kernel/linux.git/arch/xtensa/mm, branch linux-4.16.y

xtensa: fix high memory/reserved memory collision

2018-02-15T17:46:42+00:00

Xtensa memory initialization code frees high memory pages without checking whether they are in the reserved memory regions or not. That results in invalid value of totalram_pages and duplicate page usage by CMA and highmem. It produces a bunch of BUGs at startup looking like this: BUG: Bad page state in process swapper pfn:70800 page:be60c000 count:0 mapcount:-127 mapping: (null) index:0x1 flags: 0x80000000() raw: 80000000 00000000 00000001 ffffff80 00000000 be60c014 be60c014 0000000a page dumped because: nonzero mapcount Modules linked in: CPU: 0 PID: 1 Comm: swapper Tainted: G B 4.16.0-rc1-00015-g7928b2cbe55b-dirty #23 Stack: bd839d33 00000000 00000018 ba97b64c a106578c bd839d70 be60c000 00000000 a1378054 bd86a000 00000003 ba97b64c a1066166 bd839da0 be60c000 ffe00000 a1066b58 bd839dc0 be504000 00000000 000002f4 bd838000 00000000 0000001e Call Trace: [] bad_page+0xac/0xd0 [] free_pages_check_bad+0x34/0x4c [] __free_pages_ok+0xae/0x14c [] __free_pages+0x30/0x64 [] init_cma_reserved_pageblock+0x35/0x44 [] cma_init_reserved_areas+0xf4/0x148 [] do_one_initcall+0x80/0xf8 [] kernel_init_freeable+0xda/0x13c [] kernel_init+0x9/0xd0 [] ret_from_kernel_thread+0xc/0x18 Only free high memory pages that are not reserved. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov

xtensa: print kernel sections info in mem_init

2017-12-17T23:34:58+00:00

Output virtual addresses and sizes occupied by the main kernel sections: .text, .rodata, .data, .init and .bss. Signed-off-by: Max Filippov

xtensa: add support for KASAN

2017-12-17T06:37:12+00:00

Cover kernel addresses above 0x90000000 by the shadow map. Enable HAVE_ARCH_KASAN when MMU is enabled. Provide kasan_early_init that fills shadow map with writable copies of kasan_zero_page. Call kasan_early_init right after mmu initialization in the setup_arch. Provide kasan_init that allocates proper shadow map pages from the memblock and puts these pages into the shadow map for addresses from VMALLOC area to the end of KSEG. Call kasan_init right after memblock initialization. Don't use KASAN for the boot code, MMU and KASAN initialization and page fault handler. Make kernel stack size 4 times larger when KASAN is enabled to avoid stack overflows. GCC 7.3, 8 or newer is required to build the xtensa kernel with KASAN. Signed-off-by: Max Filippov

xtensa: move fixmap and kmap just above the KSEG

2017-12-17T06:37:12+00:00

The virtual address space between the page table and the VMALLOC region is big enough to host KASAN shadow map and there's enough space between the VMALLOC area and KSEG for the fixmap and kmap. Move fixmap and kmap to the gap between VMALLOC area and KSEG, just above the KSEG. Reorder entries in the kernel memory layout printing code. Drop duplicate PGTABLE_START definition, use XCHAL_PAGE_TABLE_VADDR instead. Signed-off-by: Max Filippov

xtensa: don't clear swapper_pg_dir in paging_init

2017-12-17T06:37:11+00:00

swapper_pg_dir is located in the .bss, so it's zero-initialized anyway. With KASAN enabled paging_init will be called after KASAN initialization, it must not erase page directory entries set up for KASAN shadow map. Signed-off-by: Max Filippov

xtensa: extract init_kio

2017-12-17T06:37:10+00:00

KIO region placement may be specified in the device tree, that's why it's initialized with the rest of MMU after the early_init_devtree. In order to support KASAN the MMU must be initialized earlier. Separate KIO initialization from the rest of MMU initialization. Reinitialize KIO if its location is specified in the device tree. Signed-off-by: Max Filippov

xtensa: clean up custom-controlled debug output

2017-12-17T06:37:08+00:00

Replace #ifdef'fed/commented out debug printk statements with pr_debug. Replace printk statements with pr_* equivalents. Signed-off-by: Max Filippov

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

xtensa: mm/cache: add missing EXPORT_SYMBOLs

2017-08-01T18:17:35+00:00

Functions clear_user_highpage, copy_user_highpage, flush_dcache_page, local_flush_cache_range and local_flush_cache_page may be used from modules. Export them. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov

xtensa: fix cache aliasing handling code for WT cache

2017-07-29T01:35:13+00:00

Currently building kernel for xtensa core with aliasing WT cache fails with the following messages: mm/memory.c:2152: undefined reference to `flush_dcache_page' mm/memory.c:2332: undefined reference to `local_flush_cache_page' mm/memory.c:1919: undefined reference to `local_flush_cache_range' mm/memory.c:4179: undefined reference to `copy_to_user_page' mm/memory.c:4183: undefined reference to `copy_from_user_page' This happens because implementation of these functions is only compiled when data cache is WB, which looks wrong: even when data cache doesn't need flushing it still needs invalidation. The functions like __flush_[invalidate_]dcache_* are correctly defined for both WB and WT caches (and even if they weren't that'd still be ok, just slower). Fix this by providing the same implementation of the above functions for both WB and WT cache. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov