| Message ID | 20240814085618.968833-4-samuel.holland@sifive.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | kasan: RISC-V support for KASAN_SW_TAGS using pointer masking | expand |
On Wed, Aug 14, 2024 at 10:56 AM Samuel Holland <samuel.holland@sifive.com> wrote: > > Allow architectures to override KASAN_TAG_KERNEL in asm/kasan.h. This > is needed on RISC-V, which supports 57-bit virtual addresses and 7-bit > pointer tags. For consistency, move the arm64 MTE definition of > KASAN_TAG_MIN to asm/kasan.h, since it is also architecture-dependent; > RISC-V's equivalent extension is expected to support 7-bit hardware > memory tags. > > Signed-off-by: Samuel Holland <samuel.holland@sifive.com> > --- > > arch/arm64/include/asm/kasan.h | 6 ++++-- > arch/arm64/include/asm/uaccess.h | 1 + > include/linux/kasan-tags.h | 13 ++++++++----- > 3 files changed, 13 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h > index e1b57c13f8a4..4ab419df8b93 100644 > --- a/arch/arm64/include/asm/kasan.h > +++ b/arch/arm64/include/asm/kasan.h > @@ -6,8 +6,10 @@ > > #include <linux/linkage.h> > #include <asm/memory.h> > -#include <asm/mte-kasan.h> > -#include <asm/pgtable-types.h> > + > +#ifdef CONFIG_KASAN_HW_TAGS > +#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ > +#endif > > #define arch_kasan_set_tag(addr, tag) __tag_set(addr, tag) > #define arch_kasan_reset_tag(addr) __tag_reset(addr) > diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h > index 28f665e0975a..56a09f412272 100644 > --- a/arch/arm64/include/asm/uaccess.h > +++ b/arch/arm64/include/asm/uaccess.h > @@ -22,6 +22,7 @@ > #include <asm/cpufeature.h> > #include <asm/mmu.h> > #include <asm/mte.h> > +#include <asm/mte-kasan.h> > #include <asm/ptrace.h> > #include <asm/memory.h> > #include <asm/extable.h> > diff --git a/include/linux/kasan-tags.h b/include/linux/kasan-tags.h > index 4f85f562512c..e07c896f95d3 100644 > --- a/include/linux/kasan-tags.h > +++ b/include/linux/kasan-tags.h > @@ -2,13 +2,16 @@ > #ifndef _LINUX_KASAN_TAGS_H > #define _LINUX_KASAN_TAGS_H > > +#include <asm/kasan.h> > + > +#ifndef KASAN_TAG_KERNEL > #define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ > -#define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ > -#define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ > +#endif > + > +#define KASAN_TAG_INVALID (KASAN_TAG_KERNEL - 1) /* inaccessible memory tag */ > +#define KASAN_TAG_MAX (KASAN_TAG_KERNEL - 2) /* maximum value for random tags */ > > -#ifdef CONFIG_KASAN_HW_TAGS > -#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ > -#else > +#ifndef KASAN_TAG_MIN > #define KASAN_TAG_MIN 0x00 /* minimum value for random tags */ > #endif > > -- > 2.45.1 > Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h index e1b57c13f8a4..4ab419df8b93 100644 --- a/arch/arm64/include/asm/kasan.h +++ b/arch/arm64/include/asm/kasan.h @@ -6,8 +6,10 @@ #include <linux/linkage.h> #include <asm/memory.h> -#include <asm/mte-kasan.h> -#include <asm/pgtable-types.h> + +#ifdef CONFIG_KASAN_HW_TAGS +#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ +#endif #define arch_kasan_set_tag(addr, tag) __tag_set(addr, tag) #define arch_kasan_reset_tag(addr) __tag_reset(addr) diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 28f665e0975a..56a09f412272 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -22,6 +22,7 @@ #include <asm/cpufeature.h> #include <asm/mmu.h> #include <asm/mte.h> +#include <asm/mte-kasan.h> #include <asm/ptrace.h> #include <asm/memory.h> #include <asm/extable.h> diff --git a/include/linux/kasan-tags.h b/include/linux/kasan-tags.h index 4f85f562512c..e07c896f95d3 100644 --- a/include/linux/kasan-tags.h +++ b/include/linux/kasan-tags.h @@ -2,13 +2,16 @@ #ifndef _LINUX_KASAN_TAGS_H #define _LINUX_KASAN_TAGS_H +#include <asm/kasan.h> + +#ifndef KASAN_TAG_KERNEL #define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ -#define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ -#define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ +#endif + +#define KASAN_TAG_INVALID (KASAN_TAG_KERNEL - 1) /* inaccessible memory tag */ +#define KASAN_TAG_MAX (KASAN_TAG_KERNEL - 2) /* maximum value for random tags */ -#ifdef CONFIG_KASAN_HW_TAGS -#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ -#else +#ifndef KASAN_TAG_MIN #define KASAN_TAG_MIN 0x00 /* minimum value for random tags */ #endif
Allow architectures to override KASAN_TAG_KERNEL in asm/kasan.h. This is needed on RISC-V, which supports 57-bit virtual addresses and 7-bit pointer tags. For consistency, move the arm64 MTE definition of KASAN_TAG_MIN to asm/kasan.h, since it is also architecture-dependent; RISC-V's equivalent extension is expected to support 7-bit hardware memory tags. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> --- arch/arm64/include/asm/kasan.h | 6 ++++-- arch/arm64/include/asm/uaccess.h | 1 + include/linux/kasan-tags.h | 13 ++++++++----- 3 files changed, 13 insertions(+), 7 deletions(-)