key; -#define key_replace_session_keyring() do { } while (0) - #ifdef CONFIG_KEYS #undef KEY_DEBUGGING diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index b2dd0917ca0d..6a4d82bedb03 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -186,8 +186,6 @@ static inline void set_notify_resume(struct task_struct *task) */ static inline void tracehook_notify_resume(struct pt_regs *regs) { - if (current->replacement_session_keyring) - key_replace_session_keyring(); /* * The caller just cleared TIF_NOTIFY_RESUME. This barrier * pairs with task_work_add()->set_notify_resume() after -- cgit v1.3-8-gc7d7