Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 03fdc2c2 authored by Chuck Ebbert's avatar Chuck Ebbert Committed by Linus Torvalds
Browse files

[PATCH] x86_64: enlarge window for stack growth 



Allow stack growth so the 'enter' instruction works.  Also
fixes problem in compat_sys_kexec_load() which could allocate
more than 128 bytes using compat_alloc_user_space().

Signed-off-by: default avatarChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6bfa9bb5

arch/x86_64/mm/fault.c

+4 −2
Original line number Diff line number Diff line
@@ -410,8 +410,10 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, 
	if (!(vma->vm_flags & VM_GROWSDOWN))

		goto bad_area;

	if (error_code & 4) {

		// XXX: align red zone size with ABI 

		if (address + 128 < regs->rsp)

		/* Allow userspace just enough access below the stack pointer

		 * to let the 'enter' instruction work.

		 */

		if (address + 65536 + 32 * sizeof(unsigned long) < regs->rsp)

			goto bad_area;

	}

	if (expand_stack(vma, address))