Hi Kaixiong,
On Sat, Dec 28, 2024 at 4:07 PM Kaixiong Yu <yukaixiong@xxxxxxxxxx> wrote:
> When CONFIG_SUPERH and CONFIG_VSYSCALL are defined,
> vdso_enabled belongs to arch/sh/kernel/vsyscall/vsyscall.c.
> So, move it into its own file. After this patch is applied,
> all sysctls of vm_table would be moved. So, delete vm_table.
>
> Signed-off-by: Kaixiong Yu <yukaixiong@xxxxxxxxxx>
> Reviewed-by: Kees Cook <kees@xxxxxxxxxx>
> ---
> v4:
> - const qualify struct ctl_table vdso_table
Thanks for your patch!
I gave this a try on landisk, and /proc/sys/vm/vdso_enabled
disappeared.
> --- a/arch/sh/kernel/vsyscall/vsyscall.c
> +++ b/arch/sh/kernel/vsyscall/vsyscall.c
> @@ -55,6 +67,8 @@ int __init vsyscall_init(void)
> &vsyscall_trapa_start,
> &vsyscall_trapa_end - &vsyscall_trapa_start);
>
> + register_sysctl_init("vm", vdso_table);
"failed when register_sysctl_sz vdso_table to vm"
Adding some debug prints shows that kzalloc() in
__register_sysctl_table() fails, presumably because it is called too
early in the boot process.
> +
> return 0;
> }
Moving the call to register_sysctl_init() into its own fs_initcall(),
like the gmail-whitespace-damaged patch below, fixes that.
--- a/arch/sh/kernel/vsyscall/vsyscall.c
+++ b/arch/sh/kernel/vsyscall/vsyscall.c
@@ -67,11 +67,17 @@ int __init vsyscall_init(void)
&vsyscall_trapa_start,
&vsyscall_trapa_end - &vsyscall_trapa_start);
- register_sysctl_init("vm", vdso_table);
+ return 0;
+}
+static int __init vm_sysctl_init(void)
+{
+ register_sysctl_init("vm", vdso_table);
return 0;
}
+fs_initcall(vm_sysctl_init);
+
/* Setup a VMA at program startup for the vsyscall page */
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
