From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Date: Tue, 13 Jul 2004 03:58:06 +0000 Subject: Re: serious performance regression due to NX patch Message-Id: List-Id: References: <200407100528.i6A5SF8h020094@napali.hpl.hp.com> <20040711123803.GD21264@devserv.devel.redhat.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Linus Torvalds Cc: Jakub Jelinek , davidm@hpl.hp.com, suresh.b.siddha@intel.com, jun.nakajima@intel.com, Andrew Morton , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org On Mon, 12 Jul 2004, Linus Torvalds wrote: > > so ... this should be #ifndef ia64? > > No. Make it a CONFIG_DEFAULT_NOEXEC and make the relevant architectures do > a > > define_bool DEFAULT_NOEXEC y > > in their Kconfig files. > > In general, we should _never_ use an architecture-define. They just > always end up becoming more and more hairy, and less and less obvious > what they are all about. > > So instead, make a readable and explicit config define, and let each > architecture just set it (or not) as they wish. ok - patch below. ia64 can now define it - the default is that legacy binaries have executability expectations. Ingo --- linux/fs/binfmt_elf.c.orig +++ linux/fs/binfmt_elf.c @@ -627,8 +627,14 @@ static int load_elf_binary(struct linux_ executable_stack = EXSTACK_DISABLE_X; break; } +#ifndef CONFIG_DEFAULT_NOEXEC + /* + * Legacy binaries (unless the arch defaults to noexec) have an + * expectation of executability - turn it on: + */ if (i = elf_ex.e_phnum) def_flags |= VM_EXEC | VM_MAYEXEC; +#endif /* Some simple consistency checks for the interpreter */ if (elf_interpreter) {