diff options
Diffstat (limited to 'Documentation')
45 files changed, 698 insertions, 305 deletions
diff --git a/Documentation/admin-guide/hw-vuln/spectre.rst b/Documentation/admin-guide/hw-vuln/spectre.rst index cce768afec6b..25a04cda4c2c 100644 --- a/Documentation/admin-guide/hw-vuln/spectre.rst +++ b/Documentation/admin-guide/hw-vuln/spectre.rst @@ -138,11 +138,10 @@ associated with the source address of the indirect branch. Specifically, the BHB might be shared across privilege levels even in the presence of Enhanced IBRS. -Currently the only known real-world BHB attack vector is via -unprivileged eBPF. Therefore, it's highly recommended to not enable -unprivileged eBPF, especially when eIBRS is used (without retpolines). -For a full mitigation against BHB attacks, it's recommended to use -retpolines (or eIBRS combined with retpolines). +Previously the only known real-world BHB attack vector was via unprivileged +eBPF. Further research has found attacks that don't require unprivileged eBPF. +For a full mitigation against BHB attacks it is recommended to set BHI_DIS_S or +use the BHB clearing sequence. Attack scenarios ---------------- @@ -430,6 +429,23 @@ The possible values in this file are: 'PBRSB-eIBRS: Not affected' CPU is not affected by PBRSB =========================== ======================================================= + - Branch History Injection (BHI) protection status: + +.. list-table:: + + * - BHI: Not affected + - System is not affected + * - BHI: Retpoline + - System is protected by retpoline + * - BHI: BHI_DIS_S + - System is protected by BHI_DIS_S + * - BHI: SW loop, KVM SW loop + - System is protected by software clearing sequence + * - BHI: Vulnerable + - System is vulnerable to BHI + * - BHI: Vulnerable, KVM: SW loop + - System is vulnerable; KVM is protected by software clearing sequence + Full mitigation might require a microcode update from the CPU vendor. When the necessary microcode is not available, the kernel will report vulnerability. @@ -484,7 +500,11 @@ Spectre variant 2 Systems which support enhanced IBRS (eIBRS) enable IBRS protection once at boot, by setting the IBRS bit, and they're automatically protected against - Spectre v2 variant attacks. + some Spectre v2 variant attacks. The BHB can still influence the choice of + indirect branch predictor entry, and although branch predictor entries are + isolated between modes when eIBRS is enabled, the BHB itself is not isolated + between modes. Systems which support BHI_DIS_S will set it to protect against + BHI attacks. On Intel's enhanced IBRS systems, this includes cross-thread branch target injections on SMT systems (STIBP). In other words, Intel eIBRS enables @@ -638,6 +658,18 @@ kernel command line. spectre_v2=off. Spectre variant 1 mitigations cannot be disabled. + spectre_bhi= + + [X86] Control mitigation of Branch History Injection + (BHI) vulnerability. This setting affects the deployment + of the HW BHI control and the SW BHB clearing sequence. + + on + (default) Enable the HW or SW mitigation as + needed. + off + Disable the mitigation. + For spectre_v2_user see Documentation/admin-guide/kernel-parameters.txt Mitigation selection guide diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bb884c14b2f6..213d0719e2b7 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3423,6 +3423,9 @@ arch-independent options, each of which is an aggregation of existing arch-specific options. + Note, "mitigations" is supported if and only if the + kernel was built with CPU_MITIGATIONS=y. + off Disable all optional CPU mitigations. This improves system performance, but it may also @@ -3444,6 +3447,7 @@ retbleed=off [X86] spec_rstack_overflow=off [X86] spec_store_bypass_disable=off [X86,PPC] + spectre_bhi=off [X86] spectre_v2_user=off [X86] srbds=off [X86,INTEL] ssbd=force-off [ARM64] @@ -6063,6 +6067,15 @@ sonypi.*= [HW] Sony Programmable I/O Control Device driver See Documentation/admin-guide/laptops/sonypi.rst + spectre_bhi= [X86] Control mitigation of Branch History Injection + (BHI) vulnerability. This setting affects the + deployment of the HW BHI control and the SW BHB + clearing sequence. + + on - (default) Enable the HW or SW mitigation + as needed. + off - Disable the mitigation. + spectre_v2= [X86,EARLY] Control mitigation of Spectre variant 2 (indirect branch speculation) vulnerability. The default operation protects the kernel from @@ -6599,7 +6612,7 @@ To turn off having tracepoints sent to printk, echo 0 > /proc/sys/kernel/tracepoint_printk Note, echoing 1 into this file without the - tracepoint_printk kernel cmdline option has no effect. + tp_printk kernel cmdline option has no effect. The tp_printk_stop_on_boot (see below) can also be used to stop the printing of events to console at diff --git a/Documentation/admin-guide/mm/zswap.rst b/Documentation/admin-guide/mm/zswap.rst index b42132969e31..13632671adae 100644 --- a/Documentation/admin-guide/mm/zswap.rst +++ b/Documentation/admin-guide/mm/zswap.rst @@ -155,7 +155,7 @@ Setting this parameter to 100 will disable the hysteresis. Some users cannot tolerate the swapping that comes with zswap store failures and zswap writebacks. Swapping can be disabled entirely (without disabling -zswap itself) on a cgroup-basis as follows: +zswap itself) on a cgroup-basis as follows:: echo 0 > /sys/fs/cgroup/<cgroup-name>/memory.zswap.writeback @@ -166,7 +166,7 @@ writeback (because the same pages might be rejected again and again). When there is a sizable amount of cold memory residing in the zswap pool, it can be advantageous to proactively write these cold pages to swap and reclaim the memory for other use cases. By default, the zswap shrinker is disabled. -User can enable it as follows: +User can enable it as follows:: echo Y > /sys/module/zswap/parameters/shrinker_enabled diff --git a/Documentation/admin-guide/verify-bugs-and-bisect-regressions.rst b/Documentation/admin-guide/verify-bugs-and-bisect-regressions.rst index d3504826f401..c389d4fd7599 100644 --- a/Documentation/admin-guide/verify-bugs-and-bisect-regressions.rst +++ b/Documentation/admin-guide/verify-bugs-and-bisect-regressions.rst @@ -29,7 +29,7 @@ The essence of the process (aka 'TL;DR') ======================================== *[If you are new to building or bisecting Linux, ignore this section and head -over to the* ":ref:`step-by-step guide<introguide_bissbs>`" *below. It utilizes +over to the* ':ref:`step-by-step guide <introguide_bissbs>`' *below. It utilizes the same commands as this section while describing them in brief fashion. The steps are nevertheless easy to follow and together with accompanying entries in a reference section mention many alternatives, pitfalls, and additional @@ -38,8 +38,8 @@ aspects, all of which might be essential in your present case.]* **In case you want to check if a bug is present in code currently supported by developers**, execute just the *preparations* and *segment 1*; while doing so, consider the newest Linux kernel you regularly use to be the 'working' kernel. -In the following example that's assumed to be 6.0.13, which is why the sources -of 6.0 will be used to prepare the .config file. +In the following example that's assumed to be 6.0, which is why its sources +will be used to prepare the .config file. **In case you face a regression**, follow the steps at least till the end of *segment 2*. Then you can submit a preliminary report -- or continue with @@ -61,7 +61,7 @@ will be considered the 'good' release and used to prepare the .config file. cd ~/linux/ git remote add -t master stable \ https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git - git checkout --detach v6.0 + git switch --detach v6.0 # * Hint: if you used an existing clone, ensure no stale .config is around. make olddefconfig # * Ensure the former command picked the .config of the 'working' kernel. @@ -87,7 +87,7 @@ will be considered the 'good' release and used to prepare the .config file. a) Checking out latest mainline code:: cd ~/linux/ - git checkout --force --detach mainline/master + git switch --discard-changes --detach mainline/master b) Build, install, and boot a kernel:: @@ -125,7 +125,7 @@ will be considered the 'good' release and used to prepare the .config file. a) Start by checking out the sources of the 'good' version:: cd ~/linux/ - git checkout --force --detach v6.0 + git switch --discard-changes --detach v6.0 b) Build, install, and boot a kernel as described earlier in *segment 1, section b* -- just feel free to skip the 'du' commands, as you have a rough @@ -136,8 +136,7 @@ will be considered the 'good' release and used to prepare the .config file. * **Segment 3**: perform and validate the bisection. - a) In case your 'broken' version is a stable/longterm release, add the Git - branch holding it:: + a) Retrieve the sources for your 'bad' version:: git remote set-branches --add stable linux-6.1.y git fetch stable @@ -157,11 +156,12 @@ will be considered the 'good' release and used to prepare the .config file. works with the newly built kernel. If it does, tell Git by executing ``git bisect good``; if it does not, run ``git bisect bad`` instead. - All three commands will make Git checkout another commit; then re-execute + All three commands will make Git check out another commit; then re-execute this step (e.g. build, install, boot, and test a kernel to then tell Git the outcome). Do so again and again until Git shows which commit broke things. If you run short of disk space during this process, check the - "Supplementary tasks" section below. + section 'Complementary tasks: cleanup during and after the process' + below. d) Once your finished the bisection, put a few things away:: @@ -172,14 +172,17 @@ will be considered the 'good' release and used to prepare the .config file. e) Try to verify the bisection result:: - git checkout --force --detach mainline/master + git switch --discard-changes --detach mainline/master git revert --no-edit cafec0cacaca0 + cp ~/kernel-config-working .config + ./scripts/config --set-str CONFIG_LOCALVERSION '-local-cafec0cacaca0-reverted' This is optional, as some commits are impossible to revert. But if the second command worked flawlessly, build, install, and boot one more kernel - kernel, which should not show the regression. + kernel; just this time skip the first command copying the base .config file + over, as that already has been taken care off. -* **Supplementary tasks**: cleanup during and after the process. +* **Complementary tasks**: cleanup during and after the process. a) To avoid running out of disk space during a bisection, you might need to remove some kernels you built earlier. You most likely want to keep those @@ -202,13 +205,25 @@ will be considered the 'good' release and used to prepare the .config file. the kernels you built earlier and later you might want to keep around for a week or two. +* **Optional task**: test a debug patch or a proposed fix later:: + + git fetch mainline + git switch --discard-changes --detach mainline/master + git apply /tmp/foobars-proposed-fix-v1.patch + cp ~/kernel-config-working .config + ./scripts/config --set-str CONFIG_LOCALVERSION '-local-foobars-fix-v1' + + Build, install, and boot a kernel as described in *segment 1, section b* -- + but this time omit the first command copying the build configuration over, + as that has been taken care of already. + .. _introguide_bissbs: Step-by-step guide on how to verify bugs and bisect regressions =============================================================== This guide describes how to set up your own Linux kernels for investigating bugs -or regressions you intent to report. How far you want to follow the instructions +or regressions you intend to report. How far you want to follow the instructions depends on your issue: Execute all steps till the end of *segment 1* to **verify if your kernel problem @@ -221,15 +236,17 @@ report; instead of the latter your could also head straight on and follow *segment 3* to **perform a bisection** for a full-fledged regression report developers are obliged to act upon. - :ref:`Preparations: set up everything to build your own kernels.<introprep_bissbs>` + :ref:`Preparations: set up everything to build your own kernels <introprep_bissbs>`. - :ref:`Segment 1: try to reproduce the problem with the latest codebase.<introlatestcheck_bissbs>` + :ref:`Segment 1: try to reproduce the problem with the latest codebase <introlatestcheck_bissbs>`. - :ref:`Segment 2: check if the kernels you build work fine.<introworkingcheck_bissbs>` + :ref:`Segment 2: check if the kernels you build work fine <introworkingcheck_bissbs>`. - :ref:`Segment 3: perform a bisection and validate the result.<introbisect_bissbs>` + :ref:`Segment 3: perform a bisection and validate the result <introbisect_bissbs>`. - :ref:`Supplementary tasks: cleanup during and after following this guide.<introclosure_bissbs>` + :ref:`Complementary tasks: cleanup during and after following this guide <introclosure_bissbs>`. + + :ref:`Optional tasks: test reverts, patches, or later versions <introoptional_bissbs>`. The steps in each segment illustrate the important aspects of the process, while a comprehensive reference section holds additional details for almost all of the @@ -240,24 +257,35 @@ to get things rolling again. For further details on how to report Linux kernel issues or regressions check out Documentation/admin-guide/reporting-issues.rst, which works in conjunction with this document. It among others explains why you need to verify bugs with -the latest 'mainline' kernel, even if you face a problem with a kernel from a -'stable/longterm' series; for users facing a regression it also explains that -sending a preliminary report after finishing segment 2 might be wise, as the -regression and its culprit might be known already. For further details on -what actually qualifies as a regression check out -Documentation/admin-guide/reporting-regressions.rst. +the latest 'mainline' kernel (e.g. versions like 6.0, 6.1-rc1, or 6.1-rc6), +even if you face a problem with a kernel from a 'stable/longterm' series +(say 6.0.13). + +For users facing a regression that document also explains why sending a +preliminary report after segment 2 might be wise, as the regression and its +culprit might be known already. For further details on what actually qualifies +as a regression check out Documentation/admin-guide/reporting-regressions.rst. + +If you run into any problems while following this guide or have ideas how to +improve it, :ref:`please let the kernel developers know <submit_improvements>`. .. _introprep_bissbs: Preparations: set up everything to build your own kernels --------------------------------------------------------- +The following steps lay the groundwork for all further tasks. + +Note: the instructions assume you are building and testing on the same +machine; if you want to compile the kernel on another system, check +:ref:`Build kernels on a different machine <buildhost_bis>` below. + .. _backup_bissbs: * Create a fresh backup and put system repair and restore tools at hand, just to be prepared for the unlikely case of something going sideways. - [:ref:`details<backup_bisref>`] + [:ref:`details <backup_bisref>`] .. _vanilla_bissbs: @@ -265,7 +293,7 @@ Preparations: set up everything to build your own kernels builds them automatically. That includes but is not limited to DKMS, openZFS, VirtualBox, and Nvidia's graphics drivers (including the GPLed kernel module). - [:ref:`details<vanilla_bisref>`] + [:ref:`details <vanilla_bisref>`] .. _secureboot_bissbs: @@ -276,48 +304,49 @@ Preparations: set up everything to build your own kernels their restrictions through a process initiated by ``mokutil --disable-validation``. - [:ref:`details<secureboot_bisref>`] + [:ref:`details <secureboot_bisref>`] .. _rangecheck_bissbs: * Determine the kernel versions considered 'good' and 'bad' throughout this - guide. + guide: - Do you follow this guide to verify if a bug is present in the code developers - care for? Then consider the mainline release your 'working' kernel (the newest - one you regularly use) is based on to be the 'good' version; if your 'working' - kernel for example is 6.0.11, then your 'good' kernel is 6.0. + * Do you follow this guide to verify if a bug is present in the code the + primary developers care for? Then consider the version of the newest kernel + you regularly use currently as 'good' (e.g. 6.0, 6.0.13, or 6.1-rc2). - In case you face a regression, it depends on the version range where the - regression was introduced: + * Do you face a regression, e.g. something broke or works worse after + switching to a newer kernel version? In that case it depends on the version + range during which the problem appeared: - * Something which used to work in Linux 6.0 broke when switching to Linux - 6.1-rc1? Then henceforth regard 6.0 as the last known 'good' version - and 6.1-rc1 as the first 'bad' one. + * Something regressed when updating from a stable/longterm release + (say 6.0.13) to a newer mainline series (like 6.1-rc7 or 6.1) or a + stable/longterm version based on one (say 6.1.5)? Then consider the + mainline release your working kernel is based on to be the 'good' + version (e.g. 6.0) and the first version to be broken as the 'bad' one + (e.g. 6.1-rc7, 6.1, or 6.1.5). Note, at this point it is merely assumed + that 6.0 is fine; this hypothesis will be checked in segment 2. - * Some function stopped working when updating from 6.0.11 to 6.1.4? Then for - the time being consider 6.0 as the last 'good' version and 6.1.4 as - the 'bad' one. Note, at this point it is merely assumed that 6.0 is fine; - this assumption will be checked in segment 2. + * Something regressed when switching from one mainline version (say 6.0) to + a later one (like 6.1-rc1) or a stable/longterm release based on it + (say 6.1.5)? Then regard the last working version (e.g. 6.0) as 'good' and + the first broken (e.g. 6.1-rc1 or 6.1.5) as 'bad'. - * A feature you used in 6.0.11 does not work at all or worse in 6.1.13? In - that case you want to bisect within a stable/longterm series: consider - 6.0.11 as the last known 'good' version and 6.0.13 as the first 'bad' - one. Note, in this case you still want to compile and test a mainline kernel - as explained in segment 1: the outcome will determine if you need to report - your issue to the regular developers or the stable team. + * Something regressed when updating within a stable/longterm series (say + from 6.0.13 to 6.0.15)? Then consider those versions as 'good' and 'bad' + (e.g. 6.0.13 and 6.0.15), as you need to bisect within that series. *Note, do not confuse 'good' version with 'working' kernel; the latter term throughout this guide will refer to the last kernel that has been working fine.* - [:ref:`details<rangecheck_bisref>`] + [:ref:`details <rangecheck_bisref>`] .. _bootworking_bissbs: * Boot into the 'working' kernel and briefly use the apparently broken feature. - [:ref:`details<bootworking_bisref>`] + [:ref:`details <bootworking_bisref>`] .. _diskspace_bissbs: @@ -327,7 +356,7 @@ Preparations: set up everything to build your own kernels debug symbols: both explain approaches reducing the amount of space, which should allow you to master these tasks with about 4 Gigabytes free space. - [:ref:`details<diskspace_bisref>`] + [:ref:`details <diskspace_bisref>`] .. _buildrequires_bissbs: @@ -337,7 +366,7 @@ Preparations: set up everything to build your own kernels reference section shows how to quickly install those on various popular Linux distributions. - [:ref:`details<buildrequires_bisref>`] + [:ref:`details <buildrequires_bisref>`] .. _sources_bissbs: @@ -360,14 +389,23 @@ Preparations: set up everything to build your own kernels git remote add -t master stable \ https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git - [:ref:`details<sources_bisref>`] + [:ref:`details <sources_bisref>`] + +.. _stablesources_bissbs: + +* Is one of the versions you earlier established as 'good' or 'bad' a stable or + longterm release (say 6.1.5)? Then download the code for the series it belongs + to ('linux-6.1.y' in this example):: + + git remote set-branches --add stable linux-6.1.y + git fetch stable .. _oldconfig_bissbs: * Start preparing a kernel build configuration (the '.config' file). Before doing so, ensure you are still running the 'working' kernel an earlier - step told you to boot; if you are unsure, check the current kernel release + step told you to boot; if you are unsure, check the current kernelrelease identifier using ``uname -r``. Afterwards check out the source code for the version earlier established as @@ -375,7 +413,7 @@ Preparations: set up everything to build your own kernels the version number in this and all later Git commands needs to be prefixed with a 'v':: - git checkout --detach v6.0 + git switch --discard-changes --detach v6.0 Now create a build configuration file:: @@ -398,7 +436,7 @@ Preparations: set up everything to build your own kernels 'make olddefconfig' again and check if it now picked up the right config file as base. - [:ref:`details<oldconfig_bisref>`] + [:ref:`details <oldconfig_bisref>`] .. _localmodconfig_bissbs: @@ -432,7 +470,7 @@ Preparations: set up everything to build your own kernels spending much effort on, as long as it boots and allows to properly test the feature that causes trouble. - [:ref:`details<localmodconfig_bisref>`] + [:ref:`details <localmodconfig_bisref>`] .. _tagging_bissbs: @@ -442,7 +480,7 @@ Preparations: set up everything to build your own kernels ./scripts/config --set-str CONFIG_LOCALVERSION '-local' ./scripts/config -e CONFIG_LOCALVERSION_AUTO - [:ref:`details<tagging_bisref>`] + [:ref:`details <tagging_bisref>`] .. _debugsymbols_bissbs: @@ -461,7 +499,7 @@ Preparations: set up everything to build your own kernels ./scripts/config -d DEBUG_INFO -d DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT \ -d DEBUG_INFO_DWARF4 -d DEBUG_INFO_DWARF5 -e CONFIG_DEBUG_INFO_NONE - [:ref:`details<debugsymbols_bisref>`] + [:ref:`details <debugsymbols_bisref>`] .. _configmods_bissbs: @@ -471,14 +509,14 @@ Preparations: set up everything to build your own kernels * Are you running Debian? Then you want to avoid known problems by performing additional adjustments explained in the reference section. - [:ref:`details<configmods_distros_bisref>`]. + [:ref:`details <configmods_distros_bisref>`]. * If you want to influence other aspects of the configuration, do so now using your preferred tool. Note, to use make targets like 'menuconfig' or 'nconfig', you will need to install the development files of ncurses; for 'xconfig' you likewise need the Qt5 or Qt6 headers. - [:ref:`details<configmods_individual_bisref>`]. + [:ref:`details <configmods_individual_bisref>`]. .. _saveconfig_bissbs: @@ -488,7 +526,7 @@ Preparations: set up everything to build your own kernels make olddefconfig cp .config ~/kernel-config-working - [:ref:`details<saveconfig_bisref>`] + [:ref:`details <saveconfig_bisref>`] .. _introlatestcheck_bissbs: @@ -498,16 +536,30 @@ Segment 1: try to reproduce the problem with the latest codebase The following steps verify if the problem occurs with the code currently supported by developers. In case you face a regression, it also checks that the problem is not caused by some .config change, as reporting the issue then would -be a waste of time. [:ref:`details<introlatestcheck_bisref>`] +be a waste of time. [:ref:`details <introlatestcheck_bisref>`] .. _checkoutmaster_bissbs: -* Check out the latest Linux codebase:: +* Check out the latest Linux codebase. - cd ~/linux/ - git checkout --force --detach mainline/master + * Are your 'good' and 'bad' versions from the same stable or longterm series? + Then check the `front page of kernel.org <https://kernel.org/>`_: if it + lists a release from that series without an '[EOL]' tag, checkout the series + latest version ('linux-6.1.y' in the following example):: + + cd ~/linux/ + git switch --discard-changes --detach stable/linux-6.1.y + + Your series is unsupported, if is not listed or carrying a 'end of life' + tag. In that case you might want to check if a successor series (say + linux-6.2.y) or mainline (see next point) fix the bug. - [:ref:`details<checkoutmaster_bisref>`] + * In all other cases, run:: + + cd ~/linux/ + git switch --discard-changes --detach mainline/master + + [:ref:`details <checkoutmaster_bisref>`] .. _build_bissbs: @@ -522,7 +574,7 @@ be a waste of time. [:ref:`details<introlatestcheck_bisref>`] reference section for alternatives, which obviously will require other steps to install as well. - [:ref:`details<build_bisref>`] + [:ref:`details <build_bisref>`] .. _install_bissbs: @@ -555,7 +607,7 @@ be a waste of time. [:ref:`details<introlatestcheck_bisref>`] down: if you will build more kernels as described in segment 2 and 3, you will have to perform those again after executing ``command -v installkernel [...]``. - [:ref:`details<install_bisref>`] + [:ref:`details <install_bisref>`] .. _storagespace_bissbs: @@ -568,7 +620,7 @@ be a waste of time. [:ref:`details<introlatestcheck_bisref>`] Write down or remember those two values for later: they enable you to prevent running out of disk space accidentally during a bisection. - [:ref:`details<storagespace_bisref>`] + [:ref:`details <storagespace_bisref>`] .. _kernelrelease_bissbs: @@ -595,7 +647,7 @@ be a waste of time. [:ref:`details<introlatestcheck_bisref>`] If that command does not return '0', check the reference section, as the cause for this might interfere with your testing. - [:ref:`details<tainted_bisref>`] + [:ref:`details <tainted_bisref>`] .. _recheckbroken_bissbs: @@ -603,21 +655,19 @@ be a waste of time. [:ref:`details<introlatestcheck_bisref>`] out the instructions in the reference section to ensure nothing went sideways during your tests. - [:ref:`details<recheckbroken_bisref>`] + [:ref:`details <recheckbroken_bisref>`] .. _recheckstablebroken_bissbs: -* Are you facing a problem within a stable/longterm series, but failed to - reproduce it with the mainline kernel you just built? One that according to - the `front page of kernel.org <https://kernel.org/>`_ is still supported? Then - check if the latest codebase for the particular series might already fix the - problem. To do so, add the stable series Git branch for your 'good' kernel - (again, this here is assumed to be 6.0) and check out the latest version:: +* Did you just built a stable or longterm kernel? And were you able to reproduce + the regression with it? Then you should test the latest mainline codebase as + well, because the result determines which developers the bug must be submitted + to. + + To prepare that test, check out current mainline:: cd ~/linux/ - git remote set-branches --add stable linux-6.0.y - git fetch stable - git checkout --force --detach linux-6.0.y + git switch --discard-changes --detach mainline/master Now use the checked out code to build and install another kernel using the commands the earlier steps already described in more detail:: @@ -639,14 +689,16 @@ be a waste of time. [:ref:`details<introlatestcheck_bisref>`] uname -r cat /proc/sys/kernel/tainted - Now verify if this kernel is showing the problem. + Now verify if this kernel is showing the problem. If it does, then you need + to report the bug to the primary developers; if it does not, report it to the + stable team. See Documentation/admin-guide/reporting-issues.rst for details. - [:ref:`details<recheckstablebroken_bisref>`] + [:ref:`details <recheckstablebroken_bisref>`] Do you follow this guide to verify if a problem is present in the code currently supported by Linux kernel developers? Then you are done at this point. If you later want to remove the kernel you just built, check out -:ref:`Supplementary tasks: cleanup during and after following this guide<introclosure_bissbs>`. +:ref:`Complementary tasks: cleanup during and after following this guide <introclosure_bissbs>`. In case you face a regression, move on and execute at least the next segment as well. @@ -658,7 +710,7 @@ Segment 2: check if the kernels you build work fine In case of a regression, you now want to ensure the trimmed configuration file you created earlier works as expected; a bisection with the .config file -otherwise would be a waste of time. [:ref:`details<introworkingcheck_bisref>`] +otherwise would be a waste of time. [:ref:`details <introworkingcheck_bisref>`] .. _recheckworking_bissbs: @@ -669,7 +721,7 @@ otherwise would be a waste of time. [:ref:`details<introworkingcheck_bisref>`] 'good' (once again assumed to be 6.0 here):: cd ~/linux/ - git checkout --detach v6.0 + git switch --discard-changes --detach v6.0 Now use the checked out code to configure, build, and install another kernel using the commands the previous subsection explained in more detail:: @@ -693,7 +745,7 @@ otherwise would be a waste of time. [:ref:`details<introworkingcheck_bisref>`] Now check if this kernel works as expected; if not, consult the reference section for further instructions. - [:ref:`details<recheckworking_bisref>`] + [:ref:`details <recheckworking_bisref>`] .. _introbisect_bissbs: @@ -703,18 +755,11 @@ Segment 3: perform the bisection and validate the result With all the preparations and precaution builds taken care of, you are now ready to begin the bisection. This will make you build quite a few kernels -- usually about 15 in case you encountered a regression when updating to a newer series -(say from 6.0.11 to 6.1.3). But do not worry, due to the trimmed build +(say from 6.0.13 to 6.1.5). But do not worry, due to the trimmed build configuration created earlier this works a lot faster than many people assume: overall on average it will often just take about 10 to 15 minutes to compile each kernel on commodity x86 machines. -* In case your 'bad' version is a stable/longterm release (say 6.1.5), add its - stable branch, unless you already did so earlier:: - - cd ~/linux/ - git remote set-branches --add stable linux-6.1.y - git fetch stable - .. _bisectstart_bissbs: * Start the bisection and tell Git about the versions earlier established as @@ -725,7 +770,7 @@ each kernel on commodity x86 machines. git bisect good v6.0 git bisect bad v6.1.5 - [:ref:`details<bisectstart_bisref>`] + [:ref:`details <bisectstart_bisref>`] .. _bisectbuild_bissbs: @@ -745,7 +790,7 @@ each kernel on commodity x86 machines. If compilation fails for some reason, run ``git bisect skip`` and restart executing the stack of commands from the beginning. - In case you skipped the "test latest codebase" step in the guide, check its + In case you skipped the 'test latest codebase' step in the guide, check its description as for why the 'df [...]' and 'make -s kernelrelease [...]' commands are here. @@ -754,7 +799,7 @@ each kernel on commodity x86 machines. totally normal to see release identifiers like '6.0-rc1-local-gcafec0cacaca0' if you bisect between versions 6.1 and 6.2 for example. - [:ref:`details<bisectbuild_bisref>`] + [:ref:`details <bisectbuild_bisref>`] .. _bisecttest_bissbs: @@ -794,7 +839,7 @@ each kernel on commodity x86 machines. might need to scroll up to see the message mentioning the culprit; alternatively, run ``git bisect log > ~/bisection-log``. - [:ref:`details<bisecttest_bisref>`] + [:ref:`details <bisecttest_bisref>`] .. _bisectlog_bissbs: @@ -806,7 +851,7 @@ each kernel on commodity x86 machines. cp .config ~/bisection-config-culprit git bisect reset - [:ref:`details<bisectlog_bisref>`] + [:ref:`details <bisectlog_bisref>`] .. _revert_bissbs: @@ -823,16 +868,16 @@ each kernel on commodity x86 machines. Begin by checking out the latest codebase depending on the range you bisected: * Did you face a regression within a stable/longterm series (say between - 6.0.11 and 6.0.13) that does not happen in mainline? Then check out the + 6.0.13 and 6.0.15) that does not happen in mainline? Then check out the latest codebase for the affected series like this:: git fetch stable - git checkout --force --detach linux-6.0.y + git switch --discard-changes --detach linux-6.0.y * In all other cases check out latest mainline:: git fetch mainline - git checkout --force --detach mainline/master + git switch --discard-changes --detach mainline/master If you bisected a regression within a stable/longterm series that also happens in mainline, there is one more thing to do: look up the mainline @@ -846,27 +891,33 @@ each kernel on commodity x86 machines. git revert --no-edit cafec0cacaca0 - If that fails, give up trying and move on to the next step. But if it works, - build a kernel again using the familiar command sequence:: + If that fails, give up trying and move on to the next step; if it works, + adjust the tag to facilitate the identification and prevent accidentally + overwriting another kernel:: cp ~/kernel-config-working .config + ./scripts/config --set-str CONFIG_LOCALVERSION '-local-cafec0cacaca0-reverted' + + Build a kernel using the familiar command sequence, just without copying the + the base .config over:: + make olddefconfig && - make -j $(nproc --all) && + make -j $(nproc --all) # * Check if the free space suffices holding another kernel: df -h /boot/ /lib/modules/ sudo make modules_install command -v installkernel && sudo make install - Make -s kernelrelease | tee -a ~/kernels-built + make -s kernelrelease | tee -a ~/kernels-built reboot - Now check one last time if the feature that made you perform a bisection work - with that kernel. + Now check one last time if the feature that made you perform a bisection works + with that kernel: if everything went well, it should not show the regression. - [:ref:`details<revert_bisref>`] + [:ref:`details <revert_bisref>`] .. _introclosure_bissbs: -Supplementary tasks: cleanup during and after the bisection +Complementary tasks: cleanup during and after the bisection ----------------------------------------------------------- During and after following this guide you might want or need to remove some of @@ -903,7 +954,7 @@ space might run out. kernel image and related files behind; in that case remove them as described in the reference section. - [:ref:`details<makeroom_bisref>`] + [:ref:`details <makeroom_bisref>`] .. _finishingtouch_bissbs: @@ -926,18 +977,99 @@ space might run out. the version considered 'good', and the last three or four you compiled during the actual bisection process. - [:ref:`details<finishingtouch_bisref>`] + [:ref:`details <finishingtouch_bisref>`] + +.. _introoptional_bissbs: + +Optional: test reverts, patches, or later versions +-------------------------------------------------- + +While or after reporting a bug, you might want or potentially will be asked to +test reverts, debug patches, proposed fixes, or other versions. In that case +follow these instructions. + +* Update your Git clone and check out the latest code. + + * In case you want to test mainline, fetch its latest changes before checking + its code out:: + + git fetch mainline + git switch --discard-changes --detach mainline/master + + * In case you want to test a stable or longterm kernel, first add the branch + holding the series you are interested in (6.2 in the example), unless you + already did so earlier:: + + git remote set-branches --add stable linux-6.2.y + + Then fetch the latest changes and check out the latest version from the + series:: + + git fetch stable + git switch --discard-changes --detach stable/linux-6.2.y + +* Copy your kernel build configuration over:: + + cp ~/kernel-config-working .config + +* Your next step depends on what you want to do: + + * In case you just want to test the latest codebase, head to the next step, + you are already all set. + + * In case you want to test if a revert fixes an issue, revert one or multiple + changes by specifying their commit ids:: + + git revert --no-edit cafec0cacaca0 + + Now give that kernel a special tag to facilitates its identification and + prevent accidentally overwriting another kernel:: + + ./scripts/config --set-str CONFIG_LOCALVERSION '-local-cafec0cacaca0-reverted' + + * In case you want to test a patch, store the patch in a file like + '/tmp/foobars-proposed-fix-v1.patch' and apply it like this:: + + git apply /tmp/foobars-proposed-fix-v1.patch + + In case of multiple patches, repeat this step with the others. + + Now give that kernel a special tag to facilitates its identification and + prevent accidentally overwriting another kernel:: + + ./scripts/config --set-str CONFIG_LOCALVERSION '-local-foobars-fix-v1' + +* Build a kernel using the familiar commands, just without copying the kernel + build configuration over, as that has been taken care of already:: + + make olddefconfig && + make -j $(nproc --all) + # * Check if the free space suffices holding another kernel: + df -h /boot/ /lib/modules/ + sudo make modules_install + command -v installkernel && sudo make install + make -s kernelrelease | tee -a ~/kernels-built + reboot + +* Now verify you booted the newly built kernel and check it. + +[:ref:`details <introoptional_bisref>`] .. _submit_improvements: -This concludes the step-by-step guide. +Conclusion +---------- + +You have reached the end of the step-by-step guide. Did you run into trouble following any of the above steps not cleared up by the reference section below? Did you spot errors? Or do you have ideas how to -improve the guide? Then please take a moment and let the maintainer of this +improve the guide? + +If any of that applies, please take a moment and let the maintainer of this document know by email (Thorsten Leemhuis <linux@leemhuis.info>), ideally while CCing the Linux docs mailing list (linux-doc@vger.kernel.org). Such feedback is -vital to improve this document further, which is in everybody's interest, as it +vital to improve this text further, which is in everybody's interest, as it will enable more people to master the task described here -- and hopefully also improve similar guides inspired by this one. @@ -948,10 +1080,20 @@ Reference section for the step-by-step guide This section holds additional information for almost all the items in the above step-by-step guide. +Preparations for building your own kernels +------------------------------------------ + + *The steps in this section lay the groundwork for all further tests.* + [:ref:`... <introprep_bissbs>`] + +The steps in all later sections of this guide depend on those described here. + +[:ref:`back to step-by-step guide <introprep_bissbs>`]. + .. _backup_bisref: Prepare for emergencies ------------------------ +~~~~~~~~~~~~~~~~~~~~~~~ *Create a fresh backup and put system repair and restore tools at hand.* [:ref:`... <backup_bissbs>`] @@ -966,7 +1108,7 @@ for something going sideways, even if that should not happen. .. _vanilla_bisref: Remove anything related to externally maintained kernel modules ---------------------------------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Remove all software that depends on externally developed kernel drivers or builds them automatically.* [:ref:`...<vanilla_bissbs>`] @@ -984,7 +1126,7 @@ explains in more detail. .. _secureboot_bisref: Deal with techniques like Secure Boot -------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *On platforms with 'Secure Boot' or similar techniques, prepare everything to ensure the system will permit your self-compiled kernel to boot later.* @@ -1021,7 +1163,7 @@ Afterwards, permit MokManager to reboot the machine. .. _bootworking_bisref: Boot the last kernel that was working -------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Boot into the last working kernel and briefly recheck if the feature that regressed really works.* [:ref:`...<bootworking_bissbs>`] @@ -1034,7 +1176,7 @@ the right thing. .. _diskspace_bisref: Space requirements ------------------- +~~~~~~~~~~~~~~~~~~ *Ensure to have enough free space for building Linux.* [:ref:`... <diskspace_bissbs>`] @@ -1052,32 +1194,32 @@ space by quite a few gigabytes. .. _rangecheck_bisref: Bisection range ---------------- +~~~~~~~~~~~~~~~ *Determine the kernel versions considered 'good' and 'bad' throughout this guide.* [:ref:`...<rangecheck_bissbs>`] Establishing the range of commits to be checked is mostly straightforward, except when a regression occurred when switching from a release of one stable -series to a release of a later series (e.g. from 6.0.11 to 6.1.4). In that case +series to a release of a later series (e.g. from 6.0.13 to 6.1.5). In that case Git will need some hand holding, as there is no straight line of descent. That's because with the release of 6.0 mainline carried on to 6.1 while the stable series 6.0.y branched to the side. It's therefore theoretically possible -that the issue you face with 6.1.4 only worked in 6.0.11, as it was fixed by a +that the issue you face with 6.1.5 only worked in 6.0.13, as it was fixed by a commit that went into one of the 6.0.y releases, but never hit mainline or the 6.1.y series. Thankfully that normally should not happen due to the way the stable/longterm maintainers maintain the code. It's thus pretty safe to assume 6.0 as a 'good' kernel. That assumption will be tested anyway, as that kernel will be built and tested in the segment '2' of this guide; Git would force you -to do this as well, if you tried bisecting between 6.0.11 and 6.1.13. +to do this as well, if you tried bisecting between 6.0.13 and 6.1.15. [:ref:`back to step-by-step guide <rangecheck_bissbs>`] .. _buildrequires_bisref: Install build requirements --------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~ *Install all software required to build a Linux kernel.* [:ref:`...<buildrequires_bissbs>`] @@ -1117,7 +1259,7 @@ These commands install a few packages that are often, but not always needed. You for example might want to skip installing the development headers for ncurses, which you will only need in case you later might want to adjust the kernel build configuration using make the targets 'menuconfig' or 'nconfig'; likewise omit -the headers of Qt6 is you do not plan to adjust the .config using 'xconfig'. +the headers of Qt6 if you do not plan to adjust the .config using 'xconfig'. You furthermore might need additional libraries and their development headers for tasks not covered in this guide -- for example when building utilities from @@ -1128,7 +1270,7 @@ the kernel's tools/ directory. .. _sources_bisref: Download the sources using Git ------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Retrieve the Linux mainline sources.* [:ref:`...<sources_bissbs>`] @@ -1148,7 +1290,7 @@ work better for you: .. _sources_bundle_bisref: Downloading Linux mainline sources using a bundle -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +""""""""""""""""""""""""""""""""""""""""""""""""" Use the following commands to retrieve the Linux mainline sources using a bundle:: @@ -1184,7 +1326,7 @@ First, execute the following command to retrieve the latest mainline codebase:: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git Now deepen your clone's history to the second predecessor of the mainline -release of your 'good' version. In case the latter are 6.0 or 6.0.11, 5.19 would +release of your 'good' version. In case the latter are 6.0 or 6.0.13, 5.19 would be the first predecessor and 5.18 the second -- hence deepen the history up to that version:: @@ -1219,7 +1361,7 @@ Note, shallow clones have a few peculiar characteristics: .. _oldconfig_bisref: Start defining the build configuration for your kernel ------------------------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Start preparing a kernel build configuration (the '.config' file).* [:ref:`... <oldconfig_bissbs>`] @@ -1279,7 +1421,7 @@ that file to the build machine and store it as ~/linux/.config; afterwards run .. _localmodconfig_bisref: Trim the build configuration for your kernel --------------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Disable any kernel modules apparently superfluous for your setup.* [:ref:`... <localmodconfig_bissbs>`] @@ -1328,7 +1470,7 @@ step-by-step guide mentions:: .. _tagging_bisref: Tag the kernels about to be build ---------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Ensure all the kernels you will build are clearly identifiable using a special tag and a unique version identifier.* [:ref:`... <tagging_bissbs>`] @@ -1344,7 +1486,7 @@ confusing during the bisection. .. _debugsymbols_bisref: Decide to enable or disable debug symbols ------------------------------------------ +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Decide how to handle debug symbols.* [:ref:`... <debugsymbols_bissbs>`] @@ -1373,7 +1515,7 @@ explains this process in more detail. .. _configmods_bisref: Adjust build configuration --------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~ *Check if you may want or need to adjust some other kernel configuration options:* @@ -1384,7 +1526,7 @@ kernel configuration options. .. _configmods_distros_bisref: Distro specific adjustments -~~~~~~~~~~~~~~~~~~~~~~~~~~~ +""""""""""""""""""""""""""" *Are you running* [:ref:`... <configmods_bissbs>`] @@ -1409,7 +1551,7 @@ when following this guide on a few commodity distributions. .. _configmods_individual_bisref: Individual adjustments -~~~~~~~~~~~~~~~~~~~~~~ +"""""""""""""""""""""" *If you want to influence the other aspects of the configuration, do so now.* [:ref:`... <configmods_bissbs>`] @@ -1426,13 +1568,13 @@ is missing. .. _saveconfig_bisref: Put the .config file aside --------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~ *Reprocess the .config after the latest changes and store it in a safe place.* [:ref:`... <saveconfig_bissbs>`] Put the .config you prepared aside, as you want to copy it back to the build -directory every time during this guide before you start building another +directory every time during this guide before you start building another kernel. That's because going back and forth between different versions can alter .config files in odd ways; those occasionally cause side effects that could confuse testing or in some cases render the result of your bisection @@ -1442,8 +1584,8 @@ meaningless. .. _introlatestcheck_bisref: -Try to reproduce the regression ------------------------------------------ +Try to reproduce the problem with the latest codebase +----------------------------------------------------- *Verify the regression is not caused by some .config change and check if it still occurs with the latest codebase.* [:ref:`... <introlatestcheck_bissbs>`] @@ -1490,28 +1632,28 @@ highly recommended for these reasons: Your report might be ignored if you send it to the wrong party -- and even when you get a reply there is a decent chance that developers tell you to - evaluate which of the two cases it is before they take a closer look. + evaluate which of the two cases it is before they take a closer look. [:ref:`back to step-by-step guide <introlatestcheck_bissbs>`] .. _checkoutmaster_bisref: Check out the latest Linux codebase ------------------------------------ +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Check out the latest Linux codebase.* - [:ref:`... <introlatestcheck_bissbs>`] + [:ref:`... <checkoutmaster_bissbs>`] In case you later want to recheck if an ever newer codebase might fix the problem, remember to run that ``git fetch --shallow-exclude [...]`` command again mentioned earlier to update your local Git repository. -[:ref:`back to step-by-step guide <introlatestcheck_bissbs>`] +[:ref:`back to step-by-step guide <checkoutmaster_bissbs>`] .. _build_bisref: Build your kernel ------------------ +~~~~~~~~~~~~~~~~~ *Build the image and the modules of your first kernel using the config file you prepared.* [:ref:`... <build_bissbs>`] @@ -1521,7 +1663,7 @@ yourself. Another subsection explains how to directly package your kernel up as deb, rpm or tar file. Dealing with build errors -~~~~~~~~~~~~~~~~~~~~~~~~~ +""""""""""""""""""""""""" When a build error occurs, it might be caused by some aspect of your machine's setup that often can be fixed quickly; other times though the problem lies in @@ -1552,11 +1694,11 @@ by modifying your search terms or using another line from the error messages. In the end, most issues you run into have likely been encountered and reported by others already. That includes issues where the cause is not your -system, but lies in the code. If you run into one of those, you might thus find a -solution (e.g. a patch) or workaround for your issue, too. +system, but lies in the code. If you run into one of those, you might thus find +a solution (e.g. a patch) or workaround for your issue, too. Package your kernel up -~~~~~~~~~~~~~~~~~~~~~~ +"""""""""""""""""""""" The step-by-step guide uses the default make targets (e.g. 'bzImage' and 'modules' on x86) to build the image and the modules of your kernel, which later @@ -1587,7 +1729,7 @@ distribution's kernel packages. .. _install_bisref: Put the kernel in place ------------------------ +~~~~~~~~~~~~~~~~~~~~~~~ *Install the kernel you just built.* [:ref:`... <install_bissbs>`] @@ -1630,7 +1772,7 @@ process. Afterwards add your kernel to your bootloader configuration and reboot. .. _storagespace_bisref: Storage requirements per kernel -------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Check how much storage space the kernel, its modules, and other related files like the initramfs consume.* [:ref:`... <storagespace_bissbs>`] @@ -1651,7 +1793,7 @@ need to look in different places. .. _tainted_bisref: Check if your newly built kernel considers itself 'tainted' ------------------------------------------------------------ +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Check if the kernel marked itself as 'tainted'.* [:ref:`... <tainted_bissbs>`] @@ -1670,7 +1812,7 @@ interest, as your testing might be flawed otherwise. .. _recheckbroken_bisref: Check the kernel built from a recent mainline codebase ------------------------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Verify if your bug occurs with the newly built kernel.* [:ref:`... <recheckbroken_bissbs>`] @@ -1696,7 +1838,7 @@ the kernel you built from the latest codebase. These are the most frequent: .. _recheckstablebroken_bisref: Check the kernel built from the latest stable/longterm codebase ---------------------------------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Are you facing a regression within a stable/longterm release, but failed to reproduce it with the kernel you just built using the latest mainline sources? @@ -1741,7 +1883,7 @@ ensure the kernel version you assumed to be 'good' earlier in the process (e.g. .. _recheckworking_bisref: Build your own version of the 'good' kernel -------------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Build your own variant of the working kernel and check if the feature that regressed works as expected with it.* [:ref:`... <recheckworking_bissbs>`] @@ -1767,15 +1909,25 @@ multitude of reasons why this might happen. Some ideas where to look: Note, if you found and fixed problems with the .config file, you want to use it to build another kernel from the latest codebase, as your earlier tests with -mainline and the latest version from an affected stable/longterm series were most -likely flawed. +mainline and the latest version from an affected stable/longterm series were +most likely flawed. [:ref:`back to step-by-step guide <recheckworking_bissbs>`] +Perform a bisection and validate the result +------------------------------------------- + + *With all the preparations and precaution builds taken care of, you are now + ready to begin the bisection.* [:ref:`... <introbisect_bissbs>`] + +The steps in this segment perform and validate the bisection. + +[:ref:`back to step-by-step guide <introbisect_bissbs>`]. + .. _bisectstart_bisref: Start the bisection -------------------- +~~~~~~~~~~~~~~~~~~~ *Start the bisection and tell Git about the versions earlier established as 'good' and 'bad'.* [:ref:`... <bisectstart_bissbs>`] @@ -1789,7 +1941,7 @@ for you to test. .. _bisectbuild_bisref: Build a kernel from the bisection point ---------------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *Build, install, and boot a kernel from the code Git checked out using the same commands you used earlier.* [:ref:`... <bisectbuild_bissbs>`] @@ -1817,7 +1969,7 @@ There are two things worth of note here: .. _bisecttest_bisref: Bisection checkpoint --------------------- +~~~~~~~~~~~~~~~~~~~~ *Check if the feature that regressed works in the kernel you just built.* [:ref:`... <bisecttest_bissbs>`] @@ -1831,7 +1983,7 @@ will be for nothing. .. _bisectlog_bisref: Put the bisection log away --------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~ *Store Git's bisection log and the current .config file in a safe place.* [:ref:`... <bisectlog_bissbs>`] @@ -1851,7 +2003,7 @@ ask for it after you report the regression. .. _revert_bisref: Try reverting the culprit -------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~ *Try reverting the culprit on top of the latest codebase to see if this fixes your regression.* [:ref:`... <revert_bissbs>`] @@ -1869,14 +2021,20 @@ succeeds, test that kernel version instead. [:ref:`back to step-by-step guide <revert_bissbs>`] +Cleanup steps during and after following this guide +--------------------------------------------------- -Supplementary tasks: cleanup during and after the bisection ------------------------------------------------------------ + *During and after following this guide you might want or need to remove some + of the kernels you installed.* [:ref:`... <introclosure_bissbs>`] + +The steps in this section describe clean-up procedures. + +[:ref:`back to step-by-step guide <introclosure_bissbs>`]. .. _makeroom_bisref: Cleaning up during the bisection --------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *To remove one of the kernels you installed, look up its 'kernelrelease' identifier.* [:ref:`... <makeroom_bissbs>`] @@ -1911,13 +2069,13 @@ Now remove the boot entry for the kernel from your bootloader's configuration; the steps to do that vary quite a bit between Linux distributions. Note, be careful with wildcards like '*' when deleting files or directories -for kernels manually: you might accidentally remove files of a 6.0.11 kernel +for kernels manually: you might accidentally remove files of a 6.0.13 kernel when all you want is to remove 6.0 or 6.0.1. [:ref:`back to step-by-step guide <makeroom_bissbs>`] Cleaning up after the bisection -------------------------------- +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. _finishingtouch_bisref: @@ -1932,26 +2090,105 @@ build artifacts and the Linux sources, but will leave the Git repository (~/linux/.git/) behind -- a simple ``git reset --hard`` thus will bring the sources back. -Removing the repository as well would likely be unwise at this point: there is a -decent chance developers will ask you to build another kernel to perform -additional tests. This is often required to debug an issue or check proposed -fixes. Before doing so you want to run the ``git fetch mainline`` command again -followed by ``git checkout mainline/master`` to bring your clone up to date and -checkout the latest codebase. Then apply the patch using ``git apply -<filename>`` or ``git am <filename>`` and build yet another kernel using the -familiar commands. +Removing the repository as well would likely be unwise at this point: there +is a decent chance developers will ask you to build another kernel to +perform additional tests -- like testing a debug patch or a proposed fix. +Details on how to perform those can be found in the section :ref:`Optional +tasks: test reverts, patches, or later versions <introoptional_bissbs>`. Additional tests are also the reason why you want to keep the ~/kernel-config-working file around for a few weeks. [:ref:`back to step-by-step guide <finishingtouch_bissbs>`] +.. _introoptional_bisref: -Additional reading material -=========================== +Test reverts, patches, or later versions +---------------------------------------- + + *While or after reporting a bug, you might want or potentially will be asked + to test reverts, patches, proposed fixes, or other versions.* + [:ref:`... <introoptional_bissbs>`] + +All the commands used in this section should be pretty straight forward, so +there is not much to add except one thing: when setting a kernel tag as +instructed, ensure it is not much longer than the one used in the example, as +problems will arise if the kernelrelease identifier exceeds 63 characters. + +[:ref:`back to step-by-step guide <introoptional_bissbs>`]. + + +Additional information +====================== + +.. _buildhost_bis: + +Build kernels on a different machine +------------------------------------ + +To compile kernels on another system, slightly alter the step-by-step guide's +instructions: + +* Start following the guide on the machine where you want to install and test + the kernels later. + +* After executing ':ref:`Boot into the working kernel and briefly use the + apparently broken feature <bootworking_bissbs>`', save the list of loaded + modules to a file using ``lsmod > ~/test-machine-lsmod``. Then locate the + build configuration for the running kernel (see ':ref:`Start defining the + build configuration for your kernel <oldconfig_bisref>`' for hints on where + to find it) and store it as '~/test-machine-config-working'. Transfer both + files to the home directory of your build host. + +* Continue the guide on the build host (e.g. with ':ref:`Ensure to have enough + free space for building [...] <diskspace_bissbs>`'). + +* When you reach ':ref:`Start preparing a kernel build configuration[...] + <oldconfig_bissbs>`': before running ``make olddefconfig`` for the first time, + execute the following command to base your configuration on the one from the + test machine's 'working' kernel:: + + cp ~/test-machine-config-working ~/linux/.config + +* During the next step to ':ref:`disable any apparently superfluous kernel + modules <localmodconfig_bissbs>`' use the following command instead:: -Further sources ---------------- + yes '' | make localmodconfig LSMOD=~/lsmod_foo-machine localmodconfig + +* Continue the guide, but ignore the instructions outlining how to compile, + install, and reboot into a kernel every time they come up. Instead build + like this:: + + cp ~/kernel-config-working .config + make olddefconfig && + make -j $(nproc --all) targz-pkg + + This will generate a gzipped tar file whose name is printed in the last + line shown; for example, a kernel with the kernelrelease identifier + '6.0.0-rc1-local-g928a87efa423' built for x86 machines usually will + be stored as '~/linux/linux-6.0.0-rc1-local-g928a87efa423-x86.tar.gz'. + + Copy that file to your test machine's home directory. + +* Switch to the test machine to check if you have enough space to hold another + kernel. Then extract the file you transferred:: + + sudo tar -xvzf ~/linux-6.0.0-rc1-local-g928a87efa423-x86.tar.gz -C / + + Afterwards :ref:`generate the initramfs and add the kernel to your boot + loader's configuration <install_bisref>`; on some distributions the following + command will take care of both these tasks:: + + sudo /sbin/installkernel 6.0.0-rc1-local-g928a87efa423 /boot/vmlinuz-6.0.0-rc1-local-g928a87efa423 + + Now reboot and ensure you started the intended kernel. + +This approach even works when building for another architecture: just install +cross-compilers and add the appropriate parameters to every invocation of make +(e.g. ``make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- [...]``). + +Additional reading material +--------------------------- * The `man page for 'git bisect' <https://git-scm.com/docs/git-bisect>`_ and `fighting regressions with 'git bisect' <https://git-scm.com/docs/git-bisect-lk2009.html>`_ diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst index 3712d81cb50c..6c245582d8fb 100644 --- a/Documentation/arch/x86/resctrl.rst +++ b/Documentation/arch/x86/resctrl.rst @@ -574,7 +574,7 @@ Memory b/w domain is L3 cache. MB:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;... Memory bandwidth Allocation specified in MiBps ---------------------------------------------- +---------------------------------------------- Memory bandwidth domain is L3 cache. :: diff --git a/Documentation/dev-tools/testing-overview.rst b/Documentation/dev-tools/testing-overview.rst index 0aaf6ea53608..1619e5e5cc9c 100644 --- a/Documentation/dev-tools/testing-overview.rst +++ b/Documentation/dev-tools/testing-overview.rst @@ -104,6 +104,8 @@ Some of these tools are listed below: KASAN and can be used in production. See Documentation/dev-tools/kfence.rst * lockdep is a locking correctness validator. See Documentation/locking/lockdep-design.rst +* Runtime Verification (RV) supports checking specific behaviours for a given + subsystem. See Documentation/trace/rv/runtime-verification.rst * There are several other pieces of debug instrumentation in the kernel, many of which can be found in lib/Kconfig.debug diff --git a/Documentation/devicetree/bindings/clock/keystone-gate.txt b/Documentation/devicetree/bindings/clock/keystone-gate.txt index c5aa187026e3..43f6fb6c9392 100644 --- a/Documentation/devicetree/bindings/clock/keystone-gate.txt +++ b/Documentation/devicetree/bindings/clock/keystone-gate.txt @@ -1,5 +1,3 @@ -Status: Unstable - ABI compatibility may be broken in the future - Binding for Keystone gate control driver which uses PSC controller IP. This binding uses the common clock binding[1]. diff --git a/Documentation/devicetree/bindings/clock/keystone-pll.txt b/Documentation/devicetree/bindings/clock/keystone-pll.txt index 9a3fbc665606..69b0eb7c03c9 100644 --- a/Documentation/devicetree/bindings/clock/keystone-pll.txt +++ b/Documentation/devicetree/bindings/clock/keystone-pll.txt @@ -1,5 +1,3 @@ -Status: Unstable - ABI compatibility may be broken in the future - Binding for keystone PLLs. The main PLL IP typically has a multiplier, a divider and a post divider. The additional PLL IPs like ARMPLL, DDRPLL and PAPLL are controlled by the memory mapped register where as the Main diff --git a/Documentation/devicetree/bindings/clock/ti/adpll.txt b/Documentation/devicetree/bindings/clock/ti/adpll.txt index 4c8a2ce2cd70..3122360adcf3 100644 --- a/Documentation/devicetree/bindings/clock/ti/adpll.txt +++ b/Documentation/devicetree/bindings/clock/ti/adpll.txt @@ -1,7 +1,5 @@ Binding for Texas Instruments ADPLL clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. It assumes a register-mapped ADPLL with two to three selectable input clocks and three to four children. diff --git a/Documentation/devicetree/bindings/clock/ti/apll.txt b/Documentation/devicetree/bindings/clock/ti/apll.txt index ade4dd4c30f0..bbd505c1199d 100644 --- a/Documentation/devicetree/bindings/clock/ti/apll.txt +++ b/Documentation/devicetree/bindings/clock/ti/apll.txt @@ -1,7 +1,5 @@ Binding for Texas Instruments APLL clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. It assumes a register-mapped APLL with usually two selectable input clocks (reference clock and bypass clock), with analog phase locked diff --git a/Documentation/devicetree/bindings/clock/ti/autoidle.txt b/Documentation/devicetree/bindings/clock/ti/autoidle.txt index 7c735dde9fe9..05645a10a9e3 100644 --- a/Documentation/devicetree/bindings/clock/ti/autoidle.txt +++ b/Documentation/devicetree/bindings/clock/ti/autoidle.txt @@ -1,7 +1,5 @@ Binding for Texas Instruments autoidle clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. It assumes a register mapped clock which can be put to idle automatically by hardware based on the usage and a configuration bit setting. Autoidle clock is never an individual diff --git a/Documentation/devicetree/bindings/clock/ti/clockdomain.txt b/Documentation/devicetree/bindings/clock/ti/clockdomain.txt index 9c6199249ce5..edf0b5d42768 100644 --- a/Documentation/devicetree/bindings/clock/ti/clockdomain.txt +++ b/Documentation/devicetree/bindings/clock/ti/clockdomain.txt @@ -1,7 +1,5 @@ Binding for Texas Instruments clockdomain. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1] in consumer role. Every clock on TI SoC belongs to one clockdomain, but software only needs this information for specific clocks which require diff --git a/Documentation/devicetree/bindings/clock/ti/composite.txt b/Documentation/devicetree/bindings/clock/ti/composite.txt index 33ac7c9ad053..6f7e1331b546 100644 --- a/Documentation/devicetree/bindings/clock/ti/composite.txt +++ b/Documentation/devicetree/bindings/clock/ti/composite.txt @@ -1,7 +1,5 @@ Binding for TI composite clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. It assumes a register-mapped composite clock with multiple different sub-types; diff --git a/Documentation/devicetree/bindings/clock/ti/divider.txt b/Documentation/devicetree/bindings/clock/ti/divider.txt index 9b13b32974f9..4d7c76f0b356 100644 --- a/Documentation/devicetree/bindings/clock/ti/divider.txt +++ b/Documentation/devicetree/bindings/clock/ti/divider.txt @@ -1,7 +1,5 @@ Binding for TI divider clock -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. It assumes a register-mapped adjustable clock rate divider that does not gate and has only one input clock or parent. By default the value programmed into diff --git a/Documentation/devicetree/bindings/clock/ti/dpll.txt b/Documentation/devicetree/bindings/clock/ti/dpll.txt index 37a7cb6ad07d..14a1b72c2e71 100644 --- a/Documentation/devicetree/bindings/clock/ti/dpll.txt +++ b/Documentation/devicetree/bindings/clock/ti/dpll.txt @@ -1,7 +1,5 @@ Binding for Texas Instruments DPLL clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. It assumes a register-mapped DPLL with usually two selectable input clocks (reference clock and bypass clock), with digital phase locked diff --git a/Documentation/devicetree/bindings/clock/ti/fapll.txt b/Documentation/devicetree/bindings/clock/ti/fapll.txt index c19b3f253b8c..88986ef39ddd 100644 --- a/Documentation/devicetree/bindings/clock/ti/fapll.txt +++ b/Documentation/devicetree/bindings/clock/ti/fapll.txt @@ -1,7 +1,5 @@ Binding for Texas Instruments FAPLL clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. It assumes a register-mapped FAPLL with usually two selectable input clocks (reference clock and bypass clock), and one or more child diff --git a/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt b/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt index 518e3c142276..dc69477b6e98 100644 --- a/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt +++ b/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt @@ -1,7 +1,5 @@ Binding for TI fixed factor rate clock sources. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1], and also uses the autoidle support from TI autoidle clock [2]. diff --git a/Documentation/devicetree/bindings/clock/ti/gate.txt b/Documentation/devicetree/bindings/clock/ti/gate.txt index 4982615c01b9..a8e0335b006a 100644 --- a/Documentation/devicetree/bindings/clock/ti/gate.txt +++ b/Documentation/devicetree/bindings/clock/ti/gate.txt @@ -1,7 +1,5 @@ Binding for Texas Instruments gate clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. This clock is quite much similar to the basic gate-clock [2], however, it supports a number of additional features. If no register diff --git a/Documentation/devicetree/bindings/clock/ti/interface.txt b/Documentation/devicetree/bindings/clock/ti/interface.txt index d3eb5ca92a7f..85fb1f2d2d28 100644 --- a/Documentation/devicetree/bindings/clock/ti/interface.txt +++ b/Documentation/devicetree/bindings/clock/ti/interface.txt @@ -1,7 +1,5 @@ Binding for Texas Instruments interface clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. This clock is quite much similar to the basic gate-clock [2], however, it supports a number of additional features, including diff --git a/Documentation/devicetree/bindings/clock/ti/mux.txt b/Documentation/devicetree/bindings/clock/ti/mux.txt index b33f641f1043..cd56d3c1c09f 100644 --- a/Documentation/devicetree/bindings/clock/ti/mux.txt +++ b/Documentation/devicetree/bindings/clock/ti/mux.txt @@ -1,7 +1,5 @@ Binding for TI mux clock. -Binding status: Unstable - ABI compatibility may be broken in the future - This binding uses the common clock binding[1]. It assumes a register-mapped multiplexer with multiple input clock signals or parents, one of which can be selected as output. This clock does not diff --git a/Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml b/Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml index c0d6a4fdff97..e6dc5494baee 100644 --- a/Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml +++ b/Documentation/devicetree/bindings/display/msm/qcom,sm8150-mdss.yaml @@ -53,6 +53,15 @@ patternProperties: compatible: const: qcom,sm8150-dpu + "^displayport-controller@[0-9a-f]+$": + type: object + additionalProperties: true + + properties: + compatible: + contains: + const: qcom,sm8150-dp + "^dsi@[0-9a-f]+$": type: object additionalProperties: true diff --git a/Documentation/devicetree/bindings/dts-coding-style.rst b/Documentation/devicetree/bindings/dts-coding-style.rst index a9bdd2b59dca..8a68331075a0 100644 --- a/Documentation/devicetree/bindings/dts-coding-style.rst +++ b/Documentation/devicetree/bindings/dts-coding-style.rst @@ -144,6 +144,8 @@ Example:: #dma-cells = <1>; clocks = <&clock_controller 0>, <&clock_controller 1>; clock-names = "bus", "host"; + #address-cells = <1>; + #size-cells = <1>; vendor,custom-property = <2>; status = "disabled"; diff --git a/Documentation/devicetree/bindings/eeprom/at24.yaml b/Documentation/devicetree/bindings/eeprom/at24.yaml index 1812ef31d5f1..3c36cd0510de 100644 --- a/Documentation/devicetree/bindings/eeprom/at24.yaml +++ b/Documentation/devicetree/bindings/eeprom/at24.yaml @@ -69,14 +69,10 @@ properties: - items: pattern: c32$ - items: - pattern: c32d-wl$ - - items: pattern: cs32$ - items: pattern: c64$ - items: - pattern: c64d-wl$ - - items: pattern: cs64$ - items: pattern: c128$ @@ -136,6 +132,7 @@ properties: - renesas,r1ex24128 - samsung,s524ad0xd1 - const: atmel,24c128 + - pattern: '^atmel,24c(32|64)d-wl$' # Actual vendor is st label: description: Descriptive name of the EEPROM. diff --git a/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml b/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml index 528ef3572b62..055a3351880b 100644 --- a/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml +++ b/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml @@ -94,6 +94,10 @@ properties: local-bd-address: true + qcom,local-bd-address-broken: + type: boolean + description: + boot firmware is incorrectly passing the address in big-endian order required: - compatible diff --git a/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml b/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml index afcdeed4e88a..bc813fe74fab 100644 --- a/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml +++ b/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml @@ -52,6 +52,9 @@ properties: - const: main - const: mm + power-domains: + maxItems: 1 + required: - compatible - reg diff --git a/Documentation/devicetree/bindings/remoteproc/ti,davinci-rproc.txt b/Documentation/devicetree/bindings/remoteproc/ti,davinci-rproc.txt index 25f8658e216f..48a49c516b62 100644 --- a/Documentation/devicetree/bindings/remoteproc/ti,davinci-rproc.txt +++ b/Documentation/devicetree/bindings/remoteproc/ti,davinci-rproc.txt @@ -1,9 +1,6 @@ TI Davinci DSP devices ======================= -Binding status: Unstable - Subject to changes for DT representation of clocks - and resets - The TI Davinci family of SoCs usually contains a TI DSP Core sub-system that is used to offload some of the processor-intensive tasks or algorithms, for achieving various system level goals. diff --git a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml index 65cb2e5c5eee..eb2992a447d7 100644 --- a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml +++ b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml @@ -8,7 +8,7 @@ $schema: http://devicetree.org/meta-schemas/core.yaml# title: Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART) maintainers: - - Richard Genoud <richard.genoud@gmail.com> + - Richard Genoud <richard.genoud@bootlin.com> properties: compatible: diff --git a/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml b/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml index 397f75909b20..ce1a6505eb51 100644 --- a/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml +++ b/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-dcfg.yaml @@ -51,7 +51,7 @@ properties: ranges: true patternProperties: - "^clock-controller@[0-9a-z]+$": + "^clock-controller@[0-9a-f]+$": $ref: /schemas/clock/fsl,flexspi-clock.yaml# required: diff --git a/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-scfg.yaml b/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-scfg.yaml index 8d088b5fe823..a6a511b00a12 100644 --- a/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-scfg.yaml +++ b/Documentation/devicetree/bindings/soc/fsl/fsl,layerscape-scfg.yaml @@ -41,7 +41,7 @@ properties: ranges: true patternProperties: - "^interrupt-controller@[a-z0-9]+$": + "^interrupt-controller@[a-f0-9]+$": $ref: /schemas/interrupt-controller/fsl,ls-extirq.yaml# required: diff --git a/Documentation/devicetree/bindings/soc/rockchip/grf.yaml b/Documentation/devicetree/bindings/soc/rockchip/grf.yaml index 0b87c266760c..79798c747476 100644 --- a/Documentation/devicetree/bindings/soc/rockchip/grf.yaml +++ b/Documentation/devicetree/bindings/soc/rockchip/grf.yaml @@ -171,6 +171,7 @@ allOf: unevaluatedProperties: false pcie-phy: + type: object description: Documentation/devicetree/bindings/phy/rockchip-pcie-phy.txt diff --git a/Documentation/devicetree/bindings/timer/arm,arch_timer_mmio.yaml b/Documentation/devicetree/bindings/timer/arm,arch_timer_mmio.yaml index 7a4a6ab85970..ab8f28993139 100644 --- a/Documentation/devicetree/bindings/timer/arm,arch_timer_mmio.yaml +++ b/Documentation/devicetree/bindings/timer/arm,arch_timer_mmio.yaml @@ -60,7 +60,7 @@ properties: be implemented in an always-on power domain." patternProperties: - '^frame@[0-9a-z]*$': + '^frame@[0-9a-f]+$': type: object additionalProperties: false description: A timer node has up to 8 frame sub-nodes, each with the following properties. diff --git a/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml b/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml index 10c146424baa..cd3680dc002f 100644 --- a/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml +++ b/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml @@ -27,10 +27,13 @@ properties: - qcom,msm8996-ufshc - qcom,msm8998-ufshc - qcom,sa8775p-ufshc + - qcom,sc7180-ufshc - qcom,sc7280-ufshc + - qcom,sc8180x-ufshc - qcom,sc8280xp-ufshc - qcom,sdm845-ufshc - qcom,sm6115-ufshc + - qcom,sm6125-ufshc - qcom,sm6350-ufshc - qcom,sm8150-ufshc - qcom,sm8250-ufshc @@ -42,11 +45,11 @@ properties: - const: jedec,ufs-2.0 clocks: - minItems: 8 + minItems: 7 maxItems: 11 clock-names: - minItems: 8 + minItems: 7 maxItems: 11 dma-coherent: true @@ -117,9 +120,35 @@ allOf: compatible: contains: enum: + - qcom,sc7180-ufshc + then: + properties: + clocks: + minItems: 7 + maxItems: 7 + clock-names: + items: + - const: core_clk + - const: bus_aggr_clk + - const: iface_clk + - const: core_clk_unipro + - const: ref_clk + - const: tx_lane0_sync_clk + - const: rx_lane0_sync_clk + reg: + maxItems: 1 + reg-names: + maxItems: 1 + + - if: + properties: + compatible: + contains: + enum: - qcom,msm8998-ufshc - qcom,sa8775p-ufshc - qcom,sc7280-ufshc + - qcom,sc8180x-ufshc - qcom,sc8280xp-ufshc - qcom,sm8250-ufshc - qcom,sm8350-ufshc @@ -215,6 +244,7 @@ allOf: contains: enum: - qcom,sm6115-ufshc + - qcom,sm6125-ufshc then: properties: clocks: @@ -248,7 +278,7 @@ allOf: reg: maxItems: 1 clocks: - minItems: 8 + minItems: 7 maxItems: 8 else: properties: @@ -256,7 +286,7 @@ allOf: minItems: 1 maxItems: 2 clocks: - minItems: 8 + minItems: 7 maxItems: 11 unevaluatedProperties: false diff --git a/Documentation/driver-api/virtio/writing_virtio_drivers.rst b/Documentation/driver-api/virtio/writing_virtio_drivers.rst index e14c58796d25..e5de6f5d061a 100644 --- a/Documentation/driver-api/virtio/writing_virtio_drivers.rst +++ b/Documentation/driver-api/virtio/writing_virtio_drivers.rst @@ -97,7 +97,6 @@ like this:: static struct virtio_driver virtio_dummy_driver = { .driver.name = KBUILD_MODNAME, - .driver.owner = THIS_MODULE, .id_table = id_table, .probe = virtio_dummy_probe, .remove = virtio_dummy_remove, diff --git a/Documentation/filesystems/bcachefs/index.rst b/Documentation/filesystems/bcachefs/index.rst new file mode 100644 index 000000000000..e2bd61ccd96f --- /dev/null +++ b/Documentation/filesystems/bcachefs/index.rst @@ -0,0 +1,11 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================== +bcachefs Documentation +====================== + +.. toctree:: + :maxdepth: 2 + :numbered: + + errorcodes diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index 0ea1e44fa028..1f9b4c905a6a 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -69,6 +69,7 @@ Documentation for filesystem implementations. afs autofs autofs-mount-control + bcachefs/index befs bfs btrfs diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst index b1d97fafddcf..bb5c44f8bd1c 100644 --- a/Documentation/kbuild/llvm.rst +++ b/Documentation/kbuild/llvm.rst @@ -178,7 +178,7 @@ yet. Bug reports are always welcome at the issue tracker below! - ``LLVM=1`` * - s390 - Maintained - - ``CC=clang`` + - ``LLVM=1`` (LLVM >= 18.1.0), ``CC=clang`` (LLVM < 18.1.0) * - um (User Mode) - Maintained - ``LLVM=1`` diff --git a/Documentation/mm/page_owner.rst b/Documentation/mm/page_owner.rst index 0d0334cd5179..3a45a20fc05a 100644 --- a/Documentation/mm/page_owner.rst +++ b/Documentation/mm/page_owner.rst @@ -24,10 +24,10 @@ fragmentation statistics can be obtained through gfp flag information of each page. It is already implemented and activated if page owner is enabled. Other usages are more than welcome. -It can also be used to show all the stacks and their outstanding -allocations, which gives us a quick overview of where the memory is going -without the need to screen through all the pages and match the allocation -and free operation. +It can also be used to show all the stacks and their current number of +allocated base pages, which gives us a quick overview of where the memory +is going without the need to screen through all the pages and match the +allocation and free operation. page owner is disabled by default. So, if you'd like to use it, you need to add "page_owner=on" to your boot cmdline. If the kernel is built @@ -75,42 +75,45 @@ Usage cat /sys/kernel/debug/page_owner_stacks/show_stacks > stacks.txt cat stacks.txt - prep_new_page+0xa9/0x120 - get_page_from_freelist+0x7e6/0x2140 - __alloc_pages+0x18a/0x370 - new_slab+0xc8/0x580 - ___slab_alloc+0x1f2/0xaf0 - __slab_alloc.isra.86+0x22/0x40 - kmem_cache_alloc+0x31b/0x350 - __khugepaged_enter+0x39/0x100 - dup_mmap+0x1c7/0x5ce - copy_process+0x1afe/0x1c90 - kernel_clone+0x9a/0x3c0 - __do_sys_clone+0x66/0x90 - do_syscall_64+0x7f/0x160 - entry_SYSCALL_64_after_hwframe+0x6c/0x74 - stack_count: 234 + post_alloc_hook+0x177/0x1a0 + get_page_from_freelist+0xd01/0xd80 + __alloc_pages+0x39e/0x7e0 + allocate_slab+0xbc/0x3f0 + ___slab_alloc+0x528/0x8a0 + kmem_cache_alloc+0x224/0x3b0 + sk_prot_alloc+0x58/0x1a0 + sk_alloc+0x32/0x4f0 + inet_create+0x427/0xb50 + __sock_create+0x2e4/0x650 + inet_ctl_sock_create+0x30/0x180 + igmp_net_init+0xc1/0x130 + ops_init+0x167/0x410 + setup_net+0x304/0xa60 + copy_net_ns+0x29b/0x4a0 + create_new_namespaces+0x4a1/0x820 + nr_base_pages: 16 ... ... echo 7000 > /sys/kernel/debug/page_owner_stacks/count_threshold cat /sys/kernel/debug/page_owner_stacks/show_stacks> stacks_7000.txt cat stacks_7000.txt - prep_new_page+0xa9/0x120 - get_page_from_freelist+0x7e6/0x2140 - __alloc_pages+0x18a/0x370 - alloc_pages_mpol+0xdf/0x1e0 - folio_alloc+0x14/0x50 - filemap_alloc_folio+0xb0/0x100 - page_cache_ra_unbounded+0x97/0x180 - filemap_fault+0x4b4/0x1200 - __do_fault+0x2d/0x110 - do_pte_missing+0x4b0/0xa30 - __handle_mm_fault+0x7fa/0xb70 - handle_mm_fault+0x125/0x300 - do_user_addr_fault+0x3c9/0x840 - exc_page_fault+0x68/0x150 - asm_exc_page_fault+0x22/0x30 - stack_count: 8248 + post_alloc_hook+0x177/0x1a0 + get_page_from_freelist+0xd01/0xd80 + __alloc_pages+0x39e/0x7e0 + alloc_pages_mpol+0x22e/0x490 + folio_alloc+0xd5/0x110 + filemap_alloc_folio+0x78/0x230 + page_cache_ra_order+0x287/0x6f0 + filemap_get_pages+0x517/0x1160 + filemap_read+0x304/0x9f0 + xfs_file_buffered_read+0xe6/0x1d0 [xfs] + xfs_file_read_iter+0x1f0/0x380 [xfs] + __kernel_read+0x3b9/0x730 + kernel_read_file+0x309/0x4d0 + __do_sys_finit_module+0x381/0x730 + do_syscall_64+0x8d/0x150 + entry_SYSCALL_64_after_hwframe+0x62/0x6a + nr_base_pages: 20824 ... cat /sys/kernel/debug/page_owner > page_owner_full.txt diff --git a/Documentation/networking/devlink/devlink-eswitch-attr.rst b/Documentation/networking/devlink/devlink-eswitch-attr.rst new file mode 100644 index 000000000000..08bb39ab1528 --- /dev/null +++ b/Documentation/networking/devlink/devlink-eswitch-attr.rst @@ -0,0 +1,76 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================== +Devlink E-Switch Attribute +========================== + +Devlink E-Switch supports two modes of operation: legacy and switchdev. +Legacy mode operates based on traditional MAC/VLAN steering rules. Switching +decisions are made based on MAC addresses, VLANs, etc. There is limited ability +to offload switching rules to hardware. + +On the other hand, switchdev mode allows for more advanced offloading +capabilities of the E-Switch to hardware. In switchdev mode, more switching +rules and logic can be offloaded to the hardware switch ASIC. It enables +representor netdevices that represent the slow path of virtual functions (VFs) +or scalable-functions (SFs) of the device. See more information about +:ref:`Documentation/networking/switchdev.rst <switchdev>` and +:ref:`Documentation/networking/representors.rst <representors>`. + +In addition, the devlink E-Switch also comes with other attributes listed +in the following section. + +Attributes Description +====================== + +The following is a list of E-Switch attributes. + +.. list-table:: E-Switch attributes + :widths: 8 5 45 + + * - Name + - Type + - Description + * - ``mode`` + - enum + - The mode of the device. The mode can be one of the following: + + * ``legacy`` operates based on traditional MAC/VLAN steering + rules. + * ``switchdev`` allows for more advanced offloading capabilities of + the E-Switch to hardware. + * - ``inline-mode`` + - enum + - Some HWs need the VF driver to put part of the packet + headers on the TX descriptor so the e-switch can do proper + matching and steering. Support for both switchdev mode and legacy mode. + + * ``none`` none. + * ``link`` L2 mode. + * ``network`` L3 mode. + * ``transport`` L4 mode. + * - ``encap-mode`` + - enum + - The encapsulation mode of the device. Support for both switchdev mode + and legacy mode. The mode can be one of the following: + + * ``none`` Disable encapsulation support. + * ``basic`` Enable encapsulation support. + +Example Usage +============= + +.. code:: shell + + # enable switchdev mode + $ devlink dev eswitch set pci/0000:08:00.0 mode switchdev + + # set inline-mode and encap-mode + $ devlink dev eswitch set pci/0000:08:00.0 inline-mode none encap-mode basic + + # display devlink device eswitch attributes + $ devlink dev eswitch show pci/0000:08:00.0 + pci/0000:08:00.0: mode switchdev inline-mode none encap-mode basic + + # enable encap-mode with legacy mode + $ devlink dev eswitch set pci/0000:08:00.0 mode legacy inline-mode none encap-mode basic diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst index e14d7a701b72..948c8c44e233 100644 --- a/Documentation/networking/devlink/index.rst +++ b/Documentation/networking/devlink/index.rst @@ -67,6 +67,7 @@ general. devlink-selftests devlink-trap devlink-linecard + devlink-eswitch-attr Driver-specific documentation ----------------------------- diff --git a/Documentation/networking/representors.rst b/Documentation/networking/representors.rst index decb39c19b9e..5e23386f6968 100644 --- a/Documentation/networking/representors.rst +++ b/Documentation/networking/representors.rst @@ -1,4 +1,5 @@ .. SPDX-License-Identifier: GPL-2.0 +.. _representors: ============================= Network Function Representors diff --git a/Documentation/process/embargoed-hardware-issues.rst b/Documentation/process/embargoed-hardware-issues.rst index bb2100228cc7..6e9a4597bf2c 100644 --- a/Documentation/process/embargoed-hardware-issues.rst +++ b/Documentation/process/embargoed-hardware-issues.rst @@ -252,7 +252,7 @@ an involved disclosed party. The current ambassadors list: AMD Tom Lendacky <thomas.lendacky@amd.com> Ampere Darren Hart <darren@os.amperecomputing.com> ARM Catalin Marinas <catalin.marinas@arm.com> - IBM Power Anton Blanchard <anton@linux.ibm.com> + IBM Power Michael Ellerman <ellerman@au.ibm.com> IBM Z Christian Borntraeger <borntraeger@de.ibm.com> Intel Tony Luck <tony.luck@intel.com> Qualcomm Trilok Soni <quic_tsoni@quicinc.com> diff --git a/Documentation/rust/arch-support.rst b/Documentation/rust/arch-support.rst index 5c4fa9f5d1cd..c9137710633a 100644 --- a/Documentation/rust/arch-support.rst +++ b/Documentation/rust/arch-support.rst @@ -16,7 +16,7 @@ support corresponds to ``S`` values in the ``MAINTAINERS`` file. Architecture Level of support Constraints ============= ================ ============================================== ``arm64`` Maintained Little Endian only. -``loongarch`` Maintained - +``loongarch`` Maintained \- ``um`` Maintained ``x86_64`` only. ``x86`` Maintained ``x86_64`` only. ============= ================ ============================================== diff --git a/Documentation/timers/no_hz.rst b/Documentation/timers/no_hz.rst index f8786be15183..7fe8ef9718d8 100644 --- a/Documentation/timers/no_hz.rst +++ b/Documentation/timers/no_hz.rst @@ -129,11 +129,8 @@ adaptive-tick CPUs: At least one non-adaptive-tick CPU must remain online to handle timekeeping tasks in order to ensure that system calls like gettimeofday() returns accurate values on adaptive-tick CPUs. (This is not an issue for CONFIG_NO_HZ_IDLE=y because there are no running -user processes to observe slight drifts in clock rate.) Therefore, the -boot CPU is prohibited from entering adaptive-ticks mode. Specifying a -"nohz_full=" mask that includes the boot CPU will result in a boot-time -error message, and the boot CPU will be removed from the mask. Note that -this means that your system must have at least two CPUs in order for +user processes to observe slight drifts in clock rate.) Note that this +means that your system must have at least two CPUs in order for CONFIG_NO_HZ_FULL=y to do anything for you. Finally, adaptive-ticks CPUs must have their RCU callbacks offloaded. diff --git a/Documentation/virt/kvm/x86/amd-memory-encryption.rst b/Documentation/virt/kvm/x86/amd-memory-encryption.rst index 995780088eb2..84335d119ff1 100644 --- a/Documentation/virt/kvm/x86/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/x86/amd-memory-encryption.rst @@ -46,21 +46,16 @@ SEV hardware uses ASIDs to associate a memory encryption key with a VM. Hence, the ASID for the SEV-enabled guests must be from 1 to a maximum value defined in the CPUID 0x8000001f[ecx] field. -SEV Key Management -================== +The KVM_MEMORY_ENCRYPT_OP ioctl +=============================== -The SEV guest key management is handled by a separate processor called the AMD -Secure Processor (AMD-SP). Firmware running inside the AMD-SP provides a secure -key management interface to perform common hypervisor activities such as -encrypting bootstrap code, snapshot, migrating and debugging the guest. For more -information, see the SEV Key Management spec [api-spec]_ - -The main ioctl to access SEV is KVM_MEMORY_ENCRYPT_OP. If the argument -to KVM_MEMORY_ENCRYPT_OP is NULL, the ioctl returns 0 if SEV is enabled -and ``ENOTTY`` if it is disabled (on some older versions of Linux, -the ioctl runs normally even with a NULL argument, and therefore will -likely return ``EFAULT``). If non-NULL, the argument to KVM_MEMORY_ENCRYPT_OP -must be a struct kvm_sev_cmd:: +The main ioctl to access SEV is KVM_MEMORY_ENCRYPT_OP, which operates on +the VM file descriptor. If the argument to KVM_MEMORY_ENCRYPT_OP is NULL, +the ioctl returns 0 if SEV is enabled and ``ENOTTY`` if it is disabled +(on some older versions of Linux, the ioctl tries to run normally even +with a NULL argument, and therefore will likely return ``EFAULT`` instead +of zero if SEV is enabled). If non-NULL, the argument to +KVM_MEMORY_ENCRYPT_OP must be a struct kvm_sev_cmd:: struct kvm_sev_cmd { __u32 id; @@ -87,10 +82,6 @@ guests, such as launching, running, snapshotting, migrating and decommissioning. The KVM_SEV_INIT command is used by the hypervisor to initialize the SEV platform context. In a typical workflow, this command should be the first command issued. -The firmware can be initialized either by using its own non-volatile storage or -the OS can manage the NV storage for the firmware using the module parameter -``init_ex_path``. If the file specified by ``init_ex_path`` does not exist or -is invalid, the OS will create or override the file with output from PSP. Returns: 0 on success, -negative on error @@ -434,6 +425,21 @@ issued by the hypervisor to make the guest ready for execution. Returns: 0 on success, -negative on error +Firmware Management +=================== + +The SEV guest key management is handled by a separate processor called the AMD +Secure Processor (AMD-SP). Firmware running inside the AMD-SP provides a secure +key management interface to perform common hypervisor activities such as +encrypting bootstrap code, snapshot, migrating and debugging the guest. For more +information, see the SEV Key Management spec [api-spec]_ + +The AMD-SP firmware can be initialized either by using its own non-volatile +storage or the OS can manage the NV storage for the firmware using +parameter ``init_ex_path`` of the ``ccp`` module. If the file specified +by ``init_ex_path`` does not exist or is invalid, the OS will create or +override the file with PSP non-volatile storage. + References ========== diff --git a/Documentation/virt/kvm/x86/msr.rst b/Documentation/virt/kvm/x86/msr.rst index 9315fc385fb0..3aecf2a70e7b 100644 --- a/Documentation/virt/kvm/x86/msr.rst +++ b/Documentation/virt/kvm/x86/msr.rst @@ -193,8 +193,8 @@ data: Asynchronous page fault (APF) control MSR. Bits 63-6 hold 64-byte aligned physical address of a 64 byte memory area - which must be in guest RAM and must be zeroed. This memory is expected - to hold a copy of the following structure:: + which must be in guest RAM. This memory is expected to hold the + following structure:: struct kvm_vcpu_pv_apf_data { /* Used for 'page not present' events delivered via #PF */ @@ -204,7 +204,6 @@ data: __u32 token; __u8 pad[56]; - __u32 enabled; }; Bits 5-4 of the MSR are reserved and should be zero. Bit 0 is set to 1 @@ -232,14 +231,14 @@ data: as regular page fault, guest must reset 'flags' to '0' before it does something that can generate normal page fault. - Bytes 5-7 of 64 byte memory location ('token') will be written to by the + Bytes 4-7 of 64 byte memory location ('token') will be written to by the hypervisor at the time of APF 'page ready' event injection. The content - of these bytes is a token which was previously delivered as 'page not - present' event. The event indicates the page in now available. Guest is - supposed to write '0' to 'token' when it is done handling 'page ready' - event and to write 1' to MSR_KVM_ASYNC_PF_ACK after clearing the location; - writing to the MSR forces KVM to re-scan its queue and deliver the next - pending notification. + of these bytes is a token which was previously delivered in CR2 as + 'page not present' event. The event indicates the page is now available. + Guest is supposed to write '0' to 'token' when it is done handling + 'page ready' event and to write '1' to MSR_KVM_ASYNC_PF_ACK after + clearing the location; writing to the MSR forces KVM to re-scan its + queue and deliver the next pending notification. Note, MSR_KVM_ASYNC_PF_INT MSR specifying the interrupt vector for 'page ready' APF delivery needs to be written to before enabling APF mechanism |