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2018-01-13arm64: alternatives: use tpidr_el2 on VHE hostsJames Morse1-0/+2
Now that KVM uses tpidr_el2 in the same way as Linux's cpu_offset in tpidr_el1, merge the two. This saves KVM from save/restoring tpidr_el1 on VHE hosts, and allows future code to blindly access per-cpu variables without triggering world-switch. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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>
2016-11-05arm64: Fix circular include of asm/lse.h through linux/jump_label.hCatalin Marinas1-1/+1
Commit efd9e03facd0 ("arm64: Use static keys for CPU features") introduced support for static keys in asm/cpufeature.h, including linux/jump_label.h. When CC_HAVE_ASM_GOTO is not defined, this causes a circular dependency via linux/atomic.h, asm/lse.h and asm/cpufeature.h. This patch moves the capability macros out out of asm/cpufeature.h into a separate asm/cpucaps.h and modifies some of the #includes accordingly. Fixes: efd9e03facd0 ("arm64: Use static keys for CPU features") Reported-by: Artem Savkov <asavkov@redhat.com> Tested-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-12treewide: remove redundant #include <linux/kconfig.h>Masahiro Yamada1-1/+0
Kernel source files need not include <linux/kconfig.h> explicitly because the top Makefile forces to include it with: -include $(srctree)/include/linux/kconfig.h This commit removes explicit includes except the following: * arch/s390/include/asm/facilities_src.h * tools/testing/radix-tree/linux/kernel.h These two are used for host programs. Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-12arm64: alternative: add auto-nop infrastructureMark Rutland1-17/+53
In some cases, one side of an alternative sequence is simply a number of NOPs used to balance the other side. Keeping track of this manually is tedious, and the presence of large chains of NOPs makes the code more painful to read than necessary. To ameliorate matters, this patch adds a new alternative_else_nop_endif, which automatically balances an alternative sequence with a trivial NOP sled. In many cases, we would like a NOP-sled in the default case, and instructions patched in in the presence of a feature. To enable the NOPs to be generated automatically for this case, this patch also adds a new alternative_if, and updates alternative_else and alternative_endif to work with either alternative_if or alternative_endif. Cc: Andre Przywara <andre.przywara@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Martin <dave.martin@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> [will: use new nops macro to generate nop sequences] Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-07-01arm64: fix "dc cvau" cache operation on errata-affected coreAndre Przywara1-0/+4
The ARM errata 819472, 826319, 827319 and 824069 for affected Cortex-A53 cores demand to promote "dc cvau" instructions to "dc civac" as well. Attribute the usage of the instruction in __flush_cache_user_range to also be covered by our alternative patching efforts. For that we introduce an assembly macro which both deals with alternatives while still tagging the instructions as USER. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-01Revert "arm64: alternatives: add enable parameter to conditional asm macros"Andre Przywara1-9/+3
Commit 77ee306c0aea9 ("arm64: alternatives: add enable parameter to conditional asm macros") extended the alternative assembly macros. Unfortunately this does not really work as one would expect, as the enable parameter in fact correctly protects the alternative section magic, but not the actual code sequences. This results in having both the original instruction(s) _and_ the alternative ones, if enable if false. Since there is no user of this macros anyway, just revert it. This reverts commit 77ee306c0aea9a219daec256ad25982944affef8. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: switch to relative exception tablesArd Biesheuvel1-14/+5
Instead of using absolute addresses for both the exception location and the fixup, use offsets relative to the exception table entry values. Not only does this cut the size of the exception table in half, it is also a prerequisite for KASLR, since absolute exception table entries are subject to dynamic relocation, which is incompatible with the sorting of the exception table that occurs at build time. This patch also introduces the _ASM_EXTABLE preprocessor macro (which exists on x86 as well) and its _asm_extable assembly counterpart, as shorthands to emit exception table entries. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: kernel: Add support for User Access OverrideJames Morse1-0/+72
'User Access Override' is a new ARMv8.2 feature which allows the unprivileged load and store instructions to be overridden to behave in the normal way. This patch converts {get,put}_user() and friends to use ldtr*/sttr* instructions - so that they can only access EL0 memory, then enables UAO when fs==KERNEL_DS so that these functions can access kernel memory. This allows user space's read/write permissions to be checked against the page tables, instead of testing addr<USER_DS, then using the kernel's read/write permissions. Signed-off-by: James Morse <james.morse@arm.com> [catalin.marinas@arm.com: move uao_thread_switch() above dsb()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-12-10arm64: mm: fold alternatives into .initMark Rutland1-1/+0
Currently we treat the alternatives separately from other data that's only used during initialisation, using separate .altinstructions and .altinstr_replacement linker sections. These are freed for general allocation separately from .init*. This is problematic as: * We do not remove execute permissions, as we do for .init, leaving the memory executable. * We pad between them, making the kernel Image bianry up to PAGE_SIZE bytes larger than necessary. This patch moves the two sections into the contiguous region used for .init*. This saves some memory, ensures that we remove execute permissions, and allows us to remove some code made redundant by this reorganisation. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-30arm64: alternative: put secondary CPUs into polling loop during patchWill Deacon1-1/+2
When patching the kernel text with alternatives, we may end up patching parts of the stop_machine state machine (e.g. atomic_dec_and_test in ack_state) and consequently corrupt the instruction stream of any secondary CPUs. This patch passes the cpu_online_mask to stop_machine, forcing all of the CPUs into our own callback which can place the secondary cores into a dumb (but safe!) polling loop whilst the patching is carried out. Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: alternatives: add enable parameter to conditional asm macrosWill Deacon1-3/+9
There are cases where we want to compile out both versions of an alternative code block, so add an enable parameter to the new conditional alternative assembly macros in the same way as alternative_insn. Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: kernel: Add optional CONFIG_ parameter to ALTERNATIVE()James Morse1-3/+25
Some uses of ALTERNATIVE() may depend on a feature that is disabled at compile time by a Kconfig option. In this case the unused alternative instructions waste space, and if the original instruction is a nop, it wastes time and space. This patch adds an optional 'config' option to ALTERNATIVE() and alternative_insn that allows the compiler to remove both the original and alternative instructions if the config option is not defined. Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27arm64: alternative: Provide if/else/endif assembler macrosDaniel Thompson1-0/+41
The existing alternative_insn macro has some limitations that make it hard to work with. In particular the fact it takes instructions from it own macro arguments means it doesn't play very nicely with C pre-processor macros because the macro arguments look like a string to the C pre-processor. Workarounds are (probably) possible but things start to look ugly. Introduce an alternative set of macros that allows instructions to be presented to the assembler as normal and switch everything over to the new macros. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-06-05arm64: alternative: Work around .inst assembler bugsMarc Zyngier1-7/+18
AArch64 toolchains suffer from the following bug: $ cat blah.S 1: .inst 0x01020304 .if ((. - 1b) != 4) .error "blah" .endif $ aarch64-linux-gnu-gcc -c blah.S blah.S: Assembler messages: blah.S:3: Error: non-constant expression in ".if" statement which precludes the use of msr_s and co as part of alternatives. We workaround this issue by not directly testing the labels themselves, but by moving the current output pointer by a value that should always be zero. If this value is not null, then we will trigger a backward move, which is expclicitely forbidden. This triggers the error we're after: AS arch/arm64/kvm/hyp.o arch/arm64/kvm/hyp.S: Assembler messages: arch/arm64/kvm/hyp.S:1377: Error: attempt to move .org backwards scripts/Makefile.build:294: recipe for target 'arch/arm64/kvm/hyp.o' failed make[1]: *** [arch/arm64/kvm/hyp.o] Error 1 Makefile:946: recipe for target 'arch/arm64/kvm' failed Not pretty, but at least works on the current toolchains. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-05arm64: alternative: Merge alternative-asm.h into alternative.hMarc Zyngier1-0/+27
asm/alternative-asm.h and asm/alternative.h are extremely similar, and really deserve to live in the same file (as this makes further modufications a bit easier). Fold the content of alternative-asm.h into alternative.h, and update the few users. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-12-04arm64: add module support for alternatives fixupsAndre Przywara1-1/+2
Currently the kernel patches all necessary instructions once at boot time, so modules are not covered by this. Change the apply_alternatives() function to take a beginning and an end pointer and introduce a new variant (apply_alternatives_all()) to cover the existing use case for the static kernel image section. Add a module_finalize() function to arm64 to check for an alternatives section in a module and patch only the instructions from that specific area. Since that module code is not touched before the module initialization has ended, we don't need to halt the machine before doing the patching in the module's code. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-25arm64: add alternative runtime patchingAndre Przywara1-0/+43
With a blatant copy of some x86 bits we introduce the alternative runtime patching "framework" to arm64. This is quite basic for now and we only provide the functions we need at this time. This is connected to the newly introduced feature bits. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>