From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Date: Sun, 11 Jul 2004 09:52:59 +0000 Subject: Re: serious performance regression due to NX patch Message-Id: List-Id: References: <200407100528.i6A5SF8h020094@napali.hpl.hp.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: davidm@hpl.hp.com Cc: suresh.b.siddha@intel.com, jun.nakajima@intel.com, Andrew Morton , Linus Torvalds , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org On Sun, 11 Jul 2004, Ingo Molnar wrote: > > ok, agreed. I'll check that it still does the right thing on x86. > > it doesnt seem to do the right thing for !PT_GNU_STACK applications on > x86: how about the patch below? This way we recognize the fact that x86 didnt have any executability check previously at the point where we discover that it's a 'legacy' binary. Ingo --- linux/fs/binfmt_elf.c.orig3 +++ linux/fs/binfmt_elf.c @@ -627,8 +627,14 @@ static int load_elf_binary(struct linux_ executable_stack = EXSTACK_DISABLE_X; break; } +#ifdef __i386_ + /* + * Legacy x86 binaries have an expectation of executability for + * virtually all their address-space - turn executability on: + */ if (i = elf_ex.e_phnum) def_flags |= VM_EXEC | VM_MAYEXEC; +#endif /* Some simple consistency checks for the interpreter */ if (elf_interpreter) {