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-rw-r--r--fs/proc/base.c231
1 files changed, 156 insertions, 75 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 18550c071d71..c667702dc69b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -58,7 +58,6 @@
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/file.h>
-#include <linux/fdtable.h>
#include <linux/generic-radix-tree.h>
#include <linux/string.h>
#include <linux/seq_file.h>
@@ -85,6 +84,7 @@
#include <linux/elf.h>
#include <linux/pid_namespace.h>
#include <linux/user_namespace.h>
+#include <linux/fs_parser.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
#include <linux/sched/autogroup.h>
@@ -117,6 +117,40 @@
static u8 nlink_tid __ro_after_init;
static u8 nlink_tgid __ro_after_init;
+enum proc_mem_force {
+ PROC_MEM_FORCE_ALWAYS,
+ PROC_MEM_FORCE_PTRACE,
+ PROC_MEM_FORCE_NEVER
+};
+
+static enum proc_mem_force proc_mem_force_override __ro_after_init =
+ IS_ENABLED(CONFIG_PROC_MEM_NO_FORCE) ? PROC_MEM_FORCE_NEVER :
+ IS_ENABLED(CONFIG_PROC_MEM_FORCE_PTRACE) ? PROC_MEM_FORCE_PTRACE :
+ PROC_MEM_FORCE_ALWAYS;
+
+static const struct constant_table proc_mem_force_table[] __initconst = {
+ { "always", PROC_MEM_FORCE_ALWAYS },
+ { "ptrace", PROC_MEM_FORCE_PTRACE },
+ { "never", PROC_MEM_FORCE_NEVER },
+ { }
+};
+
+static int __init early_proc_mem_force_override(char *buf)
+{
+ if (!buf)
+ return -EINVAL;
+
+ /*
+ * lookup_constant() defaults to proc_mem_force_override to preseve
+ * the initial Kconfig choice in case an invalid param gets passed.
+ */
+ proc_mem_force_override = lookup_constant(proc_mem_force_table,
+ buf, proc_mem_force_override);
+
+ return 0;
+}
+early_param("proc_mem.force_override", early_proc_mem_force_override);
+
struct pid_entry {
const char *name;
unsigned int len;
@@ -382,7 +416,7 @@ static const struct file_operations proc_pid_cmdline_ops = {
#ifdef CONFIG_KALLSYMS
/*
* Provides a wchan file via kallsyms in a proper one-value-per-file format.
- * Returns the resolved symbol. If that fails, simply return the address.
+ * Returns the resolved symbol to user space.
*/
static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
@@ -793,23 +827,31 @@ static const struct file_operations proc_single_file_operations = {
.release = single_release,
};
-
+/*
+ * proc_mem_open() can return errno, NULL or mm_struct*.
+ *
+ * - Returns NULL if the task has no mm (PF_KTHREAD or PF_EXITING)
+ * - Returns mm_struct* on success
+ * - Returns error code on failure
+ */
struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
{
struct task_struct *task = get_proc_task(inode);
- struct mm_struct *mm = ERR_PTR(-ESRCH);
+ struct mm_struct *mm;
- if (task) {
- mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
- put_task_struct(task);
+ if (!task)
+ return ERR_PTR(-ESRCH);
- if (!IS_ERR_OR_NULL(mm)) {
- /* ensure this mm_struct can't be freed */
- mmgrab(mm);
- /* but do not pin its memory */
- mmput(mm);
- }
- }
+ mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
+ put_task_struct(task);
+
+ if (IS_ERR(mm))
+ return mm == ERR_PTR(-ESRCH) ? NULL : mm;
+
+ /* ensure this mm_struct can't be freed */
+ mmgrab(mm);
+ /* but do not pin its memory */
+ mmput(mm);
return mm;
}
@@ -818,8 +860,8 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
{
struct mm_struct *mm = proc_mem_open(inode, mode);
- if (IS_ERR(mm))
- return PTR_ERR(mm);
+ if (IS_ERR_OR_NULL(mm))
+ return mm ? PTR_ERR(mm) : -ESRCH;
file->private_data = mm;
return 0;
@@ -827,12 +869,31 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
static int mem_open(struct inode *inode, struct file *file)
{
- int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
-
- /* OK to pass negative loff_t, we can catch out-of-range */
- file->f_mode |= FMODE_UNSIGNED_OFFSET;
+ if (WARN_ON_ONCE(!(file->f_op->fop_flags & FOP_UNSIGNED_OFFSET)))
+ return -EINVAL;
+ return __mem_open(inode, file, PTRACE_MODE_ATTACH);
+}
- return ret;
+static bool proc_mem_foll_force(struct file *file, struct mm_struct *mm)
+{
+ struct task_struct *task;
+ bool ptrace_active = false;
+
+ switch (proc_mem_force_override) {
+ case PROC_MEM_FORCE_NEVER:
+ return false;
+ case PROC_MEM_FORCE_PTRACE:
+ task = get_proc_task(file_inode(file));
+ if (task) {
+ ptrace_active = READ_ONCE(task->ptrace) &&
+ READ_ONCE(task->mm) == mm &&
+ READ_ONCE(task->parent) == current;
+ put_task_struct(task);
+ }
+ return ptrace_active;
+ default:
+ return true;
+ }
}
static ssize_t mem_rw(struct file *file, char __user *buf,
@@ -855,7 +916,9 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
if (!mmget_not_zero(mm))
goto free;
- flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
+ flags = write ? FOLL_WRITE : 0;
+ if (proc_mem_foll_force(file, mm))
+ flags |= FOLL_FORCE;
while (count > 0) {
size_t this_len = min_t(size_t, count, PAGE_SIZE);
@@ -932,6 +995,7 @@ static const struct file_operations proc_mem_operations = {
.write = mem_write,
.open = mem_open,
.release = mem_release,
+ .fop_flags = FOP_UNSIGNED_OFFSET,
};
static int environ_open(struct inode *inode, struct file *file)
@@ -1431,7 +1495,6 @@ static const struct file_operations proc_fail_nth_operations = {
#endif
-#ifdef CONFIG_SCHED_DEBUG
/*
* Print out various scheduling related per-task fields:
*/
@@ -1481,8 +1544,6 @@ static const struct file_operations proc_pid_sched_operations = {
.release = single_release,
};
-#endif
-
#ifdef CONFIG_SCHED_AUTOGROUP
/*
* Print out autogroup related information:
@@ -2000,7 +2061,8 @@ void pid_update_inode(struct task_struct *task, struct inode *inode)
* performed a setuid(), etc.
*
*/
-static int pid_revalidate(struct dentry *dentry, unsigned int flags)
+static int pid_revalidate(struct inode *dir, const struct qstr *name,
+ struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct task_struct *task;
@@ -2065,7 +2127,7 @@ bool proc_fill_cache(struct file *file, struct dir_context *ctx,
unsigned type = DT_UNKNOWN;
ino_t ino = 1;
- child = d_hash_and_lookup(dir, &qname);
+ child = try_lookup_noperm(&qname, dir);
if (!child) {
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
child = d_alloc_parallel(dir, &qname, &wq);
@@ -2133,7 +2195,8 @@ static int dname_to_vma_addr(struct dentry *dentry,
return 0;
}
-static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
+static int map_files_d_revalidate(struct inode *dir, const struct qstr *name,
+ struct dentry *dentry, unsigned int flags)
{
unsigned long vm_start, vm_end;
bool exact_vma_exists = false;
@@ -2151,7 +2214,7 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
goto out_notask;
mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
- if (IS_ERR_OR_NULL(mm))
+ if (IS_ERR(mm))
goto out;
if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
@@ -2276,8 +2339,8 @@ proc_map_files_instantiate(struct dentry *dentry,
inode->i_op = &proc_map_files_link_inode_operations;
inode->i_size = 64;
- d_set_d_op(dentry, &tid_map_files_dentry_operations);
- return d_splice_alias(inode, dentry);
+ return proc_splice_unmountable(inode, dentry,
+ &tid_map_files_dentry_operations);
}
static struct dentry *proc_map_files_lookup(struct inode *dir,
@@ -2437,11 +2500,9 @@ static const struct file_operations proc_map_files_operations = {
#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
struct timers_private {
- struct pid *pid;
- struct task_struct *task;
- struct sighand_struct *sighand;
- struct pid_namespace *ns;
- unsigned long flags;
+ struct pid *pid;
+ struct task_struct *task;
+ struct pid_namespace *ns;
};
static void *timers_start(struct seq_file *m, loff_t *pos)
@@ -2452,54 +2513,48 @@ static void *timers_start(struct seq_file *m, loff_t *pos)
if (!tp->task)
return ERR_PTR(-ESRCH);
- tp->sighand = lock_task_sighand(tp->task, &tp->flags);
- if (!tp->sighand)
- return ERR_PTR(-ESRCH);
-
- return seq_list_start(&tp->task->signal->posix_timers, *pos);
+ rcu_read_lock();
+ return seq_hlist_start_rcu(&tp->task->signal->posix_timers, *pos);
}
static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
{
struct timers_private *tp = m->private;
- return seq_list_next(v, &tp->task->signal->posix_timers, pos);
+
+ return seq_hlist_next_rcu(v, &tp->task->signal->posix_timers, pos);
}
static void timers_stop(struct seq_file *m, void *v)
{
struct timers_private *tp = m->private;
- if (tp->sighand) {
- unlock_task_sighand(tp->task, &tp->flags);
- tp->sighand = NULL;
- }
-
if (tp->task) {
put_task_struct(tp->task);
tp->task = NULL;
+ rcu_read_unlock();
}
}
static int show_timer(struct seq_file *m, void *v)
{
- struct k_itimer *timer;
- struct timers_private *tp = m->private;
- int notify;
static const char * const nstr[] = {
- [SIGEV_SIGNAL] = "signal",
- [SIGEV_NONE] = "none",
- [SIGEV_THREAD] = "thread",
+ [SIGEV_SIGNAL] = "signal",
+ [SIGEV_NONE] = "none",
+ [SIGEV_THREAD] = "thread",
};
- timer = list_entry((struct list_head *)v, struct k_itimer, list);
- notify = timer->it_sigev_notify;
+ struct k_itimer *timer = hlist_entry((struct hlist_node *)v, struct k_itimer, list);
+ struct timers_private *tp = m->private;
+ int notify = timer->it_sigev_notify;
+
+ guard(spinlock_irq)(&timer->it_lock);
+ if (!posixtimer_valid(timer))
+ return 0;
seq_printf(m, "ID: %d\n", timer->it_id);
- seq_printf(m, "signal: %d/%px\n",
- timer->sigq->info.si_signo,
- timer->sigq->info.si_value.sival_ptr);
- seq_printf(m, "notify: %s/%s.%d\n",
- nstr[notify & ~SIGEV_THREAD_ID],
+ seq_printf(m, "signal: %d/%px\n", timer->sigq.info.si_signo,
+ timer->sigq.info.si_value.sival_ptr);
+ seq_printf(m, "notify: %s/%s.%d\n", nstr[notify & ~SIGEV_THREAD_ID],
(notify & SIGEV_THREAD_ID) ? "tid" : "pid",
pid_nr_ns(timer->it_pid, tp->ns));
seq_printf(m, "ClockID: %d\n", timer->it_clock);
@@ -2569,10 +2624,11 @@ static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
}
task_lock(p);
- if (slack_ns == 0)
- p->timer_slack_ns = p->default_timer_slack_ns;
- else
- p->timer_slack_ns = slack_ns;
+ if (rt_or_dl_task_policy(p))
+ slack_ns = 0;
+ else if (slack_ns == 0)
+ slack_ns = p->default_timer_slack_ns;
+ p->timer_slack_ns = slack_ns;
task_unlock(p);
out:
@@ -3210,13 +3266,24 @@ static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
struct mm_struct *mm;
+ int ret = 0;
mm = get_task_mm(task);
if (mm) {
seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
- seq_printf(m, "ksm_zero_pages %lu\n", mm->ksm_zero_pages);
+ seq_printf(m, "ksm_zero_pages %ld\n", mm_ksm_zero_pages(mm));
seq_printf(m, "ksm_merging_pages %lu\n", mm->ksm_merging_pages);
seq_printf(m, "ksm_process_profit %ld\n", ksm_process_profit(mm));
+ seq_printf(m, "ksm_merge_any: %s\n",
+ test_bit(MMF_VM_MERGE_ANY, &mm->flags) ? "yes" : "no");
+ ret = mmap_read_lock_killable(mm);
+ if (ret) {
+ mmput(mm);
+ return ret;
+ }
+ seq_printf(m, "ksm_mergeable: %s\n",
+ ksm_process_mergeable(mm) ? "yes" : "no");
+ mmap_read_unlock(mm);
mmput(mm);
}
@@ -3259,9 +3326,7 @@ static const struct pid_entry tgid_base_stuff[] = {
ONE("status", S_IRUGO, proc_pid_status),
ONE("personality", S_IRUSR, proc_pid_personality),
ONE("limits", S_IRUGO, proc_pid_limits),
-#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
-#endif
#ifdef CONFIG_SCHED_AUTOGROUP
REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
#endif
@@ -3610,9 +3675,7 @@ static const struct pid_entry tid_base_stuff[] = {
ONE("status", S_IRUGO, proc_pid_status),
ONE("personality", S_IRUSR, proc_pid_personality),
ONE("limits", S_IRUGO, proc_pid_limits),
-#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
-#endif
NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
&proc_tid_comm_inode_operations,
&proc_pid_set_comm_operations, {}),
@@ -3870,12 +3933,12 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx)
if (!dir_emit_dots(file, ctx))
return 0;
- /* f_version caches the tgid value that the last readdir call couldn't
- * return. lseek aka telldir automagically resets f_version to 0.
+ /* We cache the tgid value that the last readdir call couldn't
+ * return and lseek resets it to 0.
*/
ns = proc_pid_ns(inode->i_sb);
- tid = (int)file->f_version;
- file->f_version = 0;
+ tid = (int)(intptr_t)file->private_data;
+ file->private_data = NULL;
for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
task;
task = next_tid(task), ctx->pos++) {
@@ -3890,7 +3953,7 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx)
proc_task_instantiate, task, NULL)) {
/* returning this tgid failed, save it as the first
* pid for the next readir call */
- file->f_version = (u64)tid;
+ file->private_data = (void *)(intptr_t)tid;
put_task_struct(task);
break;
}
@@ -3915,6 +3978,24 @@ static int proc_task_getattr(struct mnt_idmap *idmap,
return 0;
}
+/*
+ * proc_task_readdir() set @file->private_data to a positive integer
+ * value, so casting that to u64 is safe. generic_llseek_cookie() will
+ * set @cookie to 0, so casting to an int is safe. The WARN_ON_ONCE() is
+ * here to catch any unexpected change in behavior either in
+ * proc_task_readdir() or generic_llseek_cookie().
+ */
+static loff_t proc_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+ u64 cookie = (u64)(intptr_t)file->private_data;
+ loff_t off;
+
+ off = generic_llseek_cookie(file, offset, whence, &cookie);
+ WARN_ON_ONCE(cookie > INT_MAX);
+ file->private_data = (void *)(intptr_t)cookie; /* serialized by f_pos_lock */
+ return off;
+}
+
static const struct inode_operations proc_task_inode_operations = {
.lookup = proc_task_lookup,
.getattr = proc_task_getattr,
@@ -3925,7 +4006,7 @@ static const struct inode_operations proc_task_inode_operations = {
static const struct file_operations proc_task_operations = {
.read = generic_read_dir,
.iterate_shared = proc_task_readdir,
- .llseek = generic_file_llseek,
+ .llseek = proc_dir_llseek,
};
void __init set_proc_pid_nlink(void)
generated by cgit (git 2.34.1) at 2025-07-18 23:44:41 +0000