et>, "ebied...@xmission.com" <ebied...@xmission.com>, "aneesh.ku...@linux.ibm.com" <aneesh.ku...@linux.ibm.com>, "Edgecombe, Rick P" <rick.p.edgeco...@intel.com>, "bris...@redhat.com" <bris...@redhat.com>, "wangkefeng.w...@huawei.com" <wangkefeng.w...@huawei.com>, "ker...@esmil.dk" <ker...@esmil.dk>, "jniet...@gmail.com" <jniet...@gmail.com>, "paul.walms...@sifive.com" <paul.walms...@sifive.com>, "a...@kernel.org" <a...@kernel.org>, "w...@kernel.org" <w...@kernel.org>, "masahi...@kernel.org" <masahi...@kernel.org>, "Sakkinen, Jarkko" <jar...@profian.com>, "samitolva...@google.com" <samitolva...@google.com>, "naveen.n....@linux.ibm.com" <naveen.n....@linux.ibm.com>, "el...@google.com" <el...@google.com>, "keesc...@chromium.org" <keesc...@chromium.org>, "rost...@goodmis.org" <rost...@goodmis.org>, "nat...@kernel.org" <nat...@kernel.org>, "rmk+ker...@armlinux.org.uk" <rmk+ker...@armlinux.org.uk>, "broo...@kernel.org" <broo...@kernel.org>, "b...@alien8.de" <b...@alien8.de>, "egore...@linux.ibm .com" <egore...@linux.ibm.com>, "tsbog...@alpha.franken.de" <tsbog...@alpha.franken.de>, "linux-par...@vger.kernel.org" <linux-par...@vger.kernel.org>, "nathan...@profian.com" <nathan...@profian.com>, "dmitry.torok...@gmail.com" <dmitry.torok...@gmail.com>, "da...@davemloft.net" <da...@davemloft.net>, "kirill.shute...@linux.intel.com" <kirill.shute...@linux.intel.com>, "husc...@linux.ibm.com" <husc...@linux.ibm.com>, "pet...@infradead.org" <pet...@infradead.org>, "h...@zytor.com" <h...@zytor.com>, "sparcli...@vger.kernel.org" <sparcli...@vger.kernel.org>, "yangtie...@loongson.cn" <yangtie...@loongson.cn>, "mbe...@suse.cz" <mbe...@suse.cz>, "chenzhong...@huawei.com" <chenzhong...@huawei.com>, "a...@kernel.org" <a...@kernel.org>, "x...@kernel.org" <x...@kernel.org>, "li...@armlinux.org.uk" <li...@armlinux.org.uk>, "linux-ri...@lists.infradead.org" <linux-ri...@lists.infradead.org>, "mi...@redhat.com" <mi...@redhat.com>, "atom...@redhat.com" <atom...@redhat.com>, "a...@eecs.berkeley.edu" <a o...@eecs.berkeley.edu>, "h...@linux.ibm.com" <hca@linux .ibm.com>, "liaocha...@huawei.com" <liaocha...@huawei.com>, "ati...@atishpatra.org" <ati...@atishpatra.org>, "jpoim...@kernel.org" <jpoim...@kernel.org>, "tmri...@linux.ibm.com" <tmri...@linux.ibm.com>, "linux-m...@vger.kernel.org" <linux-m...@vger.kernel.org>, "changbin...@intel.com" <changbin...@intel.com>, "pal...@dabbelt.com" <pal...@dabbelt.com>, "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>, "linux-modu...@vger.kernel.org" <linux-modu...@vger.kernel.org> Errors-To: linuxppc-dev-bounces+archive=mail-archive....@lists.ozlabs.org Sender: "Linuxppc-dev" <linuxppc-dev-bounces+archive=mail-archive....@lists.ozlabs.org>
On Wed, Jun 15, 2022 at 08:37:07AM +0200, h...@lst.de wrote: > On Tue, Jun 14, 2022 at 03:32:38PM +0300, jar...@kernel.org wrote: > > > Like say for a next step we moved prog pack out of bpf into core code, > > > gave it it's own copy of module_alloc(), and then made kprobes use it. > > > Then we would have something with improved W^X guard rails, and kprobes > > > would not depend on modules anymore. I think maybe it's a step in the > > > right direction, even if it's not perfect. > > > > So you're saying that I should (as a first step) basically clone > > module_alloc() implementation for kprobes, and future for BPF > > use, in order to get a clean starting point? > > I don't think cloning the code helps anyone. The fact that except > for the eBPF mess everyone uses module_alloc and the related > infrastructure is a feature and not a bug. The interface should > become better than what we have right now, but there is few enough > users that this can be done in one go. > > So assuming we really care deeply enough about fancy tracing without > modules (and I'm not sure we do, even if you don't use modules it > doesn't hurt to just build the modules code, I do that all the time > for my test machines), the general approach in your series is the > right one. OK, thanks for the elaboration! However I bake it, I doubt that next version is going to be the final version, given all the angles. Therefore, I mostly Christophe's suggestions on compilation flags, and also split this into per-arch patches. That should be at least to the right direction. BR, Jarkko
