From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- Documentation/process/index.rst | 114 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 Documentation/process/index.rst (limited to 'Documentation/process/index.rst') diff --git a/Documentation/process/index.rst b/Documentation/process/index.rst new file mode 100644 index 000000000..aa7c959a5 --- /dev/null +++ b/Documentation/process/index.rst @@ -0,0 +1,114 @@ +.. raw:: latex + + \renewcommand\thesection* + \renewcommand\thesubsection* + +.. _process_index: + +============================================= +Working with the kernel development community +============================================= + +So you want to be a Linux kernel developer? Welcome! While there is a lot +to be learned about the kernel in a technical sense, it is also important +to learn about how our community works. Reading these documents will make +it much easier for you to get your changes merged with a minimum of +trouble. + +An introduction to how kernel development works +----------------------------------------------- + +Read these documents first: an understanding of the material here will ease +your entry into the kernel community. + +.. toctree:: + :maxdepth: 1 + + howto + development-process + submitting-patches + submit-checklist + +Tools and technical guides for kernel developers +------------------------------------------------ + +This is a collection of material that kernel developers should be familiar +with. + +.. toctree:: + :maxdepth: 1 + + changes + programming-language + coding-style + maintainer-pgp-guide + email-clients + applying-patches + backporting + adding-syscalls + volatile-considered-harmful + botching-up-ioctls + +Policy guides and developer statements +-------------------------------------- + +These are the rules that we try to live by in the kernel community (and +beyond). + +.. toctree:: + :maxdepth: 1 + + license-rules + code-of-conduct + code-of-conduct-interpretation + contribution-maturity-model + kernel-enforcement-statement + kernel-driver-statement + stable-api-nonsense + stable-kernel-rules + management-style + researcher-guidelines + generated-content + coding-assistants + conclave + +Dealing with bugs +----------------- + +Bugs are a fact of life; it is important that we handle them properly. The +documents below provide general advice about debugging and describe our +policies around the handling of a couple of special classes of bugs: +regressions and security problems. + +.. toctree:: + :maxdepth: 1 + + debugging/index + handling-regressions + security-bugs + threat-model + cve + embargoed-hardware-issues + +Maintainer information +---------------------- + +How to find the people who will accept your patches. + +.. toctree:: + :maxdepth: 1 + + maintainer-handbooks + maintainers + +Other material +-------------- + +Here are some other guides to the community that are of interest to most +developers: + +.. toctree:: + :maxdepth: 1 + + kernel-docs + deprecated -- cgit v1.3.1