Linux kernel
============
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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 reStructuredText 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.
code
Clone this repository
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Pull PCI fixes from Bjorn Helgaas:
- When releasing a start-aligned resource, e.g., a bridge window, save
start/end/flags for the next assignment attempt; fixes a v6.15-rc1
regression (Ilpo Järvinen)
- Move set_pcie_speed.sh from TEST_PROGS to TEST_FILE; fixes a bwctrl
selftest v6.15-rc1 regression (Ilpo Järvinen)
- Add Manivannan Sadhasivam as maintainer of native host bridge and
endpoint drivers (Manivannan Sadhasivam)
- In endpoint test driver, defer IRQ allocation from .probe() until
ioctl() to fix a regression on platforms where the Vendor/Device ID
match doesn't include driver_data (Niklas Cassel)
* tag 'pci-v6.15-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
misc: pci_endpoint_test: Defer IRQ allocation until ioctl(PCITEST_SET_IRQTYPE)
MAINTAINERS: Move Manivannan Sadhasivam as PCI Native host bridge and endpoint maintainer
selftests/pcie_bwctrl: Fix test progs list
PCI: Restore assigned resources fully after release
Pull nfsd fix from Chuck Lever:
- Revert a v6.15 patch due to a report of SELinux test failures
* tag 'nfsd-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
Revert "sunrpc: clean cache_detail immediately when flush is written frequently"
Commit a402006d48a9 ("misc: pci_endpoint_test: Remove global 'irq_type'
and 'no_msi'") changed so that the default IRQ vector requested by
pci_endpoint_test_probe() was no longer the module param 'irq_type', but
instead test->irq_type. test->irq_type is by default IRQ_TYPE_UNDEFINED
(until someone calls ioctl(PCITEST_SET_IRQTYPE)).
However, the commit also changed so that after initializing test->irq_type
to IRQ_TYPE_UNDEFINED, it also overrides it with driver_data->irq_type, if
the PCI device and vendor ID provides driver_data.
This causes a regression for PCI device and vendor IDs that do not provide
driver_data, and the host side pci_endpoint_test_driver driver failed to
probe on such platforms:
pci-endpoint-test 0001:01:00.0: Invalid IRQ type selected
pci-endpoint-test 0001:01:00.0: probe with driver pci-endpoint-test failed with error -22
Considering that the pci endpoint selftests and the old pcitest.sh always
call ioctl(PCITEST_SET_IRQTYPE) before performing any test that requires
IRQs, fix the regression by removing the allocation of IRQs in
pci_endpoint_test_probe(). The IRQ allocation will occur when
ioctl(PCITEST_SET_IRQTYPE) is called.
A positive side effect of this is that even if the endpoint controller has
issues with IRQs, the user can do still do all the tests/ioctls() that do
not require working IRQs, e.g. PCITEST_BAR and PCITEST_BARS.
This also means that we can remove the now unused irq_type from
driver_data. The irq_type will always be the one configured by the user
using ioctl(PCITEST_SET_IRQTYPE). (A user that does not know, or care
which irq_type that is used, can use PCITEST_IRQ_TYPE_AUTO. This has
superseded the need for a default irq_type in driver_data.)
[bhelgaas: add probe failure details]
Fixes: a402006d48a9c ("misc: pci_endpoint_test: Remove global 'irq_type' and 'no_msi'")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20250416142825.336554-2-cassel@kernel.org
Pull misc x86 fixes from Ingo Molnar:
- Fix 32-bit kernel boot crash if passed physical memory with more than
32 address bits
- Fix Xen PV crash
- Work around build bug in certain limited build environments
- Fix CTEST instruction decoding in insn_decoder_test
* tag 'x86-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/insn: Fix CTEST instruction decoding
x86/boot: Work around broken busybox 'truncate' tool
x86/mm: Fix _pgd_alloc() for Xen PV mode
x86/e820: Discard high memory that can't be addressed by 32-bit systems
Ondrej reports that certain SELinux tests are failing after commit
fc2a169c56de ("sunrpc: clean cache_detail immediately when flush is
written frequently"), merged during the v6.15 merge window.
Reported-by: Ondrej Mosnacek <omosnace@redhat.com>
Fixes: fc2a169c56de ("sunrpc: clean cache_detail immediately when flush is written frequently")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
I'm currently maintaining the PCI endpoint subsystem and reviewing the
native host bridge and endpoint drivers. However, this affects my endpoint
maintainership role since I cannot merge endpoint patches that depend on
the controller drivers (which is more common). Moreover, the controller
driver patches would also benefit from a helping hand in maintaining them.
So I'd like to step up to maintain the native host bridge and endpoint
drivers together with the endpoint subsystem.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250418094905.9983-1-manivannan.sadhasivam@linaro.org
Pull scheduler fix from Ingo Molnar:
"Fix sporadic crashes in dequeue_entities() due to ... bad math.
[ Arguably if pick_eevdf()/pick_next_entity() was less trusting of
complex math being correct it could have de-escalated a crash into
a warning, but that's for a different patch ]"
* tag 'sched-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/eevdf: Fix se->slice being set to U64_MAX and resulting crash
insn_decoder_test found a problem with decoding APX CTEST instructions:
Found an x86 instruction decoder bug, please report this.
ffffffff810021df 62 54 94 05 85 ff ctestneq
objdump says 6 bytes, but insn_get_length() says 5
It happens because x86-opcode-map.txt doesn't specify arguments for the
instruction and the decoder doesn't expect to see ModRM byte.
Fixes: 690ca3a3067f ("x86/insn: Add support for APX EVEX instructions to the opcode map")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org # v6.10+
Link: https://lore.kernel.org/r/20250423065815.2003231-1-kirill.shutemov@linux.intel.com
A deadlock warning occurred when invoking nfs4_put_stid following a failed
dl_recall queue operation:
T1 T2
nfs4_laundromat
nfs4_get_client_reaplist
nfs4_anylock_blockers
__break_lease
spin_lock // ctx->flc_lock
spin_lock // clp->cl_lock
nfs4_lockowner_has_blockers
locks_owner_has_blockers
spin_lock // flctx->flc_lock
nfsd_break_deleg_cb
nfsd_break_one_deleg
nfs4_put_stid
refcount_dec_and_lock
spin_lock // clp->cl_lock
When a file is opened, an nfs4_delegation is allocated with sc_count
initialized to 1, and the file_lease holds a reference to the delegation.
The file_lease is then associated with the file through kernel_setlease.
The disassociation is performed in nfsd4_delegreturn via the following
call chain:
nfsd4_delegreturn --> destroy_delegation --> destroy_unhashed_deleg -->
nfs4_unlock_deleg_lease --> kernel_setlease --> generic_delete_lease
The corresponding sc_count reference will be released after this
disassociation.
Since nfsd_break_one_deleg executes while holding the flc_lock, the
disassociation process becomes blocked when attempting to acquire flc_lock
in generic_delete_lease. This means:
1) sc_count in nfsd_break_one_deleg will not be decremented to 0;
2) The nfs4_put_stid called by nfsd_break_one_deleg will not attempt to
acquire cl_lock;
3) Consequently, no deadlock condition is created.
Given that sc_count in nfsd_break_one_deleg remains non-zero, we can
safely perform refcount_dec on sc_count directly. This approach
effectively avoids triggering deadlock warnings.
Fixes: 230ca758453c ("nfsd: put dl_stid if fail to queue dl_recall")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Commit df6f8c4d72ae ("selftests/pcie_bwctrl: Add 'set_pcie_speed.sh' to
TEST_PROGS") added set_pcie_speed.sh into TEST_PROGS but that script is a
helper that is only being called by set_pcie_cooling_state.sh, not a test
case itself. When set_pcie_speed.sh is in TEST_PROGS, selftest harness will
execute also it leading to bwctrl selftest errors:
# selftests: pcie_bwctrl: set_pcie_speed.sh
# cat: /cur_state: No such file or directory
not ok 2 selftests: pcie_bwctrl: set_pcie_speed.sh # exit=1
Place set_pcie_speed.sh into TEST_FILES instead to have it included into
installed test files but not execute it from the test harness.
Fixes: df6f8c4d72ae ("selftests/pcie_bwctrl: Add 'set_pcie_speed.sh' to TEST_PROGS")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250417124529.11391-1-ilpo.jarvinen@linux.intel.com
Pull misc perf events fixes from Ingo Molnar:
- Use POLLERR for events in error state, instead of the ambiguous
POLLHUP error value
- Fix non-sampling (counting) events on certain x86 platforms
* tag 'perf-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Fix non-sampling (counting) events on certain x86 platforms
perf/core: Change to POLLERR for pinned events with error
There is a code path in dequeue_entities() that can set the slice of a
sched_entity to U64_MAX, which sometimes results in a crash.
The offending case is when dequeue_entities() is called to dequeue a
delayed group entity, and then the entity's parent's dequeue is delayed.
In that case:
1. In the if (entity_is_task(se)) else block at the beginning of
dequeue_entities(), slice is set to
cfs_rq_min_slice(group_cfs_rq(se)). If the entity was delayed, then
it has no queued tasks, so cfs_rq_min_slice() returns U64_MAX.
2. The first for_each_sched_entity() loop dequeues the entity.
3. If the entity was its parent's only child, then the next iteration
tries to dequeue the parent.
4. If the parent's dequeue needs to be delayed, then it breaks from the
first for_each_sched_entity() loop _without updating slice_.
5. The second for_each_sched_entity() loop sets the parent's ->slice to
the saved slice, which is still U64_MAX.
This throws off subsequent calculations with potentially catastrophic
results. A manifestation we saw in production was:
6. In update_entity_lag(), se->slice is used to calculate limit, which
ends up as a huge negative number.
7. limit is used in se->vlag = clamp(vlag, -limit, limit). Because limit
is negative, vlag > limit, so se->vlag is set to the same huge
negative number.
8. In place_entity(), se->vlag is scaled, which overflows and results in
another huge (positive or negative) number.
9. The adjusted lag is subtracted from se->vruntime, which increases or
decreases se->vruntime by a huge number.
10. pick_eevdf() calls entity_eligible()/vruntime_eligible(), which
incorrectly returns false because the vruntime is so far from the
other vruntimes on the queue, causing the
(vruntime - cfs_rq->min_vruntime) * load calulation to overflow.
11. Nothing appears to be eligible, so pick_eevdf() returns NULL.
12. pick_next_entity() tries to dereference the return value of
pick_eevdf() and crashes.
Dumping the cfs_rq states from the core dumps with drgn showed tell-tale
huge vruntime ranges and bogus vlag values, and I also traced se->slice
being set to U64_MAX on live systems (which was usually "benign" since
the rest of the runqueue needed to be in a particular state to crash).
Fix it in dequeue_entities() by always setting slice from the first
non-empty cfs_rq.
Fixes: aef6987d8954 ("sched/eevdf: Propagate min_slice up the cgroup hierarchy")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/f0c2d1072be229e1bdddc73c0703919a8b00c652.1745570998.git.osandov@fb.com
The GNU coreutils version of truncate, which is the original, accepts a
% prefix for the -s size argument which means the file in question
should be padded to a multiple of the given size. This is currently used
to pad the setup block of bzImage to a multiple of 4k before appending
the decompressor.
busybox reimplements truncate but does not support this idiom, and
therefore fails the build since commit
9c54baab4401 ("x86/boot: Drop CRC-32 checksum and the build tool that generates it")
Since very little build code within the kernel depends on the 'truncate'
utility, work around this incompatibility by avoiding truncate altogether,
and relying on dd to perform the padding.
Fixes: 9c54baab4401 ("x86/boot: Drop CRC-32 checksum and the build tool that generates it")
Reported-by: <phasta@kernel.org>
Tested-by: Philipp Stanner <phasta@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250424101917.1552527-2-ardb+git@google.com
nfs.ko, nfsd.ko, and lockd.ko all use crc32_le(), which is available
only when CONFIG_CRC32 is enabled. But the only NFS kconfig option that
selected CONFIG_CRC32 was CONFIG_NFS_DEBUG, which is client-specific and
did not actually guard the use of crc32_le() even on the client.
The code worked around this bug by only actually calling crc32_le() when
CONFIG_CRC32 is built-in, instead hard-coding '0' in other cases. This
avoided randconfig build errors, and in real kernels the fallback code
was unlikely to be reached since CONFIG_CRC32 is 'default y'. But, this
really needs to just be done properly, especially now that I'm planning
to update CONFIG_CRC32 to not be 'default y'.
Therefore, make CONFIG_NFS_FS, CONFIG_NFSD, and CONFIG_LOCKD select
CONFIG_CRC32. Then remove the fallback code that becomes unnecessary,
as well as the selection of CONFIG_CRC32 from CONFIG_NFS_DEBUG.
Fixes: 1264a2f053a3 ("NFS: refactor code for calculating the crc32 hash of a filehandle")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
PCI resource fitting code in __assign_resources_sorted() runs in multiple
steps. A resource that was successfully assigned may have to be released
before the next step attempts assignment again. The assign+release cycle is
destructive to a start-aligned struct resource (bridge window or IOV
resource) because the start field is overwritten with the real address when
the resource got assigned.
One symptom:
pci 0002:00:00.0: bridge window [mem size 0x00100000]: can't assign; bogus alignment
Properly restore the resource after releasing it. The start, end, and flags
fields must be stored into the related struct pci_dev_resource in order to
be able to restore the resource to its original state.
Fixes: 96336ec70264 ("PCI: Perform reset_resource() and build fail list in sync")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/r/01eb7d40-f5b5-4ec5-b390-a5c042c30aff@roeck-us.net/
Reported-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Closes: https://lore.kernel.org/r/3578030.5fSG56mABF@workhorse
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Ondrej Jirman <megi@xff.cz>
Link: https://patch.msgid.link/20250403093137.1481-1-ilpo.jarvinen@linux.intel.com
Pull irq fix from Ingo Molnar:
"Fix crashes in the gic-v2m irqchip driver, caused by an incorrect
__init annotation"
* tag 'irq-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v2m: Prevent use after free of gicv2m_get_fwnode()