On 09/24/2018 05:18 PM, Kees Cook wrote:
> In preparation for doing more interesting LSM init probing, this converts
> the existing initcall system into an explicit call into a function pointer
> from a section-collected struct lsm_info array.
>
> Cc: James Morris <jmorris@xxxxxxxxx>
> Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx>
> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
> Cc: linux-security-module@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
> ---
> include/linux/init.h | 2 --
> include/linux/lsm_hooks.h | 12 ++++++++++++
> include/linux/module.h | 1 -
> security/integrity/iint.c | 1 +
> security/security.c | 14 +++++---------
> 5 files changed, 18 insertions(+), 12 deletions(-)
>
> diff --git a/include/linux/init.h b/include/linux/init.h
> index 77636539e77c..9c2aba1dbabf 100644
> --- a/include/linux/init.h
> +++ b/include/linux/init.h
> @@ -133,7 +133,6 @@ static inline initcall_t initcall_from_entry(initcall_entry_t *entry)
> #endif
>
> extern initcall_entry_t __con_initcall_start[], __con_initcall_end[];
> -extern initcall_entry_t __start_lsm_info[], __end_lsm_info[];
>
> /* Used for contructor calls. */
> typedef void (*ctor_fn_t)(void);
> @@ -236,7 +235,6 @@ extern bool initcall_debug;
> static exitcall_t __exitcall_##fn __exit_call = fn
>
> #define console_initcall(fn) ___define_initcall(fn,, .con_initcall)
> -#define security_initcall(fn) ___define_initcall(fn,, .lsm_info)
>
> struct obs_kernel_param {
> const char *str;
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 97a020c616ad..ad04761e5587 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -2039,6 +2039,18 @@ extern char *lsm_names;
> extern void security_add_hooks(struct security_hook_list *hooks, int count,
> char *lsm);
>
> +struct lsm_info {
> + int (*init)(void);
> +};
> +
> +extern struct lsm_info __start_lsm_info[], __end_lsm_info[];
> +
> +#define security_initcall(lsm) \
> + static struct lsm_info __lsm_##lsm \
> + __used __section(.lsm_info.init) \
> + __aligned(sizeof(unsigned long)) \
> + = { .init = lsm, }
> +
> #ifdef CONFIG_SECURITY_SELINUX_DISABLE
> /*
> * Assuring the safety of deleting a security module is up to
> diff --git a/include/linux/module.h b/include/linux/module.h
> index f807f15bebbe..264979283756 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -123,7 +123,6 @@ extern void cleanup_module(void);
> #define late_initcall_sync(fn) module_init(fn)
>
> #define console_initcall(fn) module_init(fn)
> -#define security_initcall(fn) module_init(fn)
>
> /* Each module must use one module_init(). */
> #define module_init(initfn) \
> diff --git a/security/integrity/iint.c b/security/integrity/iint.c
> index 5a6810041e5c..70d21b566955 100644
> --- a/security/integrity/iint.c
> +++ b/security/integrity/iint.c
> @@ -22,6 +22,7 @@
> #include <linux/file.h>
> #include <linux/uaccess.h>
> #include <linux/security.h>
> +#include <linux/lsm_hooks.h>
> #include "integrity.h"
>
> static struct rb_root integrity_iint_tree = RB_ROOT;
> diff --git a/security/security.c b/security/security.c
> index 41a5da2c7faf..e74f46fba591 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -43,16 +43,12 @@ char *lsm_names;
> static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
> CONFIG_DEFAULT_SECURITY;
>
> -static void __init do_security_initcalls(void)
> +static void __init major_lsm_init(void)
> {
> - initcall_t call;
> - initcall_entry_t *ce;
> + struct lsm_info *lsm;
>
> - ce = __start_lsm_info;
> - while (ce < __end_lsm_info) {
> - call = initcall_from_entry(ce);
> - call();
> - ce++;
> + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
> + lsm->init();
> }
> }
>
> @@ -82,7 +78,7 @@ int __init security_init(void)
> /*
> * Load all the remaining security modules.
> */
> - do_security_initcalls();
> + major_lsm_init();
>
> return 0;
> }
>
