linux-dev/arch/arm64/include/asm/fixmap.h, branch linus/master

arm64: entry: Allow the trampoline text to occupy multiple pages

2022-02-15T17:40:28Z

Adding a second set of vectors to .entry.tramp.text will make it larger than a single 4K page. Allow the trampoline text to occupy up to three pages by adding two more fixmap slots. Previous changes to tramp_valias allowed it to reach beyond a single page. Reviewed-by: Catalin Marinas Signed-off-by: James Morse

arm64: entry: Move the trampoline data page before the text page

2022-02-15T17:39:14Z

The trampoline code has a data page that holds the address of the vectors, which is unmapped when running in user-space. This ensures that with CONFIG_RANDOMIZE_BASE, the randomised address of the kernel can't be discovered until after the kernel has been mapped. If the trampoline text page is extended to include multiple sets of vectors, it will be larger than a single page, making it tricky to find the data page without knowing the size of the trampoline text pages, which will vary with PAGE_SIZE. Move the data page to appear before the text page. This allows the data page to be found without knowing the size of the trampoline text pages. 'tramp_vectors' is used to refer to the beginning of the .entry.tramp.text section, do that explicitly. Reviewed-by: Russell King (Oracle) Reviewed-by: Catalin Marinas Signed-off-by: James Morse

arm64/fixmap: make notes of fixed_addresses more precisely

2020-08-08T18:25:04Z

These 'compile-time allocated' memory buffers can occupy more than one page and each enum increment is page-sized. So improve the note about it. Signed-off-by: Pingfan Liu Cc: Will Deacon Link: https://lore.kernel.org/r/1596460720-19243-1-git-send-email-kernelfans@gmail.com To: linux-arm-kernel@lists.infradead.org Signed-off-by: Catalin Marinas

firmware: arm_sdei: Add ACPI GHES registration helper

2019-02-11T10:07:49Z

APEI's Generic Hardware Error Source structures do not describe whether the SDEI event is shared or private, as this information is discoverable via the API. GHES needs to know whether an event is normal or critical to avoid sharing locks or fixmap entries, but GHES shouldn't have to know about the SDEI API. Add a helper to register the GHES using the appropriate normal or critical callback. Signed-off-by: James Morse Acked-by: Catalin Marinas Signed-off-by: Rafael J. Wysocki

ACPI / APEI: Use separate fixmap pages for arm64 NMI-like notifications

2019-02-07T22:10:46Z

Now that ghes notification helpers provide the fixmap slots and take the lock themselves, multiple NMI-like notifications can be used on arm64. These should be named after their notification method as they can't all be called 'NMI'. x86's NOTIFY_NMI already is, change the SEA fixmap entry to be called FIX_APEI_GHES_SEA. Future patches can add support for FIX_APEI_GHES_SEI and FIX_APEI_GHES_SDEI_{NORMAL,CRITICAL}. Because all of ghes.c builds on both architectures, provide a constant for each fixmap entry that the architecture will never use. Signed-off-by: James Morse Signed-off-by: Rafael J. Wysocki

arm64: kaslr: Put kernel vectors address in separate data page

2017-12-11T13:41:20Z

The literal pool entry for identifying the vectors base is the only piece of information in the trampoline page that identifies the true location of the kernel. This patch moves it into a page-aligned region of the .rodata section and maps this adjacent to the trampoline text via an additional fixmap entry, which protects against any accidental leakage of the trampoline contents. Suggested-by: Ard Biesheuvel Tested-by: Laura Abbott Tested-by: Shanker Donthineni Signed-off-by: Will Deacon

arm64: mm: Map entry trampoline into trampoline and kernel page tables

2017-12-11T13:40:50Z

The exception entry trampoline needs to be mapped at the same virtual address in both the trampoline page table (which maps nothing else) and also the kernel page table, so that we can swizzle TTBR1_EL1 on exceptions from and return to EL0. This patch maps the trampoline at a fixed virtual address in the fixmap area of the kernel virtual address space, which allows the kernel proper to be randomized with respect to the trampoline when KASLR is enabled. Reviewed-by: Mark Rutland Tested-by: Laura Abbott Tested-by: Shanker Donthineni Signed-off-by: Will Deacon

ACPI / APEI: Replace ioremap_page_range() with fixmap

2017-11-07T11:12:44Z

Replace ghes_io{re,un}map_pfn_{nmi,irq}()s use of ioremap_page_range() with __set_fixmap() as ioremap_page_range() may sleep to allocate a new level of page-table, even if its passed an existing final-address to use in the mapping. The GHES driver can only be enabled for architectures that select HAVE_ACPI_APEI: Add fixmap entries to both x86 and arm64. clear_fixmap() does the TLB invalidation in __set_fixmap() for arm64 and __set_pte_vaddr() for x86. In each case its the same as the respective arch_apei_flush_tlb_one(). Reported-by: Fengguang Wu Suggested-by: Linus Torvalds Signed-off-by: James Morse Reviewed-by: Borislav Petkov Tested-by: Tyler Baicar Tested-by: Toshi Kani [ For the arm64 bits: ] Acked-by: Will Deacon [ For the x86 bits: ] Acked-by: Ingo Molnar Signed-off-by: Rafael J. Wysocki Cc: All applicable

arm64: Remove fixmap include fragility

2016-02-26T15:22:53Z

The asm-generic fixmap.h depends on each architecture's fixmap.h to pull in the definition of PAGE_KERNEL_RO, if this exists. In the absence of this, FIXMAP_PAGE_RO will not be defined. In mm/early_ioremap.c the definition of early_memremap_ro is predicated on FIXMAP_PAGE_RO being defined. Currently, the arm64 fixmap.h doesn't include pgtable.h for the definition of PAGE_KERNEL_RO, and as a knock-on effect early_memremap_ro is not always defined, leading to link-time failures when it is used. This has been observed with defconfig on next-20160226. Unfortunately, as pgtable.h includes fixmap.h, adding the include introduces a circular dependency, which is just as fragile. Instead, this patch factors out PAGE_KERNEL_RO and other prot definitions into a new pgtable-prot header which can be included by poth pgtable.h and fixmap.h, avoiding the circular dependency, and ensuring that early_memremap_ro is alwyas defined where it is used. Signed-off-by: Mark Rutland Reported-by: Ard Biesheuvel Acked-by: Ard Biesheuvel Cc: Will Deacon Signed-off-by: Catalin Marinas

arm64: mm: add functions to walk tables in fixmap

2016-02-16T15:10:46Z

As a preparatory step to allow us to allocate early page tables from unmapped memory using memblock_alloc, add new p??_{set,clear}_fixmap* functions which can be used to walk page tables outside of the linear mapping by using fixmap slots. Signed-off-by: Mark Rutland Reviewed-by: Catalin Marinas Tested-by: Ard Biesheuvel Reviewed-by: Ard Biesheuvel Tested-by: Jeremy Linton Cc: Laura Abbott Cc: Will Deacon Signed-off-by: Catalin Marinas