[PATCH mm v3 25/38] kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged
From: <hidden>
Date: 2021-12-13 21:54:49
Also in:
linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), memory management, the rest, vmalloc · Maintainers:
Catalin Marinas, Will Deacon, Andrew Morton, Linus Torvalds, Uladzislau Rezki
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. Add proper protection bits to vmalloc() allocations. 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> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> --- Changes v2->v3: - Update patch description. --- 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 28becb10d013..760caeedd749 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h@@ -115,6 +115,13 @@ 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 837ed355bfc6..58bd2f7f86d7 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c@@ -3060,6 +3060,8 @@ 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;
--
2.25.1
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