x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks

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 <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20170815154011.GB1076@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index 6369d04fd5d62ee24c0a46bdb14dbdba163fc678..81db3e92dc767f76cc571dd96f510f828fd3215d 100644 (file)
--- 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 7465c3ea5dd50f2b991a9d8db47e91654d1717a1..9867eda737695b8200384690ccdbc9f51a53f8dc 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -666,8 +666,7 @@ 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;