Re: [PATCH] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The 'enabled' debugfs file is created using `debugfs_create_file()` instead of `debugfs_create_file_unsafe()` with a `DEFINE_DEBUGFS_ATTRIBUTE` struct, leading to redundant proxying and overhead.
--

--- Patch [1]: [PATCH] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob ---
commit f5babbd146ccf4194f28506d04f5cbfb2c40150a
Author: Bradley Morgan <include@grrlz.net>

    kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob

This commit replaces the custom read/write handlers for the debugfs enabled
file with the standard DEFINE_DEBUGFS_ATTRIBUTE macro. It simplifies the
implementation and accepts integer inputs rather than characters.

> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index ca9d834d0b843..10bcc2a0926a6 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -2962,47 +2962,22 @@ static int disarm_all_kprobes(void)

[ ... ]

> -static const struct file_operations fops_kp = {
> -	.read =         read_enabled_file_bool,
> -	.write =        write_enabled_file_bool,
> -	.llseek =	default_llseek,
> -};
> +DEFINE_DEBUGFS_ATTRIBUTE(fops_kp, kprobes_enabled_get,
> +			 kprobes_enabled_set, "%llu\n");
>  
>  static int __init debugfs_kprobe_init(void)
>  {

[Severity: Low]
Will this lead to double-proxying for the debugfs file?

Since DEFINE_DEBUGFS_ATTRIBUTE natively provides debugfs_attr_read and
debugfs_attr_write operations that already include debugfs_file_get() and
debugfs_file_put() protection, passing fops_kp to debugfs_create_file()
in debugfs_kprobe_init() will cause the debugfs core to wrap it again:

kernel/kprobes.c:debugfs_kprobe_init() {
    ...
	debugfs_create_file("enabled", 0600, dir, NULL, &fops_kp);
    ...
}

Could this use debugfs_create_file_unsafe() instead?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260818014920.23870-1-include@grrlz.net?part=1