Re: [PATCH v2 24/34] kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged
From: Vincenzo Frascino <vincenzo.frascino@arm.com>
Date: 2021-12-13 15:17:31
Also in:
linux-mm, lkml
Hi Andrey, On 12/6/21 9:44 PM, andrey.konovalov@linux.dev wrote:
From: Andrey Konovalov <redacted> HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE). With MTE, a memory region must be mapped as MT_NORMAL_TAGGED to allow setting memory tags via MTE-specific instructions. This change adds proper protection bits to vmalloc() allocations.
Please avoid "this patch/this change" in patch description and use imperative mode as if you are giving a command to the code base ([1] paragraph 2).
These allocations are always backed by page_alloc pages, so the tags will actually be getting set on the corresponding physical memory. Signed-off-by: Andrey Konovalov <redacted> Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
With the change to the commit message: Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
quoted hunk ↗ jump to hunk
--- arch/arm64/include/asm/vmalloc.h | 10 ++++++++++ include/linux/vmalloc.h | 7 +++++++ mm/vmalloc.c | 2 ++ 3 files changed, 19 insertions(+)diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h index b9185503feae..3d35adf365bf 100644 --- a/arch/arm64/include/asm/vmalloc.h +++ b/arch/arm64/include/asm/vmalloc.h@@ -25,4 +25,14 @@ static inline bool arch_vmap_pmd_supported(pgprot_t prot) #endif +#define arch_vmalloc_pgprot_modify arch_vmalloc_pgprot_modify +static inline pgprot_t arch_vmalloc_pgprot_modify(pgprot_t prot) +{ + if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && + (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))) + prot = pgprot_tagged(prot); + + return prot; +} + #endif /* _ASM_ARM64_VMALLOC_H */diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index b22369f540eb..965c4bf475f1 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h@@ -108,6 +108,13 @@ static inline int arch_vmap_pte_supported_shift(unsigned long size) } #endif +#ifndef arch_vmalloc_pgprot_modify +static inline pgprot_t arch_vmalloc_pgprot_modify(pgprot_t prot) +{ + return prot; +} +#endif + /* * Highlevel APIs for driver use */diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 7be18b292679..f37d0ed99bf9 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c@@ -3033,6 +3033,8 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, return NULL; } + prot = arch_vmalloc_pgprot_modify(prot); + if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) { unsigned long size_per_node;
-- Regards, Vincenzo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel