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2018-03-12x86/efi: Use efi_switch_mm() rather than manually twiddling with %cr3Sai Praneeth1-15/+10
Use helper function efi_switch_mm() to switch to/from efi_mm when invoking any UEFI runtime services. Likewise, we need to switch back to previous mm (mm context stolen by efi_mm) after the above calls return successfully. We can use efi_switch_mm() helper function only with x86_64 kernel and "efi=old_map" disabled because, x86_32 and efi=old_map do not use efi_pgd, rather they use swapper_pg_dir. Tested-by: Bhupesh Sharma <bhsharma@redhat.com> [ardb: add #include of sched/task.h for task_lock/_unlock] Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-efi@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12efi: Use efi_mm in x86 as well as ARMSai Praneeth1-0/+1
Presently, only ARM uses mm_struct to manage EFI page tables and EFI runtime region mappings. As this is the preferred approach, let's make this data structure common across architectures. Specially, for x86, using this data structure improves code maintainability and readability. Tested-by: Bhupesh Sharma <bhsharma@redhat.com> [ardb: don't #include the world to get a declaration of struct mm_struct] Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180312084500.10764-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-20x86/speculation: Use IBRS if available before calling into firmwareDavid Woodhouse1-2/+15
Retpoline means the kernel is safe because it has no indirect branches. But firmware isn't, so use IBRS for firmware calls if it's available. Block preemption while IBRS is set, although in practice the call sites already had to be doing that. Ignore hpwdt.c for now. It's taking spinlocks and calling into firmware code, from an NMI handler. I don't want to touch that with a bargepole. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: arjan.van.de.ven@intel.com Cc: bp@alien8.de Cc: dave.hansen@intel.com Cc: jmattson@google.com Cc: karahmed@amazon.de Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Link: http://lkml.kernel.org/r/1519037457-7643-2-git-send-email-dwmw@amazon.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-13x86/efi: move asmlinkage before return typeJoe Perches1-2/+2
Make the code like the rest of the kernel. Link: http://lkml.kernel.org/r/1cd3d401626e51ea0e2333a860e76e80bc560a4c.1499284835.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-13x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3()Andy Lutomirski1-1/+1
The kernel has several code paths that read CR3. Most of them assume that CR3 contains the PGD's physical address, whereas some of them awkwardly use PHYSICAL_PAGE_MASK to mask off low bits. Add explicit mask macros for CR3 and convert all of the CR3 readers. This will keep them from breaking when PCID is enabled. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-07x86/efi: Allow invocation of arbitrary runtime servicesDavid Howells1-0/+5
Provide the ability to perform mixed-mode runtime service calls for x86 in the same way the following commit provided the ability to invoke for boot services: 0a637ee61247bd ("x86/efi: Allow invocation of arbitrary boot services") Suggested-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1486380166-31868-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-13efi: Allow bitness-agnostic protocol callsLukas Wunner1-5/+11
We already have a macro to invoke boot services which on x86 adapts automatically to the bitness of the EFI firmware: efi_call_early(). The macro allows sharing of functions across arches and bitness variants as long as those functions only call boot services. However in practice functions in the EFI stub contain a mix of boot services calls and protocol calls. Add an efi_call_proto() macro for bitness-agnostic protocol calls to allow sharing more code across arches as well as deduplicating 32 bit and 64 bit code paths. On x86, implement it using a new efi_table_attr() macro for bitness- agnostic table lookups. Refactor efi_call_early() to make use of the same macro. (The resulting object code remains identical.) Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20161112213237.8804-8-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-09x86/efi: Allow invocation of arbitrary boot servicesLukas Wunner1-9/+6
We currently allow invocation of 8 boot services with efi_call_early(). Not included are LocateHandleBuffer and LocateProtocol in particular. For graphics output or to retrieve PCI ROMs and Apple device properties, we're thus forced to use the LocateHandle + AllocatePool + LocateHandle combo, which is cumbersome and needs more code. The ARM folks allow invocation of the full set of boot services but are restricted to our 8 boot services in functions shared across arches. Thus, rather than adding just LocateHandleBuffer and LocateProtocol to struct efi_config, let's rework efi_call_early() to allow invocation of arbitrary boot services by selecting the 64 bit vs 32 bit code path in the macro itself. When compiling for 32 bit or for 64 bit without mixed mode, the unused code path is optimized away and the binary code is the same as before. But on 64 bit with mixed mode enabled, this commit adds one compare instruction to each invocation of a boot service and, depending on the code path selected, two jump instructions. (Most of the time gcc arranges the jumps in the 32 bit code path.) The result is a minuscule performance penalty and the binary code becomes slightly larger and more difficult to read when disassembled. This isn't a hot path, so these drawbacks are arguably outweighed by the attainable simplification of the C code. We have some overhead anyway for thunking or conversion between calling conventions. The 8 boot services can consequently be removed from struct efi_config. No functional change intended (for now). Example -- invocation of free_pool before (64 bit code path): 0x2d4 movq %ds:efi_early, %rdx ; efi_early 0x2db movq %ss:arg_0-0x20(%rsp), %rsi 0x2e0 xorl %eax, %eax 0x2e2 movq %ds:0x28(%rdx), %rdi ; efi_early->free_pool 0x2e6 callq *%ds:0x58(%rdx) ; efi_early->call() Example -- invocation of free_pool after (64 / 32 bit mixed code path): 0x0dc movq %ds:efi_early, %rax ; efi_early 0x0e3 cmpb $0, %ds:0x28(%rax) ; !efi_early->is64 ? 0x0e7 movq %ds:0x20(%rax), %rdx ; efi_early->call() 0x0eb movq %ds:0x10(%rax), %rax ; efi_early->boot_services 0x0ef je $0x150 0x0f1 movq %ds:0x48(%rax), %rdi ; free_pool (64 bit) 0x0f5 xorl %eax, %eax 0x0f7 callq *%rdx ... 0x150 movl %ds:0x30(%rax), %edi ; free_pool (32 bit) 0x153 jmp $0x0f5 Size of eboot.o text section: CONFIG_X86_32: 6464 before, 6318 after CONFIG_X86_64 && !CONFIG_EFI_MIXED: 7670 before, 7573 after CONFIG_X86_64 && CONFIG_EFI_MIXED: 7670 before, 8319 after Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09x86/efi: Optimize away setup_gop32/64 if unusedLukas Wunner1-2/+11
Commit 2c23b73c2d02 ("x86/efi: Prepare GOP handling code for reuse as generic code") introduced an efi_is_64bit() macro to x86 which previously only existed for arm arches. The macro is used to choose between the 64 bit or 32 bit code path in gop.c at runtime. However the code path that's going to be taken is known at compile time when compiling for x86_32 or for x86_64 with mixed mode disabled. Amend the macro to eliminate the unused code path in those cases. Size of gop.o text section: CONFIG_X86_32: 1758 before, 1299 after CONFIG_X86_64 && !CONFIG_EFI_MIXED: 2201 before, 1406 after CONFIG_X86_64 && CONFIG_EFI_MIXED: 2201 before and after Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09efi: Refactor efi_memmap_init_early() into arch-neutral codeMatt Fleming1-1/+0
Every EFI architecture apart from ia64 needs to setup the EFI memory map at efi.memmap, and the code for doing that is essentially the same across all implementations. Therefore, it makes sense to factor this out into the common code under drivers/firmware/efi/. The only slight variation is the data structure out of which we pull the initial memory map information, such as physical address, memory descriptor size and version, etc. We can address this by passing a generic data structure (struct efi_memory_map_data) as the argument to efi_memmap_init_early() which contains the minimum info required for initialising the memory map. In the process, this patch also fixes a few undesirable implementation differences: - ARM and arm64 were failing to clear the EFI_MEMMAP bit when unmapping the early EFI memory map. EFI_MEMMAP indicates whether the EFI memory map is mapped (not the regions contained within) and can be traversed. It's more correct to set the bit as soon as we memremap() the passed in EFI memmap. - Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the regular naming scheme. This patch also uses a read-write mapping for the memory map instead of the read-only mapping currently used on ARM and arm64. x86 needs the ability to update the memory map in-place when assigning virtual addresses to regions (efi_map_region()) and tagging regions when reserving boot services (efi_reserve_boot_services()). There's no way for the generic fake_mem code to know which mapping to use without introducing some arch-specific constant/hook, so just use read-write since read-only is of dubious value for the EFI memory map. Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump] Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm] Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Peter Jones <pjones@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-07-26Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "Various x86 low level modifications: - preparatory work to support virtually mapped kernel stacks (Andy Lutomirski) - support for 64-bit __get_user() on 32-bit kernels (Benjamin LaHaise) - (involved) workaround for Knights Landing CPU erratum (Dave Hansen) - MPX enhancements (Dave Hansen) - mremap() extension to allow remapping of the special VDSO vma, for purposes of user level context save/restore (Dmitry Safonov) - hweight and entry code cleanups (Borislav Petkov) - bitops code generation optimizations and cleanups with modern GCC (H. Peter Anvin) - syscall entry code optimizations (Paolo Bonzini)" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits) x86/mm/cpa: Add missing comment in populate_pdg() x86/mm/cpa: Fix populate_pgd(): Stop trying to deallocate failed PUDs x86/syscalls: Add compat_sys_preadv64v2/compat_sys_pwritev64v2 x86/smp: Remove unnecessary initialization of thread_info::cpu x86/smp: Remove stack_smp_processor_id() x86/uaccess: Move thread_info::addr_limit to thread_struct x86/dumpstack: Rename thread_struct::sig_on_uaccess_error to sig_on_uaccess_err x86/uaccess: Move thread_info::uaccess_err and thread_info::sig_on_uaccess_err to thread_struct x86/dumpstack: When OOPSing, rewind the stack before do_exit() x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm x86/dumpstack/64: Handle faults when printing the "Stack: " part of an OOPS x86/dumpstack: Try harder to get a call trace on stack overflow x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables() x86/mm/cpa: In populate_pgd(), don't set the PGD entry until it's populated x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() x86/mm: Use pte_none() to test for empty PTE x86/mm: Disallow running with 32-bit PTEs to work around erratum x86/mm: Ignore A/D bits in pte/pmd/pud_none() x86/mm: Move swap offset/type up in PTE to work around erratum x86/entry: Inline enter_from_user_mode() ...
2016-07-15x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables()Andy Lutomirski1-1/+0
kernel_unmap_pages_in_pgd() is dangerous: if a PGD entry in init_mm.pgd were to be cleared, callers would need to ensure that the pgd entry hadn't been propagated to any other pgd. Its only caller was efi_cleanup_page_tables(), and that, in turn, was unused, so just delete both functions. This leaves a couple of other helpers unused, so delete them, too. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/77ff20fdde3b75cd393be5559ad8218870520248.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-27efi: Convert efi_call_virt() to efi_call_virt_pointer()Alex Thorlton1-5/+4
This commit makes a few slight modifications to the efi_call_virt() macro to get it to work with function pointers that are stored in locations other than efi.systab->runtime, and renames the macro to efi_call_virt_pointer(). The majority of the changes here are to pull these macros up into header files so that they can be accessed from outside of drivers/firmware/efi/runtime-wrappers.c. The most significant change not directly related to the code move is to add an extra "p" argument into the appropriate efi_call macros, and use that new argument in place of the, formerly hard-coded, efi.systab->runtime pointer. The last piece of the puzzle was to add an efi_call_virt() macro back into drivers/firmware/efi/runtime-wrappers.c to wrap around the new efi_call_virt_pointer() macro - this was mainly to keep the code from looking too cluttered by adding a bunch of extra references to efi.systab->runtime everywhere. Note that I also broke up the code in the efi_call_virt_pointer() macro a bit in the process of moving it. Signed-off-by: Alex Thorlton <athorlton@sgi.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roy Franz <roy.franz@linaro.org> Cc: Russ Anderson <rja@sgi.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1466839230-12781-5-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28x86/efi: Enable runtime call flag checkingMark Rutland1-1/+3
Define ARCH_EFI_IRQ_FLAGS_MASK for x86, which will enable the generic runtime wrapper code to detect when firmware erroneously modifies flags over a runtime services function call. For x86 (both 32-bit and 64-bit), we only need check the interrupt flag. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Darren Hart <dvhart@infradead.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Hannes Reinecke <hare@suse.de> Cc: Harald Hoyer harald@redhat.com Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Kweh Hock Leong <hock.leong.kweh@intel.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raphael Hertzog <hertzog@debian.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-40-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28x86/efi: Move to generic {__,}efi_call_virt()Mark Rutland1-29/+12
Now there's a common template for {__,}efi_call_virt(), remove the duplicate logic from the x86 EFI code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-35-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28x86/efi/efifb: Move DMI based quirks handling out of generic codeArd Biesheuvel1-0/+2
The efifb quirks handling based on DMI identification of the platform is specific to x86, so move it to x86 arch code. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Peter Jones <pjones@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-19-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28x86/efi: Prepare GOP handling code for reuse as generic codeArd Biesheuvel1-0/+5
In preparation of moving this code to drivers/firmware/efi and reusing it on ARM and arm64, apply any changes that will be required to make this code build for other architectures. This should make it easier to track down problems that this move may cause to its operation on x86. Note that the generic version uses slightly different ways of casting the protocol methods and some other variables to the correct types, since such method calls are not loosely typed on ARM and arm64 as they are on x86. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-17-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-21Merge branch 'efi-core-for-linus' of ↵Linus Torvalds1-1/+27
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Ingo Molnar: "The main changes are: - Use separate EFI page tables when executing EFI firmware code. This isolates the EFI context from the rest of the kernel, which has security and general robustness advantages. (Matt Fleming) - Run regular UEFI firmware with interrupts enabled. This is already the status quo under other OSs. (Ard Biesheuvel) - Various x86 EFI enhancements, such as the use of non-executable attributes for EFI memory mappings. (Sai Praneeth Prakhya) - Various arm64 UEFI enhancements. (Ard Biesheuvel) - ... various fixes and cleanups. The separate EFI page tables feature got delayed twice already, because it's an intrusive change and we didn't feel confident about it - third time's the charm we hope!" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/mm/pat: Fix boot crash when 1GB pages are not supported by the CPU x86/efi: Only map kernel text for EFI mixed mode x86/efi: Map EFI_MEMORY_{XP,RO} memory region bits to EFI page tables x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd() efi/arm*: Perform hardware compatibility check efi/arm64: Check for h/w support before booting a >4 KB granular kernel efi/arm: Check for LPAE support before booting a LPAE kernel efi/arm-init: Use read-only early mappings efi/efistub: Prevent __init annotations from being used arm64/vmlinux.lds.S: Handle .init.rodata.xxx and .init.bss sections efi/arm64: Drop __init annotation from handle_kernel_image() x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings efi/runtime-wrappers: Run UEFI Runtime Services with interrupts enabled efi: Reformat GUID tables to follow the format in UEFI spec efi: Add Persistent Memory type name efi: Add NV memory attribute x86/efi: Show actual ending addresses in efi_print_memmap x86/efi/bgrt: Don't ignore the BGRT if the 'valid' bit is 0 efivars: Use to_efivar_entry efi: Runtime-wrapper: Get rid of the rtc_lock spinlock ...
2016-02-24efi: stub: use high allocation for converted command lineArd Biesheuvel1-0/+2
Before we can move the command line processing before the allocation of the kernel, which is required for detecting the 'nokaslr' option which controls that allocation, move the converted command line higher up in memory, to prevent it from interfering with the kernel itself. Since x86 needs the address to fit in 32 bits, use UINT_MAX as the upper bound there. Otherwise, use ULONG_MAX (i.e., no limit) Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-22x86/efi: Map EFI_MEMORY_{XP,RO} memory region bits to EFI page tablesSai Praneeth1-1/+1
Now that we have EFI memory region bits that indicate which regions do not need execute permission or read/write permission in the page tables, let's use them. We also check for EFI_NX_PE_DATA and only enforce the restrictive mappings if it's present (to allow us to ignore buggy firmware that sets bits it didn't mean to and to preserve backwards compatibility). Instead of assuming that firmware would set appropriate attributes in memory descriptor like EFI_MEMORY_RO for code and EFI_MEMORY_XP for data, we can expect some firmware out there which might only set *type* in memory descriptor to be EFI_RUNTIME_SERVICES_CODE or EFI_RUNTIME_SERVICES_DATA leaving away attribute. This will lead to improper mappings of EFI runtime regions. In order to avoid it, we check attribute and type of memory descriptor to update mappings and moreover Windows works this way. Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1455712566-16727-13-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-29x86/efi: Build our own page table structuresMatt Fleming1-0/+1
With commit e1a58320a38d ("x86/mm: Warn on W^X mappings") all users booting on 64-bit UEFI machines see the following warning, ------------[ cut here ]------------ WARNING: CPU: 7 PID: 1 at arch/x86/mm/dump_pagetables.c:225 note_page+0x5dc/0x780() x86/mm: Found insecure W+X mapping at address ffff88000005f000/0xffff88000005f000 ... x86/mm: Checked W+X mappings: FAILED, 165660 W+X pages found. ... This is caused by mapping EFI regions with RWX permissions. There isn't much we can do to restrict the permissions for these regions due to the way the firmware toolchains mix code and data, but we can at least isolate these mappings so that they do not appear in the regular kernel page tables. In commit d2f7cbe7b26a ("x86/efi: Runtime services virtual mapping") we started using 'trampoline_pgd' to map the EFI regions because there was an existing identity mapping there which we use during the SetVirtualAddressMap() call and for broken firmware that accesses those addresses. But 'trampoline_pgd' shares some PGD entries with 'swapper_pg_dir' and does not provide the isolation we require. Notably the virtual address for __START_KERNEL_map and MODULES_START are mapped by the same PGD entry so we need to be more careful when copying changes over in efi_sync_low_kernel_mappings(). This patch doesn't go the full mile, we still want to share some PGD entries with 'swapper_pg_dir'. Having completely separate page tables brings its own issues such as synchronising new mappings after memory hotplug and module loading. Sharing also keeps memory usage down. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1448658575-17029-6-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-29x86/efi: Hoist page table switching code into efi_call_virt()Matt Fleming1-0/+25
This change is a prerequisite for pending patches that switch to a dedicated EFI page table, instead of using 'trampoline_pgd' which shares PGD entries with 'swapper_pg_dir'. The pending patches make it impossible to dereference the runtime service function pointer without first switching %cr3. It's true that we now have duplicated switching code in efi_call_virt() and efi_call_phys_{prolog,epilog}() but we are sacrificing code duplication for a little more clarity and the ease of writing the page table switching code in C instead of asm. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1448658575-17029-5-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-14Merge tag 'efi-next' of ↵Ingo Molnar1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi Pull v4.4 EFI updates from Matt Fleming: - Make the EFI System Resource Table (ESRT) driver explicitly non-modular by ripping out the module_* code since Kconfig doesn't allow it to be built as a module anyway. (Paul Gortmaker) - Make the x86 efi=debug kernel parameter, which enables EFI debug code and output, generic and usable by arm64. (Leif Lindholm) - Add support to the x86 EFI boot stub for 64-bit Graphics Output Protocol frame buffer addresses. (Matt Fleming) - Detect when the UEFI v2.5 EFI_PROPERTIES_TABLE feature is enabled in the firmware and set an efi.flags bit so the kernel knows when it can apply more strict runtime mapping attributes - Ard Biesheuvel - Auto-load the efi-pstore module on EFI systems, just like we currently do for the efivars module. (Ben Hutchings) - Add "efi_fake_mem" kernel parameter which allows the system's EFI memory map to be updated with additional attributes for specific memory ranges. This is useful for testing the kernel code that handles the EFI_MEMORY_MORE_RELIABLE memmap bit even if your firmware doesn't include support. (Taku Izumi) Note: there is a semantic conflict between the following two commits: 8a53554e12e9 ("x86/efi: Fix multiple GOP device support") ae2ee627dc87 ("efifb: Add support for 64-bit frame buffer addresses") I fixed up the interaction in the merge commit, changing the type of current_fb_base from u32 to u64. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-12x86/efi: Rename print_efi_memmap() to efi_print_memmap()Taku Izumi1-0/+1
This patch renames print_efi_memmap() to efi_print_memmap() and make it global function so that we can invoke it outside of arch/x86/platform/efi/efi.c Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-10-02arch/x86/include/asm/efi.h: fix build failureAndrey Ryabinin1-0/+2
With KMEMCHECK=y, KASAN=n: arch/x86/platform/efi/efi.c:673:3: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration] arch/x86/platform/efi/efi_64.c:139:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration] arch/x86/include/asm/desc.h:121:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration] Don't #undef memcpy if KASAN=n. Fixes: 769a8089c1fd ("x86, efi, kasan: #undef memset/memcpy/memmove per arch") Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Reported-by: Ingo Molnar <mingo@kernel.org> Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-23x86, efi, kasan: #undef memset/memcpy/memmove per archAndrey Ryabinin1-0/+10
In not-instrumented code KASAN replaces instrumented memset/memcpy/memmove with not-instrumented analogues __memset/__memcpy/__memove. However, on x86 the EFI stub is not linked with the kernel. It uses not-instrumented mem*() functions from arch/x86/boot/compressed/string.c So we don't replace them with __mem*() variants in EFI stub. On ARM64 the EFI stub is linked with the kernel, so we should replace mem*() functions with __mem*(), because the EFI stub runs before KASAN sets up early shadow. So let's move these #undef mem* into arch's asm/efi.h which is also included by the EFI stub. Also, this will fix the warning in 32-bit build reported by kbuild test robot: efi-stub-helper.c:599:2: warning: implicit declaration of function 'memcpy' [akpm@linux-foundation.org: use 80 cols in comment] Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Reported-by: Fengguang Wu <fengguang.wu@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-19x86/fpu: Rename i387.h to fpu/api.hIngo Molnar1-1/+1
We already have fpu/types.h, move i387.h to fpu/api.h. The file name has become a misnomer anyway: it offers generic FPU APIs, but is not limited to i387 functionality. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01efi: Clean up the efi_call_phys_[prolog|epilog]() save/restore interactionIngo Molnar1-2/+4
Currently x86-64 efi_call_phys_prolog() saves into a global variable (save_pgd), and efi_call_phys_epilog() restores the kernel pagetables from that global variable. Change this to a cleaner save/restore pattern where the saving function returns the saved object and the restore function restores that. Apply the same concept to the 32-bit code as well. Plus this approach, as an added bonus, allows us to express the !efi_enabled(EFI_OLD_MEMMAP) situation in a clean fashion as well, via a 'NULL' return value. Cc: Tapasweni Pathak <tapaswenipathak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-11-12efi/x86: Move x86 back to libstubArd Biesheuvel1-0/+24
This reverts commit 84be880560fb, which itself reverted my original attempt to move x86 from #include'ing .c files from across the tree to using the EFI stub built as a static library. The issue that affected the original approach was that splitting the implementation into several .o files resulted in the variable 'efi_early' becoming a global with external linkage, which under -fPIC implies that references to it must go through the GOT. However, dealing with this additional GOT entry turned out to be troublesome on some EFI implementations. (GCC's visibility=hidden attribute is supposed to lift this requirement, but it turned out not to work on the 32-bit build.) Instead, use a pure getter function to get a reference to efi_early. This approach results in no additional GOT entries being generated, so there is no need for any changes in the early GOT handling. Tested-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-04Merge branch 'next' into efi-next-mergeMatt Fleming1-21/+10
Conflicts: arch/x86/boot/compressed/eboot.c
2014-10-03efi: Delete the in_nmi() conditional runtime lockingMatt Fleming1-2/+0
commit 5dc3826d9f08 ("efi: Implement mandatory locking for UEFI Runtime Services") implemented some conditional locking when accessing variable runtime services that Ingo described as "pretty disgusting". The intention with the !efi_in_nmi() checks was to avoid live-locks when trying to write pstore crash data into an EFI variable. Such lockless accesses are allowed according to the UEFI specification when we're in a "non-recoverable" state, but whether or not things are implemented correctly in actual firmware implementations remains an unanswered question, and so it would seem sensible to avoid doing any kind of unsynchronized variable accesses. Furthermore, the efi_in_nmi() tests are inadequate because they don't account for the case where we call EFI variable services from panic or oops callbacks and aren't executing in NMI context. In other words, live-locking is still possible. Let's just remove the conditional locking altogether. Now we've got the ->set_variable_nonblocking() EFI variable operation we can abort if the runtime lock is already held. Aborting is by far the safest option. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03x86/efi: Mark initialization code as suchMathias Krause1-10/+10
The 32 bit and 64 bit implementations differ in their __init annotations for some functions referenced from the common EFI code. Namely, the 32 bit variant is missing some of the __init annotations the 64 bit variant has. To solve the colliding annotations, mark the corresponding functions in efi_32.c as initialization code, too -- as it is such. Actually, quite a few more functions are only used during initialization and therefore can be marked __init. They are therefore annotated, too. Also add the __init annotation to the prototypes in the efi.h header so users of those functions will see it's meant as initialization code only. This patch also fixes the "prelog" typo. ("prologue" / "epilogue" might be more appropriate but this is C code after all, not an opera! :D) Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03x86/efi: Unexport add_efi_memmap variableMathias Krause1-1/+0
This variable was accidentally exported, even though it's only used in this compilation unit and only during initialization. Remove the bogus export, make the variable static instead and mark it as __initdata. Fixes: 200001eb140e ("x86 boot: only pick up additional EFI memmap...") Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03x86/efi: Remove unused efi_call* macrosMathias Krause1-10/+0
Complement commit 62fa6e69a436 ("x86/efi: Delete most of the efi_call* macros") and delete the stub macros for the !CONFIG_EFI case, too. In fact, there are no EFI calls in this case so we don't need a dummy for efi_call() even. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03efi: Implement mandatory locking for UEFI Runtime ServicesArd Biesheuvel1-0/+2
According to section 7.1 of the UEFI spec, Runtime Services are not fully reentrant, and there are particular combinations of calls that need to be serialized. Use a spinlock to serialize all Runtime Services with respect to all others, even if this is more than strictly needed. We've managed to get away without requiring a runtime services lock until now because most of the interactions with EFI involve EFI variables, and those operations are already serialised with __efivars->lock. Some of the assumptions underlying the decision whether locks are needed or not (e.g., SetVariable() against ResetSystem()) may not apply universally to all [new] architectures that implement UEFI. Rather than try to reason our way out of this, let's just implement at least what the spec requires in terms of locking. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-09-24Revert "efi/x86: efistub: Move shared dependencies to <asm/efi.h>"Matt Fleming1-24/+0
This reverts commit f23cf8bd5c1f ("efi/x86: efistub: Move shared dependencies to <asm/efi.h>") as well as the x86 parts of commit f4f75ad5741f ("efi: efistub: Convert into static library"). The road leading to these two reverts is long and winding. The above two commits were merged during the v3.17 merge window and turned the common EFI boot stub code into a static library. This necessitated making some symbols global in the x86 boot stub which introduced new entries into the early boot GOT. The problem was that we weren't fixing up the newly created GOT entries before invoking the EFI boot stub, which sometimes resulted in hangs or resets. This failure was reported by Maarten on his Macbook pro. The proposed fix was commit 9cb0e394234d ("x86/efi: Fixup GOT in all boot code paths"). However, that caused issues for Linus when booting his Sony Vaio Pro 11. It was subsequently reverted in commit f3670394c29f. So that leaves us back with Maarten's Macbook pro not booting. At this stage in the release cycle the least risky option is to revert the x86 EFI boot stub to the pre-merge window code structure where we explicitly #include efi-stub-helper.c instead of linking with the static library. The arm64 code remains unaffected. We can take another swing at the x86 parts for v3.18. Conflicts: arch/x86/include/asm/efi.h Tested-by: Josh Boyer <jwboyer@fedoraproject.org> Tested-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> [arm64] Tested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>, Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-07-19x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flagMatt Fleming1-0/+6
It appears that the BayTrail-T class of hardware requires EFI in order to powerdown and reboot and no other reliable method exists. This quirk is generally applicable to all hardware that has the ACPI Hardware Reduced bit set, since usually ACPI would be the preferred method. Cc: Len Brown <len.brown@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-07-07efi/x86: efistub: Move shared dependencies to <asm/efi.h>Ard Biesheuvel1-0/+25
This moves definitions depended upon both by code under arch/x86/boot and under drivers/firmware/efi to <asm/efi.h>. This is in preparation of turning the stub code under drivers/firmware/efi into a static library. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-06-19x86/efi: Move all workarounds to a separate file quirks.cSaurabh Tangri1-0/+2
Currently, it's difficult to find all the workarounds that are applied when running on EFI, because they're littered throughout various code paths. This change moves all of them into a separate file with the hope that it will be come the single location for all our well documented quirks. Signed-off-by: Saurabh Tangri <saurabh.tangri@intel.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-04-17x86/efi: Save and restore FPU context around efi_calls (i386)Ricardo Neri1-2/+15
Do a complete FPU context save/restore around the EFI calls. This required as runtime EFI firmware may potentially use the FPU. This change covers only the i386 configuration. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-04-17x86/efi: Save and restore FPU context around efi_calls (x86_64)Ricardo Neri1-0/+3
Do a complete FPU context save/restore around the EFI calls. This required as runtime EFI firmware may potentially use the FPU. This change covers only the x86_64 configuration. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-04-17x86/efi: Implement a __efi_call_virt macroRicardo Neri1-0/+10
For i386, all the EFI system runtime services functions return efi_status_t except efi_reset_system_system. Therefore, not all functions can be covered by the same macro in case the macro needs to do more than calling the function (i.e., return a value). The purpose of the __efi_call_virt macro is to be used when no return value is expected. For x86_64, this macro would not be needed as all the runtime services return u64. However, the same code is used for both x86_64 and i386. Thus, the macro __efi_call_virt is also defined to not break compilation. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-04-17x86/efi: Delete most of the efi_call* macrosMatt Fleming1-66/+8
We really only need one phys and one virt function call, and then only one assembly function to make firmware calls. Since we are not using the C type system anyway, we're not really losing much by deleting the macros apart from no longer having a check that we are passing the correct number of parameters. The lack of duplicated code seems like a worthwhile trade-off. Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-05Merge remote-tracking branch 'tip/x86/efi-mixed' into efi-for-mingoMatt Fleming1-3/+35
Conflicts: arch/x86/kernel/setup.c arch/x86/platform/efi/efi.c arch/x86/platform/efi/efi_64.c
2014-03-05Merge remote-tracking branch 'tip/x86/urgent' into efi-for-mingoMatt Fleming1-0/+1
Conflicts: arch/x86/include/asm/efi.h
2014-03-05x86/efi: Quirk out SGI UVBorislav Petkov1-0/+1
Alex reported hitting the following BUG after the EFI 1:1 virtual mapping work was merged, kernel BUG at arch/x86/mm/init_64.c:351! invalid opcode: 0000 [#1] SMP Call Trace: [<ffffffff818aa71d>] init_extra_mapping_uc+0x13/0x15 [<ffffffff818a5e20>] uv_system_init+0x22b/0x124b [<ffffffff8108b886>] ? clockevents_register_device+0x138/0x13d [<ffffffff81028dbb>] ? setup_APIC_timer+0xc5/0xc7 [<ffffffff8108b620>] ? clockevent_delta2ns+0xb/0xd [<ffffffff818a3a92>] ? setup_boot_APIC_clock+0x4a8/0x4b7 [<ffffffff8153d955>] ? printk+0x72/0x74 [<ffffffff818a1757>] native_smp_prepare_cpus+0x389/0x3d6 [<ffffffff818957bc>] kernel_init_freeable+0xb7/0x1fb [<ffffffff81535530>] ? rest_init+0x74/0x74 [<ffffffff81535539>] kernel_init+0x9/0xff [<ffffffff81541dfc>] ret_from_fork+0x7c/0xb0 [<ffffffff81535530>] ? rest_init+0x74/0x74 Getting this thing to work with the new mapping scheme would need more work, so automatically switch to the old memmap layout for SGI UV. Acked-by: Russ Anderson <rja@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-05x86/efi: Wire up CONFIG_EFI_MIXEDMatt Fleming1-0/+11
Add the Kconfig option and bump the kernel header version so that boot loaders can check whether the handover code is available if they want. The xloadflags field in the bzImage header is also updated to reflect that the kernel supports both entry points by setting both of XLF_EFI_HANDOVER_32 and XLF_EFI_HANDOVER_64 when CONFIG_EFI_MIXED=y. XLF_CAN_BE_LOADED_ABOVE_4G is disabled so that the kernel text is guaranteed to be addressable with 32-bits. Note that no boot loaders should be using the bits set in xloadflags to decide which entry point to jump to. The entire scheme is based on the concept that 32-bit bootloaders always jump to ->handover_offset and 64-bit loaders always jump to ->handover_offset + 512. We set both bits merely to inform the boot loader that it's safe to use the native handover offset even if the machine type in the PE/COFF header claims otherwise. Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-05x86/efi: Add mixed runtime services supportMatt Fleming1-0/+21
Setup the runtime services based on whether we're booting in EFI native mode or not. For non-native mode we need to thunk from 64-bit into 32-bit mode before invoking the EFI runtime services. Using the runtime services after SetVirtualAddressMap() is slightly more complicated because we need to ensure that all the addresses we pass to the firmware are below the 4GB boundary so that they can be addressed with 32-bit pointers, see efi_setup_page_tables(). Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-05x86/efi: Firmware agnostic handover entry pointsMatt Fleming1-3/+3
The EFI handover code only works if the "bitness" of the firmware and the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not possible to mix the two. This goes against the tradition that a 32-bit kernel can be loaded on a 64-bit BIOS platform without having to do anything special in the boot loader. Linux distributions, for one thing, regularly run only 32-bit kernels on their live media. Despite having only one 'handover_offset' field in the kernel header, EFI boot loaders use two separate entry points to enter the kernel based on the architecture the boot loader was compiled for, (1) 32-bit loader: handover_offset (2) 64-bit loader: handover_offset + 512 Since we already have two entry points, we can leverage them to infer the bitness of the firmware we're running on, without requiring any boot loader modifications, by making (1) and (2) valid entry points for both CONFIG_X86_32 and CONFIG_X86_64 kernels. To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot loader will always use (2). It's just that, if a single kernel image supports (1) and (2) that image can be used with both 32-bit and 64-bit boot loaders, and hence both 32-bit and 64-bit EFI. (1) and (2) must be 512 bytes apart at all times, but that is already part of the boot ABI and we could never change that delta without breaking existing boot loaders anyhow. Signed-off-by: Matt Fleming <matt.fleming@intel.com>