summaryrefslogtreecommitdiff
path: root/fs/proc/inode.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/proc/inode.c')
-rw-r--r--fs/proc/inode.c85
1 files changed, 52 insertions, 33 deletions
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index e250910cffc8..2cf3b74391ca 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -1,9 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/proc/inode.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
+#include <linux/cache.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/kernel.h>
@@ -51,7 +53,8 @@ static void proc_evict_inode(struct inode *inode)
}
}
-static struct kmem_cache * proc_inode_cachep;
+static struct kmem_cache *proc_inode_cachep __ro_after_init;
+static struct kmem_cache *pde_opener_cache __ro_after_init;
static struct inode *proc_alloc_inode(struct super_block *sb)
{
@@ -90,7 +93,7 @@ static void init_once(void *foo)
inode_init_once(&ei->vfs_inode);
}
-void __init proc_init_inodecache(void)
+void __init proc_init_kmemcache(void)
{
proc_inode_cachep = kmem_cache_create("proc_inode_cache",
sizeof(struct proc_inode),
@@ -98,6 +101,13 @@ void __init proc_init_inodecache(void)
SLAB_MEM_SPREAD|SLAB_ACCOUNT|
SLAB_PANIC),
init_once);
+ pde_opener_cache =
+ kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0,
+ SLAB_ACCOUNT|SLAB_PANIC, NULL);
+ proc_dir_entry_cache = kmem_cache_create_usercopy(
+ "proc_dir_entry", sizeof(struct proc_dir_entry), 0, SLAB_PANIC,
+ offsetof(struct proc_dir_entry, inline_name),
+ sizeof_field(struct proc_dir_entry, inline_name), NULL);
}
static int proc_show_options(struct seq_file *seq, struct dentry *root)
@@ -127,16 +137,16 @@ enum {BIAS = -1U<<31};
static inline int use_pde(struct proc_dir_entry *pde)
{
- return atomic_inc_unless_negative(&pde->in_use);
+ return likely(atomic_inc_unless_negative(&pde->in_use));
}
static void unuse_pde(struct proc_dir_entry *pde)
{
- if (atomic_dec_return(&pde->in_use) == BIAS)
+ if (unlikely(atomic_dec_return(&pde->in_use) == BIAS))
complete(pde->pde_unload_completion);
}
-/* pde is locked */
+/* pde is locked on entry, unlocked on exit */
static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
{
/*
@@ -155,9 +165,10 @@ static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
pdeo->c = &c;
spin_unlock(&pde->pde_unload_lock);
wait_for_completion(&c);
- spin_lock(&pde->pde_unload_lock);
} else {
struct file *file;
+ struct completion *c;
+
pdeo->closing = true;
spin_unlock(&pde->pde_unload_lock);
file = pdeo->file;
@@ -165,9 +176,11 @@ static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
spin_lock(&pde->pde_unload_lock);
/* After ->release. */
list_del(&pdeo->lh);
- if (pdeo->c)
- complete(pdeo->c);
- kfree(pdeo);
+ c = pdeo->c;
+ spin_unlock(&pde->pde_unload_lock);
+ if (unlikely(c))
+ complete(c);
+ kmem_cache_free(pde_opener_cache, pdeo);
}
}
@@ -186,6 +199,7 @@ void proc_entry_rundown(struct proc_dir_entry *de)
struct pde_opener *pdeo;
pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
close_pdeo(de, pdeo);
+ spin_lock(&de->pde_unload_lock);
}
spin_unlock(&de->pde_unload_lock);
}
@@ -233,11 +247,11 @@ static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t
return rv;
}
-static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts)
+static __poll_t proc_reg_poll(struct file *file, struct poll_table_struct *pts)
{
struct proc_dir_entry *pde = PDE(file_inode(file));
- unsigned int rv = DEFAULT_POLLMASK;
- unsigned int (*poll)(struct file *, struct poll_table_struct *);
+ __poll_t rv = DEFAULT_POLLMASK;
+ __poll_t (*poll)(struct file *, struct poll_table_struct *);
if (use_pde(pde)) {
poll = pde->proc_fops->poll;
if (poll)
@@ -336,31 +350,36 @@ static int proc_reg_open(struct inode *inode, struct file *file)
*
* Save every "struct file" with custom ->release hook.
*/
- pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL);
- if (!pdeo)
- return -ENOMEM;
-
- if (!use_pde(pde)) {
- kfree(pdeo);
+ if (!use_pde(pde))
return -ENOENT;
- }
- open = pde->proc_fops->open;
+
release = pde->proc_fops->release;
+ if (release) {
+ pdeo = kmem_cache_alloc(pde_opener_cache, GFP_KERNEL);
+ if (!pdeo) {
+ rv = -ENOMEM;
+ goto out_unuse;
+ }
+ }
+ open = pde->proc_fops->open;
if (open)
rv = open(inode, file);
- if (rv == 0 && release) {
- /* To know what to release. */
- pdeo->file = file;
- pdeo->closing = false;
- pdeo->c = NULL;
- spin_lock(&pde->pde_unload_lock);
- list_add(&pdeo->lh, &pde->pde_openers);
- spin_unlock(&pde->pde_unload_lock);
- } else
- kfree(pdeo);
+ if (release) {
+ if (rv == 0) {
+ /* To know what to release. */
+ pdeo->file = file;
+ pdeo->closing = false;
+ pdeo->c = NULL;
+ spin_lock(&pde->pde_unload_lock);
+ list_add(&pdeo->lh, &pde->pde_openers);
+ spin_unlock(&pde->pde_unload_lock);
+ } else
+ kmem_cache_free(pde_opener_cache, pdeo);
+ }
+out_unuse:
unuse_pde(pde);
return rv;
}
@@ -373,7 +392,7 @@ static int proc_reg_release(struct inode *inode, struct file *file)
list_for_each_entry(pdeo, &pde->pde_openers, lh) {
if (pdeo->file == file) {
close_pdeo(pde, pdeo);
- break;
+ return 0;
}
}
spin_unlock(&pde->pde_unload_lock);
@@ -419,7 +438,7 @@ static const char *proc_get_link(struct dentry *dentry,
struct delayed_call *done)
{
struct proc_dir_entry *pde = PDE(inode);
- if (unlikely(!use_pde(pde)))
+ if (!use_pde(pde))
return ERR_PTR(-EINVAL);
set_delayed_call(done, proc_put_link, pde);
return pde->data;
@@ -482,7 +501,7 @@ int proc_fill_super(struct super_block *s, void *data, int silent)
/* User space would break if executables or devices appear on proc */
s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
- s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
+ s->s_flags |= SB_NODIRATIME | SB_NOSUID | SB_NOEXEC;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = PROC_SUPER_MAGIC;
generated by cgit (git 2.34.1) at 2024-05-27 19:52:24 +0000