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-rw-r--r--fs/proc/base.c105
1 files changed, 87 insertions, 18 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 13eda8de2998..9e479d7d202b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -74,7 +74,6 @@
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/ptrace.h>
-#include <linux/tracehook.h>
#include <linux/printk.h>
#include <linux/cache.h>
#include <linux/cgroup.h>
@@ -670,10 +669,10 @@ static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
/************************************************************************/
/* permission checks */
-static int proc_fd_access_allowed(struct inode *inode)
+static bool proc_fd_access_allowed(struct inode *inode)
{
struct task_struct *task;
- int allowed = 0;
+ bool allowed = false;
/* Allow access to a task's file descriptors if it is us or we
* may use ptrace attach to the process and find out that
* information.
@@ -1762,27 +1761,27 @@ out:
return ERR_PTR(error);
}
-static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
+static int do_proc_readlink(const struct path *path, char __user *buffer, int buflen)
{
- char *tmp = (char *)__get_free_page(GFP_KERNEL);
+ char *tmp = kmalloc(PATH_MAX, GFP_KERNEL);
char *pathname;
int len;
if (!tmp)
return -ENOMEM;
- pathname = d_path(path, tmp, PAGE_SIZE);
+ pathname = d_path(path, tmp, PATH_MAX);
len = PTR_ERR(pathname);
if (IS_ERR(pathname))
goto out;
- len = tmp + PAGE_SIZE - 1 - pathname;
+ len = tmp + PATH_MAX - 1 - pathname;
if (len > buflen)
len = buflen;
if (copy_to_user(buffer, pathname, len))
len = -EFAULT;
out:
- free_page((unsigned long)tmp);
+ kfree(tmp);
return len;
}
@@ -1886,7 +1885,7 @@ void proc_pid_evict_inode(struct proc_inode *ei)
put_pid(pid);
}
-struct inode *proc_pid_make_inode(struct super_block * sb,
+struct inode *proc_pid_make_inode(struct super_block *sb,
struct task_struct *task, umode_t mode)
{
struct inode * inode;
@@ -1915,11 +1914,6 @@ struct inode *proc_pid_make_inode(struct super_block * sb,
/* Let the pid remember us for quick removal */
ei->pid = pid;
- if (S_ISDIR(mode)) {
- spin_lock(&pid->lock);
- hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
- spin_unlock(&pid->lock);
- }
task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
security_task_to_inode(task, inode);
@@ -1932,6 +1926,39 @@ out_unlock:
return NULL;
}
+/*
+ * Generating an inode and adding it into @pid->inodes, so that task will
+ * invalidate inode's dentry before being released.
+ *
+ * This helper is used for creating dir-type entries under '/proc' and
+ * '/proc/<tgid>/task'. Other entries(eg. fd, stat) under '/proc/<tgid>'
+ * can be released by invalidating '/proc/<tgid>' dentry.
+ * In theory, dentries under '/proc/<tgid>/task' can also be released by
+ * invalidating '/proc/<tgid>' dentry, we reserve it to handle single
+ * thread exiting situation: Any one of threads should invalidate its
+ * '/proc/<tgid>/task/<pid>' dentry before released.
+ */
+static struct inode *proc_pid_make_base_inode(struct super_block *sb,
+ struct task_struct *task, umode_t mode)
+{
+ struct inode *inode;
+ struct proc_inode *ei;
+ struct pid *pid;
+
+ inode = proc_pid_make_inode(sb, task, mode);
+ if (!inode)
+ return NULL;
+
+ /* Let proc_flush_pid find this directory inode */
+ ei = PROC_I(inode);
+ pid = ei->pid;
+ spin_lock(&pid->lock);
+ hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
+ spin_unlock(&pid->lock);
+
+ return inode;
+}
+
int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
struct kstat *stat, u32 request_mask, unsigned int query_flags)
{
@@ -2323,6 +2350,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
GENRADIX(struct map_files_info) fa;
struct map_files_info *p;
int ret;
+ struct vma_iterator vmi;
genradix_init(&fa);
@@ -2361,7 +2389,9 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
* routine might require mmap_lock taken in might_fault().
*/
- for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
+ pos = 2;
+ vma_iter_init(&vmi, mm, 0);
+ for_each_vma(vmi, vma) {
if (!vma->vm_file)
continue;
if (++pos <= ctx->pos)
@@ -2701,7 +2731,7 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
return -ESRCH;
length = security_getprocattr(task, PROC_I(inode)->op.lsm,
- (char*)file->f_path.dentry->d_name.name,
+ file->f_path.dentry->d_name.name,
&p);
put_task_struct(task);
if (length > 0)
@@ -3155,6 +3185,35 @@ static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
}
#endif /* CONFIG_LIVEPATCH */
+#ifdef CONFIG_KSM
+static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ struct mm_struct *mm;
+
+ mm = get_task_mm(task);
+ if (mm) {
+ seq_printf(m, "%lu\n", mm->ksm_merging_pages);
+ mmput(mm);
+ }
+
+ return 0;
+}
+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;
+
+ mm = get_task_mm(task);
+ if (mm) {
+ seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
+ mmput(mm);
+ }
+
+ return 0;
+}
+#endif /* CONFIG_KSM */
+
#ifdef CONFIG_STACKLEAK_METRICS
static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
@@ -3286,6 +3345,10 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_SECCOMP_CACHE_DEBUG
ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
#endif
+#ifdef CONFIG_KSM
+ ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
+ ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
+#endif
};
static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
@@ -3351,7 +3414,8 @@ static struct dentry *proc_pid_instantiate(struct dentry * dentry,
{
struct inode *inode;
- inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
+ inode = proc_pid_make_base_inode(dentry->d_sb, task,
+ S_IFDIR | S_IRUGO | S_IXUGO);
if (!inode)
return ERR_PTR(-ENOENT);
@@ -3619,6 +3683,10 @@ static const struct pid_entry tid_base_stuff[] = {
#ifdef CONFIG_SECCOMP_CACHE_DEBUG
ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
#endif
+#ifdef CONFIG_KSM
+ ONE("ksm_merging_pages", S_IRUSR, proc_pid_ksm_merging_pages),
+ ONE("ksm_stat", S_IRUSR, proc_pid_ksm_stat),
+#endif
};
static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
@@ -3650,7 +3718,8 @@ static struct dentry *proc_task_instantiate(struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
struct inode *inode;
- inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
+ inode = proc_pid_make_base_inode(dentry->d_sb, task,
+ S_IFDIR | S_IRUGO | S_IXUGO);
if (!inode)
return ERR_PTR(-ENOENT);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.