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authorJiri Slaby <jirislaby@gmail.com>2009-08-26 23:45:34 +0200
committerJiri Slaby <jirislaby@gmail.com>2010-07-16 09:48:46 +0200
commit7855c35da7ba16b389d17710401c4a55a3ea2102 (patch)
treec8092ed1fee23f044f9ac622a7263591901b6b35
parenteb2d55a32b9a91bca0dea299eedb560bafa8b14e (diff)
rlimits: split sys_setrlimit
Create do_setrlimit from sys_setrlimit and declare do_setrlimit in the resource header. This is the first phase to have generic do_prlimit which allows to be called from read, write and compat rlimits code. The new do_setrlimit also accepts a task pointer to change the limits of. Currently, it cannot be other than current, but this will change with locking later. Also pass tsk->group_leader to security_task_setrlimit to check whether current is allowed to change rlimits of the process and not its arbitrary thread because it makes more sense given that rlimit are per process and not per-thread. Signed-off-by: Jiri Slaby <jslaby@suse.cz>
-rw-r--r--include/linux/resource.h2
-rw-r--r--kernel/sys.c40
2 files changed, 26 insertions, 16 deletions
diff --git a/include/linux/resource.h b/include/linux/resource.h
index f1e914eefeab..cf8dc96653ee 100644
--- a/include/linux/resource.h
+++ b/include/linux/resource.h
@@ -73,6 +73,8 @@ struct rlimit {
struct task_struct;
int getrusage(struct task_struct *p, int who, struct rusage __user *ru);
+int do_setrlimit(struct task_struct *tsk, unsigned int resource,
+ struct rlimit *new_rlim);
#endif /* __KERNEL__ */
diff --git a/kernel/sys.c b/kernel/sys.c
index f2b2d7aa3818..b5b96e30e0d6 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1272,42 +1272,41 @@ SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
#endif
-SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
+int do_setrlimit(struct task_struct *tsk, unsigned int resource,
+ struct rlimit *new_rlim)
{
- struct rlimit new_rlim, *old_rlim;
+ struct rlimit *old_rlim;
int retval;
if (resource >= RLIM_NLIMITS)
return -EINVAL;
- if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
- return -EFAULT;
- if (new_rlim.rlim_cur > new_rlim.rlim_max)
+ if (new_rlim->rlim_cur > new_rlim->rlim_max)
return -EINVAL;
- if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open)
+ if (resource == RLIMIT_NOFILE && new_rlim->rlim_max > sysctl_nr_open)
return -EPERM;
- retval = security_task_setrlimit(current, resource, &new_rlim);
+ retval = security_task_setrlimit(tsk->group_leader, resource, new_rlim);
if (retval)
return retval;
- if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) {
+ if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
/*
* The caller is asking for an immediate RLIMIT_CPU
* expiry. But we use the zero value to mean "it was
* never set". So let's cheat and make it one second
* instead
*/
- new_rlim.rlim_cur = 1;
+ new_rlim->rlim_cur = 1;
}
- old_rlim = current->signal->rlim + resource;
- task_lock(current->group_leader);
- if (new_rlim.rlim_max > old_rlim->rlim_max &&
+ old_rlim = tsk->signal->rlim + resource;
+ task_lock(tsk->group_leader);
+ if (new_rlim->rlim_max > old_rlim->rlim_max &&
!capable(CAP_SYS_RESOURCE))
retval = -EPERM;
else
- *old_rlim = new_rlim;
- task_unlock(current->group_leader);
+ *old_rlim = *new_rlim;
+ task_unlock(tsk->group_leader);
if (retval || resource != RLIMIT_CPU)
goto out;
@@ -1318,14 +1317,23 @@ SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
* very long-standing error, and fixing it now risks breakage of
* applications, so we live with it
*/
- if (new_rlim.rlim_cur == RLIM_INFINITY)
+ if (new_rlim->rlim_cur == RLIM_INFINITY)
goto out;
- update_rlimit_cpu(current, new_rlim.rlim_cur);
+ update_rlimit_cpu(tsk, new_rlim->rlim_cur);
out:
return retval;
}
+SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
+{
+ struct rlimit new_rlim;
+
+ if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
+ return -EFAULT;
+ return do_setrlimit(current, resource, &new_rlim);
+}
+
/*
* It would make sense to put struct rusage in the task_struct,
* except that would make the task_struct be *really big*. After