Previously, arrays defined by struct ctl_path is terminated with an empty one. For example, when we actually only register one ctl_path, we've gone from 8 bytes to 16 bytes. So, I use ARRAY_SIZE() as a boundary condition to optimize it. Signed-off-by: Meng Tang <tangmeng@xxxxxxxxxxxxx> --- arch/csky/abiv1/alignment.c | 8 ++++---- arch/nds32/mm/alignment.c | 8 ++++---- fs/proc/proc_sysctl.c | 10 ++++++---- fs/verity/signature.c | 5 +++-- include/linux/sysctl.h | 6 +++--- kernel/pid_namespace.c | 5 +++-- kernel/seccomp.c | 7 ++++--- security/apparmor/lsm.c | 5 +++-- security/loadpin/loadpin.c | 5 +++-- security/yama/yama_lsm.c | 7 ++++--- 10 files changed, 37 insertions(+), 29 deletions(-) diff --git a/arch/csky/abiv1/alignment.c b/arch/csky/abiv1/alignment.c index 2df115d0e210..b9290a252d84 100644 --- a/arch/csky/abiv1/alignment.c +++ b/arch/csky/abiv1/alignment.c @@ -340,14 +340,14 @@ static struct ctl_table sysctl_table[2] = { {} }; -static struct ctl_path sysctl_path[2] = { - {.procname = "csky"}, - {} +static struct ctl_path sysctl_path[1] = { + {.procname = "csky"} }; +#define SYSCTL_PATH_NUM ARRAY_SIZE(sysctl_path) static int __init csky_alignment_init(void) { - register_sysctl_paths(sysctl_path, sysctl_table); + register_sysctl_paths(sysctl_path, SYSCTL_PATH_NUM, sysctl_table); return 0; } diff --git a/arch/nds32/mm/alignment.c b/arch/nds32/mm/alignment.c index 1eb7ded6992b..7145a006fc92 100644 --- a/arch/nds32/mm/alignment.c +++ b/arch/nds32/mm/alignment.c @@ -560,17 +560,17 @@ static struct ctl_table nds32_sysctl_table[2] = { {} }; -static struct ctl_path nds32_path[2] = { - {.procname = "nds32"}, - {} +static struct ctl_path nds32_path[1] = { + {.procname = "nds32"} }; +#define NDS32_PATH_NUM ARRAY_SIZE(nds32_path) /* * Initialize nds32 alignment-correction interface */ static int __init nds32_sysctl_init(void) { - register_sysctl_paths(nds32_path, nds32_sysctl_table); + register_sysctl_paths(nds32_path, NDS32_PATH_NUM, nds32_sysctl_table); return 0; } diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 9ecd5c87e8dd..7774dc159e60 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -1601,20 +1601,21 @@ static int register_leaf_sysctl_tables(const char *path, char *pos, */ struct ctl_table_header *__register_sysctl_paths( struct ctl_table_set *set, - const struct ctl_path *path, struct ctl_table *table) + const struct ctl_path *path, int ctl_path_num, struct ctl_table *table) { struct ctl_table *ctl_table_arg = table; int nr_subheaders = count_subheaders(table); struct ctl_table_header *header = NULL, **subheaders, **subheader; const struct ctl_path *component; char *new_path, *pos; + int i; pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); if (!new_path) return NULL; pos[0] = '\0'; - for (component = path; component->procname; component++) { + for (component = path, i = 0; component->procname && i < ctl_path_num; component++, i++) { pos = append_path(new_path, pos, component->procname); if (!pos) goto out; @@ -1671,10 +1672,11 @@ struct ctl_table_header *__register_sysctl_paths( * See __register_sysctl_paths for more details. */ struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, + int ctl_path_num, struct ctl_table *table) { return __register_sysctl_paths(&sysctl_table_root.default_set, - path, table); + path, ctl_path_num, table); } EXPORT_SYMBOL(register_sysctl_paths); @@ -1691,7 +1693,7 @@ struct ctl_table_header *register_sysctl_table(struct ctl_table *table) { static const struct ctl_path null_path[] = { {} }; - return register_sysctl_paths(null_path, table); + return register_sysctl_paths(null_path, ARRAY_SIZE(null_path), table); } EXPORT_SYMBOL(register_sysctl_table); diff --git a/fs/verity/signature.c b/fs/verity/signature.c index 143a530a8008..e243e8c1cc38 100644 --- a/fs/verity/signature.c +++ b/fs/verity/signature.c @@ -92,9 +92,9 @@ static struct ctl_table_header *fsverity_sysctl_header; static const struct ctl_path fsverity_sysctl_path[] = { { .procname = "fs", }, - { .procname = "verity", }, - { } + { .procname = "verity", } }; +#define FSVERITY_SYSCTL_PATH_NUM ARRAY_SIZE(fsverity_sysctl_path) static struct ctl_table fsverity_sysctl_table[] = { { @@ -112,6 +112,7 @@ static struct ctl_table fsverity_sysctl_table[] = { static int __init fsverity_sysctl_init(void) { fsverity_sysctl_header = register_sysctl_paths(fsverity_sysctl_path, + FSVERITY_SYSCTL_PATH_NUM, fsverity_sysctl_table); if (!fsverity_sysctl_header) { pr_err("sysctl registration failed!\n"); diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 889c995d8a08..f4e3ccf2dbd3 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -221,11 +221,11 @@ struct ctl_table_header *__register_sysctl_table( const char *path, struct ctl_table *table); struct ctl_table_header *__register_sysctl_paths( struct ctl_table_set *set, - const struct ctl_path *path, struct ctl_table *table); + const struct ctl_path *path, int ctl_path_num, struct ctl_table *table); struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table); struct ctl_table_header *register_sysctl_table(struct ctl_table * table); struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, - struct ctl_table *table); + int ctl_path_num, struct ctl_table *table); void unregister_sysctl_table(struct ctl_table_header * table); @@ -272,7 +272,7 @@ static inline struct ctl_table_header *register_sysctl_mount_point(const char *p } static inline struct ctl_table_header *register_sysctl_paths( - const struct ctl_path *path, struct ctl_table *table) + const struct ctl_path *path, int ctl_path_num, struct ctl_table *table) { return NULL; } diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index a46a3723bc66..ad9be671333b 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -294,7 +294,8 @@ static struct ctl_table pid_ns_ctl_table[] = { }, { } }; -static struct ctl_path kern_path[] = { { .procname = "kernel", }, { } }; +static struct ctl_path kern_path[] = { { .procname = "kernel", } }; +#define KERN_PATH_NUM ARRAY_SIZE(kern_path) #endif /* CONFIG_CHECKPOINT_RESTORE */ int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd) @@ -453,7 +454,7 @@ static __init int pid_namespaces_init(void) pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC | SLAB_ACCOUNT); #ifdef CONFIG_CHECKPOINT_RESTORE - register_sysctl_paths(kern_path, pid_ns_ctl_table); + register_sysctl_paths(kern_path, KERN_PATH_NUM, pid_ns_ctl_table); #endif return 0; } diff --git a/kernel/seccomp.c b/kernel/seccomp.c index db10e73d06e0..9488d6831cf5 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -2333,9 +2333,9 @@ static int seccomp_actions_logged_handler(struct ctl_table *ro_table, int write, static struct ctl_path seccomp_sysctl_path[] = { { .procname = "kernel", }, - { .procname = "seccomp", }, - { } + { .procname = "seccomp", } }; +#define SECCOMP_SYSCTL_PATH_NUM ARRAY_SIZE(seccomp_sysctl_path) static struct ctl_table seccomp_sysctl_table[] = { { @@ -2357,7 +2357,8 @@ static int __init seccomp_sysctl_init(void) { struct ctl_table_header *hdr; - hdr = register_sysctl_paths(seccomp_sysctl_path, seccomp_sysctl_table); + hdr = register_sysctl_paths(seccomp_sysctl_path, SECCOMP_SYSCTL_PATH_NUM, + seccomp_sysctl_table); if (!hdr) pr_warn("sysctl registration failed\n"); else diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 4f0eecb67dde..b8cfe202db65 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1729,9 +1729,9 @@ static int apparmor_dointvec(struct ctl_table *table, int write, } static struct ctl_path apparmor_sysctl_path[] = { - { .procname = "kernel", }, - { } + { .procname = "kernel", } }; +#define APPARMOR_SYSCTL_PATH_NUM ARRAY_SIZE(apparmor_sysctl_path) static struct ctl_table apparmor_sysctl_table[] = { { @@ -1747,6 +1747,7 @@ static struct ctl_table apparmor_sysctl_table[] = { static int __init apparmor_init_sysctl(void) { return register_sysctl_paths(apparmor_sysctl_path, + APPARMOR_SYSCTL_PATH_NUM, apparmor_sysctl_table) ? 0 : -ENOMEM; } #else diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c index b12f7d986b1e..7728f061f8c0 100644 --- a/security/loadpin/loadpin.c +++ b/security/loadpin/loadpin.c @@ -48,9 +48,9 @@ static DEFINE_SPINLOCK(pinned_root_spinlock); static struct ctl_path loadpin_sysctl_path[] = { { .procname = "kernel", }, - { .procname = "loadpin", }, - { } + { .procname = "loadpin", } }; +#define LOADPIN_SYSCTL_PATH_NUM ARRAY_SIZE(loadpin_sysctl_path) static struct ctl_table loadpin_sysctl_table[] = { { @@ -91,6 +91,7 @@ static void check_pinning_enforcement(struct super_block *mnt_sb) if (!ro) { if (!register_sysctl_paths(loadpin_sysctl_path, + LOADPIN_SYSCTL_PATH_NUM, loadpin_sysctl_table)) pr_notice("sysctl registration failed!\n"); else diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index 06e226166aab..d2460b963fd9 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -449,9 +449,9 @@ static int max_scope = YAMA_SCOPE_NO_ATTACH; static struct ctl_path yama_sysctl_path[] = { { .procname = "kernel", }, - { .procname = "yama", }, - { } + { .procname = "yama", } }; +#define YAMA_SYSCTL_PATH_NUM ARRAY_SIZE(yama_sysctl_path) static struct ctl_table yama_sysctl_table[] = { { @@ -467,7 +467,8 @@ static struct ctl_table yama_sysctl_table[] = { }; static void __init yama_init_sysctl(void) { - if (!register_sysctl_paths(yama_sysctl_path, yama_sysctl_table)) + if (!register_sysctl_paths(yama_sysctl_path, YAMA_SYSCTL_PATH_NUM, + yama_sysctl_table)) panic("Yama: sysctl registration failed.\n"); } #else -- 2.20.1