From: Arjan van de Ven <arjan@infradead.org>
Even though there is a global flag to disable randomisation, it's useful to
have a per process flag too; the patch below introduces this per process flag
and automatically sets it for "new" binaries.
Eventually we will want to tie this to the legacy-va-space personality
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/fs/binfmt_elf.c | 2 ++
25-akpm/fs/exec.c | 1 +
25-akpm/include/linux/sched.h | 1 +
3 files changed, 4 insertions(+)
diff -puN fs/binfmt_elf.c~randomisation-add-pf_randomize fs/binfmt_elf.c
--- 25/fs/binfmt_elf.c~randomisation-add-pf_randomize 2005-02-22 18:16:05.000000000 -0800
+++ 25-akpm/fs/binfmt_elf.c 2005-02-22 18:16:05.000000000 -0800
@@ -760,6 +760,8 @@ static int load_elf_binary(struct linux_
if (elf_read_implies_exec(loc->elf_ex, executable_stack))
current->personality |= READ_IMPLIES_EXEC;
+ if (executable_stack == EXSTACK_DISABLE_X && randomize_va_space)
+ current->flags |= PF_RANDOMIZE;
arch_pick_mmap_layout(current->mm);
/* Do this so that we can load the interpreter, if need be. We will
diff -puN fs/exec.c~randomisation-add-pf_randomize fs/exec.c
--- 25/fs/exec.c~randomisation-add-pf_randomize 2005-02-22 18:16:05.000000000 -0800
+++ 25-akpm/fs/exec.c 2005-02-22 18:16:05.000000000 -0800
@@ -877,6 +877,7 @@ int flush_old_exec(struct linux_binprm *
tcomm[i] = '\0';
set_task_comm(current, tcomm);
+ current->flags &= ~PF_RANDOMIZE;
flush_thread();
if (bprm->e_uid != current->euid || bprm->e_gid != current->egid ||
diff -puN include/linux/sched.h~randomisation-add-pf_randomize include/linux/sched.h
--- 25/include/linux/sched.h~randomisation-add-pf_randomize 2005-02-22 18:16:05.000000000 -0800
+++ 25-akpm/include/linux/sched.h 2005-02-22 18:16:05.000000000 -0800
@@ -735,6 +735,7 @@ do { if (atomic_dec_and_test(&(tsk)->usa
#define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
#define PF_SYNCWRITE 0x00200000 /* I am doing a sync write */
#define PF_BORROWED_MM 0x00400000 /* I am a kthread doing use_mm */
+#define PF_RANDOMIZE 0x00800000 /* randomize virtual address space */
/*
* Only the _current_ task can read/write to tsk->flags, but other
_