linux/include/asm-generic/mm_hooks.h

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license 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>
2017-11-01 14:07:57 +00:00
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Define generic no-op hooks for arch_dup_mmap and arch_exit_mmap
* to be included in asm-FOO/mmu_context.h for any arch FOO which
* doesn't need to hook these.
*/
#ifndef _ASM_GENERIC_MM_HOOKS_H
#define _ASM_GENERIC_MM_HOOKS_H
static inline int arch_dup_mmap(struct mm_struct *oldmm,
struct mm_struct *mm)
{
return 0;
}
static inline void arch_exit_mmap(struct mm_struct *mm)
{
}
mm/core: Do not enforce PKEY permissions on remote mm access We try to enforce protection keys in software the same way that we do in hardware. (See long example below). But, we only want to do this when accessing our *own* process's memory. If GDB set PKRU[6].AD=1 (disable access to PKEY 6), then tried to PTRACE_POKE a target process which just happened to have some mprotect_pkey(pkey=6) memory, we do *not* want to deny the debugger access to that memory. PKRU is fundamentally a thread-local structure and we do not want to enforce it on access to _another_ thread's data. This gets especially tricky when we have workqueues or other delayed-work mechanisms that might run in a random process's context. We can check that we only enforce pkeys when operating on our *own* mm, but delayed work gets performed when a random user context is active. We might end up with a situation where a delayed-work gup fails when running randomly under its "own" task but succeeds when running under another process. We want to avoid that. To avoid that, we use the new GUP flag: FOLL_REMOTE and add a fault flag: FAULT_FLAG_REMOTE. They indicate that we are walking an mm which is not guranteed to be the same as current->mm and should not be subject to protection key enforcement. Thanks to Jerome Glisse for pointing out this scenario. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Dominik Vogt <vogt@linux.vnet.ibm.com> Cc: Eric B Munson <emunson@akamai.com> Cc: Geliang Tang <geliangtang@163.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Low <jason.low2@hp.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Shachar Raindel <raindel@mellanox.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xie XiuQi <xiexiuqi@huawei.com> Cc: iommu@lists.linux-foundation.org Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-12 21:02:21 +00:00
static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
mm/core, x86/mm/pkeys: Differentiate instruction fetches As discussed earlier, we attempt to enforce protection keys in software. However, the code checks all faults to ensure that they are not violating protection key permissions. It was assumed that all faults are either write faults where we check PKRU[key].WD (write disable) or read faults where we check the AD (access disable) bit. But, there is a third category of faults for protection keys: instruction faults. Instruction faults never run afoul of protection keys because they do not affect instruction fetches. So, plumb the PF_INSTR bit down in to the arch_vma_access_permitted() function where we do the protection key checks. We also add a new FAULT_FLAG_INSTRUCTION. This is because handle_mm_fault() is not passed the architecture-specific error_code where we keep PF_INSTR, so we need to encode the instruction fetch information in to the arch-generic fault flags. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> 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: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210224.96928009@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-12 21:02:24 +00:00
bool write, bool execute, bool foreign)
mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys Today, for normal faults and page table walks, we check the VMA and/or PTE to ensure that it is compatible with the action. For instance, if we get a write fault on a non-writeable VMA, we SIGSEGV. We try to do the same thing for protection keys. Basically, we try to make sure that if a user does this: mprotect(ptr, size, PROT_NONE); *ptr = foo; they see the same effects with protection keys when they do this: mprotect(ptr, size, PROT_READ|PROT_WRITE); set_pkey(ptr, size, 4); wrpkru(0xffffff3f); // access disable pkey 4 *ptr = foo; The state to do that checking is in the VMA, but we also sometimes have to do it on the page tables only, like when doing a get_user_pages_fast() where we have no VMA. We add two functions and expose them to generic code: arch_pte_access_permitted(pte_flags, write) arch_vma_access_permitted(vma, write) These are, of course, backed up in x86 arch code with checks against the PTE or VMA's protection key. But, there are also cases where we do not want to respect protection keys. When we ptrace(), for instance, we do not want to apply the tracer's PKRU permissions to the PTEs from the process being traced. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Dominik Vogt <vogt@linux.vnet.ibm.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Low <jason.low2@hp.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Shachar Raindel <raindel@mellanox.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20160212210219.14D5D715@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-12 21:02:19 +00:00
{
/* by default, allow everything */
return true;
}
#endif /* _ASM_GENERIC_MM_HOOKS_H */