diff options
| author | David Howells <dhowells@redhat.com> | 2009-12-15 19:27:45 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-01-06 15:04:30 -0800 |
| commit | 0399123f3dcce1a515d021107ec0fb4413ca3efa (patch) | |
| tree | feb6247bb86bcb4ccaf179d086ccd95fff6f2c66 | |
| parent | 1cfe005024b5c820f9b37c9045ec87ee75a8cfb6 (diff) | |
NOMMU: Optimise away the {dac_,}mmap_min_addr tests
commit 6e1415467614e854fee660ff6648bd10fa976e95 upstream.
In NOMMU mode clamp dac_mmap_min_addr to zero to cause the tests on it to be
skipped by the compiler. We do this as the minimum mmap address doesn't make
any sense in NOMMU mode.
mmap_min_addr and round_hint_to_min() can be discarded entirely in NOMMU mode.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | include/linux/security.h | 7 | ||||
| -rw-r--r-- | kernel/sysctl.c | 2 | ||||
| -rw-r--r-- | mm/Kconfig | 1 | ||||
| -rw-r--r-- | security/Makefile | 3 |
4 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/security.h b/include/linux/security.h index 239e40d0450b..d40d23fa576a 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 0d949c517412..db23ab7e56c0 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1200,6 +1200,7 @@ static struct ctl_table vm_table[] = { .extra2 = (void *)&hugetlb_infinity, }, #endif +#ifdef CONFIG_MMU { .ctl_name = VM_LOWMEM_RESERVE_RATIO, .procname = "lowmem_reserve_ratio", @@ -1353,6 +1354,7 @@ static struct ctl_table vm_table[] = { .mode = 0644, .proc_handler = &mmap_min_addr_handler, }, +#endif #ifdef CONFIG_NUMA { .ctl_name = CTL_UNNUMBERED, diff --git a/mm/Kconfig b/mm/Kconfig index 44cf6f0a3a6d..2c19c0bac10e 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -227,6 +227,7 @@ 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 95ecc06392d7..510bbc80b9b4 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 |