r...@esmil.dk>, Jordan Niethe <jniet...@gmail.com>, Atish Patra <ati...@atishpatra.org>, Alexei Starovoitov <a...@kernel.org>, Will Deacon <w...@kernel.org>, Masahiro Yamada <masahi...@kernel.org>, Jarkko Sakkinen <jar...@profian.com>, Sami Tolvanen <samitolva...@google.com>, "Naveen N. Rao" <naveen.n....@linux.ibm.com>, Marco Elver <el...@google.com>, Kees Cook <keesc...@chromium.org>, Steven Rostedt <rost...@goodmis.org>, Nathan Chancellor <nat...@kernel.org>, Mark Brown <broo...@kernel.org>, Borislav Petkov <b...@alien8.de>, Alexander Egorenkov <egore...@linux.ibm.com>, Thomas Bogendoerfer <tsbog...@alpha.franken.de>, "linux-par...@vger.kernel.org" <linux-par...@vger.kernel.org>, Nathaniel McCallum <nathan...@profian.com>, Dmitry Torokhov <dmitry.torok...@gmail.com>, "David S. Miller" <da...@davemloft.net>, "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>, Tobias Huschle <husc...@linux.ibm.com>, "Peter Zijlstra \(Intel\)" <pet...@infradead.org>, "H. Peter Anvin" <h...@zytor.com> , "sparcli...@vger.kernel.org" <sparcli...@vger.kernel.org>, Tiezhu Yang <yangtie...@loongson.cn>, Miroslav Benes <mbe...@suse.cz>, Chen Zhongjin <chenzhong...@huawei.com>, Ard Biesheuvel <a...@kernel.org>, "x...@kernel.org" <x...@kernel.org>, "Russell King \(Oracle\)" <li...@armlinux.org.uk>, "linux-ri...@lists.infradead.org" <linux-ri...@lists.infradead.org>, Ingo Molnar <mi...@redhat.com>, Aaron Tomlin <atom...@redhat.com>, Albert Ou <a...@eecs.berkeley.edu>, Heiko Carstens <h...@linux.ibm.com>, Liao Chang <liaocha...@huawei.com>, Paul Walmsley <paul.walms...@sifive.com>, Josh Poimboeuf <jpoim...@kernel.org>, Thomas Richter <tmri...@linux.ibm.com>, "linux-m...@vger.kernel.org" <linux-m...@vger.kernel.org>, Changbin Du <changbin...@intel.com>, Palmer Dabbelt <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 Tue, Jun 14, 2022 at 12:36:25PM +0000, Christophe Leroy wrote: > > > Le 14/06/2022 à 14:26, Jarkko Sakkinen a écrit : > > On Thu, Jun 09, 2022 at 06:44:45AM -0700, Luis Chamberlain wrote: > >> On Thu, Jun 09, 2022 at 08:47:38AM +0100, Russell King (Oracle) wrote: > >>> On Wed, Jun 08, 2022 at 02:59:27AM +0300, Jarkko Sakkinen wrote: > >>>> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile > >>>> index 553866751e1a..d2bb954cd54f 100644 > >>>> --- a/arch/arm/kernel/Makefile > >>>> +++ b/arch/arm/kernel/Makefile > >>>> @@ -44,6 +44,11 @@ obj-$(CONFIG_CPU_IDLE) += cpuidle.o > >>>> obj-$(CONFIG_ISA_DMA_API) += dma.o > >>>> obj-$(CONFIG_FIQ) += fiq.o fiqasm.o > >>>> obj-$(CONFIG_MODULES) += armksyms.o module.o > >>>> +ifeq ($(CONFIG_MODULES),y) > >>>> +obj-y += module_alloc.o > >>>> +else > >>>> +obj-$(CONFIG_KPROBES) += module_alloc.o > >>>> +endif > >>> > >>> Doesn't: > >>> > >>> obj-$(CONFIG_MODULES) += module_alloc.o > >>> obj-$(CONFIG_KPROBES) += module_alloc.o > >> > >> That just begs for a new kconfig symbol for the object, and for > >> the object then to be built with it. > >> > >> The archs which override the default can use ARCH_HAS_VM_ALLOC_EXEC. > >> Please note that the respective free is important as well and its > >> not clear if we need an another define for the free. Someone has > >> to do that work. We want to ensure to noexec the code on free and > >> this can vary on each arch. > > > > Let me check if I understand this (not 100% sure). > > > > So if arch define ARCH_HAS_VMALLOC_EXEC, then this would set > > config flag CONFIG_VMALLOC_EXEC, which would be used to include > > the compilation unit? > > > > I guess you have two possible approaches. > > Either architectures select CONFIG_ARCH_HAS_VMALLOC_EXEC at all time and > then you add a CONFIG_VMALLOC_EXEC which depends on > CONFIG_ARCH_HAS_VMALLOC_EXEC and CONFIG_MODULES or CONFIG_KPROBES, > > Or architectures select CONFIG_ARCH_HAS_VMALLOC_EXEC only when either > CONFIG_MODULES or CONFIG_KPROBES is selected, in that case there is no > need for a CONFIG_VMALLOC_EXEC. Right, got it now. Thanks for the elaboration. > Christophe BR, Jarkko
