Commit 4be95131 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'work.sys_wait' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 

Pull wait syscall updates from Al Viro:
 "Consolidating sys_wait* and compat counterparts.

  Gets rid of set_fs()/double-copy mess, simplifies the whole thing
  (lifting the copyouts to the syscalls means less headache in the part
  that does actual work - fewer failure exits, to start with), gets rid
  of the overhead of field-by-field __put_user()"

* 'work.sys_wait' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  osf_wait4: switch to kernel_wait4()
  waitid(): switch copyout of siginfo to unsafe_put_user()
  wait_task_zombie: consolidate info logics
  kill wait_noreap_copyout()
  lift getrusage() from wait_noreap_copyout()
  waitid(2): leave copyout of siginfo to syscall itself
  kernel_wait4()/kernel_waitid(): delay copying status to userland
  wait4(2)/waitid(2): separate copying rusage to userland
  move compat wait4 and waitid next to native variants
parents 3bad2f1c 92ebce5a

arch/alpha/kernel/osf_sys.c

+14 −39
Original line number Diff line number Diff line
@@ -1183,48 +1183,23 @@ SYSCALL_DEFINE2(osf_getrusage, int, who, struct rusage32 __user *, ru) 
SYSCALL_DEFINE4(osf_wait4, pid_t, pid, int __user *, ustatus, int, options,

		struct rusage32 __user *, ur)

{

	struct rusage r;

	long ret, err;

	unsigned int status = 0;

	mm_segment_t old_fs;



	struct rusage r;

	long err = kernel_wait4(pid, &status, options, &r);

	if (err <= 0)

		return err;

	if (put_user(status, ustatus))

		return -EFAULT;

	if (!ur)

		return sys_wait4(pid, ustatus, options, NULL);



	old_fs = get_fs();

		

	set_fs (KERNEL_DS);

	ret = sys_wait4(pid, (unsigned int __user *) &status, options,

			(struct rusage __user *) &r);

	set_fs (old_fs);



	if (!access_ok(VERIFY_WRITE, ur, sizeof(*ur)))

		return err;

	if (put_tv32(&ur->ru_utime, &r.ru_utime))

		return -EFAULT;



	err = put_user(status, ustatus);

	if (ret < 0)

		return err ? err : ret;



	err |= __put_user(r.ru_utime.tv_sec, &ur->ru_utime.tv_sec);

	err |= __put_user(r.ru_utime.tv_usec, &ur->ru_utime.tv_usec);

	err |= __put_user(r.ru_stime.tv_sec, &ur->ru_stime.tv_sec);

	err |= __put_user(r.ru_stime.tv_usec, &ur->ru_stime.tv_usec);

	err |= __put_user(r.ru_maxrss, &ur->ru_maxrss);

	err |= __put_user(r.ru_ixrss, &ur->ru_ixrss);

	err |= __put_user(r.ru_idrss, &ur->ru_idrss);

	err |= __put_user(r.ru_isrss, &ur->ru_isrss);

	err |= __put_user(r.ru_minflt, &ur->ru_minflt);

	err |= __put_user(r.ru_majflt, &ur->ru_majflt);

	err |= __put_user(r.ru_nswap, &ur->ru_nswap);

	err |= __put_user(r.ru_inblock, &ur->ru_inblock);

	err |= __put_user(r.ru_oublock, &ur->ru_oublock);

	err |= __put_user(r.ru_msgsnd, &ur->ru_msgsnd);

	err |= __put_user(r.ru_msgrcv, &ur->ru_msgrcv);

	err |= __put_user(r.ru_nsignals, &ur->ru_nsignals);

	err |= __put_user(r.ru_nvcsw, &ur->ru_nvcsw);

	err |= __put_user(r.ru_nivcsw, &ur->ru_nivcsw);



	return err ? err : ret;

	if (put_tv32(&ur->ru_stime, &r.ru_stime))

		return -EFAULT;

	if (copy_to_user(&ur->ru_maxrss, &r.ru_maxrss,

	      sizeof(struct rusage32) - offsetof(struct rusage32, ru_maxrss)))

		return -EFAULT;

	return err;

}



/*

include/linux/resource.h

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 


struct task_struct;



int getrusage(struct task_struct *p, int who, struct rusage __user *ru);

void getrusage(struct task_struct *p, int who, struct rusage *ru);

int do_prlimit(struct task_struct *tsk, unsigned int resource,

		struct rlimit *new_rlim, struct rlimit *old_rlim);

include/linux/sched/task.h

+2 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/sched.h>



struct task_struct;

struct rusage;

union thread_union;



/*
@@ -74,6 +75,7 @@ extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, 
extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);

struct task_struct *fork_idle(int);

extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);

extern long kernel_wait4(pid_t, int *, int, struct rusage *);



extern void free_task(struct task_struct *tsk);

kernel/compat.c

+0 −66
Original line number Diff line number Diff line
@@ -396,72 +396,6 @@ int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru) 
	return 0;

}



COMPAT_SYSCALL_DEFINE4(wait4,

	compat_pid_t, pid,

	compat_uint_t __user *, stat_addr,

	int, options,

	struct compat_rusage __user *, ru)

{

	if (!ru) {

		return sys_wait4(pid, stat_addr, options, NULL);

	} else {

		struct rusage r;

		int ret;

		unsigned int status;

		mm_segment_t old_fs = get_fs();



		set_fs (KERNEL_DS);

		ret = sys_wait4(pid,

				(stat_addr ?

				 (unsigned int __user *) &status : NULL),

				options, (struct rusage __user *) &r);

		set_fs (old_fs);



		if (ret > 0) {

			if (put_compat_rusage(&r, ru))

				return -EFAULT;

			if (stat_addr && put_user(status, stat_addr))

				return -EFAULT;

		}

		return ret;

	}

}



COMPAT_SYSCALL_DEFINE5(waitid,

		int, which, compat_pid_t, pid,

		struct compat_siginfo __user *, uinfo, int, options,

		struct compat_rusage __user *, uru)

{

	siginfo_t info;

	struct rusage ru;

	long ret;

	mm_segment_t old_fs = get_fs();



	memset(&info, 0, sizeof(info));



	set_fs(KERNEL_DS);

	ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,

			 uru ? (struct rusage __user *)&ru : NULL);

	set_fs(old_fs);



	if ((ret < 0) || (info.si_signo == 0))

		return ret;



	if (uru) {

		/* sys_waitid() overwrites everything in ru */

		if (COMPAT_USE_64BIT_TIME)

			ret = copy_to_user(uru, &ru, sizeof(ru));

		else

			ret = put_compat_rusage(&ru, uru);

		if (ret)

			return -EFAULT;

	}



	BUG_ON(info.si_code & __SI_MASK);

	info.si_code |= __SI_CHLD;

	return copy_siginfo_to_user32(uinfo, &info);

}



static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,

				    unsigned len, struct cpumask *new_mask)

{

kernel/exit.c

+164 −143
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ 
#include <linux/kcov.h>

#include <linux/random.h>

#include <linux/rcuwait.h>

#include <linux/compat.h>



#include <linux/uaccess.h>

#include <asm/unistd.h>
@@ -982,14 +983,21 @@ SYSCALL_DEFINE1(exit_group, int, error_code) 
	return 0;

}



struct waitid_info {

	pid_t pid;

	uid_t uid;

	int status;

	int cause;

};



struct wait_opts {

	enum pid_type		wo_type;

	int			wo_flags;

	struct pid		*wo_pid;



	struct siginfo __user	*wo_info;

	int __user		*wo_stat;

	struct rusage __user	*wo_rusage;

	struct waitid_info	*wo_info;

	int			wo_stat;

	struct rusage		*wo_rusage;



	wait_queue_entry_t		child_wait;

	int			notask_error;
@@ -1036,34 +1044,6 @@ eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p) 
	return 1;

}



static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,

				pid_t pid, uid_t uid, int why, int status)

{

	struct siginfo __user *infop;

	int retval = wo->wo_rusage

		? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;



	put_task_struct(p);

	infop = wo->wo_info;

	if (infop) {

		if (!retval)

			retval = put_user(SIGCHLD, &infop->si_signo);

		if (!retval)

			retval = put_user(0, &infop->si_errno);

		if (!retval)

			retval = put_user((short)why, &infop->si_code);

		if (!retval)

			retval = put_user(pid, &infop->si_pid);

		if (!retval)

			retval = put_user(uid, &infop->si_uid);

		if (!retval)

			retval = put_user(status, &infop->si_status);

	}

	if (!retval)

		retval = pid;

	return retval;

}



/*

 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE.  We hold

 * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
@@ -1072,30 +1052,23 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p, 
 */

static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)

{

	int state, retval, status;

	int state, status;

	pid_t pid = task_pid_vnr(p);

	uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p));

	struct siginfo __user *infop;

	struct waitid_info *infop;



	if (!likely(wo->wo_flags & WEXITED))

		return 0;



	if (unlikely(wo->wo_flags & WNOWAIT)) {

		int exit_code = p->exit_code;

		int why;



		status = p->exit_code;

		get_task_struct(p);

		read_unlock(&tasklist_lock);

		sched_annotate_sleep();



		if ((exit_code & 0x7f) == 0) {

			why = CLD_EXITED;

			status = exit_code >> 8;

		} else {

			why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;

			status = exit_code & 0x7f;

		}

		return wait_noreap_copyout(wo, p, pid, uid, why, status);

		if (wo->wo_rusage)

			getrusage(p, RUSAGE_BOTH, wo->wo_rusage);

		put_task_struct(p);

		goto out_info;

	}

	/*

	 * Move the task's state to DEAD/TRACE, only one thread can do this.
@@ -1168,38 +1141,11 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) 
		spin_unlock_irq(&current->sighand->siglock);

	}



	retval = wo->wo_rusage

		? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;

	if (wo->wo_rusage)

		getrusage(p, RUSAGE_BOTH, wo->wo_rusage);

	status = (p->signal->flags & SIGNAL_GROUP_EXIT)

		? p->signal->group_exit_code : p->exit_code;

	if (!retval && wo->wo_stat)

		retval = put_user(status, wo->wo_stat);



	infop = wo->wo_info;

	if (!retval && infop)

		retval = put_user(SIGCHLD, &infop->si_signo);

	if (!retval && infop)

		retval = put_user(0, &infop->si_errno);

	if (!retval && infop) {

		int why;



		if ((status & 0x7f) == 0) {

			why = CLD_EXITED;

			status >>= 8;

		} else {

			why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;

			status &= 0x7f;

		}

		retval = put_user((short)why, &infop->si_code);

		if (!retval)

			retval = put_user(status, &infop->si_status);

	}

	if (!retval && infop)

		retval = put_user(pid, &infop->si_pid);

	if (!retval && infop)

		retval = put_user(uid, &infop->si_uid);

	if (!retval)

		retval = pid;

	wo->wo_stat = status;



	if (state == EXIT_TRACE) {

		write_lock_irq(&tasklist_lock);
@@ -1216,7 +1162,21 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) 
	if (state == EXIT_DEAD)

		release_task(p);



	return retval;

out_info:

	infop = wo->wo_info;

	if (infop) {

		if ((status & 0x7f) == 0) {

			infop->cause = CLD_EXITED;

			infop->status = status >> 8;

		} else {

			infop->cause = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;

			infop->status = status & 0x7f;

		}

		infop->pid = pid;

		infop->uid = uid;

	}



	return pid;

}



static int *task_stopped_code(struct task_struct *p, bool ptrace)
@@ -1252,8 +1212,8 @@ static int *task_stopped_code(struct task_struct *p, bool ptrace) 
static int wait_task_stopped(struct wait_opts *wo,

				int ptrace, struct task_struct *p)

{

	struct siginfo __user *infop;

	int retval, exit_code, *p_code, why;

	struct waitid_info *infop;

	int exit_code, *p_code, why;

	uid_t uid = 0; /* unneeded, required by compiler */

	pid_t pid;
@@ -1298,34 +1258,21 @@ unlock_sig: 
	why = ptrace ? CLD_TRAPPED : CLD_STOPPED;

	read_unlock(&tasklist_lock);

	sched_annotate_sleep();

	if (wo->wo_rusage)

		getrusage(p, RUSAGE_BOTH, wo->wo_rusage);

	put_task_struct(p);



	if (unlikely(wo->wo_flags & WNOWAIT))

		return wait_noreap_copyout(wo, p, pid, uid, why, exit_code);



	retval = wo->wo_rusage

		? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;

	if (!retval && wo->wo_stat)

		retval = put_user((exit_code << 8) | 0x7f, wo->wo_stat);

	if (likely(!(wo->wo_flags & WNOWAIT)))

		wo->wo_stat = (exit_code << 8) | 0x7f;



	infop = wo->wo_info;

	if (!retval && infop)

		retval = put_user(SIGCHLD, &infop->si_signo);

	if (!retval && infop)

		retval = put_user(0, &infop->si_errno);

	if (!retval && infop)

		retval = put_user((short)why, &infop->si_code);

	if (!retval && infop)

		retval = put_user(exit_code, &infop->si_status);

	if (!retval && infop)

		retval = put_user(pid, &infop->si_pid);

	if (!retval && infop)

		retval = put_user(uid, &infop->si_uid);

	if (!retval)

		retval = pid;

	put_task_struct(p);



	BUG_ON(!retval);

	return retval;

	if (infop) {

		infop->cause = why;

		infop->status = exit_code;

		infop->pid = pid;

		infop->uid = uid;

	}

	return pid;

}



/*
@@ -1336,7 +1283,7 @@ unlock_sig: 
 */

static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)

{

	int retval;

	struct waitid_info *infop;

	pid_t pid;

	uid_t uid;
@@ -1361,22 +1308,20 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p) 
	get_task_struct(p);

	read_unlock(&tasklist_lock);

	sched_annotate_sleep();



	if (!wo->wo_info) {

		retval = wo->wo_rusage

			? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;

	if (wo->wo_rusage)

		getrusage(p, RUSAGE_BOTH, wo->wo_rusage);

	put_task_struct(p);

		if (!retval && wo->wo_stat)

			retval = put_user(0xffff, wo->wo_stat);

		if (!retval)

			retval = pid;



	infop = wo->wo_info;

	if (!infop) {

		wo->wo_stat = 0xffff;

	} else {

		retval = wait_noreap_copyout(wo, p, pid, uid,

					     CLD_CONTINUED, SIGCONT);

		BUG_ON(retval == 0);

		infop->cause = CLD_CONTINUED;

		infop->pid = pid;

		infop->uid = uid;

		infop->status = SIGCONT;

	}



	return retval;

	return pid;

}



/*
@@ -1604,8 +1549,8 @@ end: 
	return retval;

}



SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,

		infop, int, options, struct rusage __user *, ru)

static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,

			  int options, struct rusage *ru)

{

	struct wait_opts wo;

	struct pid *pid = NULL;
@@ -1643,38 +1588,46 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, 
	wo.wo_pid	= pid;

	wo.wo_flags	= options;

	wo.wo_info	= infop;

	wo.wo_stat	= NULL;

	wo.wo_rusage	= ru;

	ret = do_wait(&wo);



	if (ret > 0) {

	if (ret > 0)

		ret = 0;

	} else if (infop) {

		/*

		 * For a WNOHANG return, clear out all the fields

		 * we would set so the user can easily tell the

		 * difference.

		 */

		if (!ret)

			ret = put_user(0, &infop->si_signo);

		if (!ret)

			ret = put_user(0, &infop->si_errno);

		if (!ret)

			ret = put_user(0, &infop->si_code);

		if (!ret)

			ret = put_user(0, &infop->si_pid);

		if (!ret)

			ret = put_user(0, &infop->si_uid);

		if (!ret)

			ret = put_user(0, &infop->si_status);

	}



	put_pid(pid);

	return ret;

}



SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,

		int, options, struct rusage __user *, ru)

SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,

		infop, int, options, struct rusage __user *, ru)

{

	struct rusage r;

	struct waitid_info info = {.status = 0};

	long err = kernel_waitid(which, upid, &info, options, ru ? &r : NULL);



	if (!err) {

		if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))

			return -EFAULT;

	}

	if (!infop)

		return err;



	user_access_begin();

	unsafe_put_user(err ? 0 : SIGCHLD, &infop->si_signo, Efault);

	unsafe_put_user(0, &infop->si_errno, Efault);

	unsafe_put_user((short)info.cause, &infop->si_code, Efault);

	unsafe_put_user(info.pid, &infop->si_pid, Efault);

	unsafe_put_user(info.uid, &infop->si_uid, Efault);

	unsafe_put_user(info.status, &infop->si_status, Efault);

	user_access_end();

	return err;

Efault:

	user_access_end();

	return -EFAULT;

}



long kernel_wait4(pid_t upid, int __user *stat_addr, int options,

		  struct rusage *ru)

{

	struct wait_opts wo;

	struct pid *pid = NULL;
@@ -1702,14 +1655,29 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr, 
	wo.wo_pid	= pid;

	wo.wo_flags	= options | WEXITED;

	wo.wo_info	= NULL;

	wo.wo_stat	= stat_addr;

	wo.wo_stat	= 0;

	wo.wo_rusage	= ru;

	ret = do_wait(&wo);

	put_pid(pid);

	if (ret > 0 && stat_addr && put_user(wo.wo_stat, stat_addr))

		ret = -EFAULT;



	return ret;

}



SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,

		int, options, struct rusage __user *, ru)

{

	struct rusage r;

	long err = kernel_wait4(upid, stat_addr, options, ru ? &r : NULL);



	if (err > 0) {

		if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))

			return -EFAULT;

	}

	return err;

}



#ifdef __ARCH_WANT_SYS_WAITPID



/*
@@ -1722,3 +1690,56 @@ SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options) 
}



#endif



#ifdef CONFIG_COMPAT

COMPAT_SYSCALL_DEFINE4(wait4,

	compat_pid_t, pid,

	compat_uint_t __user *, stat_addr,

	int, options,

	struct compat_rusage __user *, ru)

{

	struct rusage r;

	long err = kernel_wait4(pid, stat_addr, options, ru ? &r : NULL);

	if (err > 0) {

		if (ru && put_compat_rusage(&r, ru))

			return -EFAULT;

	}

	return err;

}



COMPAT_SYSCALL_DEFINE5(waitid,

		int, which, compat_pid_t, pid,

		struct compat_siginfo __user *, infop, int, options,

		struct compat_rusage __user *, uru)

{

	struct rusage ru;

	struct waitid_info info = {.status = 0};

	long err = kernel_waitid(which, pid, &info, options, uru ? &ru : NULL);



	if (!err && uru) {

		/* kernel_waitid() overwrites everything in ru */

		if (COMPAT_USE_64BIT_TIME)

			err = copy_to_user(uru, &ru, sizeof(ru));

		else

			err = put_compat_rusage(&ru, uru);

		if (err)

			return -EFAULT;

	}



	if (!infop)

		return err;



	user_access_begin();

	unsafe_put_user(err ? 0 : SIGCHLD, &infop->si_signo, Efault);

	unsafe_put_user(0, &infop->si_errno, Efault);

	unsafe_put_user((short)info.cause, &infop->si_code, Efault);

	unsafe_put_user(info.pid, &infop->si_pid, Efault);

	unsafe_put_user(info.uid, &infop->si_uid, Efault);

	unsafe_put_user(info.status, &infop->si_status, Efault);

	user_access_end();

	return err;

Efault:

	user_access_end();

	return -EFAULT;

}

#endif

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