From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- arch/x86/include/asm/set_memory.h | 141 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 arch/x86/include/asm/set_memory.h (limited to 'arch/x86/include/asm/set_memory.h') diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h new file mode 100644 index 000000000..bc97b8c0f --- /dev/null +++ b/arch/x86/include/asm/set_memory.h @@ -0,0 +1,141 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_SET_MEMORY_H +#define _ASM_X86_SET_MEMORY_H + +#include +#include + +/* + * The set_memory_* API can be used to change various attributes of a virtual + * address range. The attributes include: + * Cachability : UnCached, WriteCombining, WriteThrough, WriteBack + * Executability : eXeutable, NoteXecutable + * Read/Write : ReadOnly, ReadWrite + * Presence : NotPresent + * Encryption : Encrypted, Decrypted + * + * Within a category, the attributes are mutually exclusive. + * + * The implementation of this API will take care of various aspects that + * are associated with changing such attributes, such as: + * - Flushing TLBs + * - Flushing CPU caches + * - Making sure aliases of the memory behind the mapping don't violate + * coherency rules as defined by the CPU in the system. + * + * What this API does not do: + * - Provide exclusion between various callers - including callers that + * operation on other mappings of the same physical page + * - Restore default attributes when a page is freed + * - Guarantee that mappings other than the requested one are + * in any state, other than that these do not violate rules for + * the CPU you have. Do not depend on any effects on other mappings, + * CPUs other than the one you have may have more relaxed rules. + * The caller is required to take care of these. + */ + +int _set_memory_uc(unsigned long addr, int numpages); +int _set_memory_wc(unsigned long addr, int numpages); +int _set_memory_wt(unsigned long addr, int numpages); +int _set_memory_wb(unsigned long addr, int numpages); +int set_memory_uc(unsigned long addr, int numpages); +int set_memory_wc(unsigned long addr, int numpages); +int set_memory_wt(unsigned long addr, int numpages); +int set_memory_wb(unsigned long addr, int numpages); +int set_memory_np(unsigned long addr, int numpages); +int set_memory_4k(unsigned long addr, int numpages); +int set_memory_encrypted(unsigned long addr, int numpages); +int set_memory_decrypted(unsigned long addr, int numpages); +int set_memory_np_noalias(unsigned long addr, int numpages); + +int set_memory_array_uc(unsigned long *addr, int addrinarray); +int set_memory_array_wc(unsigned long *addr, int addrinarray); +int set_memory_array_wt(unsigned long *addr, int addrinarray); +int set_memory_array_wb(unsigned long *addr, int addrinarray); + +int set_pages_array_uc(struct page **pages, int addrinarray); +int set_pages_array_wc(struct page **pages, int addrinarray); +int set_pages_array_wt(struct page **pages, int addrinarray); +int set_pages_array_wb(struct page **pages, int addrinarray); + +/* + * For legacy compatibility with the old APIs, a few functions + * are provided that work on a "struct page". + * These functions operate ONLY on the 1:1 kernel mapping of the + * memory that the struct page represents, and internally just + * call the set_memory_* function. See the description of the + * set_memory_* function for more details on conventions. + * + * These APIs should be considered *deprecated* and are likely going to + * be removed in the future. + * The reason for this is the implicit operation on the 1:1 mapping only, + * making this not a generally useful API. + * + * Specifically, many users of the old APIs had a virtual address, + * called virt_to_page() or vmalloc_to_page() on that address to + * get a struct page* that the old API required. + * To convert these cases, use set_memory_*() on the original + * virtual address, do not use these functions. + */ + +int set_pages_uc(struct page *page, int numpages); +int set_pages_wb(struct page *page, int numpages); +int set_pages_x(struct page *page, int numpages); +int set_pages_nx(struct page *page, int numpages); +int set_pages_ro(struct page *page, int numpages); +int set_pages_rw(struct page *page, int numpages); + +extern int kernel_set_to_readonly; +void set_kernel_text_rw(void); +void set_kernel_text_ro(void); + +#ifdef CONFIG_X86_64 +/* + * Prevent speculative access to the page by either unmapping + * it (if we do not require access to any part of the page) or + * marking it uncacheable (if we want to try to retrieve data + * from non-poisoned lines in the page). + */ +static inline int set_mce_nospec(unsigned long pfn, bool unmap) +{ + unsigned long decoy_addr; + int rc; + + /* + * We would like to just call: + * set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1); + * but doing that would radically increase the odds of a + * speculative access to the poison page because we'd have + * the virtual address of the kernel 1:1 mapping sitting + * around in registers. + * Instead we get tricky. We create a non-canonical address + * that looks just like the one we want, but has bit 63 flipped. + * This relies on set_memory_XX() properly sanitizing any __pa() + * results with __PHYSICAL_MASK or PTE_PFN_MASK. + */ + decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63)); + + if (unmap) + rc = set_memory_np(decoy_addr, 1); + else + rc = set_memory_uc(decoy_addr, 1); + if (rc) + pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn); + return rc; +} +#define set_mce_nospec set_mce_nospec + +/* Restore full speculative operation to the pfn. */ +static inline int clear_mce_nospec(unsigned long pfn) +{ + return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1); +} +#define clear_mce_nospec clear_mce_nospec +#else +/* + * Few people would run a 32-bit kernel on a machine that supports + * recoverable errors because they have too much memory to boot 32-bit. + */ +#endif + +#endif /* _ASM_X86_SET_MEMORY_H */ -- cgit v1.2.3