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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Browse source 
Pull second pile of signal handling patches from Al Viro:
 "This one is just task_work_add() series + remaining prereqs for it.

  There probably will be another pull request from that tree this
  cycle - at least for helpers, to get them out of the way for per-arch
  fixes remaining in the tree."

Fix trivial conflict in kernel/irq/manage.c: the merge of Andrew's pile
had brought in commit 97fd75b7b8 ("kernel/irq/manage.c: use the
pr_foo() infrastructure to prefix printks") which changed one of the
pr_err() calls that this merge moves around.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  keys: kill task_struct->replacement_session_keyring
  keys: kill the dummy key_replace_session_keyring()
  keys: change keyctl_session_to_parent() to use task_work_add()
  genirq: reimplement exit_irq_thread() hook via task_work_add()
  task_work_add: generic process-context callbacks
  avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callers
  parisc: need to check NOTIFY_RESUME when exiting from syscall
  move key_repace_session_keyring() into tracehook_notify_resume()
  TIF_NOTIFY_RESUME is defined on all targets now
This commit is contained in:
Linus Torvalds 2012-05-31 18:47:30 -07:00
commit fb21affa49
45 changed files with 220 additions and 186 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
arch/alpha/kernel/signal.c
View file

@ -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();
}
}

2
arch/arm/kernel/signal.c
View file

@ -679,7 +679,5 @@ 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();
}
}

2
arch/avr32/kernel/entry-avr32b.S
View file

@ -587,7 +587,7 @@ fault_exit_work:
ld.w r1, r0[TI_flags]
rjmp fault_exit_work
1: mov r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK
1: mov r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NOTIFY_RESUME
tst r1, r2
breq 2f
unmask_interrupts

2
arch/avr32/kernel/signal.c
View file

@ -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();
}
}

2
arch/blackfin/kernel/signal.c
View file

@ -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();
}
}

2
arch/c6x/kernel/signal.c
View file

@ -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();
}
}

2
arch/cris/kernel/ptrace.c
View file

@ -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();
}
}

2
arch/frv/kernel/signal.c
View file

@ -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() */

2
arch/h8300/kernel/signal.c
View file

@ -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();
}
}

2
arch/hexagon/kernel/signal.c
View file

@ -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();
}
}

2
arch/ia64/kernel/process.c
View file

@ -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 */

2
arch/m32r/kernel/signal.c
View file

@ -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);

5
arch/m68k/kernel/signal.c
View file

@ -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();
}
}

5
arch/microblaze/kernel/signal.c
View file

@ -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();
}
}

2
arch/mips/kernel/signal.c
View file

@ -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();
}
}

2
arch/mn10300/kernel/signal.c
View file

@ -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();
}
}

2
arch/openrisc/kernel/signal.c
View file

@ -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();
}
}

2
arch/parisc/kernel/entry.S
View file

@ -2032,7 +2032,7 @@ syscall_check_resched:
.import do_signal,code
syscall_check_sig:
LDREG TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
ldi (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK), %r26
ldi (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK|_TIF_NOTIFY_RESUME), %r26
and,COND(<>) %r19, %r26, %r0
b,n syscall_restore /* skip past if we've nothing to do */

2
arch/parisc/kernel/signal.c
View file

@ -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();
}
}

2
arch/powerpc/kernel/signal.c
View file

@ -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();
}
}

2
arch/s390/kernel/signal.c
View file

@ -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();
}

2
arch/score/kernel/signal.c
View file

@ -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();
}
}

2
arch/sh/kernel/signal_32.c
View file

@ -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();
}
}

2
arch/sh/kernel/signal_64.c
View file

@ -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();
}
}

2
arch/sparc/kernel/signal_32.c
View file

@ -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();
}
}

2
arch/sparc/kernel/signal_64.c
View file

@ -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();
}
}

2
arch/tile/kernel/process.c
View file

@ -565,8 +565,6 @@ 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) {

5
arch/um/kernel/process.c
View file

@ -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(&current->thread.regs);
if (current->replacement_session_keyring)
key_replace_session_keyring();
}
}
void exit_thread(void)

2
arch/unicore32/kernel/signal.c
View file

@ -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();
}
}

2
arch/x86/kernel/signal.c
View file

@ -827,8 +827,6 @@ 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();

5
arch/xtensa/kernel/signal.c
View file

@ -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();
}
}

4
include/linux/interrupt.h
View file

@ -142,8 +142,6 @@ request_any_context_irq(unsigned int irq, irq_handler_t handler,
extern int __must_check
request_percpu_irq(unsigned int irq, irq_handler_t handler,
const char *devname, void __percpu *percpu_dev_id);
extern void exit_irq_thread(void);
#else
extern int __must_check
@ -177,8 +175,6 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler,
{
return request_irq(irq, handler, 0, devname, percpu_dev_id);
}
static inline void exit_irq_thread(void) { }
#endif
extern void free_irq(unsigned int, void *);

4
include/linux/key.h
View file

@ -308,9 +308,6 @@ static inline bool key_is_instantiated(const struct key *key)
#ifdef CONFIG_SYSCTL
extern ctl_table key_sysctls[];
#endif
extern void key_replace_session_keyring(void);
/*
* the userspace interface
*/
@ -334,7 +331,6 @@ extern void key_init(void);
#define key_fsuid_changed(t) do { } while(0)
#define key_fsgid_changed(t) do { } while(0)
#define key_init() do { } while(0)
#define key_replace_session_keyring() do { } while(0)
#endif /* CONFIG_KEYS */
#endif /* __KERNEL__ */

10
include/linux/sched.h
View file

@ -1301,11 +1301,6 @@ struct task_struct {
unsigned sched_reset_on_fork:1;
unsigned sched_contributes_to_load:1;
#ifdef CONFIG_GENERIC_HARDIRQS
/* IRQ handler threads */
unsigned irq_thread:1;
#endif
pid_t pid;
pid_t tgid;
@ -1313,7 +1308,6 @@ struct task_struct {
/* Canary value for the -fstack-protector gcc feature */
unsigned long stack_canary;
#endif
/*
* pointers to (original) parent process, youngest child, younger sibling,
* older sibling, respectively. (p->father can be replaced with
@ -1363,8 +1357,6 @@ struct task_struct {
* credentials (COW) */
const struct cred __rcu *cred; /* effective (overridable) subjective task
* credentials (COW) */
struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */
char comm[TASK_COMM_LEN]; /* executable name excluding path
- access with [gs]et_task_comm (which lock
it with task_lock())
@ -1400,6 +1392,8 @@ 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;

33
include/linux/task_work.h Normal file
View file

@ -0,0 +1,33 @@
#ifndef _LINUX_TASK_WORK_H
#define _LINUX_TASK_WORK_H
#include <linux/list.h>
#include <linux/sched.h>
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 */

13
include/linux/tracehook.h
View file

@ -49,6 +49,7 @@
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/security.h>
#include <linux/task_work.h>
struct linux_binprm;
/*
@ -153,7 +154,6 @@ 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()
@ -165,8 +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
}
/**
@ -184,7 +186,14 @@ static inline void set_notify_resume(struct task_struct *task)
*/
static inline void tracehook_notify_resume(struct pt_regs *regs)
{
/*
* 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(&current->task_works)))
task_work_run();
}
#endif /* TIF_NOTIFY_RESUME */
#endif /* <linux/tracehook.h> */

2
kernel/Makefile
View file

@ -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 \

9
kernel/cred.c
View file

@ -207,13 +207,6 @@ void exit_creds(struct task_struct *tsk)
validate_creds(cred);
alter_cred_subscribers(cred, -1);
put_cred(cred);
cred = (struct cred *) tsk->replacement_session_keyring;
if (cred) {
tsk->replacement_session_keyring = NULL;
validate_creds(cred);
put_cred(cred);
}
}
/**
@ -396,8 +389,6 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags)
struct cred *new;
int ret;
p->replacement_session_keyring = NULL;
if (
#ifdef CONFIG_KEYS
!p->cred->thread_keyring &&

5
kernel/exit.c
View file

@ -946,12 +946,13 @@ 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_irq_thread();
exit_task_work(tsk);
if (unlikely(in_atomic()))
printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",

1
kernel/fork.c
View file

@ -1415,6 +1415,7 @@ 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

68
kernel/irq/manage.c
View file

@ -16,6 +16,7 @@
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/task_work.h>
#include "internals.h"
@ -775,11 +776,39 @@ static void wake_threads_waitq(struct irq_desc *desc)
wake_up(&desc->wait_for_threads);
}
static void irq_thread_dtor(struct task_work *unused)
{
struct task_struct *tsk = current;
struct irq_desc *desc;
struct irqaction *action;
if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
return;
action = kthread_data(tsk);
pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
tsk->comm ? tsk->comm : "", tsk->pid, action->irq);
desc = irq_to_desc(action->irq);
/*
* If IRQTF_RUNTHREAD is set, we need to decrement
* desc->threads_active and wake possible waiters.
*/
if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
wake_threads_waitq(desc);
/* Prevent a stale desc->threads_oneshot */
irq_finalize_oneshot(desc, action);
}
/*
* Interrupt handler thread
*/
static int irq_thread(void *data)
{
struct task_work on_exit_work;
static const struct sched_param param = {
.sched_priority = MAX_USER_RT_PRIO/2,
};
@ -795,7 +824,9 @@ static int irq_thread(void *data)
handler_fn = irq_thread_fn;
sched_setscheduler(current, SCHED_FIFO, &param);
current->irq_thread = 1;
init_task_work(&on_exit_work, irq_thread_dtor, NULL);
task_work_add(current, &on_exit_work, false);
while (!irq_wait_for_interrupt(action)) {
irqreturn_t action_ret;
@ -817,44 +848,11 @@ static int irq_thread(void *data)
* cannot touch the oneshot mask at this point anymore as
* __setup_irq() might have given out currents thread_mask
* again.
*
* Clear irq_thread. Otherwise exit_irq_thread() would make
* fuzz about an active irq thread going into nirvana.
*/
current->irq_thread = 0;
task_work_cancel(current, irq_thread_dtor);
return 0;
}
/*
* Called from do_exit()
*/
void exit_irq_thread(void)
{
struct task_struct *tsk = current;
struct irq_desc *desc;
struct irqaction *action;
if (!tsk->irq_thread)
return;
action = kthread_data(tsk);
pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
tsk->comm ? tsk->comm : "", tsk->pid, action->irq);
desc = irq_to_desc(action->irq);
/*
* If IRQTF_RUNTHREAD is set, we need to decrement
* desc->threads_active and wake possible waiters.
*/
if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
wake_threads_waitq(desc);
/* Prevent a stale desc->threads_oneshot */
irq_finalize_oneshot(desc, action);
}
static void irq_setup_forced_threading(struct irqaction *new)
{
if (!force_irqthreads)

84
kernel/task_work.c Normal file
View file

@ -0,0 +1,84 @@
#include <linux/spinlock.h>
#include <linux/task_work.h>
#include <linux/tracehook.h>
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);
}
}

2
security/keys/internal.h
View file

@ -14,6 +14,7 @@
#include <linux/sched.h>
#include <linux/key-type.h>
#include <linux/task_work.h>
#ifdef __KDEBUG
#define kenter(FMT, ...) \
@ -148,6 +149,7 @@ extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
#define KEY_LOOKUP_FOR_UNLINK 0x04
extern long join_session_keyring(const char *name);
extern void key_change_session_keyring(struct task_work *twork);
extern struct work_struct key_gc_work;
extern unsigned key_gc_delay;

73
security/keys/keyctl.c
View file

@ -1454,50 +1454,57 @@ long keyctl_get_security(key_serial_t keyid,
*/
long keyctl_session_to_parent(void)
{
#ifdef TIF_NOTIFY_RESUME
struct task_struct *me, *parent;
const struct cred *mycred, *pcred;
struct cred *cred, *oldcred;
struct task_work *newwork, *oldwork;
key_ref_t keyring_r;
struct cred *cred;
int ret;
keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
if (IS_ERR(keyring_r))
return PTR_ERR(keyring_r);
ret = -ENOMEM;
newwork = kmalloc(sizeof(struct task_work), GFP_KERNEL);
if (!newwork)
goto error_keyring;
/* our parent is going to need a new cred struct, a new tgcred struct
* and new security data, so we allocate them here to prevent ENOMEM in
* our parent */
ret = -ENOMEM;
cred = cred_alloc_blank();
if (!cred)
goto error_keyring;
goto error_newwork;
cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
keyring_r = NULL;
init_task_work(newwork, key_change_session_keyring, cred);
me = current;
rcu_read_lock();
write_lock_irq(&tasklist_lock);
parent = me->real_parent;
ret = -EPERM;
oldwork = NULL;
parent = me->real_parent;
/* the parent mustn't be init and mustn't be a kernel thread */
if (parent->pid <= 1 || !parent->mm)
goto not_permitted;
goto unlock;
/* the parent must be single threaded */
if (!thread_group_empty(parent))
goto not_permitted;
goto unlock;
/* the parent and the child must have different session keyrings or
* there's no point */
mycred = current_cred();
pcred = __task_cred(parent);
if (mycred == pcred ||
mycred->tgcred->session_keyring == pcred->tgcred->session_keyring)
goto already_same;
mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) {
ret = 0;
goto unlock;
}
/* the parent must have the same effective ownership and mustn't be
* SUID/SGID */
@ -1507,50 +1514,40 @@ long keyctl_session_to_parent(void)
pcred->gid != mycred->egid ||
pcred->egid != mycred->egid ||
pcred->sgid != mycred->egid)
goto not_permitted;
goto unlock;
/* the keyrings must have the same UID */
if ((pcred->tgcred->session_keyring &&
pcred->tgcred->session_keyring->uid != mycred->euid) ||
mycred->tgcred->session_keyring->uid != mycred->euid)
goto not_permitted;
goto unlock;
/* if there's an already pending keyring replacement, then we replace
* that */
oldcred = parent->replacement_session_keyring;
/* cancel an already pending keyring replacement */
oldwork = task_work_cancel(parent, key_change_session_keyring);
/* the replacement session keyring is applied just prior to userspace
* restarting */
parent->replacement_session_keyring = cred;
cred = NULL;
set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
ret = task_work_add(parent, newwork, true);
if (!ret)
newwork = NULL;
unlock:
write_unlock_irq(&tasklist_lock);
rcu_read_unlock();
if (oldcred)
put_cred(oldcred);
return 0;
already_same:
ret = 0;
not_permitted:
write_unlock_irq(&tasklist_lock);
rcu_read_unlock();
put_cred(cred);
if (oldwork) {
put_cred(oldwork->data);
kfree(oldwork);
}
if (newwork) {
put_cred(newwork->data);
kfree(newwork);
}
return ret;
error_newwork:
kfree(newwork);
error_keyring:
key_ref_put(keyring_r);
return ret;
#else /* !TIF_NOTIFY_RESUME */
/*
* To be removed when TIF_NOTIFY_RESUME has been implemented on
* m68k/xtensa
*/
#warning TIF_NOTIFY_RESUME not implemented
return -EOPNOTSUPP;
#endif /* !TIF_NOTIFY_RESUME */
}
/*

20
security/keys/process_keys.c
View file

@ -834,23 +834,17 @@ long join_session_keyring(const char *name)
* Replace a process's session keyring on behalf of one of its children when
* the target process is about to resume userspace execution.
*/
void key_replace_session_keyring(void)
void key_change_session_keyring(struct task_work *twork)
{
const struct cred *old;
struct cred *new;
const struct cred *old = current_cred();
struct cred *new = twork->data;
if (!current->replacement_session_keyring)
kfree(twork);
if (unlikely(current->flags & PF_EXITING)) {
put_cred(new);
return;
}
write_lock_irq(&tasklist_lock);
new = current->replacement_session_keyring;
current->replacement_session_keyring = NULL;
write_unlock_irq(&tasklist_lock);
if (!new)
return;
old = current_cred();
new-> uid = old-> uid;
new-> euid = old-> euid;
new-> suid = old-> suid;