user/sven/linux.git/Documentation/admin-guide/sysctl/kernel.rst, branch v6.7.9

Merge tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2023-11-02T01:28:33Z

Pull ia64 removal and asm-generic updates from Arnd Bergmann: - The ia64 architecture gets its well-earned retirement as planned, now that there is one last (mostly) working release that will be maintained as an LTS kernel. - The architecture specific system call tables are updated for the added map_shadow_stack() syscall and to remove references to the long-gone sys_lookup_dcookie() syscall. * tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: hexagon: Remove unusable symbols from the ptrace.h uapi asm-generic: Fix spelling of architecture arch: Reserve map_shadow_stack() syscall number for all architectures syscalls: Cleanup references to sys_lookup_dcookie() Documentation: Drop or replace remaining mentions of IA64 lib/raid6: Drop IA64 support Documentation: Drop IA64 from feature descriptions kernel: Drop IA64 support from sig_fault handlers arch: Remove Itanium (IA-64) architecture

sched/topology: Change behaviour of the 'sched_energy_aware' sysctl, based on the platform

2023-10-09T15:24:44Z

The 'sched_energy_aware' sysctl is available for the admin to disable/enable energy aware scheduling(EAS). EAS is enabled only if few conditions are met by the platform. They are, asymmetric CPU capacity, no SMT, schedutil CPUfreq governor, frequency invariant load tracking etc. A platform may boot without EAS capability, but could gain such capability at runtime. For example, changing/registering the cpufreq governor to schedutil. At present, though platform doesn't support EAS, this sysctl returns 1 and it ends up calling build_perf_domains on write to 1 and NOP when writing to 0. That is confusing and un-necessary. Desired behavior would be to have this sysctl to enable/disable the EAS on supported platform. On non-supported platform write to the sysctl would return not supported error and read of the sysctl would return empty. So sched_energy_aware returns empty - EAS is not possible at this moment This will include EAS capable platforms which have at least one EAS condition false during startup, e.g. not using the schedutil cpufreq governor sched_energy_aware returns 0 - EAS is supported but disabled by admin. sched_energy_aware returns 1 - EAS is supported and enabled. User can find out the reason why EAS is not possible by checking info messages. sched_is_eas_possible returns true if the platform can do EAS at this moment. Signed-off-by: Shrikanth Hegde Signed-off-by: Ingo Molnar Tested-by: Pierre Gondois Reviewed-by: Valentin Schneider Link: https://lore.kernel.org/r/20231009060037.170765-3-sshegde@linux.vnet.ibm.com

Documentation: Drop or replace remaining mentions of IA64

2023-09-11T08:13:18Z

Drop or update mentions of IA64, as appropriate. Signed-off-by: Ard Biesheuvel

Merge tag 'io_uring-6.6-2023-09-08' of git://git.kernel.dk/linux

2023-09-09T04:32:28Z

Pull io_uring fixes from Jens Axboe: "A few fixes that should go into the 6.6-rc merge window: - Fix for a regression this merge window caused by the SQPOLL affinity patch, where we can race with SQPOLL thread shutdown and cause an oops when trying to set affinity (Gabriel) - Fix for a regression this merge window where fdinfo reading with for a ring setup with IORING_SETUP_NO_SQARRAY will attempt to deference the non-existing SQ ring array (me) - Add the patch that allows more finegrained control over who can use io_uring (Matteo) - Locking fix for a regression added this merge window for IOPOLL overflow (Pavel) - IOPOLL fix for stable, breaking our loop if helper threads are exiting (Pavel) Also had a fix for unreaped iopoll requests from io-wq from Ming, but we found an issue with that and hence it got reverted. Will get this sorted for a future rc" * tag 'io_uring-6.6-2023-09-08' of git://git.kernel.dk/linux: Revert "io_uring: fix IO hang in io_wq_put_and_exit from do_exit()" io_uring: fix unprotected iopoll overflow io_uring: break out of iowq iopoll on teardown io_uring: add a sysctl to disable io_uring system-wide io_uring/fdinfo: only print ->sq_array[] if it's there io_uring: fix IO hang in io_wq_put_and_exit from do_exit() io_uring: Don't set affinity on a dying sqpoll thread

io_uring: add a sysctl to disable io_uring system-wide

2023-09-05T14:34:07Z

Introduce a new sysctl (io_uring_disabled) which can be either 0, 1, or 2. When 0 (the default), all processes are allowed to create io_uring instances, which is the current behavior. When 1, io_uring creation is disabled (io_uring_setup() will fail with -EPERM) for unprivileged processes not in the kernel.io_uring_group group. When 2, calls to io_uring_setup() fail with -EPERM regardless of privilege. Signed-off-by: Matteo Rizzo [JEM: modified to add io_uring_group] Signed-off-by: Jeff Moyer Link: https://lore.kernel.org/r/x49y1i42j1z.fsf@segfault.boston.devel.redhat.com Signed-off-by: Jens Axboe

Documentation: admin-guide: Add riscv sysctl_perf_user_access

2023-08-16T14:28:21Z

riscv now uses this sysctl so document its usage for this architecture. Signed-off-by: Alexandre Ghiti

docs: arm64: Move arm64 documentation under Documentation/arch/

2023-06-21T14:51:51Z

Architecture-specific documentation is being moved into Documentation/arch/ as a way of cleaning up the top-level documentation directory and making the docs hierarchy more closely match the source hierarchy. Move Documentation/arm64 into arch/ (along with the Chinese equvalent translations) and fix up documentation references. Cc: Will Deacon Cc: Alex Shi Cc: Hu Haowen Cc: Paolo Bonzini Acked-by: Catalin Marinas Reviewed-by: Yantengsi Signed-off-by: Jonathan Corbet

docs: move x86 documentation into Documentation/arch/

2023-03-30T18:58:51Z

Move the x86 documentation under Documentation/arch/ as a way of cleaning up the top-level directory and making the structure of our docs more closely match the structure of the source directories it describes. All in-kernel references to the old paths have been updated. Acked-by: Dave Hansen Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org Cc: Borislav Petkov Cc: Thomas Gleixner Link: https://lore.kernel.org/lkml/20230315211523.108836-1-corbet@lwn.net/ Signed-off-by: Jonathan Corbet

kexec: introduce sysctl parameters kexec_load_limit_*

2023-02-03T06:50:05Z

kexec allows replacing the current kernel with a different one. This is usually a source of concerns for sysadmins that want to harden a system. Linux already provides a way to disable loading new kexec kernel via kexec_load_disabled, but that control is very coard, it is all or nothing and does not make distinction between a panic kexec and a normal kexec. This patch introduces new sysctl parameters, with finer tuning to specify how many times a kexec kernel can be loaded. The sysadmin can set different limits for kexec panic and kexec reboot kernels. The value can be modified at runtime via sysctl, but only with a stricter value. With these new parameters on place, a system with loadpin and verity enabled, using the following kernel parameters: sysctl.kexec_load_limit_reboot=0 sysct.kexec_load_limit_panic=1 can have a good warranty that if initrd tries to load a panic kernel, a malitious user will have small chances to replace that kernel with a different one, even if they can trigger timeouts on the disk where the panic kernel lives. Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-3-6a8531a09b9a@chromium.org Signed-off-by: Ricardo Ribalda Reviewed-by: Steven Rostedt (Google) Acked-by: Baoquan He Cc: Bagas Sanjaya Cc: "Eric W. Biederman" Cc: Guilherme G. Piccoli # Steam Deck Cc: Joel Fernandes (Google) Cc: Jonathan Corbet Cc: Philipp Rudo Cc: Ross Zwisler Cc: Sergey Senozhatsky Signed-off-by: Andrew Morton

Documentation: sysctl: correct kexec_load_disabled

2023-02-03T06:50:04Z

Patch series "kexec: Add new parameter to limit the access to kexec", v6. Add two parameter to specify how many times a kexec kernel can be loaded. These parameter allow hardening the system. While we are at it, fix a documentation issue and refactor some code. This patch (of 3): kexec_load_disabled affects both ``kexec_load`` and ``kexec_file_load`` syscalls. Make it explicit. Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-0-6a8531a09b9a@chromium.org Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-1-6a8531a09b9a@chromium.org Signed-off-by: Ricardo Ribalda Reviewed-by: Steven Rostedt (Google) Acked-by: Baoquan He Cc: Bagas Sanjaya Cc: "Eric W. Biederman" Cc: Guilherme G. Piccoli Cc: Joel Fernandes (Google) Cc: Jonathan Corbet Cc: Philipp Rudo Cc: Ross Zwisler Cc: Sergey Senozhatsky Signed-off-by: Andrew Morton