kernel/linux.git/arch/x86/include/asm/segment.h, branch linux-5.9.y

x86/xen: remove 32-bit Xen PV guest support

2020-08-11T06:26:48+00:00

Xen is requiring 64-bit machines today and since Xen 4.14 it can be built without 32-bit PV guest support. There is no need to carry the burden of 32-bit PV guest support in the kernel any longer, as new guests can be either HVM or PVH, or they can use a 64 bit kernel. Remove the 32-bit Xen PV support from the kernel. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross

x86/stackframe/32: Repair 32-bit Xen PV

2019-11-19T20:58:28+00:00

Once again RPL checks have been introduced which don't account for a 32-bit kernel living in ring 1 when running in a PV Xen domain. The case in FIXUP_FRAME has been preventing boot. Adjust BUG_IF_WRONG_CR3 as well to guard against future uses of the macro on a code path reachable when running in PV mode under Xen; I have to admit that I stopped at a certain point trying to figure out whether there are present ones. Fixes: 3c88c692c287 ("x86/stackframe/32: Provide consistent pt_regs") Signed-off-by: Jan Beulich Signed-off-by: Thomas Gleixner Cc: Stable Team Link: https://lore.kernel.org/r/0fad341f-b7f5-f859-d55d-f0084ee7087e@suse.com

Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-10-23T16:54:58+00:00

Pull x86 paravirt updates from Ingo Molnar: "Two main changes: - Remove no longer used parts of the paravirt infrastructure and put large quantities of paravirt ops under a new config option PARAVIRT_XXL=y, which is selected by XEN_PV only. (Joergen Gross) - Enable PV spinlocks on Hyperv (Yi Sun)" * 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/hyperv: Enable PV qspinlock for Hyper-V x86/hyperv: Add GUEST_IDLE_MSR support x86/paravirt: Clean up native_patch() x86/paravirt: Prevent redefinition of SAVE_FLAGS macro x86/xen: Make xen_reservation_lock static x86/paravirt: Remove unneeded mmu related paravirt ops bits x86/paravirt: Move the Xen-only pv_mmu_ops under the PARAVIRT_XXL umbrella x86/paravirt: Move the pv_irq_ops under the PARAVIRT_XXL umbrella x86/paravirt: Move the Xen-only pv_cpu_ops under the PARAVIRT_XXL umbrella x86/paravirt: Move items in pv_info under PARAVIRT_XXL umbrella x86/paravirt: Introduce new config option PARAVIRT_XXL x86/paravirt: Remove unused paravirt bits x86/paravirt: Use a single ops structure x86/paravirt: Remove clobbers from struct paravirt_patch_site x86/paravirt: Remove clobbers parameter from paravirt patch functions x86/paravirt: Make paravirt_patch_call() and paravirt_patch_jmp() static x86/xen: Add SPDX identifier in arch/x86/xen files x86/xen: Link platform-pci-unplug.o only if CONFIG_XEN_PVHVM x86/xen: Move pv specific parts of arch/x86/xen/mmu.c to mmu_pv.c x86/xen: Move pv irq related functions under CONFIG_XEN_PV umbrella

x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick

2018-10-08T08:45:02+00:00

We have a special segment descriptor entry in the GDT, whose sole purpose is to encode the CPU and node numbers in its limit (size) field. There are user-space instructions that allow the reading of the limit field, which gives us a really fast way to read the CPU and node IDs from the vDSO for example. But the naming of related functionality does not make this clear, at all: VDSO_CPU_SIZE VDSO_CPU_MASK __CPU_NUMBER_SEG GDT_ENTRY_CPU_NUMBER vdso_encode_cpu_node vdso_read_cpu_node There's a number of problems: - The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number of bits, nor does it make it clear which 'CPU' this refers to, i.e. that this is about a GDT entry whose limit encodes the CPU and node number. - Furthermore, the 'CPU_NUMBER' naming is actively misleading as well, because the segment limit encodes not just the CPU number but the node ID as well ... So use a better nomenclature all around: name everything related to this trick as 'CPUNODE', to make it clear that this is something special, and add _BITS to make it clear that these are number of bits, and propagate this to every affected name: VDSO_CPU_SIZE => VDSO_CPUNODE_BITS VDSO_CPU_MASK => VDSO_CPUNODE_MASK __CPU_NUMBER_SEG => __CPUNODE_SEG GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE vdso_encode_cpu_node => vdso_encode_cpunode vdso_read_cpu_node => vdso_read_cpunode This, beyond being less confusing, also makes it easier to grep for all related functionality: $ git grep -i cpunode arch/x86 Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode(). Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Chang S. Bae Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Markus T Metzger Cc: Peter Zijlstra Cc: Ravi Shankar Cc: Rik van Riel Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar

x86/vdso: Introduce helper functions for CPU and node number

2018-10-08T08:41:10+00:00

Clean up the CPU/node number related code a bit, to make it more apparent how we are encoding/extracting the CPU and node fields from the segment limit. No change in functionality intended. [ mingo: Wrote new changelog. ] Suggested-by: Andy Lutomirski Suggested-by: Thomas Gleixner Signed-off-by: Chang S. Bae Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Markus T Metzger Cc: Peter Zijlstra Cc: Ravi Shankar Cc: Rik van Riel Link: http://lkml.kernel.org/r/1537312139-5580-8-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar

x86/segments/64: Rename the GDT PER_CPU entry to CPU_NUMBER

2018-10-08T08:41:10+00:00

The old 'per CPU' naming was misleading: 64-bit kernels don't use this GDT entry for per CPU data, but to store the CPU (and node) ID. [ mingo: Wrote new changelog. ] Suggested-by: H. Peter Anvin Signed-off-by: Chang S. Bae Reviewed-by: Thomas Gleixner Acked-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Markus T Metzger Cc: Peter Zijlstra Cc: Ravi Shankar Cc: Rik van Riel Link: http://lkml.kernel.org/r/1537312139-5580-7-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar

x86/paravirt: Move items in pv_info under PARAVIRT_XXL umbrella

2018-09-03T14:50:36+00:00

All items but name in pv_info are needed by Xen PV only. Define them with CONFIG_PARAVIRT_XXL set only. Signed-off-by: Juergen Gross Signed-off-by: Thomas Gleixner Cc: xen-devel@lists.xenproject.org Cc: virtualization@lists.linux-foundation.org Cc: akataria@vmware.com Cc: rusty@rustcorp.com.au Cc: boris.ostrovsky@oracle.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/20180828074026.820-12-jgross@suse.com

Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables

2018-06-14T03:21:18+00:00

The changes to automatically test for working stack protector compiler support in the Kconfig files removed the special STACKPROTECTOR_AUTO option that picked the strongest stack protector that the compiler supported. That was all a nice cleanup - it makes no sense to have the AUTO case now that the Kconfig phase can just determine the compiler support directly. HOWEVER. It also meant that doing "make oldconfig" would now _disable_ the strong stackprotector if you had AUTO enabled, because in a legacy config file, the sane stack protector configuration would look like CONFIG_HAVE_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_NONE is not set # CONFIG_CC_STACKPROTECTOR_REGULAR is not set # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_STACKPROTECTOR_AUTO=y and when you ran this through "make oldconfig" with the Kbuild changes, it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version used to be disabled (because it was really enabled by AUTO), and would disable it in the new config, resulting in: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_HAS_SANE_STACKPROTECTOR=y That's dangerously subtle - people could suddenly find themselves with the weaker stack protector setup without even realizing. The solution here is to just rename not just the old RECULAR stack protector option, but also the strong one. This does that by just removing the CC_ prefix entirely for the user choices, because it really is not about the compiler support (the compiler support now instead automatially impacts _visibility_ of the options to users). This results in "make oldconfig" actually asking the user for their choice, so that we don't have any silent subtle security model changes. The end result would generally look like this: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_STACKPROTECTOR=y CONFIG_STACKPROTECTOR_STRONG=y CONFIG_CC_HAS_SANE_STACKPROTECTOR=y where the "CC_" versions really are about internal compiler infrastructure, not the user selections. Acked-by: Masahiro Yamada Signed-off-by: Linus Torvalds

x86/xen: Support early interrupts in xen pv guests

2017-11-27T23:28:56+00:00

Add early interrupt handlers activated by idt_setup_early_handler() to the handlers supported by Xen pv guests. This will allow for early WARN() calls not crashing the guest. Suggested-by: Andy Lutomirski Signed-off-by: Juergen Gross Signed-off-by: Thomas Gleixner Cc: xen-devel@lists.xenproject.org Cc: boris.ostrovsky@oracle.com Link: https://lkml.kernel.org/r/20171124084221.30172-1-jgross@suse.com

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