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2024-11-02s390/vdso: Drop LBASE_VDSOThomas Weißschuh1-1/+1
This constant is always "0", providing no value and making the logic harder to understand. Also prepare for a consolidation of the vdso linkerscript logic by aligning it with other architectures. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-3-b64f0842d512@linutronix.de
2024-09-13s390/vdso: Wire up getrandom() vdso implementationHeiko Carstens1-0/+3
Provide the s390 specific vdso getrandom() architecture backend. _vdso_rng_data required data is placed within the _vdso_data vvar page, by using a hardcoded offset larger than vdso_data. As required the chacha20 implementation does not write to the stack. The implementation follows more or less the arm64 implementations and makes use of vector instructions. It has a fallback to the getrandom() system call for machines where the vector facility is not installed. The check if the vector facility is installed, as well as an optimization for machines with the vector-enhancements facility 2, is implemented with alternatives, avoiding runtime checks. Note that __kernel_getrandom() is implemented without the vdso user wrapper which would setup a stack frame for odd cases (aka very old glibc variants) where the caller has not done that. All callers of __kernel_getrandom() are required to setup a stack frame, like the C ABI requires it. The vdso testcases vdso_test_getrandom and vdso_test_chacha pass. Benchmark on a z16: $ ./vdso_test_getrandom bench-single vdso: 25000000 times in 0.493703559 seconds syscall: 25000000 times in 6.584025337 seconds Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-09-13s390/vdso: Allow alternatives in vdso codeHeiko Carstens1-0/+4
Implement the infrastructure required to allow alternatives in vdso code. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-02-14s390/vdso: remove unused ENTRY in linker scriptsHeiko Carstens1-1/+0
When linking vdso64.so.dbg with ld.lld, there is a warning about not finding _start for the starting address: ld.lld: warning: cannot find entry symbol _start; not setting start address Fix this by removing the unused ENTRY in both vdso linker scripts. See commit e247172854a5 ("powerpc/vdso: Remove unused ENTRY in linker scripts"), which solved the same problem for powerpc, for further details. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-30s390/vdso: add .got.plt in vdso linker scriptSumanth Korikkar1-0/+1
KCFLAGS="-mno-pic-data-is-text-relative" make leads to bfd assertion error in s390_got_pointer(): LD arch/s390/kernel/vdso64/vdso64.so.dbg ld: BFD version 2.35-18.fc33 assertion fail elf-s390-common.c:74 readelf -Wr vdso64_generic.o | grep GOT 0000000000000032 000000110000001a R_390_GOTENT 0000000000000000 _vdso_data + 2 (...) Add .got.plt in linker script to avoid this. Suggested-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-08s390/vdso: rename VDSO64_LBASE to VDSO_LBASESven Schnelle1-1/+1
Will be used by both vdso32 and vdso64, so change the name. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-07-08s390/vdso64: add sigreturn,rt_sigreturn and restart_syscallSven Schnelle1-0/+3
Add minimalistic trampolines to vdso64 so we can return from signal without using the stack which requires pgm check handler hacks when NX is enabled. restart_syscall will be called from vdso to work around the architectural limitation that the syscall number might be encoded in the svc instruction, and therefore can not be changed. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09s390/vdso: implement generic vdso time namespace supportHeiko Carstens1-1/+4
Implement generic vdso time namespace support which also enables time namespaces for s390. This is quite similar to what arm64 has. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09s390/vdso: move data page before code pagesHeiko Carstens1-3/+1
For consistency with x86 and arm64 move the data page before code pages. Similar to commit 601255ae3c98 ("arm64: vdso: move data page before code pages"). Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-11-23s390/vdso: reimplement getcpu vdso syscallHeiko Carstens1-1/+1
Implement the previously removed getcpu vdso syscall by using the TOD programmable field to pass the cpu number to user space. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23s390/mm: remove set_fs / rework address space handlingHeiko Carstens1-1/+0
Remove set_fs support from s390. With doing this rework address space handling and simplify it. As a result address spaces are now setup like this: CPU running in | %cr1 ASCE | %cr7 ASCE | %cr13 ASCE ----------------------------|-----------|-----------|----------- user space | user | user | kernel kernel, normal execution | kernel | user | kernel kernel, kvm guest execution | gmap | user | kernel To achieve this the getcpu vdso syscall is removed in order to avoid secondary address mode and a separate vdso address space in for user space. The getcpu vdso syscall will be implemented differently with a subsequent patch. The kernel accesses user space always via secondary address space. This happens in different ways: - with mvcos in home space mode and directly read/write to secondary address space - with mvcs/mvcp in primary space mode and copy from primary space to secondary space or vice versa - with e.g. cs in secondary space mode and access secondary space Switching translation modes happens with sacf before and after instructions which access user space, like before. Lazy handling of control register reloading is removed in the hope to make everything simpler, but at the cost of making kernel entry and exit a bit slower. That is: on kernel entry the primary asce is always changed to contain the kernel asce, and on kernel exit the primary asce is changed again so it contains the user asce. In kernel mode there is only one exception to the primary asce: when kvm guests are executed the primary asce contains the gmap asce (which describes the guest address space). The primary asce is reset to kernel asce whenever kvm guest execution is interrupted, so that this doesn't has to be taken into account for any user space accesses. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-26s390/mm: use new mm defines instead of magic valuesHeiko Carstens1-1/+3
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-11s390/vdso: optimize getcpu system callMartin Schwidefsky1-0/+1
Add the CPU number to the per-cpu vdso data page and add the __kernel_getcpu function to the vdso object to retrieve the CPU number in user space. Suggested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25[S390] introduce vdso on s390Martin Schwidefsky1-0/+138
Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for CLOCK_REALTIME/CLOCK_MONOTONIC. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>