Skip to content

Commit

Permalink
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…
Browse files Browse the repository at this point in the history 
…/git/viro/vfs

Pull vfs fixes from Al Viro:
 "A nasty bug in fs/namespace.c caught by Andrey + a couple of less
  serious unpleasantness - ecryptfs misc device playing hopeless games
  with try_module_get() and palinfo procfs support being...  not quite
  correctly done, to be polite."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  mnt: release locks on error path in do_loopback
  palinfo fixes
  procfs: add proc_remove_subtree()
  ecryptfs: close rmmod race
  • Loading branch information
Linus Torvalds committed Apr 9, 2013
2 parents 43ecdb0 + e9c5d8a commit e8f2b54
Show file tree
Hide file tree
Showing 5 changed files with 107 additions and 107 deletions.
77 changes: 13 additions & 64 deletions arch/ia64/kernel/palinfo.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -849,17 +849,6 @@ static palinfo_entry_t palinfo_entries[]={

#define NR_PALINFO_ENTRIES (int) ARRAY_SIZE(palinfo_entries)

/*
* this array is used to keep track of the proc entries we create. This is
* required in the module mode when we need to remove all entries. The procfs code
* does not do recursion of deletion
*
* Notes:
* - +1 accounts for the cpuN directory entry in /proc/pal
*/
#define NR_PALINFO_PROC_ENTRIES (NR_CPUS*(NR_PALINFO_ENTRIES+1))

static struct proc_dir_entry *palinfo_proc_entries[NR_PALINFO_PROC_ENTRIES];
static struct proc_dir_entry *palinfo_dir;

/*
Expand Down Expand Up @@ -971,60 +960,32 @@ palinfo_read_entry(char *page, char **start, off_t off, int count, int *eof, voi
static void __cpuinit
create_palinfo_proc_entries(unsigned int cpu)
{
# define CPUSTR "cpu%d"

pal_func_cpu_u_t f;
struct proc_dir_entry **pdir;
struct proc_dir_entry *cpu_dir;
int j;
char cpustr[sizeof(CPUSTR)];


/*
* we keep track of created entries in a depth-first order for
* cleanup purposes. Each entry is stored into palinfo_proc_entries
*/
sprintf(cpustr,CPUSTR, cpu);
char cpustr[3+4+1]; /* cpu numbers are up to 4095 on itanic */
sprintf(cpustr, "cpu%d", cpu);

cpu_dir = proc_mkdir(cpustr, palinfo_dir);
if (!cpu_dir)
return;

f.req_cpu = cpu;

/*
* Compute the location to store per cpu entries
* We dont store the top level entry in this list, but
* remove it finally after removing all cpu entries.
*/
pdir = &palinfo_proc_entries[cpu*(NR_PALINFO_ENTRIES+1)];
*pdir++ = cpu_dir;
for (j=0; j < NR_PALINFO_ENTRIES; j++) {
f.func_id = j;
*pdir = create_proc_read_entry(
palinfo_entries[j].name, 0, cpu_dir,
palinfo_read_entry, (void *)f.value);
pdir++;
create_proc_read_entry(
palinfo_entries[j].name, 0, cpu_dir,
palinfo_read_entry, (void *)f.value);
}
}

static void
remove_palinfo_proc_entries(unsigned int hcpu)
{
int j;
struct proc_dir_entry *cpu_dir, **pdir;

pdir = &palinfo_proc_entries[hcpu*(NR_PALINFO_ENTRIES+1)];
cpu_dir = *pdir;
*pdir++=NULL;
for (j=0; j < (NR_PALINFO_ENTRIES); j++) {
if ((*pdir)) {
remove_proc_entry ((*pdir)->name, cpu_dir);
*pdir ++= NULL;
}
}

if (cpu_dir) {
remove_proc_entry(cpu_dir->name, palinfo_dir);
}
char cpustr[3+4+1]; /* cpu numbers are up to 4095 on itanic */
sprintf(cpustr, "cpu%d", hcpu);
remove_proc_subtree(cpustr, palinfo_dir);
}

static int __cpuinit palinfo_cpu_callback(struct notifier_block *nfb,
Expand Down Expand Up @@ -1058,6 +1019,8 @@ palinfo_init(void)

printk(KERN_INFO "PAL Information Facility v%s\n", PALINFO_VERSION);
palinfo_dir = proc_mkdir("pal", NULL);
if (!palinfo_dir)
return -ENOMEM;

/* Create palinfo dirs in /proc for all online cpus */
for_each_online_cpu(i) {
Expand All @@ -1073,22 +1036,8 @@ palinfo_init(void)
static void __exit
palinfo_exit(void)
{
int i = 0;

/* remove all nodes: depth first pass. Could optimize this */
for_each_online_cpu(i) {
remove_palinfo_proc_entries(i);
}

/*
* Remove the top level entry finally
*/
remove_proc_entry(palinfo_dir->name, NULL);

/*
* Unregister from cpu notifier callbacks
*/
unregister_hotcpu_notifier(&palinfo_cpu_notifier);
remove_proc_subtree("pal", NULL);
}

module_init(palinfo_init);
Expand Down
14 changes: 2 additions & 12 deletions fs/ecryptfs/miscdev.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -80,13 +80,6 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
int rc;

mutex_lock(&ecryptfs_daemon_hash_mux);
rc = try_module_get(THIS_MODULE);
if (rc == 0) {
rc = -EIO;
printk(KERN_ERR "%s: Error attempting to increment module use "
"count; rc = [%d]\n", __func__, rc);
goto out_unlock_daemon_list;
}
rc = ecryptfs_find_daemon_by_euid(&daemon);
if (!rc) {
rc = -EINVAL;
Expand All @@ -96,7 +89,7 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
if (rc) {
printk(KERN_ERR "%s: Error attempting to spawn daemon; "
"rc = [%d]\n", __func__, rc);
goto out_module_put_unlock_daemon_list;
goto out_unlock_daemon_list;
}
mutex_lock(&daemon->mux);
if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
Expand All @@ -108,9 +101,6 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
atomic_inc(&ecryptfs_num_miscdev_opens);
out_unlock_daemon:
mutex_unlock(&daemon->mux);
out_module_put_unlock_daemon_list:
if (rc)
module_put(THIS_MODULE);
out_unlock_daemon_list:
mutex_unlock(&ecryptfs_daemon_hash_mux);
return rc;
Expand Down Expand Up @@ -147,7 +137,6 @@ ecryptfs_miscdev_release(struct inode *inode, struct file *file)
"bug.\n", __func__, rc);
BUG();
}
module_put(THIS_MODULE);
return rc;
}

Expand Down Expand Up @@ -471,6 +460,7 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf,


static const struct file_operations ecryptfs_miscdev_fops = {
.owner = THIS_MODULE,
.open = ecryptfs_miscdev_open,
.poll = ecryptfs_miscdev_poll,
.read = ecryptfs_miscdev_read,
Expand Down
2 changes: 1 addition & 1 deletion fs/namespace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1690,7 +1690,7 @@ static int do_loopback(struct path *path, const char *old_name,

if (IS_ERR(mnt)) {
err = PTR_ERR(mnt);
goto out;
goto out2;
}

err = graft_tree(mnt, path);
Expand Down
119 changes: 89 additions & 30 deletions fs/proc/generic.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -755,37 +755,8 @@ void pde_put(struct proc_dir_entry *pde)
free_proc_entry(pde);
}

/*
* Remove a /proc entry and free it if it's not currently in use.
*/
void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
static void entry_rundown(struct proc_dir_entry *de)
{
struct proc_dir_entry **p;
struct proc_dir_entry *de = NULL;
const char *fn = name;
unsigned int len;

spin_lock(&proc_subdir_lock);
if (__xlate_proc_name(name, &parent, &fn) != 0) {
spin_unlock(&proc_subdir_lock);
return;
}
len = strlen(fn);

for (p = &parent->subdir; *p; p=&(*p)->next ) {
if (proc_match(len, fn, *p)) {
de = *p;
*p = de->next;
de->next = NULL;
break;
}
}
spin_unlock(&proc_subdir_lock);
if (!de) {
WARN(1, "name '%s'\n", name);
return;
}

spin_lock(&de->pde_unload_lock);
/*
* Stop accepting new callers into module. If you're
Expand Down Expand Up @@ -817,6 +788,40 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
spin_lock(&de->pde_unload_lock);
}
spin_unlock(&de->pde_unload_lock);
}

/*
* Remove a /proc entry and free it if it's not currently in use.
*/
void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
{
struct proc_dir_entry **p;
struct proc_dir_entry *de = NULL;
const char *fn = name;
unsigned int len;

spin_lock(&proc_subdir_lock);
if (__xlate_proc_name(name, &parent, &fn) != 0) {
spin_unlock(&proc_subdir_lock);
return;
}
len = strlen(fn);

for (p = &parent->subdir; *p; p=&(*p)->next ) {
if (proc_match(len, fn, *p)) {
de = *p;
*p = de->next;
de->next = NULL;
break;
}
}
spin_unlock(&proc_subdir_lock);
if (!de) {
WARN(1, "name '%s'\n", name);
return;
}

entry_rundown(de);

if (S_ISDIR(de->mode))
parent->nlink--;
Expand All @@ -827,3 +832,57 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
pde_put(de);
}
EXPORT_SYMBOL(remove_proc_entry);

int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
{
struct proc_dir_entry **p;
struct proc_dir_entry *root = NULL, *de, *next;
const char *fn = name;
unsigned int len;

spin_lock(&proc_subdir_lock);
if (__xlate_proc_name(name, &parent, &fn) != 0) {
spin_unlock(&proc_subdir_lock);
return -ENOENT;
}
len = strlen(fn);

for (p = &parent->subdir; *p; p=&(*p)->next ) {
if (proc_match(len, fn, *p)) {
root = *p;
*p = root->next;
root->next = NULL;
break;
}
}
if (!root) {
spin_unlock(&proc_subdir_lock);
return -ENOENT;
}
de = root;
while (1) {
next = de->subdir;
if (next) {
de->subdir = next->next;
next->next = NULL;
de = next;
continue;
}
spin_unlock(&proc_subdir_lock);

entry_rundown(de);
next = de->parent;
if (S_ISDIR(de->mode))
next->nlink--;
de->nlink = 0;
if (de == root)
break;
pde_put(de);

spin_lock(&proc_subdir_lock);
de = next;
}
pde_put(root);
return 0;
}
EXPORT_SYMBOL(remove_proc_subtree);
2 changes: 2 additions & 0 deletions include/linux/proc_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -117,6 +117,7 @@ struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
const struct file_operations *proc_fops,
void *data);
extern void remove_proc_entry(const char *name, struct proc_dir_entry *parent);
extern int remove_proc_subtree(const char *name, struct proc_dir_entry *parent);

struct pid_namespace;

Expand Down Expand Up @@ -202,6 +203,7 @@ static inline struct proc_dir_entry *proc_create_data(const char *name,
return NULL;
}
#define remove_proc_entry(name, parent) do {} while (0)
#define remove_proc_subtree(name, parent) do {} while (0)

static inline struct proc_dir_entry *proc_symlink(const char *name,
struct proc_dir_entry *parent,const char *dest) {return NULL;}
Expand Down

0 comments on commit e8f2b54

Please sign in to comment.