diff --git a/include/linux/security.h b/include/linux/security.h index 466cbadbd1ef..2c627d361c02 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -95,8 +95,13 @@ struct seq_file; extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb); extern int cap_netlink_recv(struct sk_buff *skb, int cap); +#ifdef CONFIG_MMU extern unsigned long mmap_min_addr; extern unsigned long dac_mmap_min_addr; +#else +#define dac_mmap_min_addr 0UL +#endif + /* * Values used in the task_security_ops calls */ @@ -121,6 +126,7 @@ struct request_sock; #define LSM_UNSAFE_PTRACE 2 #define LSM_UNSAFE_PTRACE_CAP 4 +#ifdef CONFIG_MMU /* * If a hint addr is less than mmap_min_addr change hint to be as * low as possible but still greater than mmap_min_addr @@ -135,6 +141,7 @@ static inline unsigned long round_hint_to_min(unsigned long hint) } extern int mmap_min_addr_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); +#endif #ifdef CONFIG_SECURITY diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 45e4bef0012a..856a24eadf7e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1214,6 +1214,7 @@ static struct ctl_table vm_table[] = { .proc_handler = proc_dointvec_jiffies, }, #endif +#ifdef CONFIG_MMU { .procname = "mmap_min_addr", .data = &dac_mmap_min_addr, @@ -1221,6 +1222,7 @@ static struct ctl_table vm_table[] = { .mode = 0644, .proc_handler = mmap_min_addr_handler, }, +#endif #ifdef CONFIG_NUMA { .procname = "numa_zonelist_order", diff --git a/mm/Kconfig b/mm/Kconfig index 43ea8c3a2bbf..ee9f3e0f2b69 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -221,6 +221,7 @@ config KSM config DEFAULT_MMAP_MIN_ADDR int "Low address space to protect from user allocation" + depends on MMU default 4096 help This is the portion of low virtual memory which should be protected diff --git a/security/Makefile b/security/Makefile index bb44e350c618..da20a193c8dd 100644 --- a/security/Makefile +++ b/security/Makefile @@ -8,7 +8,8 @@ subdir-$(CONFIG_SECURITY_SMACK) += smack subdir-$(CONFIG_SECURITY_TOMOYO) += tomoyo # always enable default capabilities -obj-y += commoncap.o min_addr.o +obj-y += commoncap.o +obj-$(CONFIG_MMU) += min_addr.o # Object file lists obj-$(CONFIG_SECURITY) += security.o capability.o