When one attempts to create a directory in /proc with an invalid name,
such as one in a subdirectory that doesn't exist, one with a name beyond
256 characters, or a reserved name such as '.' or '..', the kernel
throws a warning message that looks like this:
[ 7913.252558] name 'invalid_name'
This warning message is nearly the same for all invalid cases, including
the removal of a nonexistent directory. This patch clarifies the warning
message and differentiates the invalid creation/removal cases so as to
allow the user to more quickly understand their mistake.
Signed-off-by: Fabrizio D'Angelo <[email protected]>
Signed-off-by: Joel Savitz <[email protected]>
---
fs/proc/generic.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 64e9ee1b129e..df04fd4f02af 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -173,7 +173,7 @@ static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
len = next - cp;
de = pde_subdir_find(de, cp, len);
if (!de) {
- WARN(1, "name '%s'\n", name);
+ WARN(1, "invalid proc dir name '%s'\n", name);
return -ENOENT;
}
cp += len + 1;
@@ -386,15 +386,15 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
qstr.name = fn;
qstr.len = strlen(fn);
if (qstr.len == 0 || qstr.len >= 256) {
- WARN(1, "name len %u\n", qstr.len);
+ WARN(1, "invalid proc dir name len %u\n", qstr.len);
return NULL;
}
if (qstr.len == 1 && fn[0] == '.') {
- WARN(1, "name '.'\n");
+ WARN(1, "invalid proc dir name '.'\n");
return NULL;
}
if (qstr.len == 2 && fn[0] == '.' && fn[1] == '.') {
- WARN(1, "name '..'\n");
+ WARN(1, "invalid proc dir name '..'\n");
return NULL;
}
if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
@@ -402,7 +402,7 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
return NULL;
}
if (is_empty_pde(*parent)) {
- WARN(1, "attempt to add to permanently empty directory");
+ WARN(1, "attempt to add to permanently empty directory in proc");
return NULL;
}
@@ -670,7 +670,7 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
rb_erase(&de->subdir_node, &parent->subdir);
write_unlock(&proc_subdir_lock);
if (!de) {
- WARN(1, "name '%s'\n", name);
+ WARN(1, "unable to remove nonexistent proc dir '%s'\n", name);
return;
}
--
2.23.0
On Sun, Oct 20, 2019 at 06:17:42PM -0400, Joel Savitz wrote:
> When one attempts to create a directory in /proc with an invalid name,
> such as one in a subdirectory that doesn't exist, one with a name beyond
> 256 characters, or a reserved name such as '.' or '..', the kernel
> throws a warning message that looks like this:
>
> [ 7913.252558] name 'invalid_name'
Yes, the important part is filename:line which uniquely identifies
the issue.
> This warning message is nearly the same for all invalid cases, including
> the removal of a nonexistent directory. This patch clarifies the warning
> message and differentiates the invalid creation/removal cases so as to
> allow the user to more quickly understand their mistake.
> --- a/fs/proc/generic.c
> +++ b/fs/proc/generic.c
> @@ -173,7 +173,7 @@ static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
> len = next - cp;
> de = pde_subdir_find(de, cp, len);
> if (!de) {
> - WARN(1, "name '%s'\n", name);
> + WARN(1, "invalid proc dir name '%s'\n", name);
Wrong string anyway, this is nonexistent name, directory or not.
> - WARN(1, "name len %u\n", qstr.len);
> + WARN(1, "invalid proc dir name len %u\n", qstr.len);
> return NULL;
> }
> if (qstr.len == 1 && fn[0] == '.') {
> - WARN(1, "name '.'\n");
> + WARN(1, "invalid proc dir name '.'\n");
> return NULL;
> }
> if (qstr.len == 2 && fn[0] == '.' && fn[1] == '.') {
> - WARN(1, "name '..'\n");
> + WARN(1, "invalid proc dir name '..'\n");
> return NULL;
> }
> if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
> @@ -402,7 +402,7 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
> return NULL;
> }
> if (is_empty_pde(*parent)) {
> - WARN(1, "attempt to add to permanently empty directory");
> + WARN(1, "attempt to add to permanently empty directory in proc");
"proc" will be spilled over all backtrace.
> @@ -670,7 +670,7 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
> rb_erase(&de->subdir_node, &parent->subdir);
> write_unlock(&proc_subdir_lock);
> if (!de) {
> - WARN(1, "name '%s'\n", name);
> + WARN(1, "unable to remove nonexistent proc dir '%s'\n", name);
I'm not sure if such chatty strings are necessary.