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

[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
......@@ -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))
......
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