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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko From: Maciej Wieczor-Retman Cc: m.wieczorretman@pm.me, Maciej Wieczor-Retman , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v12 04/15] x86/kasan: Add arch specific kasan functions Message-ID: In-Reply-To: References: Feedback-ID: 164464600:user:proton X-Pm-Message-ID: f12ade9a7d415496909ab469ba49499df63371a3 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Stat-Signature: adm9o8149kg6cmhc4scatg1xcthzpwuy X-Rspamd-Queue-Id: 701C2140016 X-Rspam-User: X-Rspamd-Server: rspam03 X-HE-Tag: 1774881219-632403 X-HE-Meta: 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Maciej Wieczor-Retman KASAN's software tag-based mode needs multiple macros/functions to handle tag and pointer interactions - to set, retrieve and reset tags from the top bits of a pointer. Mimic functions currently used by arm64 but change the tag's position to bits [60:57] in the pointer. Signed-off-by: Maciej Wieczor-Retman Reviewed-by: Andrey Ryabinin --- Changelog v9: - Rename KASAN_TAG_BYTE_MASK to KASAN_TAG_BITS_MASK. - Add Andrey Ryabinin's Reviewed-by tag. Changelog v7: - Add KASAN_TAG_BYTE_MASK to avoid circular includes and avoid removing KASAN_TAG_MASK from mmzone.h. - Remove Andrey's Acked-by tag. Changelog v6: - Remove empty line after ifdef CONFIG_KASAN_SW_TAGS - Add ifdef 64 bit to avoid problems in vdso32. - Add Andrey's Acked-by tag. Changelog v4: - Rewrite __tag_set() without pointless casts and make it more readable. Changelog v3: - Reorder functions so that __tag_*() etc are above the arch_kasan_*() ones. - Remove CONFIG_KASAN condition from __tag_set() arch/x86/include/asm/kasan.h | 42 ++++++++++++++++++++++++++++++++++-- include/linux/kasan-tags.h | 2 ++ include/linux/mmzone.h | 2 +- 3 files changed, 43 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h index d7e33c7f096b..c868ae734f68 100644 --- a/arch/x86/include/asm/kasan.h +++ b/arch/x86/include/asm/kasan.h @@ -3,6 +3,8 @@ #define _ASM_X86_KASAN_H =20 #include +#include +#include #define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL) #define KASAN_SHADOW_SCALE_SHIFT 3 =20 @@ -24,8 +26,43 @@ =09=09=09=09=09=09 KASAN_SHADOW_SCALE_SHIFT))) =20 #ifndef __ASSEMBLER__ +#include +#include +#include + +#ifdef CONFIG_KASAN_SW_TAGS +#define __tag_shifted(tag)=09=09FIELD_PREP(GENMASK_ULL(60, 57), tag) +#define __tag_reset(addr)=09=09(sign_extend64((u64)(addr), 56)) +#define __tag_get(addr)=09=09=09((u8)FIELD_GET(GENMASK_ULL(60, 57), (u64)a= ddr)) +#else +#define __tag_shifted(tag)=09=090UL +#define __tag_reset(addr)=09=09(addr) +#define __tag_get(addr)=09=09=090 +#endif /* CONFIG_KASAN_SW_TAGS */ + +#ifdef CONFIG_64BIT +static inline void *__tag_set(const void *__addr, u8 tag) +{ +=09u64 addr =3D (u64)__addr; + +=09addr &=3D ~__tag_shifted(KASAN_TAG_BITS_MASK); +=09addr |=3D __tag_shifted(tag & KASAN_TAG_BITS_MASK); + +=09return (void *)addr; +} +#else +static inline void *__tag_set(void *__addr, u8 tag) +{ +=09return __addr; +} +#endif + +#define arch_kasan_set_tag(addr, tag)=09__tag_set(addr, tag) +#define arch_kasan_reset_tag(addr)=09__tag_reset(addr) +#define arch_kasan_get_tag(addr)=09__tag_get(addr) =20 #ifdef CONFIG_KASAN + void __init kasan_early_init(void); void __init kasan_init(void); void __init kasan_populate_shadow_for_vaddr(void *va, size_t size, int nid= ); @@ -34,8 +71,9 @@ static inline void kasan_early_init(void) { } static inline void kasan_init(void) { } static inline void kasan_populate_shadow_for_vaddr(void *va, size_t size, =09=09=09=09=09=09 int nid) { } -#endif =20 -#endif +#endif /* CONFIG_KASAN */ + +#endif /* __ASSEMBLER__ */ =20 #endif diff --git a/include/linux/kasan-tags.h b/include/linux/kasan-tags.h index ad5c11950233..36cc4f70674a 100644 --- a/include/linux/kasan-tags.h +++ b/include/linux/kasan-tags.h @@ -10,6 +10,8 @@ #define KASAN_TAG_WIDTH=09=090 #endif =20 +#define KASAN_TAG_BITS_MASK=09((1UL << KASAN_TAG_WIDTH) - 1) + #ifndef KASAN_TAG_KERNEL #define KASAN_TAG_KERNEL=090xFF /* native kernel pointers tag */ #endif diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 7de42be81d4b..61df894ad105 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1266,7 +1266,7 @@ static inline bool zone_is_empty(const struct zone *z= one) #define NODES_MASK=09=09((1UL << NODES_WIDTH) - 1) #define SECTIONS_MASK=09=09((1UL << SECTIONS_WIDTH) - 1) #define LAST_CPUPID_MASK=09((1UL << LAST_CPUPID_SHIFT) - 1) -#define KASAN_TAG_MASK=09=09((1UL << KASAN_TAG_WIDTH) - 1) +#define KASAN_TAG_MASK=09=09KASAN_TAG_BITS_MASK #define ZONEID_MASK=09=09((1UL << ZONEID_SHIFT) - 1) =20 static inline enum zone_type memdesc_zonenum(memdesc_flags_t flags) --=20 2.53.0