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-rw-r--r--fs/proc/array.c7
-rw-r--r--fs/proc/base.c31
-rw-r--r--fs/proc/inode.c37
-rw-r--r--fs/proc/internal.h3
-rw-r--r--fs/proc/root.c1
-rw-r--r--fs/proc/task_mmu.c1
6 files changed, 53 insertions, 27 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 81818adb8e9e..51a4213afa2e 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -245,7 +245,7 @@ void render_sigset_t(struct seq_file *m, const char *header,
if (sigismember(set, i+2)) x |= 2;
if (sigismember(set, i+3)) x |= 4;
if (sigismember(set, i+4)) x |= 8;
- seq_printf(m, "%x", x);
+ seq_putc(m, hex_asc[x]);
} while (i >= 4);
seq_putc(m, '\n');
@@ -342,10 +342,11 @@ static inline void task_cap(struct seq_file *m, struct task_struct *p)
static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
{
+ seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p));
#ifdef CONFIG_SECCOMP
- seq_put_decimal_ull(m, "Seccomp:\t", p->seccomp.mode);
- seq_putc(m, '\n');
+ seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
#endif
+ seq_putc(m, '\n');
}
static inline void task_context_switch_counts(struct seq_file *m,
diff --git a/fs/proc/base.c b/fs/proc/base.c
index ca651ac00660..9b99df4893a4 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -104,9 +104,12 @@
* in /proc for a task before it execs a suid executable.
*/
+static u8 nlink_tid;
+static u8 nlink_tgid;
+
struct pid_entry {
const char *name;
- int len;
+ unsigned int len;
umode_t mode;
const struct inode_operations *iop;
const struct file_operations *fop;
@@ -139,13 +142,13 @@ struct pid_entry {
* Count the number of hardlinks for the pid_entry table, excluding the .
* and .. links.
*/
-static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
+static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
unsigned int n)
{
unsigned int i;
unsigned int count;
- count = 0;
+ count = 2;
for (i = 0; i < n; ++i) {
if (S_ISDIR(entries[i].mode))
++count;
@@ -1967,7 +1970,7 @@ out:
struct map_files_info {
fmode_t mode;
- unsigned long len;
+ unsigned int len;
unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
};
@@ -2412,14 +2415,14 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
* Yes, it does not scale. And it should not. Don't add
* new entries into /proc/<tgid>/ without very good reasons.
*/
- last = &ents[nents - 1];
- for (p = ents; p <= last; p++) {
+ last = &ents[nents];
+ for (p = ents; p < last; p++) {
if (p->len != dentry->d_name.len)
continue;
if (!memcmp(dentry->d_name.name, p->name, p->len))
break;
}
- if (p > last)
+ if (p >= last)
goto out;
error = proc_pident_instantiate(dir, dentry, task, p);
@@ -2444,7 +2447,7 @@ static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
if (ctx->pos >= nents + 2)
goto out;
- for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
+ for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
if (!proc_fill_cache(file, ctx, p->name, p->len,
proc_pident_instantiate, task, p))
break;
@@ -3068,8 +3071,7 @@ static int proc_pid_instantiate(struct inode *dir,
inode->i_fop = &proc_tgid_base_operations;
inode->i_flags|=S_IMMUTABLE;
- set_nlink(inode, 2 + pid_entry_count_dirs(tgid_base_stuff,
- ARRAY_SIZE(tgid_base_stuff)));
+ set_nlink(inode, nlink_tgid);
d_set_d_op(dentry, &pid_dentry_operations);
@@ -3361,8 +3363,7 @@ static int proc_task_instantiate(struct inode *dir,
inode->i_fop = &proc_tid_base_operations;
inode->i_flags|=S_IMMUTABLE;
- set_nlink(inode, 2 + pid_entry_count_dirs(tid_base_stuff,
- ARRAY_SIZE(tid_base_stuff)));
+ set_nlink(inode, nlink_tid);
d_set_d_op(dentry, &pid_dentry_operations);
@@ -3552,3 +3553,9 @@ static const struct file_operations proc_task_operations = {
.iterate_shared = proc_task_readdir,
.llseek = generic_file_llseek,
};
+
+void __init set_proc_pid_nlink(void)
+{
+ nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
+ nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
+}
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index e69ebe648a34..783bc19644d1 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -138,6 +138,16 @@ static void unuse_pde(struct proc_dir_entry *pde)
/* pde is locked */
static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
{
+ /*
+ * close() (proc_reg_release()) can't delete an entry and proceed:
+ * ->release hook needs to be available at the right moment.
+ *
+ * rmmod (remove_proc_entry() et al) can't delete an entry and proceed:
+ * "struct file" needs to be available at the right moment.
+ *
+ * Therefore, first process to enter this function does ->release() and
+ * signals its completion to the other process which does nothing.
+ */
if (pdeo->closing) {
/* somebody else is doing that, just wait */
DECLARE_COMPLETION_ONSTACK(c);
@@ -147,12 +157,13 @@ static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
spin_lock(&pde->pde_unload_lock);
} else {
struct file *file;
- pdeo->closing = 1;
+ pdeo->closing = true;
spin_unlock(&pde->pde_unload_lock);
file = pdeo->file;
pde->proc_fops->release(file_inode(file), file);
spin_lock(&pde->pde_unload_lock);
- list_del_init(&pdeo->lh);
+ /* After ->release. */
+ list_del(&pdeo->lh);
if (pdeo->c)
complete(pdeo->c);
kfree(pdeo);
@@ -167,6 +178,8 @@ void proc_entry_rundown(struct proc_dir_entry *de)
if (atomic_add_return(BIAS, &de->in_use) != BIAS)
wait_for_completion(&c);
+ /* ->pde_openers list can't grow from now on. */
+
spin_lock(&de->pde_unload_lock);
while (!list_empty(&de->pde_openers)) {
struct pde_opener *pdeo;
@@ -312,16 +325,17 @@ static int proc_reg_open(struct inode *inode, struct file *file)
struct pde_opener *pdeo;
/*
- * What for, you ask? Well, we can have open, rmmod, remove_proc_entry
- * sequence. ->release won't be called because ->proc_fops will be
- * cleared. Depending on complexity of ->release, consequences vary.
+ * Ensure that
+ * 1) PDE's ->release hook will be called no matter what
+ * either normally by close()/->release, or forcefully by
+ * rmmod/remove_proc_entry.
+ *
+ * 2) rmmod isn't blocked by opening file in /proc and sitting on
+ * the descriptor (including "rmmod foo </proc/foo" scenario).
*
- * We can't wait for mercy when close will be done for real, it's
- * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release
- * by hand in remove_proc_entry(). For this, save opener's credentials
- * for later.
+ * Save every "struct file" with custom ->release hook.
*/
- pdeo = kzalloc(sizeof(struct pde_opener), GFP_KERNEL);
+ pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL);
if (!pdeo)
return -ENOMEM;
@@ -338,7 +352,8 @@ static int proc_reg_open(struct inode *inode, struct file *file)
if (rv == 0 && release) {
/* To know what to release. */
pdeo->file = file;
- /* Strictly for "too late" ->release in proc_reg_release(). */
+ 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);
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 5378441ec1b7..bbba5d22aada 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -203,7 +203,7 @@ struct proc_dir_entry *proc_create_mount_point(const char *name);
struct pde_opener {
struct file *file;
struct list_head lh;
- int closing;
+ bool closing;
struct completion *c;
};
extern const struct inode_operations proc_link_inode_operations;
@@ -211,6 +211,7 @@ extern const struct inode_operations proc_link_inode_operations;
extern const struct inode_operations proc_pid_link_inode_operations;
extern void proc_init_inodecache(void);
+void set_proc_pid_nlink(void);
extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
extern int proc_fill_super(struct super_block *, void *data, int flags);
extern void proc_entry_rundown(struct proc_dir_entry *);
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 8d3e484055a6..4bd0373576b5 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -122,6 +122,7 @@ void __init proc_root_init(void)
int err;
proc_init_inodecache();
+ set_proc_pid_nlink();
err = register_filesystem(&proc_fs_type);
if (err)
return;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 35b92d81692f..958f32545064 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1588,6 +1588,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap_unlock(orig_pte, ptl);
+ cond_resched();
return 0;
}
#ifdef CONFIG_HUGETLB_PAGE
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-18 06:57:17 +0000