tjh.dev
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
code
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Pull kvm fixes from Paolo Bonzini:
"RISC-V:
- Fix compilation without RISCV_ISA_ZICBOM
- Fix kvm_riscv_vcpu_timer_pending() for Sstc
ARM:
- Fix a bug preventing restoring an ITS containing mappings for very
large and very sparse device topology
- Work around a relocation handling error when compiling the nVHE
object with profile optimisation
- Fix for stage-2 invalidation holding the VM MMU lock for too long
by limiting the walk to the largest block mapping size
- Enable stack protection and branch profiling for VHE
- Two selftest fixes
x86:
- add compat implementation for KVM_X86_SET_MSR_FILTER ioctl
selftests:
- synchronize includes between include/uapi and tools/include/uapi"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
tools: include: sync include/api/linux/kvm.h
KVM: x86: Add compat handler for KVM_X86_SET_MSR_FILTER
KVM: x86: Copy filter arg outside kvm_vm_ioctl_set_msr_filter()
kvm: Add support for arch compat vm ioctls
RISC-V: KVM: Fix kvm_riscv_vcpu_timer_pending() for Sstc
RISC-V: Fix compilation without RISCV_ISA_ZICBOM
KVM: arm64: vgic: Fix exit condition in scan_its_table()
KVM: arm64: nvhe: Fix build with profile optimization
KVM: selftests: Fix number of pages for memory slot in memslot_modification_stress_test
KVM: arm64: selftests: Fix multiple versions of GIC creation
KVM: arm64: Enable stack protection and branch profiling for VHE
KVM: arm64: Limit stage2_apply_range() batch size to largest block
KVM: arm64: Work out supported block level at compile time
This reverts commit 72a95859728a7866522e6633818bebc1c2519b17.
It broke reboots on big-endian MIPS and MIPS64 malta QEMU instances,
which use the syscon driver. Little-endian is not effected, which means
likely it's important to handle regmap_get_val_endian() in this function
after all.
Fixes: 72a95859728a ("mfd: syscon: Remove repetition of the regmap_get_val_endian()")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Lee Jones <lee@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide a definition of KVM_CAP_DIRTY_LOG_RING_ACQ_REL.
Fixes: 17601bfed909 ("KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option")
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit bfca3dd3d068 ("kernel/utsname_sysctl.c: print kernel arch") added
a new entry to the uts_kern_table[] array, but didn't update the
UTS_PROC_xyz enumerators of older entries, breaking anything that used
them.
Which is admittedly not many cases: it's really just the two uses of
uts_proc_notify() in kernel/sys.c. But apparently journald-systemd
actually uses this to detect hostname changes.
Reported-by: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Fixes: bfca3dd3d068 ("kernel/utsname_sysctl.c: print kernel arch")
Link: https://lore.kernel.org/lkml/0c2b92a6-0f25-9538-178f-eee3b06da23f@secunet.com/
Link: https://linux-regtracking.leemhuis.info/regzbot/regression/0c2b92a6-0f25-9538-178f-eee3b06da23f@secunet.com/
Cc: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The KVM_X86_SET_MSR_FILTER ioctls contains a pointer in the passed in
struct which means it has a different struct size depending on whether
it gets called from 32bit or 64bit code.
This patch introduces compat code that converts from the 32bit struct to
its 64bit counterpart which then gets used going forward internally.
With this applied, 32bit QEMU can successfully set MSR bitmaps when
running on 64bit kernels.
Reported-by: Andrew Randrianasulu <randrianasulu@gmail.com>
Fixes: 1a155254ff937 ("KVM: x86: Introduce MSR filtering")
Signed-off-by: Alexander Graf <graf@amazon.com>
Message-Id: <20221017184541.2658-4-graf@amazon.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull perf fixes from Borislav Petkov:
- Fix raw data handling when perf events are used in bpf
- Rework how SIGTRAPs get delivered to events to address a bunch of
problems with it. Add a selftest for that too
* tag 'perf_urgent_for_v6.1_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
bpf: Fix sample_flags for bpf_perf_event_output
selftests/perf_events: Add a SIGTRAP stress test with disables
perf: Fix missing SIGTRAPs
In the next patch we want to introduce a second caller to
set_msr_filter() which constructs its own filter list on the stack.
Refactor the original function so it takes it as argument instead of
reading it through copy_from_user().
Signed-off-by: Alexander Graf <graf@amazon.com>
Message-Id: <20221017184541.2658-3-graf@amazon.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull scheduler fixes from Borislav Petkov:
- Adjust code to not trip up CFI
- Fix sched group cookie matching
* tag 'sched_urgent_for_v6.1_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Introduce struct balance_callback to avoid CFI mismatches
sched/core: Fix comparison in sched_group_cookie_match()
* Raw data is also filled by bpf_perf_event_output.
* Add sample_flags to indicate raw data.
* This eliminates the segfaults as shown below:
Run ./samples/bpf/trace_output
BUG pid 9 cookie 1001000000004 sized 4
BUG pid 9 cookie 1001000000004 sized 4
BUG pid 9 cookie 1001000000004 sized 4
Segmentation fault (core dumped)
Fixes: 838d9bb62d13 ("perf: Use sample_flags for raw_data")
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/20221007081327.1047552-1-sumanthk@linux.ibm.com
We will introduce the first architecture specific compat vm ioctl in the
next patch. Add all necessary boilerplate to allow architectures to
override compat vm ioctls when necessary.
Signed-off-by: Alexander Graf <graf@amazon.com>
Message-Id: <20221017184541.2658-2-graf@amazon.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull objtool fix from Borislav Petkov:
- Fix ORC stack unwinding when GCOV is enabled
* tag 'objtool_urgent_for_v6.1_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/unwind/orc: Fix unreliable stack dump with gcov
Introduce distinct struct balance_callback instead of performing function
pointer casting which will trip CFI. Avoids warnings as found by Clang's
future -Wcast-function-type-strict option:
In file included from kernel/sched/core.c:84:
kernel/sched/sched.h:1755:15: warning: cast from 'void (*)(struct rq *)' to 'void (*)(struct callback_head *)' converts to incompatible function type [-Wcast-function-type-strict]
head->func = (void (*)(struct callback_head *))func;
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
No binary differences result from this change.
This patch is a cleanup based on Brad Spengler/PaX Team's modifications
to sched code in their last public patch of grsecurity/PaX based on my
understanding of the code. Changes or omissions from the original code
are mine and don't reflect the original grsecurity/PaX code.
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1724
Link: https://lkml.kernel.org/r/20221008000758.2957718-1-keescook@chromium.org
Add a SIGTRAP stress test that exercises repeatedly enabling/disabling
an event while it concurrently keeps firing.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/Y0E3uG7jOywn7vy3@elver.google.com/
KVM/riscv fixes for 6.1, take #1
- Fix compilation without RISCV_ISA_ZICBOM
- Fix kvm_riscv_vcpu_timer_pending() for Sstc
Pull x86 fixes from Borislav Petkov:
"As usually the case, right after a major release, the tip urgent
branches accumulate a couple more fixes than normal. And here is the
x86, a bit bigger, urgent pile.
- Use the correct CPU capability clearing function on the error path
in Intel perf LBR
- A CFI fix to ftrace along with a simplification
- Adjust handling of zero capacity bit mask for resctrl cache
allocation on AMD
- A fix to the AMD microcode loader to attempt patch application on
every logical thread
- A couple of topology fixes to handle CPUID leaf 0x1f enumeration
info properly
- Drop a -mabi=ms compiler option check as both compilers support it
now anyway
- A couple of fixes to how the initial, statically allocated FPU
buffer state is setup and its interaction with dynamic states at
runtime"
* tag 'x86_urgent_for_v6.0_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Fix copy_xstate_to_uabi() to copy init states correctly
perf/x86/intel/lbr: Use setup_clear_cpu_cap() instead of clear_cpu_cap()
ftrace,kcfi: Separate ftrace_stub() and ftrace_stub_graph()
x86/ftrace: Remove ftrace_epilogue()
x86/resctrl: Fix min_cbm_bits for AMD
x86/microcode/AMD: Apply the patch early on every logical thread
x86/topology: Fix duplicated core ID within a package
x86/topology: Fix multiple packages shown on a single-package system
hwmon/coretemp: Handle large core ID value
x86/Kconfig: Drop check for -mabi=ms for CONFIG_EFI_STUB
x86/fpu: Exclude dynamic states from init_fpstate
x86/fpu: Fix the init_fpstate size check with the actual size
x86/fpu: Configure init_fpstate attributes orderly
README