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2020-07-23debugfs: Add access restriction optionPeter Enderborg
Since debugfs include sensitive information it need to be treated carefully. But it also has many very useful debug functions for userspace. With this option we can have same configuration for system with need of debugfs and a way to turn it off. This gives a extra protection for exposure on systems where user-space services with system access are attacked. It is controlled by a configurable default value that can be override with a kernel command line parameter. (debugfs=) It can be on or off, but also internally on but not seen from user-space. This no-mount mode do not register a debugfs as filesystem, but client can register their parts in the internal structures. This data can be readed with a debugger or saved with a crashkernel. When it is off clients get EPERM error when accessing the functions for registering their components. Signed-off-by: Peter Enderborg <peter.enderborg@sony.com> Link: https://lore.kernel.org/r/20200716071511.26864-3-peter.enderborg@sony.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-21Merge tag 'thunderbolt-for-v5.9' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-next Mika writes: thunderbolt: Changes for v5.9 merge window This includes following Thunderbolt/USB4 changes for v5.9 merge window: * Improvements around NHI (Native Host Interface) HopID allocation * Improvements to tunneling and USB3 bandwidth management support * Add KUnit tests for path walking and tunneling * Initial support for USB4 retimer firmware upgrade * Implement Thunderbolt device firmware upgrade mechanism that runs the NVM image authentication when the device is disconnected. * A couple of small non-critical fixes * tag 'thunderbolt-for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt: (32 commits) thunderbolt: Fix old style declaration warning thunderbolt: Add support for authenticate on disconnect thunderbolt: Add support for separating the flush to SPI and authenticate thunderbolt: Ensure left shift of 512 does not overflow a 32 bit int thunderbolt: Add support for on-board retimers thunderbolt: Implement USB4 port sideband operations for retimer access thunderbolt: Retry USB4 block read operation thunderbolt: Generalize usb4_switch_do_[read|write]_data() thunderbolt: Split common NVM functionality into a separate file thunderbolt: Add Intel USB-IF ID to the NVM upgrade supported list thunderbolt: Add KUnit tests for tunneling thunderbolt: Add USB3 bandwidth management thunderbolt: Make tb_port_get_link_speed() available to other files thunderbolt: Implement USB3 bandwidth negotiation routines thunderbolt: Increase DP DPRX wait timeout thunderbolt: Report consumed bandwidth in both directions thunderbolt: Make usb4_switch_map_pcie_down() also return enabled ports thunderbolt: Make usb4_switch_map_usb3_down() also return enabled ports thunderbolt: Do not tunnel USB3 if link is not USB4 thunderbolt: Add DP IN resources for all routers ...
2020-07-20dm dust: add interface to list all badblocksyangerkun
This interface may help anyone who want to know all badblocks without querying for each block. [Bryan: DMEMIT message if no blocks are in the bad block list.] Signed-off-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Bryan Gurney <bgurney@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-07-20dm dust: report some message results directly back to useryangerkun
Some messages (queryblock, countbadblocks, removebadblock) are best reported directly to user directly. Do so with DMEMIT. [Bryan: maintain __func__ output in DMEMIT messages] Signed-off-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Bryan Gurney <bgurney@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-07-17blk-cgroup: show global disk stats in root cgroup io.statBoris Burkov
In order to improve consistency and usability in cgroup stat accounting, we would like to support the root cgroup's io.stat. Since the root cgroup has processes doing io even if the system has no explicitly created cgroups, we need to be careful to avoid overhead in that case. For that reason, the rstat algorithms don't handle the root cgroup, so just turning the file on wouldn't give correct statistics. To get around this, we simulate flushing the iostat struct by filling it out directly from global disk stats. The result is a root cgroup io.stat file consistent with both /proc/diskstats and io.stat. Note that in order to collect the disk stats, we needed to iterate over devices. To facilitate that, we had to change the linkage of a disk_type to external so that it can be used from blk-cgroup.c to iterate over disks. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Boris Burkov <boris@bur.io> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-15platform/x86: thinkpad_acpi: lap or desk mode interfaceMark Pearson
Newer Lenovo Thinkpad platforms have support to identify whether the system is on-lap or not using an ACPI DYTC event from the firmware. This patch provides the ability to retrieve the current mode via sysfs entrypoints and will be used by userspace for thermal mode and WWAN functionality Co-developed-by: Nitin Joshi <njoshi1@lenovo.com> Signed-off-by: Nitin Joshi <njoshi1@lenovo.com> Reviewed-by: Sugumaran <slacshiminar@lenovo.com> Reviewed-by: Bastien Nocera <bnocera@redhat.com> Signed-off-by: Mark Pearson <markpearson@lenovo.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-07-13dm verity: add "panic_on_corruption" error handling modeJeongHyeon Lee
Samsung smart phones may need the ability to panic on corruption. Not all devices provide the bootloader support needed to use the existing "restart_on_corruption" mode. Additional details for why Samsung needs this new mode can be found here: https://www.redhat.com/archives/dm-devel/2020-June/msg00235.html Signed-off-by: jhs2.lee <jhs2.lee@samsung.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-07-13Documentation: numaperf: eliminate duplicated wordRandy Dunlap
Drop the duplicated word "not". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-mm@vger.kernel.org Cc: Mike Rapoport <rppt@kernel.org> Link: https://lore.kernel.org/r/20200707180414.10467-2-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-13doc: yama: Swap HTTP for HTTPS and replace dead linkKees Cook
Replace one dead link for the same person's original presentation on the topic and swap an HTTP URL with HTTPS. While here, linkify the text to make it more readable when rendered. Link: https://lore.kernel.org/lkml/20200708073346.13177-1-grandmaster@al2klimov.de/ Co-developed-by: Alexander A. Klimov <grandmaster@al2klimov.de> Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/202007091141.C008B89EC@keescook Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-13Documentation/security-bugs: Explain why plain text is preferredKees Cook
The security contact list gets regular reports contained in archive attachments. This tends to add some back-and-forth delay in dealing with security reports since we have to ask for plain text, etc. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://lore.kernel.org/r/202007091110.205DC6A9@keescook Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-08xen: Mark "xen_nopvspin" parameter obsoleteZhenzhong Duan
Map "xen_nopvspin" to "nopvspin", fix stale description of "xen_nopvspin" as we use qspinlock now. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08x86/kvm: Add "nopvspin" parameter to disable PV spinlocksZhenzhong Duan
There are cases where a guest tries to switch spinlocks to bare metal behavior (e.g. by setting "xen_nopvspin" on XEN platform and "hv_nopvspin" on HYPER_V). That feature is missed on KVM, add a new parameter "nopvspin" to disable PV spinlocks for KVM guest. The new 'nopvspin' parameter will also replace Xen and Hyper-V specific parameters in future patches. Define variable nopvsin as global because it will be used in future patches as above. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08Documentation: update for gcc 4.9 requirementRandy Dunlap
Update Documentation for the gcc v4.9 upgrade requirement. Fixes: 5429ef62bcf3 ("compiler/gcc: Raise minimum GCC version for kernel builds to 4.8") Fixes: 6ec4476ac825 ("Raise gcc version requirement to 4.9") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-08ext4: add inline encryption supportEric Biggers
Wire up ext4 to support inline encryption via the helper functions which fs/crypto/ now provides. This includes: - Adding a mount option 'inlinecrypt' which enables inline encryption on encrypted files where it can be used. - Setting the bio_crypt_ctx on bios that will be submitted to an inline-encrypted file. Note: submit_bh_wbc() in fs/buffer.c also needed to be patched for this part, since ext4 sometimes uses ll_rw_block() on file data. - Not adding logically discontiguous data to bios that will be submitted to an inline-encrypted file. - Not doing filesystem-layer crypto on inline-encrypted files. Co-developed-by: Satya Tangirala <satyat@google.com> Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20200702015607.1215430-5-satyat@google.com Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-07-05doc: cgroup: add f2fs and xfs to supported list for writebackEric Sandeen
f2fs and xfs have both added support for cgroup writeback: 578c647 f2fs: implement cgroup writeback support adfb5fb xfs: implement cgroup aware writeback so add them to the supported list in the docs. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Link: https://lore.kernel.org/r/c8271324-9132-388c-5242-d7699f011892@redhat.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Replace HTTP links with HTTPS ones: LVMAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200627103138.71885-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05docs: CIFS: remove a spam-site URLJonathan Corbet
protocolfreedom.org may have one contained something useful, but now it wants to sell us new credit cards. Take it out. Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Replace HTTP links with HTTPS ones: CIFSAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Link: https://lore.kernel.org/r/20200627103125.71828-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Replace HTTP links with HTTPS ones: DRBD driverAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200627103111.71771-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Replace HTTP links with HTTPS ones: Documentation/admin-guideAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200627072935.62652-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: xfs: drop doubled wordRandy Dunlap
Drop the doubled word "for". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: linux-xfs@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-14-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: tainted-kernels: drop doubled wordRandy Dunlap
Drop the doubled word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-13-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: sysctl/kernel: drop doubled wordRandy Dunlap
Drop the doubled word "set". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-12-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: intel-speed-select: drop doubled wordsRandy Dunlap
Drop the doubled words "that" and "and". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: platform-driver-x86@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-11-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: intel_pstate: drop doubled wordRandy Dunlap
Drop the doubled word "to". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Len Brown <lenb@kernel.org> Cc: linux-pm@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-10-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: arm-ccn: drop doubled wordRandy Dunlap
Drop the doubled word "as". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-9-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: pnfs-scsi-server: drop doubled wordRandy Dunlap
Drop the doubled word "with". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <anna.schumaker@netapp.com> Cc: linux-nfs@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-8-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: pnfs-block-server: drop doubled wordRandy Dunlap
Drop the doubled word "with". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <anna.schumaker@netapp.com> Cc: linux-nfs@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-7-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: mm/ksm: drop doubled wordRandy Dunlap
Drop the doubled word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Link: https://lore.kernel.org/r/20200704032020.21923-6-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: media/building: drop doubled wordsRandy Dunlap
Drop some doubled words. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: linux-media@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-5-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: dm-integrity: drop doubled wordsRandy Dunlap
Drop the doubled words "on" and "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: dm-devel@redhat.com Link: https://lore.kernel.org/r/20200704032020.21923-4-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: cgroup-v1/rdma: drop doubled wordRandy Dunlap
Drop the doubled word "echo". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: cgroups@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-3-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation/admin-guide: cgroup-v2: drop doubled wordRandy Dunlap
Drop the doubled word "of". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: cgroups@vger.kernel.org Link: https://lore.kernel.org/r/20200704032020.21923-2-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-04media: samsung: Rename Samsung and Exynos to lowercaseKrzysztof Kozlowski
Fix up inconsistent usage of upper and lowercase letters in "Samsung" and "Exynos" names. "SAMSUNG" and "EXYNOS" are not abbreviations but regular trademarked names. Therefore they should be written with lowercase letters starting with capital letter. The lowercase "Exynos" name is promoted by its manufacturer Samsung Electronics Co., Ltd., in advertisement materials and on website. Although advertisement materials usually use uppercase "SAMSUNG", the lowercase version is used in all legal aspects (e.g. on Wikipedia and in privacy/legal statements on https://www.samsung.com/semiconductor/privacy-global/). Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-07-02arm64/crash_core: Export TCR_EL1.T1SZ in vmcoreinfoBhupesh Sharma
TCR_EL1.TxSZ, which controls the VA space size, is configured by a single kernel image to support either 48-bit or 52-bit VA space. If the ARMv8.2-LVA optional feature is present and we are running with a 64KB page size, then it is possible to use 52-bits of address space for both userspace and kernel addresses. However, any kernel binary that supports 52-bit must also be able to fall back to 48-bit at early boot time if the hardware feature is not present. Since TCR_EL1.T1SZ indicates the size of the memory region addressed by TTBR1_EL1, export the same in vmcoreinfo. User-space utilities like makedumpfile and crash-utility need to read this value from vmcoreinfo for determining if a virtual address lies in the linear map range. While at it also add documentation for TCR_EL1.T1SZ variable being added to vmcoreinfo. It indicates the size offset of the memory region addressed by TTBR1_EL1. Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com> Tested-by: John Donnelly <john.p.donnelly@oracle.com> Tested-by: Kamlakant Patel <kamlakantp@marvell.com> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Steve Capper <steve.capper@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Dave Anderson <anderson@redhat.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org Link: https://lore.kernel.org/r/1589395957-24628-3-git-send-email-bhsharma@redhat.com [catalin.marinas@arm.com: removed vabits_actual from the commit log] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-02crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfoBhupesh Sharma
Right now user-space tools like 'makedumpfile' and 'crash' need to rely on a best-guess method of determining value of 'MAX_PHYSMEM_BITS' supported by underlying kernel. This value is used in user-space code to calculate the bit-space required to store a section for SPARESMEM (similar to the existing calculation method used in the kernel implementation): #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS) Now, regressions have been reported in user-space utilities like 'makedumpfile' and 'crash' on arm64, with the recently added kernel support for 52-bit physical address space, as there is no clear method of determining this value in user-space (other than reading kernel CONFIG flags). As per suggestion from makedumpfile maintainer (Kazu), it makes more sense to append 'MAX_PHYSMEM_BITS' to vmcoreinfo in the core code itself rather than in arch-specific code, so that the user-space code for other archs can also benefit from this addition to the vmcoreinfo and use it as a standard way of determining 'SECTIONS_SHIFT' value in user-land. A reference 'makedumpfile' implementation which reads the 'MAX_PHYSMEM_BITS' value from vmcoreinfo in a arch-independent fashion is available here: While at it also update vmcoreinfo documentation for 'MAX_PHYSMEM_BITS' variable being added to vmcoreinfo. 'MAX_PHYSMEM_BITS' defines the maximum supported physical address space memory. Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com> Tested-by: John Donnelly <john.p.donnelly@oracle.com> Acked-by: Dave Young <dyoung@redhat.com> Cc: Boris Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Anderson <anderson@redhat.com> Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com> Cc: x86@kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org Link: https://lore.kernel.org/r/1589395957-24628-2-git-send-email-bhsharma@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-02cpufreq: Specify default governor on command lineQuentin Perret
Currently, the only way to specify the default CPUfreq governor is via Kconfig options, which suits users who can build the kernel themselves perfectly. However, for those who use a distro-like kernel (such as Android, with the Generic Kernel Image project), the only way to use a non-default governor is to boot to userspace, and to then switch using the sysfs interface. Being able to specify the default governor on the command line, like is the case for cpuidle, would allow those users to specify their governor of choice earlier on, and to simplify the userspace boot procedure slighlty. To support this use-case, add a kernel command line parameter allowing the default governor for CPUfreq to be specified, which takes precedence over the built-in default. This implementation has one notable limitation: the default governor must be registered before the driver. This is solved for builtin governors and drivers using appropriate *_initcall() functions. And in the modular case, this must be reflected as a constraint on the module loading order. Signed-off-by: Quentin Perret <qperret@google.com> [ Viresh: Converted 'default_governor' to a string and parsing it only at initcall level, and several updates to cpufreq_init_policy(). ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02cpufreq: intel_pstate: Allow raw energy performance preference valueSrinivas Pandruvada
Currently using attribute "energy_performance_preference", user space can write one of the four per-defined preference string. These preference strings gets mapped to a hard-coded Energy-Performance Preference (EPP) or Energy-Performance Bias (EPB) knob. These four values are supposed to cover broad spectrum of use cases, but are not uniformly distributed in the range. There are number of cases, where this is not enough. For example: Suppose user wants more performance when connected to AC. Instead of using default "balance performance", the "performance" setting can be used. This changes EPP value from 0x80 to 0x00. But setting EPP to 0, results in electrical and thermal issues on some platforms. This results in aggressive throttling, which causes a drop in performance. But some value between 0x80 and 0x00 results in better performance. But that value can't be fixed as the power curve is not linear. In some cases just changing EPP from 0x80 to 0x75 is enough to get significant performance gain. Similarly on battery the default "balance_performance" mode can be aggressive in power consumption. But picking up the next choice "balance power" results in too much loss of performance, which results in bad user experience in use cases like "Google Hangout". It was observed that some value between these two EPP is optimal. This change allows fine grain EPP tuning for platform like Chromebook or for users who wants to fine tune power and performance. Here based on the product and use cases, different EPP values can be set. This change is similar to the change done for: /sys/devices/system/cpu/cpu*/power/energy_perf_bias where user has choice to write a predefined string or raw value. The change itself is trivial. When user preference doesn't match predefined string preferences and value is an unsigned integer and in range, use that value for EPP. When the EPP feature is not present writing raw value is not supported. Suggested-by: Len Brown <lenb@kernel.org> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02cpufreq: intel_pstate: Allow enable/disable energy efficiencySrinivas Pandruvada
By default intel_pstate the driver disables energy efficiency by setting MSR_IA32_POWER_CTL bit 19 for Kaby Lake desktop CPU model in HWP mode. This CPU model is also shared by Coffee Lake desktop CPUs. This allows these systems to reach maximum possible frequency. But this adds power penalty, which some customers don't want. They want some way to enable/ disable dynamically. So, add an additional attribute "energy_efficiency" under /sys/devices/system/cpu/intel_pstate/ for these CPU models. This allows to read and write bit 19 ("Disable Energy Efficiency Optimization") in the MSR IA32_POWER_CTL. This attribute is present in both HWP and non-HWP mode as this has an effect in both modes. Refer to Intel Software Developer's manual for details. The scope of this bit is package wide. Also these systems are single package systems. So read/write MSR on the current CPU is enough. The energy efficiency (EE) bit setting needs to be preserved during suspend/resume and CPU offline/online operation. To do this: - Restoring the EE setting from the cpufreq resume() callback, if there is change from the system default. - By default, don't disable EE from cpufreq init() callback for matching CPU models. Since the scope is package wide and is a single package system, move the disable EE calls from init() callback to intel_pstate_init() function, which is called only once. Suggested-by: Len Brown <lenb@kernel.org> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-06-29Merge branches 'doc.2020.06.29a', 'fixes.2020.06.29a', ↵Paul E. McKenney
'kfree_rcu.2020.06.29a', 'rcu-tasks.2020.06.29a', 'scale.2020.06.29a', 'srcu.2020.06.29a' and 'torture.2020.06.29a' into HEAD doc.2020.06.29a: Documentation updates. fixes.2020.06.29a: Miscellaneous fixes. kfree_rcu.2020.06.29a: kfree_rcu() updates. rcu-tasks.2020.06.29a: RCU Tasks updates. scale.2020.06.29a: Read-side scalability tests. srcu.2020.06.29a: SRCU updates. torture.2020.06.29a: Torture-test updates.
2020-06-29torture: Dump ftrace at shutdown only if requestedPaul E. McKenney
If there is a large number of torture tests running concurrently, all of which are dumping large ftrace buffers at shutdown time, the resulting dumping can take a very long time, particularly on systems with rotating-rust storage. This commit therefore adds a default-off torture.ftrace_dump_at_shutdown module parameter that enables shutdown-time ftrace-buffer dumping. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29rcutorture: Add races with task-exit processingPaul E. McKenney
Several variants of Linux-kernel RCU interact with task-exit processing, including preemptible RCU, Tasks RCU, and Tasks Trace RCU. This commit therefore adds testing of this interaction to rcutorture by adding rcutorture.read_exit_burst and rcutorture.read_exit_delay kernel-boot parameters. These kernel parameters control the frequency and spacing of special read-then-exit kthreads that are spawned. [ paulmck: Apply feedback from Dan Carpenter's static checker. ] [ paulmck: Reduce latency to avoid false-positive shutdown hangs. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29refperf: Rename refperf.c to refscale.c and change internal namesPaul E. McKenney
This commit further avoids conflation of refperf with the kernel's perf feature by renaming kernel/rcu/refperf.c to kernel/rcu/refscale.c, and also by similarly renaming the functions and variables inside this file. This has the side effect of changing the names of the kernel boot parameters, so kernel-parameters.txt and ver_functions.sh are also updated. The rcutorture --torture type remains refperf, and this will be addressed in a separate commit. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29doc: Document rcuperf's module parametersPaul E. McKenney
This commit adds documentation for the rcuperf module parameters. Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29rcu/tree: cache specified number of objectsUladzislau Rezki (Sony)
In order to reduce the dynamic need for pages in kfree_rcu(), pre-allocate a configurable number of pages per CPU and link them in a list. When kfree_rcu() reclaims objects, the object's container page is cached into a list instead of being released to the low-level page allocator. Such an approach provides O(1) access to free pages while also reducing the number of requests to the page allocator. It also makes the kfree_rcu() code to have free pages available during a low memory condition. A read-only sysfs parameter (rcu_min_cached_objs) reflects the minimum number of allowed cached pages per CPU. Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-27Merge tag 'for-5.8/dm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: - Quite a few DM zoned target fixes and a Zone append fix in DM core. Considering the amount of dm-zoned changes that went in during the 5.8 merge window these fixes are not that surprising. - A few DM writecache target fixes. - A fix to Documentation index to include DM ebs target docs. - Small cleanup to use struct_size() in DM core's retrieve_deps(). * tag 'for-5.8/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm writecache: add cond_resched to loop in persistent_memory_claim() dm zoned: Fix reclaim zone selection dm zoned: Fix random zone reclaim selection dm: update original bio sector on Zone Append dm zoned: Fix metadata zone size check docs: device-mapper: add dm-ebs.rst to an index file dm ioctl: use struct_size() helper in retrieve_deps() dm writecache: skip writecache_wait when using pmem mode dm writecache: correct uncommitted_block when discarding uncommitted entry dm zoned: assign max_io_len correctly dm zoned: fix uninitialized pointer dereference
2020-06-26Merge branch 'mauro' into docs-nextJonathan Corbet
A big set of fixes and RST conversions from Mauro. He swears that this is the last RST conversion set, which is certainly cause for celebration.
2020-06-26docs: move nommu-mmap.txt to admin-guide and rename to ReSTMauro Carvalho Chehab
The nommu-mmap.txt file provides description of user visible behaviuour. So, move it to the admin-guide. As it is already at the ReST, also rename it. Suggested-by: Mike Rapoport <rppt@linux.ibm.com> Suggested-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/3a63d1833b513700755c85bf3bda0a6c4ab56986.1592918949.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-26docs: sysctl/kernel: document randomStephen Kitt
This documents the random directory, based on the behaviour seen in drivers/char/random.c. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20200623112514.10650-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-26docs: hugetlbpage.rst: fix some warningsMauro Carvalho Chehab
Some new command line parameters were added at hugetlbpage.rst. Adjust them in order to properly parse that part of the file, avoiding those warnings: Documentation/admin-guide/mm/hugetlbpage.rst:105: WARNING: Unexpected indentation. Documentation/admin-guide/mm/hugetlbpage.rst:108: WARNING: Unexpected indentation. Documentation/admin-guide/mm/hugetlbpage.rst:109: WARNING: Block quote ends without a blank line; unexpected unindent. Documentation/admin-guide/mm/hugetlbpage.rst:112: WARNING: Block quote ends without a blank line; unexpected unindent. Documentation/admin-guide/mm/hugetlbpage.rst:120: WARNING: Unexpected indentation. Documentation/admin-guide/mm/hugetlbpage.rst:121: WARNING: Block quote ends without a blank line; unexpected unindent. Documentation/admin-guide/mm/hugetlbpage.rst:132: WARNING: Unexpected indentation. Documentation/admin-guide/mm/hugetlbpage.rst:135: WARNING: Block quote ends without a blank line; unexpected unindent. Fixes: cd9fa28b5351 ("hugetlbfs: clean up command line processing") Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/86b6796b1a84e18b24314ecd29318951c1479ca2.1592895969.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>