talos-op-linux/arch/x86/entry/vdso, branch master

kbuild: rename hostprogs-y/always to hostprogs/always-y

2020-02-03T16:53:07+00:00

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

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

2020-01-28T20:11:23+00:00

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

x86/vdso: Zap vvar pages when switching to a time namespace

2020-01-14T11:20:59+00:00

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 Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191112012724.250792-27-dima@arista.com

x86/vdso: On timens page fault prefault also VVAR page

2020-01-14T11:20:59+00:00

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 Co-developed-by: Andrei Vagin Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191112012724.250792-26-dima@arista.com

x86/vdso: Handle faults on timens page

2020-01-14T11:20:58+00:00

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 Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191112012724.250792-25-dima@arista.com

x86/vdso: Add time napespace page

2020-01-14T11:20:58+00:00

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 Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191112012724.250792-23-dima@arista.com

x86/vdso: Provide vdso_data offset on vvar_page

2020-01-14T11:20:57+00:00

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 Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191112012724.250792-22-dima@arista.com

x86/vdso: Restrict splitting VVAR VMA

2020-01-14T11:20:56+00:00

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 Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20191112012724.250792-20-dima@arista.com

x86/vdso: Provide missing include file

2019-12-29T12:41:31+00:00

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 Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/36224.1575599767@turing-police

Merge tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

2019-12-01T22:00:59+00:00

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/20191108210236.1296047-1-arnd@arndb.de/ * 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 ...