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-rw-r--r--fs/proc/array.c16
-rw-r--r--fs/proc/base.c45
-rw-r--r--fs/proc/generic.c1
-rw-r--r--fs/proc/inode.c37
-rw-r--r--fs/proc/internal.h4
-rw-r--r--fs/proc/root.c1
-rw-r--r--fs/proc/task_mmu.c30
-rw-r--r--fs/proc/task_nommu.c28
8 files changed, 90 insertions, 72 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 89600fd5963d..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,
@@ -412,10 +413,11 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
mm = get_task_mm(task);
if (mm) {
vsize = task_vsize(mm);
- if (permitted) {
- eip = KSTK_EIP(task);
- esp = KSTK_ESP(task);
- }
+ /*
+ * esp and eip are intentionally zeroed out. There is no
+ * non-racy way to read them without freezing the task.
+ * Programs that need reliable values can use ptrace(2).
+ */
}
get_task_comm(tcomm, task);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index c2964d890c9a..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;
@@ -832,6 +835,7 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
unsigned long addr = *ppos;
ssize_t copied;
char *page;
+ unsigned int flags;
if (!mm)
return 0;
@@ -844,6 +848,11 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
if (!atomic_inc_not_zero(&mm->mm_users))
goto free;
+ /* Maybe we should limit FOLL_FORCE to actual ptrace users? */
+ flags = FOLL_FORCE;
+ if (write)
+ flags |= FOLL_WRITE;
+
while (count > 0) {
int this_len = min_t(int, count, PAGE_SIZE);
@@ -852,7 +861,7 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
break;
}
- this_len = access_remote_vm(mm, addr, page, this_len, write);
+ this_len = access_remote_vm(mm, addr, page, this_len, flags);
if (!this_len) {
if (!copied)
copied = -EIO;
@@ -964,8 +973,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
max_len = min_t(size_t, PAGE_SIZE, count);
this_len = min(max_len, this_len);
- retval = access_remote_vm(mm, (env_start + src),
- page, this_len, 0);
+ retval = access_remote_vm(mm, (env_start + src), page, this_len, 0);
if (retval <= 0) {
ret = retval;
@@ -1007,6 +1015,9 @@ static ssize_t auxv_read(struct file *file, char __user *buf,
{
struct mm_struct *mm = file->private_data;
unsigned int nwords = 0;
+
+ if (!mm)
+ return 0;
do {
nwords += 2;
} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
@@ -1959,7 +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 */
};
@@ -2404,14 +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);
@@ -2436,7 +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;
@@ -3060,8 +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);
@@ -3353,8 +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);
@@ -3544,3 +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/generic.c b/fs/proc/generic.c
index 5f2dc2032c79..7eb3cefcf2a3 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -479,6 +479,7 @@ struct proc_dir_entry *proc_create_mount_point(const char *name)
}
return ent;
}
+EXPORT_SYMBOL(proc_create_mount_point);
struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
struct proc_dir_entry *parent,
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..109876a24d2c 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -195,7 +195,6 @@ static inline bool is_empty_pde(const struct proc_dir_entry *pde)
{
return S_ISDIR(pde->mode) && !pde->proc_iops;
}
-struct proc_dir_entry *proc_create_mount_point(const char *name);
/*
* inode.c
@@ -203,7 +202,7 @@ 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 +210,7 @@ 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 6909582ce5e5..958f32545064 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -266,24 +266,15 @@ static int do_maps_open(struct inode *inode, struct file *file,
* /proc/PID/maps that is the stack of the main task.
*/
static int is_stack(struct proc_maps_private *priv,
- struct vm_area_struct *vma, int is_pid)
+ struct vm_area_struct *vma)
{
- int stack = 0;
-
- if (is_pid) {
- stack = vma->vm_start <= vma->vm_mm->start_stack &&
- vma->vm_end >= vma->vm_mm->start_stack;
- } else {
- struct inode *inode = priv->inode;
- struct task_struct *task;
-
- rcu_read_lock();
- task = pid_task(proc_pid(inode), PIDTYPE_PID);
- if (task)
- stack = vma_is_stack_for_task(vma, task);
- rcu_read_unlock();
- }
- return stack;
+ /*
+ * We make no effort to guess what a given thread considers to be
+ * its "stack". It's not even well-defined for programs written
+ * languages like Go.
+ */
+ return vma->vm_start <= vma->vm_mm->start_stack &&
+ vma->vm_end >= vma->vm_mm->start_stack;
}
static void
@@ -354,7 +345,7 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
goto done;
}
- if (is_stack(priv, vma, is_pid))
+ if (is_stack(priv, vma))
name = "[stack]";
}
@@ -1597,6 +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
@@ -1669,7 +1661,7 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
seq_file_path(m, file, "\n\t= ");
} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
seq_puts(m, " heap");
- } else if (is_stack(proc_priv, vma, is_pid)) {
+ } else if (is_stack(proc_priv, vma)) {
seq_puts(m, " stack");
}
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index faacb0c0d857..37175621e890 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -124,25 +124,17 @@ unsigned long task_statm(struct mm_struct *mm,
}
static int is_stack(struct proc_maps_private *priv,
- struct vm_area_struct *vma, int is_pid)
+ struct vm_area_struct *vma)
{
struct mm_struct *mm = vma->vm_mm;
- int stack = 0;
-
- if (is_pid) {
- stack = vma->vm_start <= mm->start_stack &&
- vma->vm_end >= mm->start_stack;
- } else {
- struct inode *inode = priv->inode;
- struct task_struct *task;
-
- rcu_read_lock();
- task = pid_task(proc_pid(inode), PIDTYPE_PID);
- if (task)
- stack = vma_is_stack_for_task(vma, task);
- rcu_read_unlock();
- }
- return stack;
+
+ /*
+ * We make no effort to guess what a given thread considers to be
+ * its "stack". It's not even well-defined for programs written
+ * languages like Go.
+ */
+ return vma->vm_start <= mm->start_stack &&
+ vma->vm_end >= mm->start_stack;
}
/*
@@ -184,7 +176,7 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
if (file) {
seq_pad(m, ' ');
seq_file_path(m, file, "");
- } else if (mm && is_stack(priv, vma, is_pid)) {
+ } else if (mm && is_stack(priv, vma)) {
seq_pad(m, ' ');
seq_printf(m, "[stack]");
}
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