From 01578e36163cdd0e4fd61d9976de15f13364e26d Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 15 Aug 2017 17:40:11 +0200 Subject: [PATCH] x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks 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 Signed-off-by: Thomas Gleixner Reviewed-by: Dmitry Safonov Cc: stable@vger.kernel.org Cc: Andy Lutomirski Cc: Andrew Morton Cc: Borislav Petkov Cc: Linus Torvalds Cc: "Kirill A. Shutemov" Link: http://lkml.kernel.org/r/20170815154011.GB1076@redhat.com --- arch/x86/mm/mmap.c | 3 +-- fs/binfmt_elf.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index c94df122815a..a88cfbfbd078 100644 --- 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; } diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 879ff9c7ffd0..6466153f2bf0 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -664,8 +664,7 @@ static unsigned long randomize_stack_top(unsigned long 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; -- 2.20.1