4.12-stable review patch. If anyone has any objections, please let me know.
------------------ From: Oleg Nesterov <[email protected]> commit 01578e36163cdd0e4fd61d9976de15f13364e26d upstream. The ADDR_NO_RANDOMIZE checks in stack_maxrandom_size() and randomize_stack_top() are not required. PF_RANDOMIZE is set by load_elf_binary() only if ADDR_NO_RANDOMIZE is not set, no need to re-check after that. Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Dmitry Safonov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/mm/mmap.c | 3 +-- fs/binfmt_elf.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -50,8 +50,7 @@ unsigned long tasksize_64bit(void) static unsigned long stack_maxrandom_size(unsigned long task_size) { unsigned long max = 0; - if ((current->flags & PF_RANDOMIZE) && - !(current->personality & ADDR_NO_RANDOMIZE)) { + if (current->flags & PF_RANDOMIZE) { max = (-1UL) & __STACK_RND_MASK(task_size == tasksize_32bit()); max <<= PAGE_SHIFT; } --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -666,8 +666,7 @@ static unsigned long randomize_stack_top { unsigned long random_variable = 0; - if ((current->flags & PF_RANDOMIZE) && - !(current->personality & ADDR_NO_RANDOMIZE)) { + if (current->flags & PF_RANDOMIZE) { random_variable = get_random_long(); random_variable &= STACK_RND_MASK; random_variable <<= PAGE_SHIFT;
