diff options
| -rw-r--r-- | fs/binfmt_elf.c | 13 | ||||
| -rw-r--r-- | include/asm-x86_64/elf.h | 4 |
2 files changed, 13 insertions, 4 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 4349113881fbf..537893a16014c 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -500,17 +500,22 @@ out: #define INTERPRETER_AOUT 1 #define INTERPRETER_ELF 2 +#ifndef STACK_RND_MASK +#define STACK_RND_MASK 0x7ff /* with 4K pages 8MB of VA */ +#endif static unsigned long randomize_stack_top(unsigned long stack_top) { unsigned int random_variable = 0; - if (current->flags & PF_RANDOMIZE) - random_variable = get_random_int() % (8*1024*1024); + if (current->flags & PF_RANDOMIZE) { + random_variable = get_random_int() & STACK_RND_MASK; + random_variable <<= PAGE_SHIFT; + } #ifdef CONFIG_STACK_GROWSUP - return PAGE_ALIGN(stack_top + random_variable); + return PAGE_ALIGN(stack_top) + random_variable; #else - return PAGE_ALIGN(stack_top - random_variable); + return PAGE_ALIGN(stack_top) - random_variable; #endif } diff --git a/include/asm-x86_64/elf.h b/include/asm-x86_64/elf.h index 43862cd6a569d..c98633af07d26 100644 --- a/include/asm-x86_64/elf.h +++ b/include/asm-x86_64/elf.h @@ -8,6 +8,7 @@ #include <asm/ptrace.h> #include <asm/user.h> #include <asm/processor.h> +#include <asm/compat.h> /* x86-64 relocation types */ #define R_X86_64_NONE 0 /* No reloc */ @@ -157,6 +158,9 @@ extern int dump_task_fpu (struct task_struct *, elf_fpregset_t *); #define ELF_CORE_COPY_TASK_REGS(tsk, elf_regs) dump_task_regs(tsk, elf_regs) #define ELF_CORE_COPY_FPREGS(tsk, elf_fpregs) dump_task_fpu(tsk, elf_fpregs) +/* 1GB for 64bit, 8MB for 32bit */ +#define STACK_RND_MASK (is_compat_task() ? 0x7ff : 0x3fffff) + #endif #endif |