diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c index 7f0fcf219a26e4cec52d2e5bbd729601c356d261..f38085ff3c3d64606ebbffee6c771185a0e74809 100644 --- a/arch/i386/mm/fault.c +++ b/arch/i386/mm/fault.c @@ -380,12 +380,12 @@ fastcall void __kprobes do_page_fault(struct pt_regs *regs, goto bad_area; if (error_code & 4) { /* - * accessing the stack below %esp is always a bug. - * The "+ 32" is there due to some instructions (like - * pusha) doing post-decrement on the stack and that - * doesn't show up until later.. + * Accessing the stack below %esp is always a bug. + * The large cushion allows instructions like enter + * and pusha to work. ("enter $65535,$31" pushes + * 32 pointers and then decrements %esp by 65535.) */ - if (address + 32 < regs->esp) + if (address + 65536 + 32 * sizeof(unsigned long) < regs->esp) goto bad_area; } if (expand_stack(vma, address))