Messages in this thread Patch in this message | | | Date | Thu, 22 Jun 2006 20:33:04 -0400 | From | Chuck Ebbert <> | Subject | [patch] x86_64: enlarge window for stack growth |
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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: Chuck Ebbert <76306.1226@compuserve.com>
--- 2.6.17-rc6-64.orig/arch/x86_64/mm/fault.c +++ 2.6.17-rc6-64/arch/x86_64/mm/fault.c @@ -410,8 +410,10 @@ asmlinkage void __kprobes do_page_fault( 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)) -- Chuck "You can't read a newspaper if you can't read." --George W. Bush - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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