Commit 01578e36 authored Aug 15, 2017 by Oleg Nesterov Committed by Thomas Gleixner Aug 16, 2017

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 <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: stable@vger.kernel.org
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

parent 47ac5484

arch/x86/mm/mmap.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}

fs/binfmt_elf.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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;

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