Commit c16b63e0 authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen

[PATCH] i386/x86-64: Don't randomize stack top when no randomization personality is set

Based on patch from Frank van Maarseveen <frankvm@frankvm.com>, but
extended.
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent d5d9ca6d
...@@ -37,6 +37,7 @@ ...@@ -37,6 +37,7 @@
#include <linux/kallsyms.h> #include <linux/kallsyms.h>
#include <linux/ptrace.h> #include <linux/ptrace.h>
#include <linux/random.h> #include <linux/random.h>
#include <linux/personality.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <asm/pgtable.h> #include <asm/pgtable.h>
...@@ -905,7 +906,7 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *u_info) ...@@ -905,7 +906,7 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
unsigned long arch_align_stack(unsigned long sp) unsigned long arch_align_stack(unsigned long sp)
{ {
if (randomize_va_space) if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
sp -= get_random_int() % 8192; sp -= get_random_int() % 8192;
return sp & ~0xf; return sp & ~0xf;
} }
...@@ -845,7 +845,7 @@ int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) ...@@ -845,7 +845,7 @@ int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
unsigned long arch_align_stack(unsigned long sp) unsigned long arch_align_stack(unsigned long sp)
{ {
if (randomize_va_space) if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
sp -= get_random_int() % 8192; sp -= get_random_int() % 8192;
return sp & ~0xf; return sp & ~0xf;
} }
...@@ -515,7 +515,8 @@ static unsigned long randomize_stack_top(unsigned long stack_top) ...@@ -515,7 +515,8 @@ static unsigned long randomize_stack_top(unsigned long stack_top)
{ {
unsigned int random_variable = 0; unsigned int random_variable = 0;
if (current->flags & PF_RANDOMIZE) { if ((current->flags & PF_RANDOMIZE) &&
!(current->personality & ADDR_NO_RANDOMIZE)) {
random_variable = get_random_int() & STACK_RND_MASK; random_variable = get_random_int() & STACK_RND_MASK;
random_variable <<= PAGE_SHIFT; random_variable <<= PAGE_SHIFT;
} }
......
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