• Andrew Morton's avatar
    [PATCH] x86 vsyscall alignment fix · a50d447d
    Andrew Morton authored
    From: Andy Whitcroft <andyw@uk.ibm.com>
    
    The vsyscall implementation for ia32 provides two different vsyscall pages;
    one to use int80 and the other to use sysenter.  Each includes a common
    signal trailer.  The kernel requires the alignment of routines in this
    trailer be consistent in both copies.  However this is not enforced at
    compile time.  Failure to maintain this alignment typically leads to an
    obscure SIGSEGV in init during boot.  This critical alignment requirement
    is not well documented.
    
    Below is a patch to better document the alignment requirements and to
    enforce the requirement.
    a50d447d
vsyscall-int80.S 1.35 KB