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charset="utf-8" Content-Transfer-Encoding: quoted-printable Rework the constant to make the resulting sysreg value (and computation) obvious at the usage site and clearly indicate that the GCR_EL1.Exclude is specifically set by a KASAN policy. As a result, is now KASAN-agnostic and writers of GCR_EL1 explicitly depend on KASAN headers, as they should. Signed-off-by: Pierre-Cl=C3=A9ment Tosi --- arch/arm64/include/asm/mte-kasan.h | 16 ++++++++++++++++ arch/arm64/include/asm/sysreg.h | 16 ---------------- arch/arm64/kernel/entry.S | 3 ++- arch/arm64/kernel/mte.c | 4 +++- 4 files changed, 21 insertions(+), 18 deletions(-) diff --git a/arch/arm64/include/asm/mte-kasan.h b/arch/arm64/include/asm/mt= e-kasan.h index 9d00e9460b0f..6f63c788470a 100644 --- a/arch/arm64/include/asm/mte-kasan.h +++ b/arch/arm64/include/asm/mte-kasan.h @@ -5,10 +5,26 @@ #ifndef __ASM_MTE_KASAN_H #define __ASM_MTE_KASAN_H =20 +#include +#include +#include + #include #include #include =20 +/* + * KASAN always uses a whole byte for its tags. With CONFIG_KASAN_HW_TAGS = it + * only uses tags in the range 0xF0-0xFF, which we map to MTE tags 0x0-0xF= . + */ +#ifdef CONFIG_KASAN_HW_TAGS +#define __MTE_TAG_MIN (KASAN_TAG_MIN & 0xf) +#define __MTE_TAG_MAX (KASAN_TAG_MAX & 0xf) +#define KASAN_GCR_INCL GENMASK(__MTE_TAG_MAX, __MTE_TAG_MIN) +#else +#define KASAN_GCR_INCL UL(0) +#endif + #ifndef __ASSEMBLER__ =20 #include diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysre= g.h index 51c6a54d7146..7d82c769ae69 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -11,7 +11,6 @@ =20 #include #include -#include #include =20 #include @@ -921,21 +920,6 @@ #define SYS_GCR_EL1_RRND (BIT(16)) #define SYS_GCR_EL1_EXCL_MASK 0xffffUL =20 -#ifdef CONFIG_KASAN_HW_TAGS -/* - * KASAN always uses a whole byte for its tags. With CONFIG_KASAN_HW_TAGS = it - * only uses tags in the range 0xF0-0xFF, which we map to MTE tags 0x0-0xF= . - */ -#define __MTE_TAG_MIN (KASAN_TAG_MIN & 0xf) -#define __MTE_TAG_MAX (KASAN_TAG_MAX & 0xf) -#define __MTE_TAG_INCL GENMASK(__MTE_TAG_MAX, __MTE_TAG_MIN) -#define KERNEL_GCR_EL1_EXCL (SYS_GCR_EL1_EXCL_MASK & ~__MTE_TAG_INCL) -#else -#define KERNEL_GCR_EL1_EXCL SYS_GCR_EL1_EXCL_MASK -#endif - -#define KERNEL_GCR_EL1 (SYS_GCR_EL1_RRND | KERNEL_GCR_EL1_EXCL) - /* RGSR_EL1 Definitions */ #define SYS_RGSR_EL1_TAG_MASK 0xfUL #define SYS_RGSR_EL1_SEED_SHIFT 8 diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 8d17f61d1b5b..d1d9a7a049a7 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -176,7 +177,7 @@ alternative_else_nop_endif alternative_cb ARM64_ALWAYS_SYSTEM, kasan_hw_tags_enable b 1f alternative_cb_end - mov \tmp, KERNEL_GCR_EL1 + mov \tmp, #(SYS_GCR_EL1_RRND | (SYS_GCR_EL1_EXCL_MASK & ~KASAN_GCR_INCL)) msr_s SYS_GCR_EL1, \tmp 1: #endif diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 0d998289edcb..725f48faec3e 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include =20 @@ -320,7 +321,8 @@ void mte_cpu_setup(void) MAIR_ATTRIDX(MAIR_ATTR_NORMAL_TAGGED, MT_NORMAL_TAGGED)); =20 - write_sysreg_s(KERNEL_GCR_EL1, SYS_GCR_EL1); + write_sysreg_s(SYS_GCR_EL1_RRND | (SYS_GCR_EL1_EXCL_MASK & ~KASAN_GCR_INC= L), + SYS_GCR_EL1); =20 /* * If GCR_EL1.RRND=3D1 is implemented the same way as RRND=3D0, then --=20 2.56.0.455.g6c5a503b38-goog