Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux

* 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux:
  unistd: add __NR_prlimit64 syscall numbers
  rlimits: implement prlimit64 syscall
  rlimits: switch more rlimit syscalls to do_prlimit
  rlimits: redo do_setrlimit to more generic do_prlimit
  rlimits: add rlimit64 structure
  rlimits: do security check under task_lock
  rlimits: allow setrlimit to non-current tasks
  rlimits: split sys_setrlimit
  rlimits: selinux, do rlimits changes under task_lock
  rlimits: make sure ->rlim_max never grows in sys_setrlimit
  rlimits: add task_struct to update_rlimit_cpu
  rlimits: security, add task_struct to setrlimit

Fix up various system call number conflicts.  We not only added fanotify
system calls in the meantime, but asm-generic/unistd.h added a wait4
along with a range of reserved per-architecture system calls.

3 files changed, 13 insertions, 7 deletions

diff --git a/security/capability.c b/security/capability.c
index a0bbf30..95a6599 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -411,7 +411,8 @@ static int cap_task_getioprio(struct task_struct *p)
 	return 0;
 }
 
-static int cap_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
+static int cap_task_setrlimit(struct task_struct *p, unsigned int resource,
+		struct rlimit *new_rlim)
 {
 	return 0;
 }
diff --git a/security/security.c b/security/security.c
index 7461b1b..c53949f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -780,9 +780,10 @@ int security_task_getioprio(struct task_struct *p)
 	return security_ops->task_getioprio(p);
 }
 
-int security_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
+int security_task_setrlimit(struct task_struct *p, unsigned int resource,
+		struct rlimit *new_rlim)
 {
-	return security_ops->task_setrlimit(resource, new_rlim);
+	return security_ops->task_setrlimit(p, resource, new_rlim);
 }
 
 int security_task_setscheduler(struct task_struct *p,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 9b40f4c..42043f9 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2284,12 +2284,15 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
 	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
 			  PROCESS__RLIMITINH, NULL);
 	if (rc) {
+		/* protect against do_prlimit() */
+		task_lock(current);
 		for (i = 0; i < RLIM_NLIMITS; i++) {
 			rlim = current->signal->rlim + i;
 			initrlim = init_task.signal->rlim + i;
 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
 		}
-		update_rlimit_cpu(current->signal->rlim[RLIMIT_CPU].rlim_cur);
+		task_unlock(current);
+		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
 	}
 }
 
@@ -3333,16 +3336,17 @@ static int selinux_task_getioprio(struct task_struct *p)
 	return current_has_perm(p, PROCESS__GETSCHED);
 }
 
-static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
+static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
+		struct rlimit *new_rlim)
 {
-	struct rlimit *old_rlim = current->signal->rlim + resource;
+	struct rlimit *old_rlim = p->signal->rlim + resource;
 
 	/* Control the ability to change the hard limit (whether
 	   lowering or raising it), so that the hard limit can
 	   later be used as a safe reset point for the soft limit
 	   upon context transitions.  See selinux_bprm_committing_creds. */
 	if (old_rlim->rlim_max != new_rlim->rlim_max)
-		return current_has_perm(current, PROCESS__SETRLIMIT);
+		return current_has_perm(p, PROCESS__SETRLIMIT);
 
 	return 0;
 }