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2026-08-11alpha: don't leak hardware-fabricated FP exception bits to user spaceMatt Turner1-11/+77
On EV6 and later the hardware records exception status bits in the FPCR before delivering a software completion trap, and those bits can be wrong for the instruction that trapped. Converting a double that is exactly representable as a subnormal float sets FPCR_UNF even though the result is exact, and an underflow trap additionally sets FPCR_INE even when the emulated operation turns out to be exact. alpha_fp_emul() only wrote the FPCR when soft-fp raised an exception, so whenever it determined that the instruction was exact the fabricated bits stayed in the FPCR and were reported to user space by fetestexcept(). Pass the exception summary register down from do_entArith() so the handler can tell which exceptions the hardware attributed to the trapping instruction, and always write the FPCR. Clear the exceptions that the trap reported but that soft-fp did not raise. EXC_SUM reports only the underflow or overflow when the hardware also set INE, so treat INE as a candidate in that case, and treat a trap with no reported exception as a denormal operand trap, for which the hardware can fabricate INE and UNF as well. Bits that software has already confirmed in ieee_state belong to this or an earlier instruction and are never cleared. The imprecise path passes no summary. There the trap was taken somewhere in the trap shadow, so EXC_SUM is not attribution for the instruction being re-executed -- and only EV6, which traps precisely and so never takes that path, has fabricated bits to clear. For the same reason the clearing is guarded by implver(), matching swcr_update_status(). On an UP1500 (EV68) this takes the glibc math testsuite from 831 failures to 28, the remainder being unrelated to exception status. This belongs with the preceding fix to ieee_swcr_to_fpcr(), and should not be backported without it -- nor it without this. That fix stops FPCR_DNOD being set unconditionally, so denormal operand traps start firing again. Those traps very often find an exact result, which is precisely the case where the old code left the FPCR unwritten and the fabricated bits visible. Applied alone it would make spurious exception flags more common, not less. One case cannot be resolved here: an inexact instruction without the software completion suffix never traps, so its INE reaches the FPCR without being recorded anywhere else. Such a bit is indistinguishable from an INE the hardware fabricated for a trapping instruction, and is lost if an underflow or overflow trap with an exact result follows it. The FPCR is the only record of those instructions and it carries no attribution. The bug predates the git history, so there is no commit to reference in a Fixes tag. Cc: stable@vger.kernel.org # 5.15+ Signed-off-by: Matt Turner <mattst88@gmail.com> Reviewed-by: Magnus Lindholm <linmag7@gmail.com> Tested-by: Magnus Lindholm <linmag7@gmail.com> Link: https://lore.kernel.org/r/20260803-alpha-fp-exceptions-v1-2-c99d75608e60@gmail.com Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
2024-05-03alpha: missing includesAl Viro1-6/+1
... and missing externs in proto.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-09-18alpha: move __udiv_qrnnd library function to arch/alpha/lib/Linus Torvalds3-166/+1
We already had the implementation for __udiv_qrnnd (unsigned divide for multi-precision arithmetic) as part of the alpha math emulation code. But you can disable the math emulation code - even if you shouldn't - and then the MPI code that actually wants this functionality (and is needed by various crypto functions) will fail to build. So move the extended-precision divide code to be a regular library function, just like all the regular division code is. That way ie is available regardless of math-emulation. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-25alpha: fp_emul: avoid init/cleanup_module namesArnd Bergmann1-2/+4
This is one of the last modules using the old calling conventions for module init/exit functions. Change it over to the style used everywhere else. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Matt Turner <mattst88@gmail.com>
2021-07-25alpha: __udiv_qrnnd should be exportedCorentin Labbe1-0/+2
When building an alpha kernel with mpi set as module, I hit this build error: ERROR: "__udiv_qrnnd" [lib/mpi/mpi.ko] undefined! make[2]: *** [scripts/Makefile.modpost:92: __modpost] Error 1 make[1]: *** [Makefile:1266: modules] Error 2 This is due to __udiv_qrnnd not exported. Signed-off-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Matt Turner <mattst88@gmail.com>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner1-0/+1
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier for more missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
2017-09-04alpha: math-emu: Fix modular buildBen Hutchings1-0/+1
Commit 00fc0e0dda62 ("alpha: move exports to actual definitions") also removed the exports of the math emulator hooks, which are defined in C code. In case anyone cares about the option of CONFIG_MATHEMU=m, add exports next to those definitions. Also add a MODULE_LICENSE. Fixes: 00fc0e0dda62 ("alpha: move exports to actual definitions") Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2017-03-02sched/headers: Prepare for the removal of <asm/ptrace.h> from <linux/sched.h>Ingo Molnar1-0/+1
Fix up missing #includes in other places that rely on sched.h doing that for them. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> 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>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-17alpha: change to new Makefile flag variablesmatt mooney1-1/+1
Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-05-26Revert "endian: #define __BYTE_ORDER"Linus Torvalds1-0/+5
This reverts commit b3b77c8caef1750ebeea1054e39e358550ea9f55, which was also totally broken (see commit 0d2daf5cc858 that reverted the crc32 version of it). As reported by Stephen Rothwell, it causes problems on big-endian machines: > In file included from fs/jfs/jfs_types.h:33, > from fs/jfs/jfs_incore.h:26, > from fs/jfs/file.c:22: > fs/jfs/endian24.h:36:101: warning: "__LITTLE_ENDIAN" is not defined The kernel has never had that crazy "__BYTE_ORDER == __LITTLE_ENDIAN" model. It's not how we do things, and it isn't how we _should_ do things. So don't go there. Requested-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25endian: #define __BYTE_ORDERJoakim Tjernlund1-5/+0
Linux does not define __BYTE_ORDER in its endian header files which makes some header files bend backwards to get at the current endian. Lets #define __BYTE_ORDER in big_endian.h/litte_endian.h to make it easier for header files that are used in user space too. In userspace the convention is that 1. _both_ __LITTLE_ENDIAN and __BIG_ENDIAN are defined, 2. you have to test for e.g. __BYTE_ORDER == __BIG_ENDIAN. Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-17alpha: fix conversion from denormal float to doubleIvan Kokshaysky1-1/+1
The trap handler does properly update the fraction, but not the exponent... Thanks to Paolo Bonzini for the bug report and the testcase. Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Paolo Bonzini <bonzini@gnu.org> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds4-0/+607
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!