X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fcpuset.c;h=1535af3a912d9d7e6a21fb7d6c610e808c1cddda;hb=beb07c1a56e2cff3842e22c473bd1aaaea08e532;hp=72248d1b9e3f7a18198796ad1134c9abb2fd4b4e;hpb=683aa4012f53b2ada0f430487e05d37b0d94e90a;p=linux-2.6

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 72248d1b9e..1535af3a91 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -41,6 +41,7 @@
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>
+#include <linux/security.h>
 #include <linux/slab.h>
 #include <linux/smp_lock.h>
 #include <linux/spinlock.h>
@@ -392,11 +393,11 @@ static int cpuset_fill_super(struct super_block *sb, void *unused_data,
 	return 0;
 }
 
-static struct super_block *cpuset_get_sb(struct file_system_type *fs_type,
-					int flags, const char *unused_dev_name,
-					void *data)
+static int cpuset_get_sb(struct file_system_type *fs_type,
+			 int flags, const char *unused_dev_name,
+			 void *data, struct vfsmount *mnt)
 {
-	return get_sb_single(fs_type, flags, data, cpuset_fill_super);
+	return get_sb_single(fs_type, flags, data, cpuset_fill_super, mnt);
 }
 
 static struct file_system_type cpuset_fs_type = {
@@ -1177,6 +1178,7 @@ static int attach_task(struct cpuset *cs, char *pidbuf, char **ppathbuf)
 	cpumask_t cpus;
 	nodemask_t from, to;
 	struct mm_struct *mm;
+	int retval;
 
 	if (sscanf(pidbuf, "%d", &pid) != 1)
 		return -EIO;
@@ -1205,6 +1207,12 @@ static int attach_task(struct cpuset *cs, char *pidbuf, char **ppathbuf)
 		get_task_struct(tsk);
 	}
 
+	retval = security_task_setscheduler(tsk, 0, NULL);
+	if (retval) {
+		put_task_struct(tsk);
+		return retval;
+	}
+
 	mutex_lock(&callback_mutex);
 
 	task_lock(tsk);
@@ -2231,19 +2239,25 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs)
  * So only GFP_KERNEL allocations, if all nodes in the cpuset are
  * short of memory, might require taking the callback_mutex mutex.
  *
- * The first loop over the zonelist in mm/page_alloc.c:__alloc_pages()
- * calls here with __GFP_HARDWALL always set in gfp_mask, enforcing
- * hardwall cpusets - no allocation on a node outside the cpuset is
- * allowed (unless in interrupt, of course).
+ * The first call here from mm/page_alloc:get_page_from_freelist()
+ * has __GFP_HARDWALL set in gfp_mask, enforcing hardwall cpusets, so
+ * no allocation on a node outside the cpuset is allowed (unless in
+ * interrupt, of course).
  *
- * The second loop doesn't even call here for GFP_ATOMIC requests
- * (if the __alloc_pages() local variable 'wait' is set).  That check
- * and the checks below have the combined affect in the second loop of
- * the __alloc_pages() routine that:
+ * The second pass through get_page_from_freelist() doesn't even call
+ * here for GFP_ATOMIC calls.  For those calls, the __alloc_pages()
+ * variable 'wait' is not set, and the bit ALLOC_CPUSET is not set
+ * in alloc_flags.  That logic and the checks below have the combined
+ * affect that:
  *	in_interrupt - any node ok (current task context irrelevant)
  *	GFP_ATOMIC   - any node ok
  *	GFP_KERNEL   - any node in enclosing mem_exclusive cpuset ok
  *	GFP_USER     - only nodes in current tasks mems allowed ok.
+ *
+ * Rule:
+ *    Don't call cpuset_zone_allowed() if you can't sleep, unless you
+ *    pass in the __GFP_HARDWALL flag set in gfp_flag, which disables
+ *    the code that might scan up ancestor cpusets and sleep.
  **/
 
 int __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
@@ -2255,6 +2269,7 @@ int __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
 	if (in_interrupt())
 		return 1;
 	node = z->zone_pgdat->node_id;
+	might_sleep_if(!(gfp_mask & __GFP_HARDWALL));
 	if (node_isset(node, current->mems_allowed))
 		return 1;
 	if (gfp_mask & __GFP_HARDWALL)	/* If hardwall request, stop here */
@@ -2427,31 +2442,43 @@ void __cpuset_memory_pressure_bump(void)
  */
 static int proc_cpuset_show(struct seq_file *m, void *v)
 {
+	struct pid *pid;
 	struct task_struct *tsk;
 	char *buf;
-	int retval = 0;
+	int retval;
 
+	retval = -ENOMEM;
 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf)
-		return -ENOMEM;
+		goto out;
 
-	tsk = m->private;
+	retval = -ESRCH;
+	pid = m->private;
+	tsk = get_pid_task(pid, PIDTYPE_PID);
+	if (!tsk)
+		goto out_free;
+
+	retval = -EINVAL;
 	mutex_lock(&manage_mutex);
+
 	retval = cpuset_path(tsk->cpuset, buf, PAGE_SIZE);
 	if (retval < 0)
-		goto out;
+		goto out_unlock;
 	seq_puts(m, buf);
 	seq_putc(m, '\n');
-out:
+out_unlock:
 	mutex_unlock(&manage_mutex);
+	put_task_struct(tsk);
+out_free:
 	kfree(buf);
+out:
 	return retval;
 }
 
 static int cpuset_open(struct inode *inode, struct file *file)
 {
-	struct task_struct *tsk = PROC_I(inode)->task;
-	return single_open(file, proc_cpuset_show, tsk);
+	struct pid *pid = PROC_I(inode)->pid;
+	return single_open(file, proc_cpuset_show, pid);
 }
 
 struct file_operations proc_cpuset_operations = {