kernel/linux.git/arch/x86/boot/compressed/string.c, branch linux-5.9.y

x86/boot: Provide KASAN compatible aliases for string routines

2019-05-24T06:44:16+00:00

The KASAN subsystem wraps calls to memcpy(), memset() and memmove() to sanitize the arguments before invoking the actual routines, which have been renamed to __memcpy(), __memset() and __memmove(), respectively. When CONFIG_KASAN is enabled for the kernel build but KASAN code generation is disabled for the compilation unit (which is needed for things like the EFI stub or the decompressor), the string routines are just #define'd to their __ prefixed names so that they are simply invoked directly. This does however rely on those __ prefixed names to exist in the symbol namespace, which is not currently the case for the x86 decompressor, which may lead to errors like drivers/firmware/efi/libstub/tpm.o: In function `efi_retrieve_tpm2_eventlog': tpm.c:(.text+0x2a8): undefined reference to `__memcpy' So let's expose the __ prefixed symbols in the decompressor when KASAN is enabled. Signed-off-by: Ard Biesheuvel Acked-by: Jarkko Sakkinen Cc: Andrey Konovalov Cc: Borislav Petkov Cc: Linus Torvalds Cc: Matthew Garrett Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Signed-off-by: Ingo Molnar

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

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 Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

x86/boot: Warn on future overlapping memcpy() use

2016-05-03T06:15:58+00:00

If an overlapping memcpy() is ever attempted, we should at least report it, in case it might lead to problems, so it could be changed to a memmove() call instead. Suggested-by: Ingo Molnar Signed-off-by: Kees Cook Cc: Andy Lutomirski Cc: Baoquan He Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Lasse Collin Cc: Linus Torvalds Cc: One Thousand Gnomes Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Yinghai Lu Link: http://lkml.kernel.org/r/1462229461-3370-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar

x86/boot: Extract error reporting functions

2016-05-03T06:15:58+00:00

Currently to use warn(), a caller would need to include misc.h. However, this means they would get the (unavailable during compressed boot) gcc built-in memcpy family of functions. But since string.c is defining these memcpy functions for use by misc.c, we end up in a weird circular dependency. To break this loop, move the error reporting functions outside of misc.c with their own header so that they can be independently included by other sources. Since the screen-writing routines use memmove(), keep the low-level *_putstr() functions in misc.c. Signed-off-by: Kees Cook Cc: Andy Lutomirski Cc: Baoquan He Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Lasse Collin Cc: Linus Torvalds Cc: One Thousand Gnomes Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Yinghai Lu Link: http://lkml.kernel.org/r/1462229461-3370-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar

x86/boot: Rename overlapping memcpy() to memmove()

2016-04-28T09:02:29+00:00

Instead of having non-standard memcpy() behavior, explicitly call the new function memmove(), make it available to the decompressors, and switch the two overlap cases (screen scrolling and ELF parsing) to use memmove(). Additionally documents the purpose of compressed/string.c. Suggested-by: Lasse Collin Signed-off-by: Kees Cook Cc: Andrew Morton Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Baoquan He Cc: Borislav Petkov Cc: Dmitry Vyukov Cc: H.J. Lu Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Yinghai Lu Link: http://lkml.kernel.org/r/20160426214606.GA5758@www.outflux.net Signed-off-by: Ingo Molnar

x86/boot: Make memcpy() handle overlaps

2016-04-22T08:00:50+00:00

Two uses of memcpy() (screen scrolling and ELF parsing) were handling overlapping memory areas. While there were no explicitly noticed bugs here (yet), it is best to fix this so that the copying will always be safe. Instead of making a new memmove() function that might collide with other memmove() definitions in the decompressors, this just makes the compressed boot code's copy of memcpy() overlap-safe. Suggested-by: Lasse Collin Reported-by: Yinghai Lu Signed-off-by: Kees Cook Cc: Andrew Morton Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Baoquan He Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Dmitry Vyukov Cc: H. Peter Anvin Cc: H.J. Lu Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1461185746-8017-5-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar

x86, boot: Remove misc.h inclusion from compressed/string.c

2014-05-08T15:00:06+00:00

Given the fact that we removed inclusion of boot.h from boot/string.c does not look like we need misc.h inclusion in compressed/string.c. So remove it. misc.h was also pulling in string_32.h which in turn had macros for memcmp and memcpy. So we don't need to #undef memcmp and memcpy anymore. Signed-off-by: Vivek Goyal Link: http://lkml.kernel.org/r/1398447972-27896-3-git-send-email-vgoyal@redhat.com Signed-off-by: H. Peter Anvin

x86, boot: Move memset() definition in compressed/string.c

2014-03-19T22:44:09+00:00

Currently compressed/misc.c needs to link against memset(). I think one of the reasons of this need is inclusion of various header files which define static inline functions and use memset() inside these. For example, include/linux/bitmap.h I think trying to include "../string.h" and using builtin version of memset does not work because by the time "#define memset" shows up, it is too late. Some other header file has already used memset() and expects to find a definition during link phase. Currently we have a C definitoin of memset() in misc.c. Move it to compressed/string.c so that others can use it if need be. Signed-off-by: Vivek Goyal Link: http://lkml.kernel.org/r/1395170800-11059-6-git-send-email-vgoyal@redhat.com Signed-off-by: H. Peter Anvin

x86, boot: Move memcmp() into string.h and string.c

2014-03-19T22:44:04+00:00

Try to treat memcmp() in same way as memcpy() and memset(). Provide a declaration in boot/string.h and by default user gets a memcmp() which maps to builtin function. Move optimized definition of memcmp() in boot/string.c. Now a user can do #undef memcmp and link against string.c to use optimzied memcmp(). It also simplifies boot/compressed/string.c where we had to redefine memcmp(). That extra definition is gone now. Signed-off-by: Vivek Goyal Link: http://lkml.kernel.org/r/1395170800-11059-5-git-send-email-vgoyal@redhat.com Signed-off-by: H. Peter Anvin

x86, boot: Move optimized memcpy() 32/64 bit versions to compressed/string.c

2014-03-19T22:43:59+00:00

Move optimized versions of memcpy to compressed/string.c This will allow any other code to use these functions too if need be in future. Again trying to put definition in a common place instead of hiding it in misc.c Signed-off-by: Vivek Goyal Link: http://lkml.kernel.org/r/1395170800-11059-4-git-send-email-vgoyal@redhat.com Signed-off-by: H. Peter Anvin