From: Ingo Molnar <mingo@elte.hu>
i've attached the latest version of the NX patch. It applies cleanly to
2.6.7 and works fine. See below the delta relative to the last iteration
you have in your tree. There are two changes:
- dont print 'you have no NX!' on non-NX CPUs - we aint no PR company
for CPU makers.
- make the heap non-executable on PT_GNU_STACK binaries.
- make all data mmap()s (and the heap) executable on !PT_GNU_STACK
(legacy) binaries. This has no effect on non-NX CPUs, but should be
much more compatible on NX CPUs. The only effect it has it has on
non-NX CPUs is the extra 'x' bit displayed in /proc/PID/maps.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/binfmt_elf.c | 5 +++++
25-akpm/fs/exec.c | 1 +
25-akpm/include/asm-i386/page.h | 2 +-
3 files changed, 7 insertions(+), 1 deletion(-)
diff -puN fs/binfmt_elf.c~nx-update fs/binfmt_elf.c
--- 25/fs/binfmt_elf.c~nx-update 2004-06-19 13:39:19.611142872 -0700
+++ 25-akpm/fs/binfmt_elf.c 2004-06-19 13:39:19.618141808 -0700
@@ -490,6 +490,7 @@ static int load_elf_binary(struct linux_
char passed_fileno[6];
struct files_struct *files;
int executable_stack = EXSTACK_DEFAULT;
+ unsigned long def_flags = 0;
/* Get the exec-header */
elf_ex = *((struct elfhdr *) bprm->buf);
@@ -621,7 +622,10 @@ static int load_elf_binary(struct linux_
executable_stack = EXSTACK_ENABLE_X;
else
executable_stack = EXSTACK_DISABLE_X;
+ break;
}
+ if (i == elf_ex.e_phnum)
+ def_flags |= VM_EXEC | VM_MAYEXEC;
/* Some simple consistency checks for the interpreter */
if (elf_interpreter) {
@@ -689,6 +693,7 @@ static int load_elf_binary(struct linux_
current->mm->end_code = 0;
current->mm->mmap = NULL;
current->flags &= ~PF_FORKNOEXEC;
+ current->mm->def_flags = def_flags;
/* Do this immediately, since STACK_TOP as used in setup_arg_pages
may depend on the personality. */
diff -puN fs/exec.c~nx-update fs/exec.c
--- 25/fs/exec.c~nx-update 2004-06-19 13:39:19.612142720 -0700
+++ 25-akpm/fs/exec.c 2004-06-19 13:39:19.619141656 -0700
@@ -430,6 +430,7 @@ int setup_arg_pages(struct linux_binprm
mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
else
mpnt->vm_flags = VM_STACK_FLAGS;
+ mpnt->vm_flags |= mm->def_flags;
mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7];
insert_vm_struct(mm, mpnt);
mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
diff -puN include/asm-i386/page.h~nx-update include/asm-i386/page.h
--- 25/include/asm-i386/page.h~nx-update 2004-06-19 13:39:19.614142416 -0700
+++ 25-akpm/include/asm-i386/page.h 2004-06-19 13:39:19.620141504 -0700
@@ -138,7 +138,7 @@ static __inline__ int get_order(unsigned
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
-#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
+#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#endif /* __KERNEL__ */
_