Re: [PATCH 1/8] sysctl: introduce sysctl SYSCTL_U8_MAX and SYSCTL_LONG_S32_MAX

[Joel Granados]

On Sun, Feb 25, 2024 at 12:05:31PM +0800, wenyang.linux@xxxxxxxxxxx wrote:
> From: Wen Yang <wenyang.linux@xxxxxxxxxxx>
> 
> The boundary check of multiple modules uses these static variables (such as
> two_five_five, n_65535, ue_int_max, etc), and they are also not changed.
> Therefore, add them to the shared sysctl_vals and sysctl_long_vals to avoid
> duplication.
> 
> Also rearranged sysctl_vals and sysctl_long_vals in numerical order.
> 
> Signed-off-by: Wen Yang <wenyang.linux@xxxxxxxxxxx>
> Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Joel Granados <j.granados@xxxxxxxxxxx>
> Cc: Christian Brauner <brauner@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
>  include/linux/sysctl.h | 15 +++++++++------
>  kernel/sysctl.c        |  4 ++--
>  2 files changed, 11 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
> index ee7d33b89e9e..b7a13e4c411c 100644
> --- a/include/linux/sysctl.h
> +++ b/include/linux/sysctl.h
> @@ -45,19 +45,22 @@ struct ctl_dir;
>  #define SYSCTL_FOUR			((void *)&sysctl_vals[4])
>  #define SYSCTL_ONE_HUNDRED		((void *)&sysctl_vals[5])
>  #define SYSCTL_TWO_HUNDRED		((void *)&sysctl_vals[6])
> -#define SYSCTL_ONE_THOUSAND		((void *)&sysctl_vals[7])
> -#define SYSCTL_THREE_THOUSAND		((void *)&sysctl_vals[8])
> -#define SYSCTL_INT_MAX			((void *)&sysctl_vals[9])
> +#define SYSCTL_U8_MAX			((void *)&sysctl_vals[7])
> +#define SYSCTL_ONE_THOUSAND		((void *)&sysctl_vals[8])
> +#define SYSCTL_THREE_THOUSAND		((void *)&sysctl_vals[9])
> +#define SYSCTL_U16_MAX			((void *)&sysctl_vals[10])
> +#define SYSCTL_INT_MAX			((void *)&sysctl_vals[11])
> +#define SYSCTL_NEG_ONE			((void *)&sysctl_vals[12])
>  
>  /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
> -#define SYSCTL_MAXOLDUID		((void *)&sysctl_vals[10])
> -#define SYSCTL_NEG_ONE			((void *)&sysctl_vals[11])
> +#define SYSCTL_MAXOLDUID		SYSCTL_U16_MAX
>  
>  extern const int sysctl_vals[];
>  
>  #define SYSCTL_LONG_ZERO	((void *)&sysctl_long_vals[0])
>  #define SYSCTL_LONG_ONE		((void *)&sysctl_long_vals[1])
> -#define SYSCTL_LONG_MAX		((void *)&sysctl_long_vals[2])
> +#define SYSCTL_LONG_S32_MAX	((void *)&sysctl_long_vals[2])
> +#define SYSCTL_LONG_MAX		((void *)&sysctl_long_vals[3])
>  
>  extern const unsigned long sysctl_long_vals[];
>  
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 157f7ce2942d..e1e00937cb29 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -82,10 +82,10 @@
>  #endif
>  
>  /* shared constants to be used in various sysctls */
> -const int sysctl_vals[] = { 0, 1, 2, 3, 4, 100, 200, 1000, 3000, INT_MAX, 65535, -1 };
> +const int sysctl_vals[] = { 0, 1, 2, 3, 4, 100, 200, U8_MAX, 1000, 3000, 65535, INT_MAX, -1, };
Why do you insert the new values instead of just appending?
I figure that the patch would be much smaller if you appended.

>  EXPORT_SYMBOL(sysctl_vals);
>  
> -const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX };
> +const unsigned long sysctl_long_vals[] = { 0, 1, S32_MAX, LONG_MAX, };
Same here. Why insert instead of append?
>  EXPORT_SYMBOL_GPL(sysctl_long_vals);
>  
>  #if defined(CONFIG_SYSCTL)
> -- 
> 2.25.1
> 

-- 

Joel Granados

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