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2020-02-17x86/vdso: Use generic VDSO clock mode storageThomas Gleixner1-3/+3
Switch to the generic VDSO clock mode storage. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Vincenzo Frascino <[email protected]> (VDSO parts) Acked-by: Juergen Gross <[email protected]> (Xen parts) Acked-by: Paolo Bonzini <[email protected]> (KVM parts) Link: https://lkml.kernel.org/r/[email protected]
2020-02-17x86/vdso: Move VDSO clocksource state tracking to callbackThomas Gleixner1-0/+4
All architectures which use the generic VDSO code have their own storage for the VDSO clock mode. That's pointless and just requires duplicate code. X86 abuses the function which retrieves the architecture specific clock mode storage to mark the clocksource as used in the VDSO. That's silly because this is invoked on every tick when the VDSO data is updated. Move this functionality to the clocksource::enable() callback so it gets invoked once when the clocksource is installed. This allows to make the clock mode storage generic. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Michael Kelley <[email protected]> (Hyper-V parts) Reviewed-by: Vincenzo Frascino <[email protected]> (VDSO parts) Acked-by: Juergen Gross <[email protected]> (Xen parts) Link: https://lkml.kernel.org/r/[email protected]
2020-02-04kbuild: rename hostprogs-y/always to hostprogs/always-yMasahiro Yamada1-1/+1
In old days, the "host-progs" syntax was used for specifying host programs. It was renamed to the current "hostprogs-y" in 2004. It is typically useful in scripts/Makefile because it allows Kbuild to selectively compile host programs based on the kernel configuration. This commit renames like follows: always -> always-y hostprogs-y -> hostprogs So, scripts/Makefile will look like this: always-$(CONFIG_BUILD_BIN2C) += ... always-$(CONFIG_KALLSYMS) += ... ... hostprogs := $(always-y) $(always-m) I think this makes more sense because a host program is always a host program, irrespective of the kernel configuration. We want to specify which ones to compile by CONFIG options, so always-y will be handier. The "always", "hostprogs-y", "hostprogs-m" will be kept for backward compatibility for a while. Signed-off-by: Masahiro Yamada <[email protected]>
2020-01-28Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups all around the map" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/CPU/AMD: Remove amd_get_topology_early() x86/tsc: Remove redundant assignment x86/crash: Use resource_size() x86/cpu: Add a missing prototype for arch_smt_update() x86/nospec: Remove unused RSB_FILL_LOOPS x86/vdso: Provide missing include file x86/Kconfig: Correct spelling and punctuation Documentation/x86/boot: Fix typo x86/boot: Fix a comment's incorrect file reference x86/process: Remove set but not used variables prev and next x86/Kconfig: Fix Kconfig indentation
2020-01-14x86/vdso: Zap vvar pages when switching to a time namespaceDmitry Safonov1-0/+27
The VVAR page layout depends on whether a task belongs to the root or non-root time namespace. Whenever a task changes its namespace, the VVAR page tables are cleared and then they will be re-faulted with a corresponding layout. Co-developed-by: Andrei Vagin <[email protected]> Signed-off-by: Andrei Vagin <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-14x86/vdso: On timens page fault prefault also VVAR pageDmitry Safonov1-1/+16
As timens page has offsets to data on VVAR page VVAR is going to be accessed shortly. Set it up with timens in one page fault as optimization. Suggested-by: Thomas Gleixner <[email protected]> Co-developed-by: Andrei Vagin <[email protected]> Signed-off-by: Andrei Vagin <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-14x86/vdso: Handle faults on timens pageDmitry Safonov1-2/+52
If a task belongs to a time namespace then the VVAR page which contains the system wide VDSO data is replaced with a namespace specific page which has the same layout as the VVAR page. Co-developed-by: Andrei Vagin <[email protected]> Signed-off-by: Andrei Vagin <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-14x86/vdso: Add time napespace pageDmitry Safonov2-2/+12
To support time namespaces in the VDSO with a minimal impact on regular non time namespace affected tasks, the namespace handling needs to be hidden in a slow path. The most obvious place is vdso_seq_begin(). If a task belongs to a time namespace then the VVAR page which contains the system wide VDSO data is replaced with a namespace specific page which has the same layout as the VVAR page. That page has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. The extra check in the case that vdso_data->seq is odd, e.g. a concurrent update of the VDSO data is in progress, is not really affecting regular tasks which are not part of a time namespace as the task is spin waiting for the update to finish and vdso_data->seq to become even again. If a time namespace task hits that code path, it invokes the corresponding time getter function which retrieves the real VVAR page, reads host time and then adds the offset for the requested clock which is stored in the special VVAR page. Allocate the time namespace page among VVAR pages and place vdso_data on it. Provide __arch_get_timens_vdso_data() helper for VDSO code to get the code-relative position of VVARs on that special page. Co-developed-by: Andrei Vagin <[email protected]> Signed-off-by: Andrei Vagin <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-14x86/vdso: Provide vdso_data offset on vvar_pageDmitry Safonov2-2/+11
VDSO support for time namespaces needs to set up a page with the same layout as VVAR. That timens page will be placed on position of VVAR page inside namespace. That page has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. To prepare the time namespace page the kernel needs to know the vdso_data offset. Provide arch_get_vdso_data() helper for locating vdso_data on VVAR page. Co-developed-by: Andrei Vagin <[email protected]> Signed-off-by: Andrei Vagin <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-14x86/vdso: Restrict splitting VVAR VMADmitry Safonov1-0/+13
Forbid splitting VVAR VMA resulting in a stricter ABI and reducing the amount of corner-cases to consider while working further on VDSO time namespace support. As the offset from timens to VVAR page is computed compile-time, the pages in VVAR should stay together and not being partically mremap()'ed. Co-developed-by: Andrei Vagin <[email protected]> Signed-off-by: Andrei Vagin <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-10x86/vdso: Enable sanitizers for vma.oJann Horn1-0/+3
The vDSO makefile opts out of all sanitizers (and objtool validation); however, vma.o is a normal kernel object file (and already has objtool validation selectively enabled), so turn the sanitizers back on for that file. Signed-off-by: Jann Horn <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Marco Elver <[email protected]> Cc: Paul E. McKenney <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-30Merge tag 'v5.5-rc4' into locking/kcsan, to resolve conflictsIngo Molnar3-6/+4
Conflicts: init/main.c lib/Kconfig.debug Signed-off-by: Ingo Molnar <[email protected]>
2019-12-29x86/vdso: Provide missing include fileValdis Klētnieks1-0/+1
When building with C=1, sparse issues a warning: CHECK arch/x86/entry/vdso/vdso32-setup.c arch/x86/entry/vdso/vdso32-setup.c:28:28: warning: symbol 'vdso32_enabled' was not declared. Should it be static? Provide the missing header file. Signed-off-by: Valdis Kletnieks <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/36224.1575599767@turing-police
2019-12-01Merge tag 'y2038-cleanups-5.5' of ↵Linus Torvalds1-3/+3
git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground Pull y2038 cleanups from Arnd Bergmann: "y2038 syscall implementation cleanups This is a series of cleanups for the y2038 work, mostly intended for namespace cleaning: the kernel defines the traditional time_t, timeval and timespec types that often lead to y2038-unsafe code. Even though the unsafe usage is mostly gone from the kernel, having the types and associated functions around means that we can still grow new users, and that we may be missing conversions to safe types that actually matter. There are still a number of driver specific patches needed to get the last users of these types removed, those have been submitted to the respective maintainers" Link: https://lore.kernel.org/lkml/[email protected]/ * tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (26 commits) y2038: alarm: fix half-second cut-off y2038: ipc: fix x32 ABI breakage y2038: fix typo in powerpc vdso "LOPART" y2038: allow disabling time32 system calls y2038: itimer: change implementation to timespec64 y2038: move itimer reset into itimer.c y2038: use compat_{get,set}_itimer on alpha y2038: itimer: compat handling to itimer.c y2038: time: avoid timespec usage in settimeofday() y2038: timerfd: Use timespec64 internally y2038: elfcore: Use __kernel_old_timeval for process times y2038: make ns_to_compat_timeval use __kernel_old_timeval y2038: socket: use __kernel_old_timespec instead of timespec y2038: socket: remove timespec reference in timestamping y2038: syscalls: change remaining timeval to __kernel_old_timeval y2038: rusage: use __kernel_old_timeval y2038: uapi: change __kernel_time_t to __kernel_old_time_t y2038: stat: avoid 'time_t' in 'struct stat' y2038: ipc: remove __kernel_time_t reference from headers y2038: vdso: powerpc: avoid timespec references ...
2019-11-25Merge branch 'x86/build' into x86/asm, to pick up completed topic branchIngo Molnar1-2/+0
Signed-off-by: Ingo Molnar <[email protected]>
2019-11-16x86, kcsan: Enable KCSAN for x86Marco Elver1-0/+3
This patch enables KCSAN for x86, with updates to build rules to not use KCSAN for several incompatible compilation units. Signed-off-by: Marco Elver <[email protected]> Acked-by: Paul E. McKenney <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2019-11-15y2038: vdso: change time_t to __kernel_old_time_tArnd Bergmann1-3/+3
Only x86 uses the 'time' syscall in vdso, so change that to __kernel_old_time_t as a preparation for removing 'time_t' and '__kernel_time_t' later. Reviewed-by: Thomas Gleixner <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]>
2019-11-15x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.oMasahiro Yamada1-2/+0
CFLAGS_REMOVE_*.o syntax is used to drop particular flags when building objects from C files. It has no effect for assembly files. vdso-note.o is compiled from the assembly file, vdso-note.S, hence CFLAGS_REMOVE_vdso-note.o is meaningless. Neither vvar.c nor vvar.S is found in the vdso directory. Since there is no source file to create vvar.o, CFLAGS_REMOVE_vvar.o is also meaningless. Signed-off-by: Masahiro Yamada <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-10-18x86/asm: Use SYM_INNER_LABEL instead of GLOBALJiri Slaby1-1/+1
The GLOBAL macro had several meanings and is going away. Convert all the inner function labels marked with GLOBAL to use SYM_INNER_LABEL instead. Signed-off-by: Jiri Slaby <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: [email protected] Cc: Masami Hiramatsu <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: "Steven Rostedt (VMware)" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-09-20Merge tag 'kbuild-v5.4' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - add modpost warn exported symbols marked as 'static' because 'static' and EXPORT_SYMBOL is an odd combination - break the build early if gold linker is used - optimize the Bison rule to produce .c and .h files by a single pattern rule - handle PREEMPT_RT in the module vermagic and UTS_VERSION - warn CONFIG options leaked to the user-space except existing ones - make single targets work properly - rebuild modules when module linker scripts are updated - split the module final link stage into scripts/Makefile.modfinal - fix the missed error code in merge_config.sh - improve the error message displayed on the attempt of the O= build in unclean source tree - remove 'clean-dirs' syntax - disable -Wimplicit-fallthrough warning for Clang - add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC - remove ARCH_{CPP,A,C}FLAGS variables - add $(BASH) to run bash scripts - change *CFLAGS_<basetarget>.o to take the relative path to $(obj) instead of the basename - stop suppressing Clang's -Wunused-function warnings when W=1 - fix linux/export.h to avoid genksyms calculating CRC of trimmed exported symbols - misc cleanups * tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (63 commits) genksyms: convert to SPDX License Identifier for lex.l and parse.y modpost: use __section in the output to *.mod.c modpost: use MODULE_INFO() for __module_depends export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols export.h: remove defined(__KERNEL__), which is no longer needed kbuild: allow Clang to find unused static inline functions for W=1 build kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN kbuild: refactor scripts/Makefile.extrawarn merge_config.sh: ignore unwanted grep errors kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj) modpost: add NOFAIL to strndup modpost: add guid_t type definition kbuild: add $(BASH) to run scripts with bash-extension kbuild: remove ARCH_{CPP,A,C}FLAGS kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC kbuild: Do not enable -Wimplicit-fallthrough for clang for now kbuild: clean up subdir-ymn calculation in Makefile.clean kbuild: remove unneeded '+' marker from cmd_clean kbuild: remove clean-dirs syntax kbuild: check clean srctree even earlier ...
2019-09-04kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)Masahiro Yamada1-1/+2
Kbuild provides per-file compiler flag addition/removal: CFLAGS_<basetarget>.o CFLAGS_REMOVE_<basetarget>.o AFLAGS_<basetarget>.o AFLAGS_REMOVE_<basetarget>.o CPPFLAGS_<basetarget>.lds HOSTCFLAGS_<basetarget>.o HOSTCXXFLAGS_<basetarget>.o The <basetarget> is the filename of the target with its directory and suffix stripped. This syntax comes into a trouble when two files with the same basename appear in one Makefile, for example: obj-y += foo.o obj-y += dir/foo.o CFLAGS_foo.o := <some-flags> Here, the <some-flags> applies to both foo.o and dir/foo.o The real world problem is: scripts/kconfig/util.c scripts/kconfig/lxdialog/util.c Both files are compiled into scripts/kconfig/mconf, but only the latter should be given with the ncurses flags. It is more sensible to use the relative path to the Makefile, like this: obj-y += foo.o CFLAGS_foo.o := <some-flags> obj-y += dir/foo.o CFLAGS_dir/foo.o := <other-flags> At first, I attempted to replace $(basetarget) with $*. The $* variable is replaced with the stem ('%') part in a pattern rule. This works with most of cases, but does not for explicit rules. For example, arch/ia64/lib/Makefile reuses rule_as_o_S in its own explicit rules, so $* will be empty, resulting in ignoring the per-file AFLAGS. I introduced a new variable, target-stem, which can be used also from explicit rules. Signed-off-by: Masahiro Yamada <[email protected]> Acked-by: Marc Zyngier <[email protected]>
2019-08-23clocksource/drivers/hyperv: Allocate Hyper-V TSC page staticallyTianyu Lan1-1/+1
Prepare to add Hyper-V sched clock callback and move Hyper-V Reference TSC initialization much earlier in the boot process. Earlier initialization is needed so that it happens while the timestamp value is still 0 and no discontinuity in the timestamp will occur when pv_ops.time.sched_clock calculates its offset. The earlier initialization requires that the Hyper-V TSC page be allocated statically instead of with vmalloc(), so fixup the references to the TSC page and the method of getting its physical address. Signed-off-by: Tianyu Lan <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Acked-by: Daniel Lezcano <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-07-20Merge tag 'kbuild-v5.3-2' of ↵Linus Torvalds1-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - match the directory structure of the linux-libc-dev package to that of Debian-based distributions - fix incorrect include/config/auto.conf generation when Kconfig creates it along with the .config file - remove misleading $(AS) from documents - clean up precious tag files by distclean instead of mrproper - add a new coccinelle patch for devm_platform_ioremap_resource migration - refactor module-related scripts to read modules.order instead of $(MODVERDIR)/*.mod files to get the list of created modules - remove MODVERDIR - update list of header compile-test - add -fcf-protection=none flag to avoid conflict with the retpoline flags when CONFIG_RETPOLINE=y - misc cleanups * tag 'kbuild-v5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits) kbuild: add -fcf-protection=none when using retpoline flags kbuild: update compile-test header list for v5.3-rc1 kbuild: split out *.mod out of {single,multi}-used-m rules kbuild: remove 'prepare1' target kbuild: remove the first line of *.mod files kbuild: create *.mod with full directory path and remove MODVERDIR kbuild: export_report: read modules.order instead of .tmp_versions/*.mod kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod kbuild: modsign: read modules.order instead of $(MODVERDIR)/*.mod kbuild: modinst: read modules.order instead of $(MODVERDIR)/*.mod scsi: remove pointless $(MODVERDIR)/$(obj)/53c700.ver kbuild: remove duplication from modules.order in sub-directories kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin} kbuild: do not create empty modules.order in the prepare stage coccinelle: api: add devm_platform_ioremap_resource script kbuild: compile-test headers listed in header-test-m as well kbuild: remove unused hostcc-option kbuild: remove tag files by distclean instead of mrproper kbuild: add --hash-style= and --build-id unconditionally kbuild: get rid of misleading $(AS) from documents ...
2019-07-18proc/sysctl: add shared variables for range checkMatteo Croce1-5/+2
In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 248 Add a const int array containing the most commonly used values, some macros to refer more easily to the correct array member, and use them instead of creating a local one for every object file. This is the bloat-o-meter output comparing the old and new binary compiled with the default Fedora config: # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164) Data old new delta sysctl_vals - 12 +12 __kstrtab_sysctl_vals - 12 +12 max 14 10 -4 int_max 16 - -16 one 68 - -68 zero 128 28 -100 Total: Before=20583249, After=20583085, chg -0.00% [[email protected]: tipc: remove two unused variables] Link: http://lkml.kernel.org/r/[email protected] [[email protected]: fix net/ipv6/sysctl_net_ipv6.c] [[email protected]: proc/sysctl: make firmware loader table conditional] Link: http://lkml.kernel.org/r/[email protected] [[email protected]: fix fs/eventpoll.c] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Matteo Croce <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> Acked-by: Kees Cook <[email protected]> Reviewed-by: Aaron Tomlin <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Stephen Rothwell <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-07-17kbuild: add --hash-style= and --build-id unconditionallyMasahiro Yamada1-3/+2
As commit 1e0221374e30 ("mips: vdso: drop unnecessary cc-ldoption") explained, these flags are supported by the minimal required version of binutils. They are supported by ld.lld too. Signed-off-by: Masahiro Yamada <[email protected]> Reviewed-by: Nathan Chancellor <[email protected]> Tested-by: Nathan Chancellor <[email protected]>
2019-07-12x86/vdso: Fix flip/flop vdso build bugNaohiro Aota1-6/+6
Two consecutive "make" on an already compiled kernel tree will show different behavior: $ make CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool CHK include/generated/compile.h VDSOCHK arch/x86/entry/vdso/vdso64.so.dbg VDSOCHK arch/x86/entry/vdso/vdso32.so.dbg Kernel: arch/x86/boot/bzImage is ready (#3) Building modules, stage 2. MODPOST 12 modules $ make make CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool CHK include/generated/compile.h VDSO arch/x86/entry/vdso/vdso64.so.dbg OBJCOPY arch/x86/entry/vdso/vdso64.so VDSO2C arch/x86/entry/vdso/vdso-image-64.c CC arch/x86/entry/vdso/vdso-image-64.o VDSO arch/x86/entry/vdso/vdso32.so.dbg OBJCOPY arch/x86/entry/vdso/vdso32.so VDSO2C arch/x86/entry/vdso/vdso-image-32.c CC arch/x86/entry/vdso/vdso-image-32.o AR arch/x86/entry/vdso/built-in.a AR arch/x86/entry/built-in.a AR arch/x86/built-in.a GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o <snip> This is causing "LD vmlinux" once every two times even without any modifications. This is the same bug fixed in commit 92a4728608a8 ("x86/boot: Fix if_changed build flip/flop bug"). Two "if_changed" cannot be used in one target. Fix this merging two commands into one function. Fixes: 7ac870747988 ("x86/vdso: Switch to generic vDSO implementation") Signed-off-by: Naohiro Aota <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Vincenzo Frascino <[email protected]> Reviewed-by: Vincenzo Frascino <[email protected]> Reviewed-by: Masahiro Yamada <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-07-03clocksource/drivers: Continue making Hyper-V clocksource ISA agnosticMichael Kelley1-1/+1
Continue consolidating Hyper-V clock and timer code into an ISA independent Hyper-V clocksource driver. Move the existing clocksource code under drivers/hv and arch/x86 to the new clocksource driver while separating out the ISA dependencies. Update Hyper-V initialization to call initialization and cleanup routines since the Hyper-V synthetic clock is not independently enumerated in ACPI. Update Hyper-V clocksource users in KVM and VDSO to get definitions from the new include file. No behavior is changed and no new functionality is added. Suggested-by: Marc Zyngier <[email protected]> Signed-off-by: Michael Kelley <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Vitaly Kuznetsov <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: Sunil Muthuswamy <[email protected]> Cc: KY Srinivasan <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-22x86/vdso: Add clock_gettime64() entry pointVincenzo Frascino2-0/+9
Linux 5.1 gained the new clock_gettime64() syscall to address the Y2038 problem on 32bit systems. The x86 VDSO is missing support for this variant of clock_gettime(). Update the x86 specific vDSO library accordingly so it exposes the new time getter. [ tglx: Massaged changelog ] Signed-off-by: Vincenzo Frascino <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Russell King <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Paul Burton <[email protected]> Cc: Daniel Lezcano <[email protected]> Cc: Mark Salyzyn <[email protected]> Cc: Peter Collingbourne <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Huw Davies <[email protected]> Cc: Shijith Thotton <[email protected]> Cc: Andre Przywara <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-22x86/vdso: Add clock_getres() entry pointVincenzo Frascino3-0/+20
The generic vDSO library provides an implementation of clock_getres() that can be leveraged by each architecture. Add the clock_getres() VDSO entry point on x86. [ tglx: Massaged changelog and cleaned up the function signature formatting ] Signed-off-by: Vincenzo Frascino <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Russell King <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Paul Burton <[email protected]> Cc: Daniel Lezcano <[email protected]> Cc: Mark Salyzyn <[email protected]> Cc: Peter Collingbourne <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Huw Davies <[email protected]> Cc: Shijith Thotton <[email protected]> Cc: Andre Przywara <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-22x86/vdso: Switch to generic vDSO implementationVincenzo Frascino3-218/+37
The x86 vDSO library requires some adaptations to take advantage of the newly introduced generic vDSO library. Introduce the following changes: - Modification of vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday [ tglx: Massaged changelog and cleaned up the function signature formatting ] Signed-off-by: Vincenzo Frascino <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Russell King <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Paul Burton <[email protected]> Cc: Daniel Lezcano <[email protected]> Cc: Mark Salyzyn <[email protected]> Cc: Peter Collingbourne <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Huw Davies <[email protected]> Cc: Shijith Thotton <[email protected]> Cc: Andre Przywara <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-21x86/vdso: Prevent segfaults due to hoisted vclock readsAndy Lutomirski1-2/+13
GCC 5.5.0 sometimes cleverly hoists reads of the pvclock and/or hvclock pages before the vclock mode checks. This creates a path through vclock_gettime() in which no vclock is enabled at all (due to disabled TSC on old CPUs, for example) but the pvclock or hvclock page nevertheless read. This will segfault on bare metal. This fixes commit 459e3a21535a ("gcc-9: properly declare the {pv,hv}clock_page storage") in the sense that, before that commit, GCC didn't seem to generate the offending code. There was nothing wrong with that commit per se, and -stable maintainers should backport this to all supported kernels regardless of whether the offending commit was present, since the same crash could just as easily be triggered by the phase of the moon. On GCC 9.1.1, this doesn't seem to affect the generated code at all, so I'm not too concerned about performance regressions from this fix. Cc: [email protected] Cc: [email protected] Cc: Borislav Petkov <[email protected]> Reported-by: Duncan Roe <[email protected]> Signed-off-by: Andy Lutomirski <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 223Thomas Gleixner2-2/+2
Based on 1 normalized pattern(s): subject to the gnu public license v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 9 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Allison Randal <[email protected]> Reviewed-by: Alexios Zavras <[email protected]> Reviewed-by: Steve Winslow <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 214Thomas Gleixner1-1/+1
Based on 1 normalized pattern(s): subject to the gpl v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 2 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Allison Randal <[email protected]> Reviewed-by: Steve Winslow <[email protected]> Reviewed-by: Alexios Zavras <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-05-08x86/vdso: Remove hpet_page from vDSOJia Zhang1-3/+0
This trivial cleanup finalizes the removal of vDSO HPET support. Fixes: 1ed95e52d902 ("x86/vdso: Remove direct HPET access through the vDSO") Signed-off-by: Jia Zhang <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-05-06Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2-7/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "This includes the following changes: - cpu_has() cleanups - sync_bitops.h modernization to the rmwcc.h facility, similarly to bitops.h - continued LTO annotations/fixes - misc cleanups and smaller cleanups" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/um/vdso: Drop unnecessary cc-ldoption x86/vdso: Rename variable to fix -Wshadow warning x86/cpu/amd: Exclude 32bit only assembler from 64bit build x86/asm: Mark all top level asm statements as .text x86/build/vdso: Add FORCE to the build rule of %.so x86/asm: Modernize sync_bitops.h x86/mm: Convert some slow-path static_cpu_has() callers to boot_cpu_has() x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has() x86/asm: Clarify static_cpu_has()'s intended use x86/uaccess: Fix implicit cast of __user pointer x86/cpufeature: Remove __pure attribute to _static_cpu_has()
2019-05-01gcc-9: properly declare the {pv,hv}clock_page storageLinus Torvalds1-2/+2
The pvlock_page and hvclock_page variables are (as the name implies) addresses to pages, created by the linker script. But we declared them as just "extern u8" variables, which _works_, but now that gcc does some more bounds checking, it causes warnings like warning: array subscript 1 is outside array bounds of ‘u8[1]’ when we then access more than one byte from those variables. Fix this by simply making the declaration of the variables match reality, which makes the compiler happy too. Signed-off-by: Linus Torvalds <[email protected]>
2019-04-19x86/vdso: Rename variable to fix -Wshadow warningLeonardo Brás1-6/+7
The go32() and go64() functions has an argument and a local variable called ‘name’. Rename both to clarify the code and to fix a warning with -Wshadow. Signed-off-by: Leonardo Brás <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Michal Marek <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/20181023011022.GA6574@WindFlash Signed-off-by: Ingo Molnar <[email protected]>
2019-04-18x86/build/vdso: Add FORCE to the build rule of %.soMasahiro Yamada1-1/+1
$(call if_changed,...) must have FORCE as a prerequisite. Signed-off-by: Masahiro Yamada <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-12-26Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kprobes: Remove trampoline_handler() prototype x86/kernel: Fix more -Wmissing-prototypes warnings x86: Fix various typos in comments x86/headers: Fix -Wmissing-prototypes warning x86/process: Avoid unnecessary NULL check in get_wchan() x86/traps: Complete prototype declarations x86/mce: Fix -Wmissing-prototypes warnings x86/gart: Rewrite early_gart_iommu_check() comment
2018-12-26Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2-35/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "Two changes: - Remove (some) remnants of the vDSO's fake section table mechanism that were left behind when the vDSO build process reverted to using "objdump -S" to strip the userspace image. - Remove hardcoded POPCNT mnemonics now that the minimum binutils version supports the symbolic form" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Remove a stale/misleading comment from the linker script x86/vdso: Remove obsolete "fake section table" reservation x86: Use POPCNT mnemonics in arch_hweight.h
2018-12-15x86/vdso: Pass --eh-frame-hdr to the linkerAlistair Strachan1-1/+2
Commit 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link") accidentally broke unwinding from userspace, because ld would strip the .eh_frame sections when linking. Originally, the compiler would implicitly add --eh-frame-hdr when invoking the linker, but when this Makefile was converted from invoking ld via the compiler, to invoking it directly (like vmlinux does), the flag was missed. (The EH_FRAME section is important for the VDSO shared libraries, but not for vmlinux.) Fix the problem by explicitly specifying --eh-frame-hdr, which restores parity with the old method. See relevant bug reports for additional info: https://bugzilla.kernel.org/show_bug.cgi?id=201741 https://bugzilla.redhat.com/show_bug.cgi?id=1659295 Fixes: 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link") Reported-by: Florian Weimer <[email protected]> Reported-by: Carlos O'Donell <[email protected]> Reported-by: "H. J. Lu" <[email protected]> Signed-off-by: Alistair Strachan <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Tested-by: Laura Abbott <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Carlos O'Donell <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: [email protected] Cc: Laura Abbott <[email protected]> Cc: stable <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: X86 ML <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2018-12-07x86/vdso: Drop implicit common-page-size linker flagNick Desaulniers1-2/+2
GNU linker's -z common-page-size's default value is based on the target architecture. arch/x86/entry/vdso/Makefile sets it to the architecture default, which is implicit and redundant. Drop it. Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Reported-by: Dmitry Golovin <[email protected]> Reported-by: Bill Wendling <[email protected]> Suggested-by: Dmitry Golovin <[email protected]> Suggested-by: Rui Ueyama <[email protected]> Signed-off-by: Nick Desaulniers <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Fangrui Song <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: https://github.com/ClangBuiltLinux/linux/issues/31
2018-12-05x86/vdso: Remove a stale/misleading comment from the linker scriptSean Christopherson1-5/+0
Once upon a time, vdso2c aggressively stripped data from the vDSO image when generating the final userspace image. This included stripping the .altinstructions and .altinstr_replacement sections. Eventually, the stripping process reverted to "objdump -S" and no longer removed the aforementioned sections, but the comment remained. Keeping the .alt* sections at the end of the PT_LOAD segment is no longer necessary, but there's no harm in doing so and it's a helpful reminder that they don't need to be included in the final vDSO image, i.e. someone may want to take another stab at zapping/stripping the unneeded sections. Signed-off-by: Sean Christopherson <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: da861e18eccc ("x86, vdso: Get rid of the fake section mechanism") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-12-05x86/vdso: Remove obsolete "fake section table" reservationSean Christopherson2-30/+0
At one point the vDSO image was manually stripped down by vdso2c in an attempt to minimize the size of the image mapped into userspace. Part of that stripping process involved building a fake section table so as not to break userspace processes that parse the section table. Memory for the fake section table was reserved in the .rodata section so that vdso2c could simply copy the entire PT_LOAD segment into the userspace image after building the fake table. Eventually, the entire fake section table approach was dropped in favor of stripping the vdso "the old fashioned way", i.e. via objdump -S. But, the reservation in .rodata for the fake table was left behind. Remove the reserveration along with a few other related defines and section entries. Removing the fake section table placeholder zaps a whopping 0x340 bytes from the 64-bit vDSO image, which drops the current image's size to under 4k, i.e. reduces the effective size of the userspace vDSO mapping by a full page. Signed-off-by: Sean Christopherson <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: da861e18eccc ("x86, vdso: Get rid of the fake section mechanism") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-12-03x86: Fix various typos in commentsIngo Molnar1-1/+1
Go over arch/x86/ and fix common typos in comments, and a typo in an actual function argument name. No change in functionality intended. Cc: Thomas Gleixner <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-10-26x86: convert vdso to use vm_fault_tMatthew Wilcox1-15/+9
Return vm_fault_t codes directly from the appropriate mm routines instead of converting from errnos ourselves. Fixes a minor bug where we'd return SIGBUS instead of the correct OOM code if we ran out of memory allocating page tables. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Nicolas Pitre <[email protected]> Cc: Souptick Joarder <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2018-10-23Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds1-150/+60
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso updates from Ingo Molnar: "Two main changes: - Cleanups, simplifications and CLOCK_TAI support (Thomas Gleixner) - Improve code generation (Andy Lutomirski)" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Rearrange do_hres() to improve code generation x86/vdso: Document vgtod_ts better x86/vdso: Remove "memory" clobbers in the vDSO syscall fallbacks x66/vdso: Add CLOCK_TAI support x86/vdso: Move cycle_last handling into the caller x86/vdso: Simplify the invalid vclock case x86/vdso: Replace the clockid switch case x86/vdso: Collapse coarse functions x86/vdso: Collapse high resolution functions x86/vdso: Introduce and use vgtod_ts x86/vdso: Use unsigned int consistently for vsyscall_gtod_data:: Seq x86/vdso: Enforce 64bit clocksource x86/time: Implement clocksource_arch_init() clocksource: Provide clocksource_arch_init()
2018-10-08x86/fsgsbase/64: Clean up various detailsIngo Molnar1-0/+1
So: - use 'extern' consistently for APIs - fix weird header guard - clarify code comments - reorder APIs by type Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Chang S. Bae <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Markus T Metzger <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi Shankar <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-10-08x86/segments: Introduce the 'CPUNODE' naming to better document the segment ↵Ingo Molnar1-1/+1
limit CPU/node NR trick 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 <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Chang S. Bae <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Markus T Metzger <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi Shankar <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-10-08x86/vdso: Initialize the CPU/node NR segment descriptor earlierChang S. Bae1-32/+1
Currently the CPU/node NR segment descriptor (GDT_ENTRY_CPU_NUMBER) is initialized relatively late during CPU init, from the vCPU code, which has a number of disadvantages, such as hotplug CPU notifiers and SMP cross-calls. Instead just initialize it much earlier, directly in cpu_init(). This reduces complexity and increases robustness. [ mingo: Wrote new changelog. ] Suggested-by: H. Peter Anvin <[email protected]> Suggested-by: Andy Lutomirski <[email protected]> Signed-off-by: Chang S. Bae <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Markus T Metzger <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi Shankar <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
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