On Mon, Aug 26, 2024 at 8:05 AM Kaixiong Yu <yukaixiong@xxxxxxxxxx> wrote:
>
> The dac_mmap_min_addr belongs to min_addr.c, move it into
> its own file from /kernel/sysctl.c. In the previous Linux kernel
> boot process, sysctl_init_bases needs to be executed before
> init_mmap_min_addr, So, register_sysctl_init should be executed
> before update_mmap_min_addr in init_mmap_min_addr.
>
> Signed-off-by: Kaixiong Yu <yukaixiong@xxxxxxxxxx>
> ---
> kernel/sysctl.c | 9 ---------
> security/min_addr.c | 11 +++++++++++
> 2 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 41d4afc978e6..0c0bab3dad7d 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -2059,15 +2059,6 @@ static struct ctl_table vm_table[] = {
> .proc_handler = proc_dointvec_minmax,
> .extra1 = SYSCTL_ZERO,
> },
> -#ifdef CONFIG_MMU
> - {
> - .procname = "mmap_min_addr",
> - .data = &dac_mmap_min_addr,
> - .maxlen = sizeof(unsigned long),
> - .mode = 0644,
> - .proc_handler = mmap_min_addr_handler,
> - },
> -#endif
> #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
> (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
> {
> diff --git a/security/min_addr.c b/security/min_addr.c
> index 0ce267c041ab..b2f61649e110 100644
> --- a/security/min_addr.c
> +++ b/security/min_addr.c
> @@ -44,8 +44,19 @@ int mmap_min_addr_handler(const struct ctl_table *table, int write,
> return ret;
> }
>
> +static struct ctl_table min_addr_sysctl_table[] = {
> + {
> + .procname = "mmap_min_addr",
> + .data = &dac_mmap_min_addr,
> + .maxlen = sizeof(unsigned long),
> + .mode = 0644,
> + .proc_handler = mmap_min_addr_handler,
> + },
> +};
I haven't chased all of the Kconfig deps to see if there is a problem,
but please provide a quick explanation in the commit description about
why it is okay to drop the CONFIG_MMU check.
> static int __init init_mmap_min_addr(void)
> {
> + register_sysctl_init("vm", min_addr_sysctl_table);
> update_mmap_min_addr();
>
> return 0;
> --
> 2.25.1
--
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