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-rw-r--r--fs/proc/base.c172
1 files changed, 105 insertions, 67 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 9c8ca6cd3ce4..ebea9501afb8 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -209,12 +209,53 @@ static int proc_root_link(struct dentry *dentry, struct path *path)
return result;
}
+/*
+ * If the user used setproctitle(), we just get the string from
+ * user space at arg_start, and limit it to a maximum of one page.
+ */
+static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
+ size_t count, unsigned long pos,
+ unsigned long arg_start)
+{
+ char *page;
+ int ret, got;
+
+ if (pos >= PAGE_SIZE)
+ return 0;
+
+ page = (char *)__get_free_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ ret = 0;
+ got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
+ if (got > 0) {
+ int len = strnlen(page, got);
+
+ /* Include the NUL character if it was found */
+ if (len < got)
+ len++;
+
+ if (len > pos) {
+ len -= pos;
+ if (len > count)
+ len = count;
+ len -= copy_to_user(buf, page+pos, len);
+ if (!len)
+ len = -EFAULT;
+ ret = len;
+ }
+ }
+ free_page((unsigned long)page);
+ return ret;
+}
+
static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
size_t count, loff_t *ppos)
{
unsigned long arg_start, arg_end, env_start, env_end;
unsigned long pos, len;
- char *page;
+ char *page, c;
/* Check if process spawned far enough to have cmdline. */
if (!mm->env_end)
@@ -231,28 +272,42 @@ static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
return 0;
/*
- * We have traditionally allowed the user to re-write
- * the argument strings and overflow the end result
- * into the environment section. But only do that if
- * the environment area is contiguous to the arguments.
+ * We allow setproctitle() to overwrite the argument
+ * strings, and overflow past the original end. But
+ * only when it overflows into the environment area.
*/
- if (env_start != arg_end || env_start >= env_end)
+ if (env_start != arg_end || env_end < env_start)
env_start = env_end = arg_end;
-
- /* .. and limit it to a maximum of one page of slop */
- if (env_end >= arg_end + PAGE_SIZE)
- env_end = arg_end + PAGE_SIZE - 1;
+ len = env_end - arg_start;
/* We're not going to care if "*ppos" has high bits set */
- pos = arg_start + *ppos;
-
- /* .. but we do check the result is in the proper range */
- if (pos < arg_start || pos >= env_end)
+ pos = *ppos;
+ if (pos >= len)
+ return 0;
+ if (count > len - pos)
+ count = len - pos;
+ if (!count)
return 0;
- /* .. and we never go past env_end */
- if (env_end - pos < count)
- count = env_end - pos;
+ /*
+ * Magical special case: if the argv[] end byte is not
+ * zero, the user has overwritten it with setproctitle(3).
+ *
+ * Possible future enhancement: do this only once when
+ * pos is 0, and set a flag in the 'struct file'.
+ */
+ if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
+ return get_mm_proctitle(mm, buf, count, pos, arg_start);
+
+ /*
+ * For the non-setproctitle() case we limit things strictly
+ * to the [arg_start, arg_end[ range.
+ */
+ pos += arg_start;
+ if (pos < arg_start || pos >= arg_end)
+ return 0;
+ if (count > arg_end - pos)
+ count = arg_end - pos;
page = (char *)__get_free_page(GFP_KERNEL);
if (!page)
@@ -262,48 +317,11 @@ static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
while (count) {
int got;
size_t size = min_t(size_t, PAGE_SIZE, count);
- long offset;
-
- /*
- * Are we already starting past the official end?
- * We always include the last byte that is *supposed*
- * to be NUL
- */
- offset = (pos >= arg_end) ? pos - arg_end + 1 : 0;
- got = access_remote_vm(mm, pos - offset, page, size + offset, FOLL_ANON);
- if (got <= offset)
+ got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
+ if (got <= 0)
break;
- got -= offset;
-
- /* Don't walk past a NUL character once you hit arg_end */
- if (pos + got >= arg_end) {
- int n = 0;
-
- /*
- * If we started before 'arg_end' but ended up
- * at or after it, we start the NUL character
- * check at arg_end-1 (where we expect the normal
- * EOF to be).
- *
- * NOTE! This is smaller than 'got', because
- * pos + got >= arg_end
- */
- if (pos < arg_end)
- n = arg_end - pos - 1;
-
- /* Cut off at first NUL after 'n' */
- got = n + strnlen(page+n, offset+got-n);
- if (got < offset)
- break;
- got -= offset;
-
- /* Include the NUL if it existed */
- if (got < size)
- got++;
- }
-
- got -= copy_to_user(buf, page+offset, got);
+ got -= copy_to_user(buf, page, got);
if (unlikely(!got)) {
if (!len)
len = -EFAULT;
@@ -532,8 +550,7 @@ static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
unsigned long totalpages = totalram_pages() + total_swap_pages;
unsigned long points = 0;
- points = oom_badness(task, NULL, NULL, totalpages) *
- 1000 / totalpages;
+ points = oom_badness(task, totalpages) * 1000 / totalpages;
seq_printf(m, "%lu\n", points);
return 0;
@@ -1962,9 +1979,12 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
goto out;
if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
- down_read(&mm->mmap_sem);
- exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
- up_read(&mm->mmap_sem);
+ status = down_read_killable(&mm->mmap_sem);
+ if (!status) {
+ exact_vma_exists = !!find_exact_vma(mm, vm_start,
+ vm_end);
+ up_read(&mm->mmap_sem);
+ }
}
mmput(mm);
@@ -2010,8 +2030,11 @@ static int map_files_get_link(struct dentry *dentry, struct path *path)
if (rc)
goto out_mmput;
+ rc = down_read_killable(&mm->mmap_sem);
+ if (rc)
+ goto out_mmput;
+
rc = -ENOENT;
- down_read(&mm->mmap_sem);
vma = find_exact_vma(mm, vm_start, vm_end);
if (vma && vma->vm_file) {
*path = vma->vm_file->f_path;
@@ -2107,7 +2130,11 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
if (!mm)
goto out_put_task;
- down_read(&mm->mmap_sem);
+ result = ERR_PTR(-EINTR);
+ if (down_read_killable(&mm->mmap_sem))
+ goto out_put_mm;
+
+ result = ERR_PTR(-ENOENT);
vma = find_exact_vma(mm, vm_start, vm_end);
if (!vma)
goto out_no_vma;
@@ -2118,6 +2145,7 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
out_no_vma:
up_read(&mm->mmap_sem);
+out_put_mm:
mmput(mm);
out_put_task:
put_task_struct(task);
@@ -2160,7 +2188,12 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
mm = get_task_mm(task);
if (!mm)
goto out_put_task;
- down_read(&mm->mmap_sem);
+
+ ret = down_read_killable(&mm->mmap_sem);
+ if (ret) {
+ mmput(mm);
+ goto out_put_task;
+ }
nr_files = 0;
@@ -3061,6 +3094,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#ifdef CONFIG_STACKLEAK_METRICS
ONE("stack_depth", S_IRUGO, proc_stack_depth),
#endif
+#ifdef CONFIG_PROC_PID_ARCH_STATUS
+ ONE("arch_status", S_IRUGO, proc_pid_arch_status),
+#endif
};
static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
@@ -3077,8 +3113,7 @@ static const struct file_operations proc_tgid_base_operations = {
struct pid *tgid_pidfd_to_pid(const struct file *file)
{
- if (!d_is_dir(file->f_path.dentry) ||
- (file->f_op != &proc_tgid_base_operations))
+ if (file->f_op != &proc_tgid_base_operations)
return ERR_PTR(-EBADF);
return proc_pid(file_inode(file));
@@ -3449,6 +3484,9 @@ static const struct pid_entry tid_base_stuff[] = {
#ifdef CONFIG_LIVEPATCH
ONE("patch_state", S_IRUSR, proc_pid_patch_state),
#endif
+#ifdef CONFIG_PROC_PID_ARCH_STATUS
+ ONE("arch_status", S_IRUGO, proc_pid_arch_status),
+#endif
};
static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
generated by cgit (git 2.34.1) at 2025-02-25 14:29:59 +0000