On Tue, Oct 18, 2022 at 02:33:53PM +0300, Kirill A. Shutemov wrote: > IOMMU and SVM-capable devices know nothing about LAM and only expect > canonical addresses. Attempt to pass down tagged pointer will lead to > address translation failure. > > By default do not allow to enable both LAM and use SVM in the same > process. > > The new ARCH_FORCE_TAGGED_SVM arch_prctl() overrides the limitation. > By using the arch_prctl() userspace takes responsibility to never pass > tagged address to the device. Reviewed-by: Ashok Raj <ashok.raj@xxxxxxxxx> > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > --- > arch/x86/include/asm/mmu.h | 6 ++++-- > arch/x86/include/asm/mmu_context.h | 2 ++ > arch/x86/include/uapi/asm/prctl.h | 1 + > arch/x86/kernel/process_64.c | 13 +++++++++++++ > drivers/iommu/iommu-sva-lib.c | 12 ++++++++++++ > include/linux/mmu_context.h | 4 ++++ > 6 files changed, 36 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h > index 2fdb390040b5..cce9b32b0d6d 100644 > --- a/arch/x86/include/asm/mmu.h > +++ b/arch/x86/include/asm/mmu.h > @@ -9,9 +9,11 @@ > #include <linux/bits.h> > > /* Uprobes on this MM assume 32-bit code */ > -#define MM_CONTEXT_UPROBE_IA32 BIT(0) > +#define MM_CONTEXT_UPROBE_IA32 BIT(0) > /* vsyscall page is accessible on this MM */ > -#define MM_CONTEXT_HAS_VSYSCALL BIT(1) > +#define MM_CONTEXT_HAS_VSYSCALL BIT(1) Nit: Looks like the two above format changes got in here :-) Cheers, Ashok
