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charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Queue-Id: 30288140008 X-Rspamd-Server: rspam02 X-Stat-Signature: wizaafdtdp7fe531iagkgn9tcziwxwhy X-HE-Tag: 1761768507-292809 X-HE-Meta: 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 i41Kpebc sEZAm5wBieuJdGuNuubEgAdo3PH9pZYca9md8yUztouiM7CnJbrQiQTLbS6yXaRBzt7Lgg9HPjc8JI6+5J0oNrdVOXJI0a2vYylqjvHTgBMsyFcopYv5du9NAK6JNXAZWEV1Z15CUZADqzDBZm2Q3TBssvXwZYw9O06/5sl3sK9KTd7lrnNiOvQFSlb4bndEP7sxtIajVIanGkH1J8oj5GXdMDXh8Vqg4H3gO28p4UZXMDWBfGJ3KlX8ZH+3Q3syH8EbKHj47gOz8erCY4yyBbRP4d+iHbBcK6tIc2hbgQY5mnGGXv6oV/QA/Dg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Maciej Wieczor-Retman For an address to be canonical it has to have its top bits equal to each other. The number of bits depends on the paging level and whether they're supposed to be ones or zeroes depends on whether the address points to kernel or user space. With Linear Address Masking (LAM) enabled, the definition of linear address canonicality is modified. Not all of the previously required bits need to be equal, only the first and last from the previously equal bitmask. So for example a 5-level paging kernel address needs to have bits [63] and [56] set. Change the canonical checking function to use bit masks instead of bit shifts. Signed-off-by: Maciej Wieczor-Retman --- Changelog v6: - Use bitmasks to check both kernel and userspace addresses (Dave Hansen and Samuel Holland). Changelog v4: - Add patch to the series. arch/x86/include/asm/page.h | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h index bcf5cad3da36..df2c93b90a6b 100644 --- a/arch/x86/include/asm/page.h +++ b/arch/x86/include/asm/page.h @@ -82,14 +82,37 @@ static __always_inline void *pfn_to_kaddr(unsigned long= pfn) =09return __va(pfn << PAGE_SHIFT); } =20 +/* + * CONFIG_KASAN_SW_TAGS requires LAM which changes the canonicality checks= . + */ +#ifdef CONFIG_KASAN_SW_TAGS +static __always_inline u64 __canonical_address(u64 vaddr, u8 vaddr_bits) +{ +=09return (vaddr | BIT_ULL(63) | BIT_ULL(vaddr_bits - 1)); +} +#else static __always_inline u64 __canonical_address(u64 vaddr, u8 vaddr_bits) { =09return ((s64)vaddr << (64 - vaddr_bits)) >> (64 - vaddr_bits); } +#endif + +#ifdef CONFIG_KASAN_SW_TAGS +#define CANONICAL_MASK(vaddr_bits) (BIT_ULL(63) | BIT_ULL(vaddr_bits - 1)) +#else +#define CANONICAL_MASK(vaddr_bits) GENMASK_ULL(63, vaddr_bits) +#endif =20 static __always_inline u64 __is_canonical_address(u64 vaddr, u8 vaddr_bits= ) { -=09return __canonical_address(vaddr, vaddr_bits) =3D=3D vaddr; +=09unsigned long cmask =3D CANONICAL_MASK(vaddr_bits); + +=09/* +=09 * Kernel canonical address & cmask will evaluate to cmask while +=09 * userspace canonical address & cmask will evaluate to zero. +=09 */ +=09u64 result =3D (vaddr & cmask) =3D=3D cmask || !(vaddr & cmask); +=09return result; } =20 #endif=09/* __ASSEMBLER__ */ --=20 2.51.0