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charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: AFD661C0005 X-Stat-Signature: urpd6f4he59icf1gmeafrghku1eo11fd X-Rspam-User: X-HE-Tag: 1761768468-450598 X-HE-Meta: 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 S88PDIy/ qHNZRjBRJNyC0NZWgVCenlAtiMSNyFoI8IQI114TnxWr0Gsk0RYBCfrhMQDobCqtN5UpVDpppUCiKGVrxRgh59DwadV9n5I3rdB3ztrnMEfOXtYB8eXxouNCF4mg8G8OlSJ9aVA6C5Y6TufZOVIs+YVeRAALuXkcf3Tif3p4g0z+XWWJ/Vo9vfvFj9QWG7204maonx9lPI9eG+l6j8gvuTOvNpVh04+hz9Snd4ANL5mbB1MGA0bkkaEPrxTvi4spRGAXkKf2o0fDXPgaKvrIVOgvN7JgZK1ZwLy1ZVIM9bxqe0UsFld0z4eYL9A== 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 In KASAN's generic mode the default value in shadow memory is zero. During initialization of shadow memory pages they are allocated and zeroed. In KASAN's tag-based mode the default tag for the arm64 architecture is 0xFE which corresponds to any memory that should not be accessed. On x86 (where tags are 4-bit wide instead of 8-bit wide) that tag is 0xE so during the initializations all the bytes in shadow memory pages should be filled with it. Use memblock_alloc_try_nid_raw() instead of memblock_alloc_try_nid() to avoid zeroing out the memory so it can be set with the KASAN invalid tag. Signed-off-by: Maciej Wieczor-Retman --- Changelog v2: - Remove dense mode references, use memset() instead of kasan_poison(). arch/x86/mm/kasan_init_64.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 998b6010d6d3..e69b7210aaae 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -34,6 +34,18 @@ static __init void *early_alloc(size_t size, int nid, bo= ol should_panic) =09return ptr; } =20 +static __init void *early_raw_alloc(size_t size, int nid, bool should_pani= c) +{ +=09void *ptr =3D memblock_alloc_try_nid_raw(size, size, +=09=09=09__pa(MAX_DMA_ADDRESS), MEMBLOCK_ALLOC_ACCESSIBLE, nid); + +=09if (!ptr && should_panic) +=09=09panic("%pS: Failed to allocate page, nid=3D%d from=3D%lx\n", +=09=09 (void *)_RET_IP_, nid, __pa(MAX_DMA_ADDRESS)); + +=09return ptr; +} + static void __init kasan_populate_pmd(pmd_t *pmd, unsigned long addr, =09=09=09=09 unsigned long end, int nid) { @@ -63,8 +75,9 @@ static void __init kasan_populate_pmd(pmd_t *pmd, unsigne= d long addr, =09=09if (!pte_none(*pte)) =09=09=09continue; =20 -=09=09p =3D early_alloc(PAGE_SIZE, nid, true); -=09=09entry =3D pfn_pte(PFN_DOWN(__pa(p)), PAGE_KERNEL); +=09=09p =3D early_raw_alloc(PAGE_SIZE, nid, true); +=09=09memset(p, PAGE_SIZE, KASAN_SHADOW_INIT); +=09=09entry =3D pfn_pte(PFN_DOWN(__pa_nodebug(p)), PAGE_KERNEL); =09=09set_pte_at(&init_mm, addr, pte, entry); =09} while (pte++, addr +=3D PAGE_SIZE, addr !=3D end); } @@ -436,7 +449,7 @@ void __init kasan_init(void) =09 * it may contain some garbage. Now we can clear and write protect it, =09 * since after the TLB flush no one should write to it. =09 */ -=09memset(kasan_early_shadow_page, 0, PAGE_SIZE); +=09memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE); =09for (i =3D 0; i < PTRS_PER_PTE; i++) { =09=09pte_t pte; =09=09pgprot_t prot; --=20 2.51.0