[PATCH] alloc_tag: move memory_allocation_profiling_sysctls into .rodata

[PATCH] alloc_tag: move memory_allocation_profiling_sysctls into .rodata

[Joel Granados]

Remove the change in file mode permissions done before initializing the
sysctl. It is not necessary as the writing of the kernel variable will
be blocked by the proc_mem_profiling_handler when writing is disallowed
(also controlled by mem_profiling_support).

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 lib/alloc_tag.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 27fee57a5c91db8067c05bff974a9e801e0ef6a0..846a5b5b44a4e5f530605c97a200e03260e73d77 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -783,7 +783,7 @@ static int proc_mem_profiling_handler(const struct ctl_table *table, int write,
 }
 
 
-static struct ctl_table memory_allocation_profiling_sysctls[] = {
+static const struct ctl_table memory_allocation_profiling_sysctls[] = {
 	{
 		.procname	= "mem_profiling",
 		.data		= &mem_alloc_profiling_key,
@@ -798,9 +798,6 @@ static struct ctl_table memory_allocation_profiling_sysctls[] = {
 
 static void __init sysctl_init(void)
 {
-	if (!mem_profiling_support)
-		memory_allocation_profiling_sysctls[0].mode = 0444;
-
 	register_sysctl_init("vm", memory_allocation_profiling_sysctls);
 }
 #else /* CONFIG_SYSCTL */

---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20251215-jag-alloc_tag_const-dc9d7c3f7a8f

Best regards,
-- 
Joel Granados <joel.granados@kernel.org>

Re: [PATCH] alloc_tag: move memory_allocation_profiling_sysctls into .rodata

[Suren Baghdasaryan]

On Mon, Dec 15, 2025 at 7:47 AM Joel Granados <joel.granados@kernel.org> wrote:
>
> Remove the change in file mode permissions done before initializing the
> sysctl. It is not necessary as the writing of the kernel variable will
> be blocked by the proc_mem_profiling_handler when writing is disallowed
> (also controlled by mem_profiling_support).

Right. When this code was written,
memory_allocation_profiling_sysctls.proc_handler was using
proc_do_static_key(), so this mode update was needed. But now that we
use proc_mem_profiling_handler(), it can be indeed removed.
Thanks for the cleanup!

>
> Signed-off-by: Joel Granados <joel.granados@kernel.org>

Acked-by: Suren Baghdasaryan <surenb@google.com>

> ---
>  lib/alloc_tag.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> index 27fee57a5c91db8067c05bff974a9e801e0ef6a0..846a5b5b44a4e5f530605c97a200e03260e73d77 100644
> --- a/lib/alloc_tag.c
> +++ b/lib/alloc_tag.c
> @@ -783,7 +783,7 @@ static int proc_mem_profiling_handler(const struct ctl_table *table, int write,
>  }
>
>
> -static struct ctl_table memory_allocation_profiling_sysctls[] = {
> +static const struct ctl_table memory_allocation_profiling_sysctls[] = {
>         {
>                 .procname       = "mem_profiling",
>                 .data           = &mem_alloc_profiling_key,
> @@ -798,9 +798,6 @@ static struct ctl_table memory_allocation_profiling_sysctls[] = {
>
>  static void __init sysctl_init(void)
>  {
> -       if (!mem_profiling_support)
> -               memory_allocation_profiling_sysctls[0].mode = 0444;
> -
>         register_sysctl_init("vm", memory_allocation_profiling_sysctls);
>  }
>  #else /* CONFIG_SYSCTL */
>
> ---
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> change-id: 20251215-jag-alloc_tag_const-dc9d7c3f7a8f
>
> Best regards,
> --
> Joel Granados <joel.granados@kernel.org>
>
>