[RFC PATCH v2 06/15] arm64: set_memory: Implement set_memory_pkey()
From: Kevin Brodsky <hidden>
Date: 2025-01-08 10:34:28
Also in:
linux-hardening, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Implement set_memory_pkey() using POE if supported. Signed-off-by: Kevin Brodsky <redacted> --- arch/arm64/include/asm/set_memory.h | 4 ++++ arch/arm64/mm/pageattr.c | 21 +++++++++++++++++++++ 2 files changed, 25 insertions(+)
diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
index 90f61b17275e..b6cd6de34abf 100644
--- a/arch/arm64/include/asm/set_memory.h
+++ b/arch/arm64/include/asm/set_memory.h@@ -19,4 +19,8 @@ bool kernel_page_present(struct page *page); int set_memory_encrypted(unsigned long addr, int numpages); int set_memory_decrypted(unsigned long addr, int numpages); +#ifdef CONFIG_ARCH_HAS_KPKEYS +int set_memory_pkey(unsigned long addr, int numpages, int pkey); +#endif + #endif /* _ASM_ARM64_SET_MEMORY_H */
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 39fd1f7ff02a..3b8fec532b18 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c@@ -292,6 +292,27 @@ int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid) return set_memory_valid(addr, nr, valid); } +#ifdef CONFIG_ARCH_HAS_KPKEYS +int set_memory_pkey(unsigned long addr, int numpages, int pkey) +{ + unsigned long set_prot = 0; + + if (!system_supports_poe()) + return 0; + + if (!__is_lm_address(addr)) + return -EINVAL; + + set_prot |= pkey & BIT(0) ? PTE_PO_IDX_0 : 0; + set_prot |= pkey & BIT(1) ? PTE_PO_IDX_1 : 0; + set_prot |= pkey & BIT(2) ? PTE_PO_IDX_2 : 0; + + return __change_memory_common(addr, PAGE_SIZE * numpages, + __pgprot(set_prot), + __pgprot(PTE_PO_IDX_MASK)); +} +#endif + #ifdef CONFIG_DEBUG_PAGEALLOC /* * This is - apart from the return value - doing the same
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2.47.0