Commit c57bef02 authored by Barret Rhoden's avatar Barret Rhoden Committed by Eric W. Biederman
Browse files

prlimit: make do_prlimit() static 



There are no other callers in the kernel.

Fixed up a comment format and whitespace issue when moving do_prlimit()
higher in sys.c.

Signed-off-by: default avatarBarret Rhoden <brho@google.com>
Link: https://lkml.kernel.org/r/20220106172041.522167-3-brho@google.com


Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
parent ffb217a1

include/linux/resource.h

+0 −2
Original line number Original line Diff line number Diff line
@@ -8,7 +8,5 @@ 
struct task_struct;

struct task_struct;





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





#endif
 
#endif

kernel/sys.c

+59 −57
Original line number Original line Diff line number Diff line
@@ -1424,6 +1424,65 @@ SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 
	return errno;

	return errno;

}

}





/* make sure you are allowed to change @tsk limits before calling this */

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

		      struct rlimit *new_rlim, struct rlimit *old_rlim)

{

	struct rlimit *rlim;

	int retval = 0;



	if (resource >= RLIM_NLIMITS)

		return -EINVAL;

	if (new_rlim) {

		if (new_rlim->rlim_cur > new_rlim->rlim_max)

			return -EINVAL;

		if (resource == RLIMIT_NOFILE &&

				new_rlim->rlim_max > sysctl_nr_open)

			return -EPERM;

	}



	/* protect tsk->signal and tsk->sighand from disappearing */

	read_lock(&tasklist_lock);

	if (!tsk->sighand) {

		retval = -ESRCH;

		goto out;

	}



	rlim = tsk->signal->rlim + resource;

	task_lock(tsk->group_leader);

	if (new_rlim) {

		/*

		 * Keep the capable check against init_user_ns until cgroups can

		 * contain all limits.

		 */

		if (new_rlim->rlim_max > rlim->rlim_max &&

				!capable(CAP_SYS_RESOURCE))

			retval = -EPERM;

		if (!retval)

			retval = security_task_setrlimit(tsk, resource, new_rlim);

	}

	if (!retval) {

		if (old_rlim)

			*old_rlim = *rlim;

		if (new_rlim)

			*rlim = *new_rlim;

	}

	task_unlock(tsk->group_leader);



	/*

	 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not

	 * infinite. In case of RLIM_INFINITY the posix CPU timer code

	 * ignores the rlimit.

	 */

	if (!retval && new_rlim && resource == RLIMIT_CPU &&

	    new_rlim->rlim_cur != RLIM_INFINITY &&

	    IS_ENABLED(CONFIG_POSIX_TIMERS))

		update_rlimit_cpu(tsk, new_rlim->rlim_cur);

out:

	read_unlock(&tasklist_lock);

	return retval;

}



SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)

SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)

{

{

	struct rlimit value;

	struct rlimit value;
@@ -1567,63 +1626,6 @@ static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 
		rlim->rlim_max = (unsigned long)rlim64->rlim_max;

		rlim->rlim_max = (unsigned long)rlim64->rlim_max;

}

}





/* make sure you are allowed to change @tsk limits before calling this */

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

		struct rlimit *new_rlim, struct rlimit *old_rlim)

{

	struct rlimit *rlim;

	int retval = 0;



	if (resource >= RLIM_NLIMITS)

		return -EINVAL;

	if (new_rlim) {

		if (new_rlim->rlim_cur > new_rlim->rlim_max)

			return -EINVAL;

		if (resource == RLIMIT_NOFILE &&

				new_rlim->rlim_max > sysctl_nr_open)

			return -EPERM;

	}



	/* protect tsk->signal and tsk->sighand from disappearing */

	read_lock(&tasklist_lock);

	if (!tsk->sighand) {

		retval = -ESRCH;

		goto out;

	}



	rlim = tsk->signal->rlim + resource;

	task_lock(tsk->group_leader);

	if (new_rlim) {

		/* Keep the capable check against init_user_ns until

		   cgroups can contain all limits */

		if (new_rlim->rlim_max > rlim->rlim_max &&

				!capable(CAP_SYS_RESOURCE))

			retval = -EPERM;

		if (!retval)

			retval = security_task_setrlimit(tsk, resource, new_rlim);

	}

	if (!retval) {

		if (old_rlim)

			*old_rlim = *rlim;

		if (new_rlim)

			*rlim = *new_rlim;

	}

	task_unlock(tsk->group_leader);



	/*

	 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not

	 * infinite. In case of RLIM_INFINITY the posix CPU timer code

	 * ignores the rlimit.

	 */

	 if (!retval && new_rlim && resource == RLIMIT_CPU &&

	     new_rlim->rlim_cur != RLIM_INFINITY &&

	     IS_ENABLED(CONFIG_POSIX_TIMERS))

		update_rlimit_cpu(tsk, new_rlim->rlim_cur);

out:

	read_unlock(&tasklist_lock);

	return retval;

}



/* rcu lock must be held */

/* rcu lock must be held */

static int check_prlimit_permission(struct task_struct *task,

static int check_prlimit_permission(struct task_struct *task,

				    unsigned int flags)

				    unsigned int flags)