kernel.git/arch/arm64/kernel/vdso, branch linux-4.19.y

arm64: vdso: remove commas between macro name and arguments

2021-05-22T08:59:21Z

LLVM's integrated assembler appears to assume an argument with default value is passed whenever it sees a comma right after the macro name. It will be fine if the number of following arguments is one less than the number of parameters specified in the macro definition. Otherwise, it fails. For example, the following code works: $ cat foo.s .macro foo arg1=2, arg2=4 ldr r0, [r1, #\arg1] ldr r0, [r1, #\arg2] .endm foo, arg2=8 $ llvm-mc -triple=armv7a -filetype=obj foo.s -o ias.o arm-linux-gnueabihf-objdump -dr ias.o ias.o: file format elf32-littlearm Disassembly of section .text: 00000000 <.text>: 0: e5910001 ldr r0, [r1, #2] 4: e5910003 ldr r0, [r1, #8] While the the following code would fail: $ cat foo.s .macro foo arg1=2, arg2=4 ldr r0, [r1, #\arg1] ldr r0, [r1, #\arg2] .endm foo, arg1=2, arg2=8 $ llvm-mc -triple=armv7a -filetype=obj foo.s -o ias.o foo.s:6:14: error: too many positional arguments foo, arg1=2, arg2=8 This causes build failures as follows: arch/arm64/kernel/vdso/gettimeofday.S:230:24: error: too many positional arguments clock_gettime_return, shift=1 ^ arch/arm64/kernel/vdso/gettimeofday.S:253:24: error: too many positional arguments clock_gettime_return, shift=1 ^ arch/arm64/kernel/vdso/gettimeofday.S:274:24: error: too many positional arguments clock_gettime_return, shift=1 This error is not in mainline because commit 28b1a824a4f4 ("arm64: vdso: Substitute gettimeofday() with C implementation") rewrote this assembler file in C as part of a 25 patch series that is unsuitable for stable. Just remove the comma in the clock_gettime_return invocations in 4.19 so that GNU as and LLVM's integrated assembler work the same. Link: https://github.com/ClangBuiltLinux/linux/issues/1349 Suggested-by: Nathan Chancellor Reviewed-by: Nathan Chancellor Signed-off-by: Jian Cai Signed-off-by: Greg Kroah-Hartman

arm64/vdso: Discard .note.gnu.property sections in vDSO

2021-05-22T08:59:19Z

[ Upstream commit 388708028e6937f3fc5fc19aeeb847f8970f489c ] The arm64 assembler in binutils 2.32 and above generates a program property note in a note section, .note.gnu.property, to encode used x86 ISAs and features. But the kernel linker script only contains a single NOTE segment: PHDRS { text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */ dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ note PT_NOTE FLAGS(4); /* PF_R */ } The NOTE segment generated by the vDSO linker script is aligned to 4 bytes. But the .note.gnu.property section must be aligned to 8 bytes on arm64. $ readelf -n vdso64.so Displaying notes found in: .note Owner Data size Description Linux 0x00000004 Unknown note type: (0x00000000) description data: 06 00 00 00 readelf: Warning: note with invalid namesz and/or descsz found at offset 0x20 readelf: Warning: type: 0x78, namesize: 0x00000100, descsize: 0x756e694c, alignment: 8 Since the note.gnu.property section in the vDSO is not checked by the dynamic linker, discard the .note.gnu.property sections in the vDSO. Similar to commit 4caffe6a28d31 ("x86/vdso: Discard .note.gnu.property sections in vDSO"), but for arm64. Signed-off-by: Bill Wendling Reviewed-by: Kees Cook Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20210423205159.830854-1-morbo@google.com Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

arm64: vdso: Fix clock_getres() for CLOCK_REALTIME

2019-05-31T13:46:21Z

[ Upstream commit 81fb8736dd81da3fe94f28968dac60f392ec6746 ] clock_getres() in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; where 'hrtimer_resolution' depends on whether or not high resolution timers are enabled, which is a runtime decision. The vDSO incorrectly returns the constant CLOCK_REALTIME_RES. Fix this by exposing 'hrtimer_resolution' in the vDSO datapage and returning that instead. Reviewed-by: Catalin Marinas Signed-off-by: Vincenzo Frascino [will: Use WRITE_ONCE(), move adr off COARSE path, renumber labels, use 'w' reg] Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

arm64: arch_timer: Ensure counter register reads occur with seqlock held

2019-05-22T05:37:35Z

commit 75a19a0202db21638a1c2b424afb867e1f9a2376 upstream. When executing clock_gettime(), either in the vDSO or via a system call, we need to ensure that the read of the counter register occurs within the seqlock reader critical section. This ensures that updates to the clocksource parameters (e.g. the multiplier) are consistent with the counter value and therefore avoids the situation where time appears to go backwards across multiple reads. Extend the vDSO logic so that the seqlock critical section covers the read of the counter register as well as accesses to the data page. Since reads of the counter system registers are not ordered by memory barrier instructions, introduce dependency ordering from the counter read to a subsequent memory access so that the seqlock memory barriers apply to the counter access in both the vDSO and the system call paths. Cc: Cc: Marc Zyngier Tested-by: Vincenzo Frascino Link: https://lore.kernel.org/linux-arm-kernel/alpine.DEB.2.21.1902081950260.1662@nanos.tec.linutronix.de/ Reported-by: Thomas Gleixner Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

arm64: Add build salt to the vDSO

2018-07-17T16:18:05Z

The vDSO needs to have a unique build id in a similar manner to the kernel and modules. Use the build salt macro. Acked-by: Will Deacon Signed-off-by: Laura Abbott Signed-off-by: Masahiro Yamada

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2017-11-15T18:56:56Z

Pull arm64 updates from Will Deacon: "The big highlight is support for the Scalable Vector Extension (SVE) which required extensive ABI work to ensure we don't break existing applications by blowing away their signal stack with the rather large new vector context (<= 2 kbit per vector register). There's further work to be done optimising things like exception return, but the ABI is solid now. Much of the line count comes from some new PMU drivers we have, but they're pretty self-contained and I suspect we'll have more of them in future. Plenty of acronym soup here: - initial support for the Scalable Vector Extension (SVE) - improved handling for SError interrupts (required to handle RAS events) - enable GCC support for 128-bit integer types - remove kernel text addresses from backtraces and register dumps - use of WFE to implement long delay()s - ACPI IORT updates from Lorenzo Pieralisi - perf PMU driver for the Statistical Profiling Extension (SPE) - perf PMU driver for Hisilicon's system PMUs - misc cleanups and non-critical fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits) arm64: Make ARMV8_DEPRECATED depend on SYSCTL arm64: Implement __lshrti3 library function arm64: support __int128 on gcc 5+ arm64/sve: Add documentation arm64/sve: Detect SVE and activate runtime support arm64/sve: KVM: Hide SVE from CPU features exposed to guests arm64/sve: KVM: Treat guest SVE use as undefined instruction execution arm64/sve: KVM: Prevent guests from using SVE arm64/sve: Add sysctl to set the default vector length for new processes arm64/sve: Add prctl controls for userspace vector length management arm64/sve: ptrace and ELF coredump support arm64/sve: Preserve SVE registers around EFI runtime service calls arm64/sve: Preserve SVE registers around kernel-mode NEON use arm64/sve: Probe SVE capabilities and usable vector lengths arm64: cpufeature: Move sys_caps_initialised declarations arm64/sve: Backend logic for setting the vector length arm64/sve: Signal handling support arm64/sve: Support vector length resetting for new processes arm64/sve: Core task context handling arm64/sve: Low-level CPU setup ...

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

2017-11-02T10:10:55Z

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

arm64: vdso: fix clock_getres for 4GiB-aligned res

2017-10-31T09:49:33Z

The vdso tries to check for a NULL res pointer in __kernel_clock_getres, but only checks the lower 32 bits as is uses CBZ on the W register the res pointer is held in. Thus, if the res pointer happened to be aligned to a 4GiB boundary, we'd spuriously skip storing the timespec to it, while returning a zero error code to the caller. Prevent this by checking the whole pointer, using CBZ on the X register the res pointer is held in. Fixes: 9031fefde6f2ac1d ("arm64: VDSO support") Signed-off-by: Mark Rutland Reported-by: Andrew Pinski Reported-by: Mark Salyzyn Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Will Deacon

arm64/vdso: Fix nsec handling for CLOCK_MONOTONIC_RAW

2017-06-20T08:41:51Z

Recently vDSO support for CLOCK_MONOTONIC_RAW was added in 49eea433b326 ("arm64: Add support for CLOCK_MONOTONIC_RAW in clock_gettime() vDSO"). Noticing that the core timekeeping code never set tkr_raw.xtime_nsec, the vDSO implementation didn't bother exposing it via the data page and instead took the unshifted tk->raw_time.tv_nsec value which was then immediately shifted left in the vDSO code. Unfortunately, by accellerating the MONOTONIC_RAW clockid, it uncovered potential 1ns time inconsistencies caused by the timekeeping core not handing sub-ns resolution. Now that the core code has been fixed and is actually setting tkr_raw.xtime_nsec, we need to take that into account in the vDSO by adding it to the shifted raw_time value, in order to fix the user-visible inconsistency. Rather than do that at each use (and expand the data page in the process), instead perform the shift/addition operation when populating the data page and remove the shift from the vDSO code entirely. [jstultz: minor whitespace tweak, tried to improve commit message to make it more clear this fixes a regression] Reported-by: John Stultz Signed-off-by: Will Deacon Signed-off-by: John Stultz Tested-by: Daniel Mentz Acked-by: Kevin Brodsky Cc: Prarit Bhargava Cc: Richard Cochran Cc: Stephen Boyd Cc: "stable #4 . 8+" Cc: Miroslav Lichvar Link: http://lkml.kernel.org/r/1496965462-20003-4-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner

arm64: drop non-existing vdso-offsets.h from .gitignore

2017-03-30T18:29:30Z

Since commit a66649dab350 ("arm64: fix vdso-offsets.h dependency"), include/generated/vdso-offsets.h is directly generated without arch/arm64/kernel/vdso/vdso-offsets.h. Signed-off-by: Masahiro Yamada Signed-off-by: Will Deacon