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2019-03-06x86/boot/KASLR: Always return a value from process_mem_regionLouis Taylor
When compiling with -Wreturn-type, clang warns: arch/x86/boot/compressed/kaslr.c:704:1: warning: control may reach end of non-void function [-Wreturn-type] This function's return statement should have been placed outside the ifdeffed region. Move it there. Fixes: 690eaa532057 ("x86/boot/KASLR: Limit KASLR to extract the kernel in immovable memory only") Signed-off-by: Louis Taylor <louis@kragniz.eu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: bp@alien8.de Cc: hpa@zytor.com Cc: fanc.fnst@cn.fujitsu.com Cc: bhe@redhat.com Cc: kirill.shutemov@linux.intel.com Cc: jflat@chromium.org Link: https://lkml.kernel.org/r/20190302184929.28971-1-louis@kragniz.eu
2019-02-06x86/boot: Fix randconfig build error due to MEMORY_HOTREMOVEBorislav Petkov
When building randconfigs, one of the failures is: ld: arch/x86/boot/compressed/kaslr.o: in function `choose_random_location': kaslr.c:(.text+0xbf7): undefined reference to `count_immovable_mem_regions' ld: kaslr.c:(.text+0xcbe): undefined reference to `immovable_mem' make[2]: *** [arch/x86/boot/compressed/vmlinux] Error 1 because CONFIG_ACPI is not enabled in this particular .config but CONFIG_MEMORY_HOTREMOVE is and count_immovable_mem_regions() is unresolvable because it is defined in compressed/acpi.c which is the compilation unit that depends on CONFIG_ACPI. Add CONFIG_ACPI to the explicit dependencies for MEMORY_HOTREMOVE. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Chao Fan <fanc.fnst@cn.fujitsu.com> Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20190205131033.9564-1-bp@alien8.de
2019-02-01x86/boot/KASLR: Limit KASLR to extract the kernel in immovable memory onlyChao Fan
KASLR may randomly choose a range which is located in movable memory regions. As a result, this will break memory hotplug and make the movable memory chosen by KASLR immovable. Therefore, limit KASLR to choose memory regions in the immovable range after consulting the SRAT table. [ bp: - Rewrite commit message. - Trim comments. ] Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Baoquan He <bhe@redhat.com> Cc: caoj.fnst@cn.fujitsu.com Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: indou.takao@jp.fujitsu.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: kasong@redhat.com Cc: Kees Cook <keescook@chromium.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: msys.mizuma@gmail.com Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190123110850.12433-8-fanc.fnst@cn.fujitsu.com
2019-02-01x86/boot: Parse SRAT table and count immovable memory regionsChao Fan
Parse SRAT for the immovable memory regions and use that information to control which offset KASLR selects so that it doesn't overlap with any movable region. [ bp: - Move struct mem_vector where it is visible so that it builds. - Correct comments. - Rewrite commit message. ] Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Baoquan He <bhe@redhat.com> Cc: <caoj.fnst@cn.fujitsu.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <indou.takao@jp.fujitsu.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: <kasong@redhat.com> Cc: <keescook@chromium.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <msys.mizuma@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190123110850.12433-7-fanc.fnst@cn.fujitsu.com
2018-09-10x86/boot/KASLR: Remove return value from handle_mem_options()Chao Fan
It's not used by its sole user, so remove this unused functionality. Also remove a stray unused variable that GCC didn't warn about for some reason. Suggested-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> Cc: Baoquan He <bhe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kirill.shutemov@linux.intel.com Link: http://lkml.kernel.org/r/20180807015705.21697-1-fanc.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-08-22module: allow symbol exports to be disabledArd Biesheuvel
To allow existing C code to be incorporated into the decompressor or the UEFI stub, introduce a CPP macro that turns all EXPORT_SYMBOL_xxx declarations into nops, and #define it in places where such exports are undesirable. Note that this gets rid of a rather dodgy redefine of linux/export.h's header guard. Link: http://lkml.kernel.org/r/20180704083651.24360-3-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-30x86/boot/KASLR: Make local variable mem_limit staticzhong jiang
Fix the following sparse warning: arch/x86/boot/compressed/kaslr.c:102:20: warning: symbol 'mem_limit' was not declared. Should it be static? Signed-off-by: zhong jiang <zhongjiang@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: <gregkh@linuxfoundation.org> Link: https://lkml.kernel.org/r/1532958273-47725-1-git-send-email-zhongjiang@huawei.com
2018-07-03x86/boot/KASLR: Skip specified number of 1GB huge pages when doing physical ↵Baoquan He
randomization (KASLR) When KASLR is enabled then 1GB huge pages allocations might regress sporadically. To reproduce on a KVM guest with 4GB RAM: - add the following options to the kernel command-line: 'default_hugepagesz=1G hugepagesz=1G hugepages=1' - boot the guest and check number of 1GB pages reserved: # grep HugePages_Total /proc/meminfo - sporadically, every couple of bootups the output of this command shows that when booting with "nokaslr" HugePages_Total is always 1, while booting without "nokaslr" sometimes HugePages_Total is set as 0 (that is, reserving the 1GB page failed). Note that you may need to boot a few times to trigger the issue, because it's somewhat non-deterministic. The root cause is that kernel may be put into the only good 1GB huge page in the [0x40000000, 0x7fffffff] physical range randomly. Below is the dmesg output snippet from the KVM guest. We can see that only [0x40000000, 0x7fffffff] region is good 1GB huge page, [0x100000000, 0x13fffffff] will be touched by the memblock top-down allocation: [...] e820: BIOS-provided physical RAM map: [...] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable [...] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved [...] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved [...] BIOS-e820: [mem 0x0000000000100000-0x00000000bffdffff] usable [...] BIOS-e820: [mem 0x00000000bffe0000-0x00000000bfffffff] reserved [...] BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved [...] BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved [...] BIOS-e820: [mem 0x0000000100000000-0x000000013fffffff] usable Besides, on bare-metal machines with larger memory, one less 1GB huge page might be available with KASLR enabled. That too is because the kernel image might be randomized into those "good" 1GB huge pages. To fix this, firstly parse the kernel command-line to get how many 1GB huge pages are specified. Then try to skip the specified number of 1GB huge pages when decide which memory region kernel can be randomized into. Also change the name of handle_mem_memmap() as handle_mem_options() since it handles not only 'mem=' and 'memmap=', but also 'hugepagesxxx' now. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: douly.fnst@cn.fujitsu.com Cc: fanc.fnst@cn.fujitsu.com Cc: indou.takao@jp.fujitsu.com Cc: keescook@chromium.org Cc: lcapitulino@redhat.com Cc: yasu.isimatu@gmail.com Link: http://lkml.kernel.org/r/20180625031656.12443-3-bhe@redhat.com [ Rewrote the changelog, fixed style problems in the code. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-03x86/boot/KASLR: Add two new functions for 1GB huge pages handlingBaoquan He
Introduce two new functions: parse_gb_huge_pages() and process_gb_huge_pages(), which handle a conflict between KASLR and huge pages of 1GB. These two functions will be used in the next patch: - parse_gb_huge_pages() is used to parse kernel command-line to get how many 1GB huge pages have been specified. A static global variable 'max_gb_huge_pages' is added to store the number. - process_gb_huge_pages() is used to skip as many 1GB huge pages as possible from the passed in memory region according to the specified number. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: douly.fnst@cn.fujitsu.com Cc: fanc.fnst@cn.fujitsu.com Cc: indou.takao@jp.fujitsu.com Cc: keescook@chromium.org Cc: lcapitulino@redhat.com Cc: yasu.isimatu@gmail.com Link: http://lkml.kernel.org/r/20180625031656.12443-2-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-19x86/mm: Unify pgtable_l5_enabled usage in early boot codeKirill A. Shutemov
Usually pgtable_l5_enabled is defined using cpu_feature_enabled(). cpu_feature_enabled() is not available in early boot code. We use several different preprocessor tricks to get around it. It's messy. Unify them all. If cpu_feature_enabled() is not yet available, USE_EARLY_PGTABLE_L5 can be defined before all includes. It makes pgtable_l5_enabled rely on __pgtable_l5_enabled variable instead. This approach fits all early users. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180518103528.59260-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-12x86/mm: Do not auto-massage page protectionsDave Hansen
A PTE is constructed from a physical address and a pgprotval_t. __PAGE_KERNEL, for instance, is a pgprot_t and must be converted into a pgprotval_t before it can be used to create a PTE. This is done implicitly within functions like pfn_pte() by massage_pgprot(). However, this makes it very challenging to set bits (and keep them set) if your bit is being filtered out by massage_pgprot(). This moves the bit filtering out of pfn_pte() and friends. For users of PAGE_KERNEL*, filtering will be done automatically inside those macros but for users of __PAGE_KERNEL*, they need to do their own filtering now. Note that we also just move pfn_pte/pmd/pud() over to check_pgprot() instead of massage_pgprot(). This way, we still *look* for unsupported bits and properly warn about them if we find them. This might happen if an unfiltered __PAGE_KERNEL* value was passed in, for instance. - printk format warning fix from: Arnd Bergmann <arnd@arndb.de> - boot crash fix from: Tom Lendacky <thomas.lendacky@amd.com> - crash bisected by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reported-and-fixed-by: Arnd Bergmann <arnd@arndb.de> Fixed-by: Tom Lendacky <thomas.lendacky@amd.com> Bisected-by: Mike Galbraith <efault@gmx.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180406205509.77E1D7F6@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-16x86/mm: Initialize 'pgdir_shift' and 'ptrs_per_p4d' at boot-timeKirill A. Shutemov
Switching between paging modes requires the folding of the p4d page table level when we only have 4 paging levels, which means we need to adjust 'pgdir_shift' and 'ptrs_per_p4d' during early boot according to paging mode. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> 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-mm@kvack.org Link: http://lkml.kernel.org/r/20180214182542.69302-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-16x86/mm: Initialize 'pgtable_l5_enabled' at boot-timeKirill A. Shutemov
'pgtable_l5_enabled' indicates which paging mode we are using. We need to initialize it at boot-time according to machine capability. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> 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-mm@kvack.org Link: http://lkml.kernel.org/r/20180214182542.69302-2-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-14x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variableKirill A. Shutemov
For boot-time switching between 4- and 5-level paging we need to be able to fold p4d page table level at runtime. It requires variable PGDIR_SHIFT and PTRS_PER_P4D. The change doesn't affect the kernel image size much: text data bss dec hex filename 8628091 4734304 1368064 14730459 e0c4db vmlinux.before 8628393 4734340 1368064 14730797 e0c62d vmlinux.after Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214111656.88514-7-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-14x86/mm: Introduce 'pgtable_l5_enabled'Kirill A. Shutemov
The new flag would indicate what paging mode we are in. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214111656.88514-5-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-23x86/boot/KASLR: Remove unused variableChao Fan
There are two variables "rc" in mem_avoid_memmap. One at the top of the function and another one inside the while() loop. Drop the outer one as it is unused. Cleanup some whitespace damage while at it. Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: gregkh@linuxfoundation.org Cc: n-horiguchi@ah.jp.nec.com Cc: keescook@chromium.org Link: https://lkml.kernel.org/r/20171123090847.15293-1-fanc.fnst@cn.fujitsu.com
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
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>
2017-08-31x86/boot/KASLR: Work around firmware bugs by excluding EFI_BOOT_SERVICES_* ↵Naoya Horiguchi
and EFI_LOADER_* from KASLR's choice There's a potential bug in how we select the KASLR kernel address n the early boot code. The KASLR boot code currently chooses the kernel image's physical memory location from E820_TYPE_RAM regions by walking over all e820 entries. E820_TYPE_RAM includes EFI_BOOT_SERVICES_CODE and EFI_BOOT_SERVICES_DATA as well, so those regions can end up hosting the kernel image. According to the UEFI spec, all memory regions marked as EfiBootServicesCode and EfiBootServicesData are available as free memory after the first call to ExitBootServices(). I.e. so such regions should be usable for the kernel, per spec. In real life however, we have workarounds for broken x86 firmware, where we keep such regions reserved until SetVirtualAddressMap() is done. See the following code in should_map_region(): static bool should_map_region(efi_memory_desc_t *md) { ... /* * Map boot services regions as a workaround for buggy * firmware that accesses them even when they shouldn't. * * See efi_{reserve,free}_boot_services(). */ if (md->type =3D=3D EFI_BOOT_SERVICES_CODE || md->type =3D=3D EFI_BOOT_SERVICES_DATA) return false; This workaround suppressed a boot crash, but potential issues still remain because no one prevents the regions from overlapping with kernel image by KASLR. So let's make sure that EFI_BOOT_SERVICES_{CODE|DATA} regions are never chosen as kernel memory for the workaround to work fine. Furthermore, EFI_LOADER_{CODE|DATA} regions are also excluded because they can be used after ExitBootServices() as defined in EFI spec. As a result, we choose kernel address only from EFI_CONVENTIONAL_MEMORY which is the only memory type we know to be safely free. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Baoquan He <bhe@redhat.com> Cc: Junichi Nomura <j-nomura@ce.jp.nec.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: fanc.fnst@cn.fujitsu.com Cc: izumi.taku@jp.fujitsu.com Link: http://lkml.kernel.org/r/20170828074444.GC23181@hori1.linux.bs1.fc.nec.co.jp [ Rewrote/fixed/clarified the changelog and the in code comments. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-17x86/boot/KASLR: Prefer mirrored memory regions for the kernel physical addressBaoquan He
Currently KASLR will parse all e820 entries of RAM type and add all candidate positions into the slots array. After that we choose one slot randomly as the new position which the kernel will be decompressed into and run at. On systems with EFI enabled, e820 memory regions are coming from EFI memory regions by combining adjacent regions. These EFI memory regions have various attributes, and the "mirrored" attribute is one of them. The physical memory region whose descriptors in EFI memory map has EFI_MEMORY_MORE_RELIABLE attribute (bit: 16) are mirrored. The address range mirroring feature of the kernel arranges such mirrored regions into normal zones and other regions into movable zones. With the mirroring feature enabled, the code and data of the kernel can only be located in the more reliable mirrored regions. However, the current KASLR code doesn't check EFI memory entries, and could choose a new kernel position in non-mirrored regions. This will break the intended functionality of the address range mirroring feature. To fix this, if EFI is detected, iterate EFI memory map and pick the mirrored region to process for adding candidate of randomization slot. If EFI is disabled or no mirrored region found, still process the e820 memory map. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: ard.biesheuvel@linaro.org Cc: fanc.fnst@cn.fujitsu.com Cc: izumi.taku@jp.fujitsu.com Cc: keescook@chromium.org Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: n-horiguchi@ah.jp.nec.com Cc: thgarnie@google.com Link: http://lkml.kernel.org/r/1502722464-20614-3-git-send-email-bhe@redhat.com [ Rewrote most of the text. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-18x86/boot/KASLR: Rename process_e820_entry() into process_mem_region()Baoquan He
Now process_e820_entry() is not limited to e820 entry processing, rename it to process_mem_region(). And adjust the code comment accordingly. Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: fanc.fnst@cn.fujitsu.com Cc: izumi.taku@jp.fujitsu.com Cc: matt@codeblueprint.co.uk Cc: thgarnie@google.com Link: http://lkml.kernel.org/r/1499603862-11516-4-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-18x86/boot/KASLR: Switch to pass struct mem_vector to process_e820_entry()Baoquan He
This makes process_e820_entry() be able to process any kind of memory region. Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: fanc.fnst@cn.fujitsu.com Cc: izumi.taku@jp.fujitsu.com Cc: matt@codeblueprint.co.uk Cc: thgarnie@google.com Link: http://lkml.kernel.org/r/1499603862-11516-3-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-18x86/boot/KASLR: Wrap e820 entries walking code into new function ↵Baoquan He
process_e820_entries() The original function process_e820_entry() only takes care of each e820 entry passed. And move the E820_TYPE_RAM checking logic into process_e820_entries(). And remove the redundent local variable 'addr' definition in find_random_phys_addr(). Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: fanc.fnst@cn.fujitsu.com Cc: izumi.taku@jp.fujitsu.com Cc: matt@codeblueprint.co.uk Cc: thgarnie@google.com Link: http://lkml.kernel.org/r/1499603862-11516-2-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-03Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "The main changes in this cycle were KASLR improvements for rare environments with special boot options, by Baoquan He. Also misc smaller changes/cleanups" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/debug: Extend the lower bound of crash kernel low reservations x86/boot: Remove unused copy_*_gs() functions x86/KASLR: Use the right memcpy() implementation Documentation/kernel-parameters.txt: Update 'memmap=' boot option description x86/KASLR: Handle the memory limit specified by the 'memmap=' and 'mem=' boot options x86/KASLR: Parse all 'memmap=' boot option entries
2017-06-30x86/boot/KASLR: Fix kexec crash due to 'virt_addr' calculation bugBaoquan He
Kernel text KASLR is separated into physical address and virtual address randomization. And for virtual address randomization, we only randomiza to get an offset between 16M and KERNEL_IMAGE_SIZE. So the initial value of 'virt_addr' should be LOAD_PHYSICAL_ADDR, but not the original kernel loading address 'output'. The bug will cause kernel boot failure if kernel is loaded at a different position than the address, 16M, which is decided at compiled time. Kexec/kdump is such practical case. To fix it, just assign LOAD_PHYSICAL_ADDR to virt_addr as initial value. Tested-by: Dave Young <dyoung@redhat.com> Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 8391c73 ("x86/KASLR: Randomize virtual address separately") Link: http://lkml.kernel.org/r/1498567146-11990-3-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-31x86/KASLR: Use the right memcpy() implementationArnd Bergmann
The decompressor has its own implementation of the string functions, but has to include the right header to get those, while implicitly including linux/string.h may result in a link error: arch/x86/boot/compressed/kaslr.o: In function `choose_random_location': kaslr.c:(.text+0xf51): undefined reference to `_mmx_memcpy' This has appeared now as KASLR started using memcpy(), via: d52e7d5a952c ("x86/KASLR: Parse all 'memmap=' boot option entries") Other files in the decompressor already do the same thing. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Baoquan He <bhe@redhat.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170530091446.1000183-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-24x86/KASLR: Handle the memory limit specified by the 'memmap=' and 'mem=' ↵Baoquan He
boot options The 'mem=' boot option limits the max address a system can use - any memory region above the limit will be removed. Furthermore, the 'memmap=nn[KMG]' variant (with no offset specified) has the same behaviour as 'mem='. KASLR needs to consider this when choosing the random position for decompressing the kernel. Do it. Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dan.j.williams@intel.com Cc: douly.fnst@cn.fujitsu.com Cc: dyoung@redhat.com Link: http://lkml.kernel.org/r/1494654390-23861-3-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-24x86/KASLR: Parse all 'memmap=' boot option entriesBaoquan He
In commit: f28442497b5c ("x86/boot: Fix KASLR and memmap= collision") ... the memmap= option is parsed so that KASLR can avoid those reserved regions. It uses cmdline_find_option() to get the value if memmap= is specified, however the problem is that cmdline_find_option() can only find the last entry if multiple memmap entries are provided. This is not correct. Address this by checking each command line token for a "memmap=" match and parse each instance instead of using cmdline_find_option(). Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dan.j.williams@intel.com Cc: douly.fnst@cn.fujitsu.com Cc: dyoung@redhat.com Cc: m.mizuma@jp.fujitsu.com Link: http://lkml.kernel.org/r/1494654390-23861-2-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-28x86/KASLR: Fix kexec kernel boot crash when KASLR randomization failsBaoquan He
Dave found that a kdump kernel with KASLR enabled will reset to the BIOS immediately if physical randomization failed to find a new position for the kernel. A kernel with the 'nokaslr' option works in this case. The reason is that KASLR will install a new page table for the identity mapping, while it missed building it for the original kernel location if KASLR physical randomization fails. This only happens in the kexec/kdump kernel, because the identity mapping has been built for kexec/kdump in the 1st kernel for the whole memory by calling init_pgtable(). Here if physical randomizaiton fails, it won't build the identity mapping for the original area of the kernel but change to a new page table '_pgtable'. Then the kernel will triple fault immediately caused by no identity mappings. The normal kernel won't see this bug, because it comes here via startup_32() and CR3 will be set to _pgtable already. In startup_32() the identity mapping is built for the 0~4G area. In KASLR we just append to the existing area instead of entirely overwriting it for on-demand identity mapping building. So the identity mapping for the original area of kernel is still there. To fix it we just switch to the new identity mapping page table when physical KASLR succeeds. Otherwise we keep the old page table unchanged just like "nokaslr" does. Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Dave Young <dyoung@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1493278940-5885-1-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-29x86/boot/e820: Separate the E820 ABI structures from the in-kernel structuresIngo Molnar
Linus pointed out that relying on the compiler to pack structures with enums is fragile not just for the kernel, but for external tooling as well which might rely on our UAPI headers. So separate the two from each other: introduce 'struct boot_e820_entry', which is the boot protocol entry format. This actually simplifies the code, as e820__update_table() is now never called directly with boot protocol table entries - we can rely on append_e820_table() and do a e820__update_table() call afterwards. ( This will allow further simplifications of __e820__update_table(), but that will be done in a separate patch. ) This change also has the side effect of not modifying the bootparams structure anymore - which might be useful for debugging. In theory we could even constify the boot_params structure - at least from the E820 code's point of view. Remove the uapi/asm/e820/types.h file, as it's not used anymore - all kernel side E820 types are defined in asm/e820/types.h. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Prefix the E820_* type names with "E820_TYPE_"Ingo Molnar
So there's a number of constants that start with "E820" but which are not types - these create a confusing mixture when seen together with 'enum e820_type' values: E820MAP E820NR E820_X_MAX E820MAX To better differentiate the 'enum e820_type' values prefix them with E820_TYPE_. No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Rename everything to e820_tableIngo Molnar
No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Rename 'e820_map' variables to 'e820_array'Ingo Molnar
In line with the rename to 'struct e820_array', harmonize the naming of common e820 table variable names as well: e820 => e820_array e820_saved => e820_array_saved e820_map => e820_array initial_e820 => e820_array_init This makes the variable names more consistent and easier to grep for. No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Rename the basic e820 data types to 'struct e820_entry' and ↵Ingo Molnar
'struct e820_array' The 'e820entry' and 'e820map' names have various annoyances: - the missing underscore departs from the usual kernel style and makes the code look weird, - in the past I kept confusing the 'map' with the 'entry', because a 'map' is ambiguous in that regard, - it's not really clear from the 'e820map' that this is a regular C array. Rename them to 'struct e820_entry' and 'struct e820_array' accordingly. ( Leave the legacy UAPI header alone but do the rename in the bootparam.h and e820/types.h file - outside tools relying on these defines should either adjust their code, or should use the legacy header, or should create their private copies for the definitions. ) No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-25x86/boot: Fix KASLR and memmap= collisionDave Jiang
CONFIG_RANDOMIZE_BASE=y relocates the kernel to a random base address. However it does not take into account the memmap= parameter passed in from the kernel command line. This results in the kernel sometimes being put in the middle of memmap. Teach KASLR to not insert the kernel in memmap defined regions. We support up to 4 memmap regions: any additional regions will cause KASLR to disable. The mem_avoid set has been augmented to add up to 4 unusable regions of memmaps provided by the user to exclude those regions from the set of valid address range to insert the uncompressed kernel image. The nn@ss ranges will be skipped by the mem_avoid set since it indicates that memory is useable. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@kernel.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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: dan.j.williams@intel.com Cc: david@fromorbit.com Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/148417664156.131935.2248592164852799738.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-08x86/mm: Refactor KASLR entropy functionsThomas Garnier
Move the KASLR entropy functions into arch/x86/lib to be used in early kernel boot for KASLR memory randomization. Signed-off-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: Alexander Popov <alpopov@ptsecurity.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Baoquan He <bhe@redhat.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lv Zheng <lv.zheng@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/1466556426-32664-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-08x86/KASLR: Fix boot crash with certain memory configurationsBaoquan He
Ye Xiaolong reported this boot crash: | | XZ-compressed data is corrupt | | -- System halted | Fix the bug in mem_avoid_overlap() of finding the earliest overlap. Reported-and-tested-by: Ye Xiaolong <xiaolong.ye@intel.com> Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-26x86/KASLR: Allow randomization below the load addressYinghai Lu
Currently the kernel image physical address randomization's lower boundary is the original kernel load address. For bootloaders that load kernels into very high memory (e.g. kexec), this means randomization takes place in a very small window at the top of memory, ignoring the large region of physical memory below the load address. Since mem_avoid[] is already correctly tracking the regions that must be avoided, this patch changes the minimum address to whatever is less: 512M (to conservatively avoid unknown things in lower memory) or the load address. Now, for example, if the kernel is loaded at 8G, [512M, 8G) will be added to the list of possible physical memory positions. Signed-off-by: Yinghai Lu <yinghai@kernel.org> [ Rewrote the changelog, refactored the code to use min(). ] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.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> Link: http://lkml.kernel.org/r/1464216334-17200-6-git-send-email-keescook@chromium.org [ Edited the changelog some more, plus the code comment as well. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-26x86/KASLR: Extend kernel image physical address randomization to addresses ↵Kees Cook
larger than 4G We want the physical address to be randomized anywhere between 16MB and the top of physical memory (up to 64TB). This patch exchanges the prior slots[] array for the new slot_areas[] array, and lifts the limitation of KERNEL_IMAGE_SIZE on the physical address offset for 64-bit. As before, process_e820_entry() walks memory and populates slot_areas[], splitting on any detected mem_avoid collisions. Finally, since the slots[] array and its associated functions are not needed any more, so they are removed. Based on earlier patches by Baoquan He. Originally-from: Baoquan He <bhe@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.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: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1464216334-17200-5-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-26x86/KASLR: Randomize virtual address separatelyBaoquan He
The current KASLR implementation randomizes the physical and virtual addresses of the kernel together (both are offset by the same amount). It calculates the delta of the physical address where vmlinux was linked to load and where it is finally loaded. If the delta is not equal to 0 (i.e. the kernel was relocated), relocation handling needs be done. On 64-bit, this patch randomizes both the physical address where kernel is decompressed and the virtual address where kernel text is mapped and will execute from. We now have two values being chosen, so the function arguments are reorganized to pass by pointer so they can be directly updated. Since relocation handling only depends on the virtual address, we must check the virtual delta, not the physical delta for processing kernel relocations. This also populates the page table for the new virtual address range. 32-bit does not support a separate virtual address, so it continues to use the physical offset for its virtual offset. Additionally updates the sanity checks done on the resulting kernel addresses since they are potentially separate now. [kees: rewrote changelog, limited virtual split to 64-bit only, update checks] [kees: fix CONFIG_RANDOMIZE_BASE=n boot failure] Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.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: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1464216334-17200-4-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-26x86/KASLR: Clarify identity map interfaceKees Cook
This extracts the call to prepare_level4() into a top-level function that the user of the pagetable.c interface must call to initialize the new page tables. For clarity and to match the "finalize" function, it has been renamed to initialize_identity_maps(). This function also gains the initialization of mapping_info so we don't have to do it each time in add_identity_map(). Additionally add copyright notice to the top, to make it clear that the bulk of the pagetable.c code was written by Yinghai, and that I just added bugs later. :) Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.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: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1464216334-17200-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-26x86/KASLR, x86/power: Remove x86 hibernation restrictionsKees Cook
With the following fix: 70595b479ce1 ("x86/power/64: Fix crash whan the hibernation code passes control to the image kernel") ... there is no longer a problem with hibernation resuming a KASLR-booted kernel image, so remove the restriction. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.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: Jonathan Corbet <corbet@lwn.net> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linux PM list <linux-pm@vger.kernel.org> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20160613221002.GA29719@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-10x86/KASLR: Clarify purpose of each get_random_long()Kees Cook
KASLR will be calling get_random_long() twice, but the debug output won't distinguishing between them. This patch adds a report on when it is fetching the physical vs virtual address. With this, once the virtual offset is separate, the report changes from: KASLR using RDTSC... KASLR using RDTSC... into: Physical KASLR using RDTSC... Virtual KASLR using RDTSC... Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1462825332-10505-7-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-10x86/KASLR: Add virtual address choosing functionBaoquan He
To support randomizing the kernel virtual address separately from the physical address, this patch adds find_random_virt_addr() to choose a slot anywhere between LOAD_PHYSICAL_ADDR and KERNEL_IMAGE_SIZE. Since this address is virtual, not physical, we can place the kernel anywhere in this region, as long as it is aligned and (in the case of kernel being larger than the slot size) placed with enough room to load the entire kernel image. For clarity and readability, find_random_addr() is renamed to find_random_phys_addr() and has "size" renamed to "image_size" to match find_random_virt_addr(). Signed-off-by: Baoquan He <bhe@redhat.com> [ Rewrote changelog, refactored slot calculation for readability. ] [ Renamed find_random_phys_addr() and size argument. ] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1462825332-10505-6-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-10x86/KASLR: Return earliest overlap when avoiding regionsKees Cook
In preparation for being able to detect where to split up contiguous memory regions that overlap with memory regions to avoid, we need to pass back what the earliest overlapping region was. This modifies the overlap checker to return that information. Based on a separate mem_min_overlap() implementation by Baoquan He. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1462825332-10505-5-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-10x86/KASLR: Add 'struct slot_area' to manage random_addr slotsBaoquan He
In order to support KASLR moving the kernel anywhere in physical memory (which could be up to 64TB), we need to handle counting the potential randomization locations in a more efficient manner. In the worst case with 64TB, there could be roughly 32 * 1024 * 1024 randomization slots if CONFIG_PHYSICAL_ALIGN is 0x1000000. Currently the starting address of candidate positions is stored into the slots[] array, one at a time. This method would cost too much memory and it's also very inefficient to get and save the slot information into the slot array one by one. This patch introduces 'struct slot_area' to manage each contiguous region of randomization slots. Each slot_area will contain the starting address and how many available slots are in this area. As with the original code, the slot_areas[] will avoid the mem_avoid[] regions. Since setup_data is a linked list, it could contain an unknown number of memory regions to be avoided, which could cause us to fragment the contiguous memory that the slot_area array is tracking. In normal operation this level of fragmentation will be extremely rare, but we choose a suitably large value (100) for the array. If setup_data forces the slot_area array to become highly fragmented and there are more slots available beyond the first 100 found, the rest will be ignored for KASLR selection. The function store_slot_info() is used to calculate the number of slots available in the passed-in memory region and stores it into slot_areas[] after adjusting for alignment and size requirements. Signed-off-by: Baoquan He <bhe@redhat.com> [ Rewrote changelog, squashed with new functions. ] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1462825332-10505-4-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-10x86/boot: Add missing file header commentsKees Cook
There were some files with missing header comments. Since they are included from both compressed and regular kernels, make note of that. Also corrects a typo in the mem_avoid comments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1462825332-10505-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-10x86/boot: Comment what finalize_identity_maps() doesBorislav Petkov
So it is not really obvious that finalize_identity_maps() doesn't do any finalization but it *actually* writes CR3 with the ident PGD. Comment that at the call site. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: bhe@redhat.com Cc: dyoung@redhat.com Cc: jkosina@suse.cz Cc: linux-tip-commits@vger.kernel.org Cc: luto@kernel.org Cc: vgoyal@redhat.com Cc: yinghai@kernel.org Link: http://lkml.kernel.org/r/20160507100541.GA24613@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-07x86/KASLR: Build identity mappings on demandKees Cook
Currently KASLR only supports relocation in a small physical range (from 16M to 1G), due to using the initial kernel page table identity mapping. To support ranges above this, we need to have an identity mapping for the desired memory range before we can decompress (and later run) the kernel. 32-bit kernels already have the needed identity mapping. This patch adds identity mappings for the needed memory ranges on 64-bit kernels. This happens in two possible boot paths: If loaded via startup_32(), we need to set up the needed identity map. If loaded from a 64-bit bootloader, the bootloader will have already set up an identity mapping, and we'll start via the compressed kernel's startup_64(). In this case, the bootloader's page tables need to be avoided while selecting the new uncompressed kernel location. If not, the decompressor could overwrite them during decompression. To accomplish this, we could walk the pagetable and find every page that is used, and add them to mem_avoid, but this needs extra code and will require increasing the size of the mem_avoid array. Instead, we can create a new set of page tables for our own identity mapping instead. The pages for the new page table will come from the _pagetable section of the compressed kernel, which means they are already contained by in mem_avoid array. To do this, we reuse the code from the uncompressed kernel's identity mapping routines. The _pgtable will be shared by both the 32-bit and 64-bit paths to reduce init_size, as now the compressed kernel's _rodata to _end will contribute to init_size. To handle the possible mappings, we need to increase the existing page table buffer size: When booting via startup_64(), we need to cover the old VO, params, cmdline and uncompressed kernel. In an extreme case we could have them all beyond the 512G boundary, which needs (2+2)*4 pages with 2M mappings. And we'll need 2 for first 2M for VGA RAM. One more is needed for level4. This gets us to 19 pages total. When booting via startup_32(), KASLR could move the uncompressed kernel above 4G, so we need to create extra identity mappings, which should only need (2+2) pages at most when it is beyond the 512G boundary. So 19 pages is sufficient for this case as well. The resulting BOOT_*PGT_SIZE defines use the "_SIZE" suffix on their names to maintain logical consistency with the existing BOOT_HEAP_SIZE and BOOT_STACK_SIZE defines. This patch is based on earlier patches from Yinghai Lu and Baoquan He. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1462572095-11754-4-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-07x86/KASLR: Improve comments around the mem_avoid[] logicKees Cook
This attempts to improve the comments that describe how the memory range used for decompression is avoided. Additionally uses an enum instead of raw numbers for the mem_avoid[] indexing. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20160506194459.GA16480@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-07x86/boot: Simplify pointer casting in choose_random_location()Borislav Petkov
Pass them down as 'unsigned long' directly and get rid of more casting and assignments. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: bhe@redhat.com Cc: dyoung@redhat.com Cc: linux-tip-commits@vger.kernel.org Cc: luto@kernel.org Cc: vgoyal@redhat.com Cc: yinghai@kernel.org Link: http://lkml.kernel.org/r/20160506115015.GI24044@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>