From: Arjan van de Ven <arjan@infradead.org>
This first patch of the series introduces a sysctl (default off) that
enables/disables the randomisation feature globally. Since randomisation may
make it harder to debug really tricky situations (reproducability goes down),
the sysadmin needs a way to disable it globally.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/include/linux/kernel.h | 3 +++
25-akpm/include/linux/sysctl.h | 1 +
25-akpm/kernel/sysctl.c | 11 +++++++++++
3 files changed, 15 insertions(+)
diff -puN include/linux/kernel.h~randomisation-global-sysctl include/linux/kernel.h
--- 25/include/linux/kernel.h~randomisation-global-sysctl 2005-02-02 15:22:12.963943944 -0800
+++ 25-akpm/include/linux/kernel.h 2005-02-02 15:22:12.970942880 -0800
@@ -278,6 +278,9 @@ struct sysinfo {
extern void BUILD_BUG(void);
#define BUILD_BUG_ON(condition) do { if (condition) BUILD_BUG(); } while(0)
+
+extern int randomize_va_space;
+
/* Trap pasters of __FUNCTION__ at compile-time */
#if __GNUC__ > 2 || __GNUC_MINOR__ >= 95
#define __FUNCTION__ (__func__)
diff -puN include/linux/sysctl.h~randomisation-global-sysctl include/linux/sysctl.h
--- 25/include/linux/sysctl.h~randomisation-global-sysctl 2005-02-02 15:22:12.964943792 -0800
+++ 25-akpm/include/linux/sysctl.h 2005-02-02 15:22:12.971942728 -0800
@@ -135,6 +135,7 @@ enum
KERN_HZ_TIMER=65, /* int: hz timer on or off */
KERN_UNKNOWN_NMI_PANIC=66, /* int: unknown nmi panic flag */
KERN_BOOTLOADER_TYPE=67, /* int: boot loader type */
+ KERN_RANDOMIZE=68, /* int: randomize virtual address space */
};
diff -puN kernel/sysctl.c~randomisation-global-sysctl kernel/sysctl.c
--- 25/kernel/sysctl.c~randomisation-global-sysctl 2005-02-02 15:22:12.966943488 -0800
+++ 25-akpm/kernel/sysctl.c 2005-02-02 15:22:12.972942576 -0800
@@ -121,6 +121,8 @@ extern int sysctl_hz_timer;
extern int acct_parm[];
#endif
+int randomize_va_space;
+
static int parse_table(int __user *, int, void __user *, size_t __user *, void __user *, size_t,
ctl_table *, void **);
static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
@@ -632,6 +634,15 @@ static ctl_table kern_table[] = {
.proc_handler = &proc_dointvec,
},
#endif
+ {
+ .ctl_name = KERN_RANDOMIZE,
+ .procname = "randomize_va_space",
+ .data = &randomize_va_space,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+
{ .ctl_name = 0 }
};
_