Overall cleanup done allows to now have the JPEG handling
done in the same way as other formats in continuous mode,
allowing to achieve a faster framerate in all resolutions.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Whenever receiving an OVERRUN event or an end of frame, the driver stops
currently ongoing DMA transfer since the DCMI stops sending data to dma.
Not doing this would lead to having DMA & DCMI no more synchronized in term
of expected data to be copied.
Since this is done in irq handler context, it is not possible to make any
call that would lead to scheduling hence dmaengine_terminate_sync are not
possible.
Since the dcmi driver is NOT using dma callbacks, it is possible thus to
call instead dmaengine_terminate_async (aka without synchronize) and call
again right after a new dmaengine_submit to setup again a new transfer.
And since this is now a dmaengine_submit_async, there is no need to release
the spinlock around calls to the dmaengine_submit_async.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Move all the type of frame handling within the dcmi_irq_thread
handler and do not rely on dma_callback as previously.
This simplifies the code by having only a single path for both
compressed and uncompressed data while also making the system
more reactive since irq_handler have more chances to be called
faster than the dma completion callback. Indeed, in case of the
dma completion callback, this run as a tasklet created by the
dma framework upon getting an interrupt from the dma and run
at a lower priority level than other irq handlers.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Rework of the spin_lock calls in preparation of the rework
of the data handling of the driver. Keep it straight forward
with basically spin_lock protection around everything except
dmaengine calls that might sleep (ex: synchronize / terminate)
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Ensure to stop the dma transfer whenever receiving a overrun
to avoid having a buffer partially filled with a frame and
partially with the next frame.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Perform the dmaengine prep_slave_sg call within buf_prepare and
mark the descriptor as reusable in order to avoid having to redo
this at every start of the dma.
This also allow to remove the mutex used by the driver to protect
dma descriptors related piece of codes.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Perform the dma channel configuration at probe time right after
the channel allocation since this is fixed for the whole lifetime
of the driver.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Letting the compiler remove these functions when the kernel is built
without CONFIG_PM_SLEEP support is simpler and less heavier for builds
than the use of __maybe_unused attributes.
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Slightly different version of MT9M114 camera module is used in a several
devices like ASUS Nexus 7 (2012) or ASUS Transformer Prime TF201 and is
called Aptina MI1040. The only difference found so far is lacking ability
to poll STATE register during power on sequence, which causes driver to
fail with time out error. Add state_standby_polling flag to diverge models
and address quirk found in MI1040.
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The Aptina MI1040 is a slightly different version of the MT9M114 camera
module. It is used in several devices, such as the ASUS Nexus 7 (2012) and
the ASUS Transformer Prime TF201. The compatible "onnn,mt9m114" is placed
first in the enum, as it is considered the default compatible value.
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
DS90UB954-Q1 is an FPDLink-III deserializer that is mostly register
compatible with DS90UB960-Q1. The main difference is that it supports half
of the RX and TX ports, i.e. 2x FPDLink RX ports and 1x CSI TX port.
A couple of differences are between the status registers and the
strobe setting registers. Hence accommodate these differences in
the UB960 driver so that we can reuse a large part of the existing code.
Link: https://www.ti.com/lit/gpn/ds90ub954-q1
Reviewed-by: Jai Luthra <jai.luthra@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The current bindings duplicate the port definitions for each FPD-Link RX
and CSI-2 TX ports. This results in a large amount of repeated schema
blocks and makes it harder to extend the bindings for new devices.
Refactor the bindings by introducing shared deftinitions for FPD-Link
input ports and CSI-2 output ports. No functional change intended.
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Yemike Abhilash Chandra <y-abhilashchandra@ti.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The Arducam IMX577 module requires a longer reset time than the 1000µs
configured in the current driver. Increase the wait time after power-on
to ensure proper initialization.
Signed-off-by: Wenmeng Liu <wenmeng.liu@oss.qualcomm.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Linux 7.0-rc2
* tag 'v7.0-rc2': (372 commits)
Linux 7.0-rc2
firewire: ohci: initialize page array to use alloc_pages_bulk() correctly
KVM: always define KVM_CAP_SYNC_MMU
KVM: remove CONFIG_KVM_GENERIC_MMU_NOTIFIER
selftests/bpf: Avoid simplification of crafted bounds test
selftests/bpf: Test refinement of single-value tnum
bpf: Improve bounds when tnum has a single possible value
bpf: Introduce tnum_step to step through tnum's members
bpf: Fix race in devmap on PREEMPT_RT
bpf: Fix race in cpumap on PREEMPT_RT
selftests/bpf: Add tests for special fields races
bpf: Retire rcu_trace_implies_rcu_gp() from local storage
bpf: Delay freeing fields in local storage
bpf: Lose const-ness of map in map_check_btf()
bpf: Register dtor for freeing special fields
PCI: Correct PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value
smb: client: Use snprintf in cifs_set_cifscreds
mm/slab: initialize slab->stride early to avoid memory ordering issues
smb: client: Don't log plaintext credentials in cifs_set_cifscreds
smb: client: fix broken multichannel with krb5+signing
...
Pull kvm fixes from Paolo Bonzini:
"Arm:
- Make sure we don't leak any S1POE state from guest to guest when
the feature is supported on the HW, but not enabled on the host
- Propagate the ID registers from the host into non-protected VMs
managed by pKVM, ensuring that the guest sees the intended feature
set
- Drop double kern_hyp_va() from unpin_host_sve_state(), which could
bite us if we were to change kern_hyp_va() to not being idempotent
- Don't leak stage-2 mappings in protected mode
- Correctly align the faulting address when dealing with single page
stage-2 mappings for PAGE_SIZE > 4kB
- Fix detection of virtualisation-capable GICv5 IRS, due to the
maintainer being obviously fat fingered... [his words, not mine]
- Remove duplication of code retrieving the ASID for the purpose of
S1 PT handling
- Fix slightly abusive const-ification in vgic_set_kvm_info()
Generic:
- Remove internal Kconfigs that are now set on all architectures
- Remove per-architecture code to enable KVM_CAP_SYNC_MMU, all
architectures finally enable it in Linux 7.0"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: always define KVM_CAP_SYNC_MMU
KVM: remove CONFIG_KVM_GENERIC_MMU_NOTIFIER
KVM: arm64: Deduplicate ASID retrieval code
irqchip/gic-v5: Fix inversion of IRS_IDR0.virt flag
KVM: arm64: Revert accidental drop of kvm_uninit_stage2_mmu() for non-NV VMs
KVM: arm64: Fix protected mode handling of pages larger than 4kB
KVM: arm64: vgic: Handle const qualifier from gic_kvm_info allocation type
KVM: arm64: Remove redundant kern_hyp_va() in unpin_host_sve_state()
KVM: arm64: Fix ID register initialization for non-protected pKVM guests
KVM: arm64: Optimise away S1POE handling when not supported by host
KVM: arm64: Hide S1POE from guests when not supported by the host
Pull debugobjects fix from Thomas Gleixner:
"A single fix for debugobjects.
The deferred page initialization prevents debug objects from
allocating slab pages until the initialization is complete. That
causes depletion of the pool and disabling of debugobjects.
The reason is that debugobjects uses __GFP_HIGH for allocations as it
might be invoked from arbitrary contexts. When PREEMPT_COUNT is
disabled there is no way to know whether the context is safe to set
__GFP_KSWAPD_RECLAIM.
This worked until v6.18. Since then allocations w/o a reclaim flag
cause new_slab() to end up in alloc_frozen_pages_nolock_noprof(),
which returns early when deferred page initialization has not yet
completed.
Work around that when PREEMPT_COUNT is enabled as the preempt counter
allows debugobjects to add __GFP_KSWAPD_RECLAIM to the GFP flags when
the context is preemtible. When PREEMPT_COUNT is disabled the context
is unknown and the reclaim bit can't be set because the caller might
hold locks which might deadlock in the allocator.
That makes debugobjects depend on PREEMPT_COUNT ||
!DEFERRED_STRUCT_PAGE_INIT, which limits the coverage slightly, but
keeps it functional for most cases"
* tag 'core-debugobjects-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debugobject: Make it work with deferred page initialization - again
Pull x86 fixes from Ingo Molnar:
- Fix speculative safety in fred_extint()
- Fix __WARN_printf() trap in early_fixup_exception()
- Fix clang-build boot bug for unusual alignments, triggered by
CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B=y
- Replace the final few __ASSEMBLY__ stragglers that snuck in lately
into non-UAPI x86 headers and use __ASSEMBLER__ consistently (again)
* tag 'x86-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/headers: Replace __ASSEMBLY__ stragglers with __ASSEMBLER__
x86/cfi: Fix CFI rewrite for odd alignments
x86/bug: Handle __WARN_printf() trap in early_fixup_exception()
x86/fred: Correct speculative safety in fred_extint()
Pull timer fix from Ingo Molnar:
"Improve the inlining of jiffies_to_msecs() and jiffies_to_usecs(), for
the common HZ=100, 250 or 1000 cases. Only use a function call for odd
HZ values like HZ=300 that generate more code.
The function call overhead showed up in performance tests of the TCP
code"
* tag 'timers-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time/jiffies: Inline jiffies_to_msecs() and jiffies_to_usecs()
Pull scheduler fixes from Ingo Molnar:
- Fix zero_vruntime tracking when there's a single task running
- Fix slice protection logic
- Fix the ->vprot logic for reniced tasks
- Fix lag clamping in mixed slice workloads
- Fix objtool uaccess warning (and bug) in the
!CONFIG_RSEQ_SLICE_EXTENSION case caused by unexpected un-inlining,
which triggers with older compilers
- Fix a comment in the rseq registration rseq_size bound check code
- Fix a legacy RSEQ ABI quirk that handled 32-byte area sizes
differently, which special size we now reached naturally and want to
avoid. The visible ugliness of the new reserved field will be avoided
the next time the RSEQ area is extended.
* tag 'sched-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq: slice ext: Ensure rseq feature size differs from original rseq size
rseq: Clarify rseq registration rseq_size bound check comment
sched/core: Fix wakeup_preempt's next_class tracking
rseq: Mark rseq_arm_slice_extension_timer() __always_inline
sched/fair: Fix lag clamp
sched/eevdf: Update se->vprot in reweight_entity()
sched/fair: Only set slice protection at pick time
sched/fair: Fix zero_vruntime tracking
Pull perf events fixes from Ingo Molnar:
- Fix lock ordering bug found by lockdep in perf_event_wakeup()
- Fix uncore counter enumeration on Granite Rapids and Sierra Forest
- Fix perf_mmap() refcount bug found by Syzkaller
- Fix __perf_event_overflow() vs perf_remove_from_context() race
* tag 'perf-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix __perf_event_overflow() vs perf_remove_from_context() race
perf/core: Fix refcount bug and potential UAF in perf_mmap
perf/x86/intel/uncore: Add per-scheduler IMC CAS count events
perf/core: Fix invalid wait context in ctx_sched_in()
Pull locking fix from Ingo Molnar:
"Now that LLVM 22 has been released officially, require a release
version to use the new CONFIG_WARN_CONTEXT_ANALYSIS feature.
In particular this avoids the widely used Android clang 22.0.1
pre-release build which is known to be broken for this usecase"
* tag 'locking-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
lib/Kconfig.debug: Require a release version of LLVM 22 for context analysis
Pull irqchip driver fixes from Ingo Molnar:
- Fix frozen interrupt bug in the sifive-plic driver
- Limit per-device MSI interrupts on uncommon gic-v3-its hardware
variants
- Address Sparse warning by constifying a variable in the MMP driver
- Revert broken commit and also fix an error check in the ls-extirq
driver
* tag 'irq-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/ls-extirq: Fix devm_of_iomap() error check
Revert "irqchip/ls-extirq: Use for_each_of_imap_item iterator"
irqchip/mmp: Make icu_irq_chip variable static const
irqchip/gic-v3-its: Limit number of per-device MSIs to the range the ITS supports
irqchip/sifive-plic: Fix frozen interrupt due to affinity setting
Pull SCSI fixes from James Bottomley:
"All changes in drivers (well technically SES is enclosure services,
but its change is minor). The biggest is the write combining change in
lpfc followed by the additional NULL checks in mpi3mr"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: ufs: core: Fix shift out of bounds when MAXQ=32
scsi: ufs: core: Move link recovery for hibern8 exit failure to wl_resume
scsi: ufs: core: Fix possible NULL pointer dereference in ufshcd_add_command_trace()
scsi: snic: MAINTAINERS: Update snic maintainers
scsi: snic: Remove unused linkstatus
scsi: pm8001: Fix use-after-free in pm8001_queue_command()
scsi: mpi3mr: Add NULL checks when resetting request and reply queues
scsi: ufs: core: Reset urgent_bkops_lvl to allow runtime PM power mode
scsi: ses: Fix devices attaching to different hosts
scsi: ufs: core: Fix RPMB region size detection for UFS 2.2
scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT
scsi: lpfc: Properly set WC for DPP mapping
Pull bpf fixes from Alexei Starovoitov:
- Fix alignment of arm64 JIT buffer to prevent atomic tearing (Fuad
Tabba)
- Fix invariant violation for single value tnums in the verifier
(Harishankar Vishwanathan, Paul Chaignon)
- Fix a bunch of issues found by ASAN in selftests/bpf (Ihor Solodrai)
- Fix race in devmpa and cpumap on PREEMPT_RT (Jiayuan Chen)
- Fix show_fdinfo of kprobe_multi when cookies are not present (Jiri
Olsa)
- Fix race in freeing special fields in BPF maps to prevent memory
leaks (Kumar Kartikeya Dwivedi)
- Fix OOB read in dmabuf_collector (T.J. Mercier)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (36 commits)
selftests/bpf: Avoid simplification of crafted bounds test
selftests/bpf: Test refinement of single-value tnum
bpf: Improve bounds when tnum has a single possible value
bpf: Introduce tnum_step to step through tnum's members
bpf: Fix race in devmap on PREEMPT_RT
bpf: Fix race in cpumap on PREEMPT_RT
selftests/bpf: Add tests for special fields races
bpf: Retire rcu_trace_implies_rcu_gp() from local storage
bpf: Delay freeing fields in local storage
bpf: Lose const-ness of map in map_check_btf()
bpf: Register dtor for freeing special fields
selftests/bpf: Fix OOB read in dmabuf_collector
selftests/bpf: Fix a memory leak in xdp_flowtable test
bpf: Fix stack-out-of-bounds write in devmap
bpf: Fix kprobe_multi cookies access in show_fdinfo callback
bpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing
selftests/bpf: Don't override SIGSEGV handler with ASAN
selftests/bpf: Check BPFTOOL env var in detect_bpftool_path()
selftests/bpf: Fix out-of-bounds array access bugs reported by ASAN
selftests/bpf: Fix array bounds warning in jit_disasm_helpers
...
Pull driver core fixes from Danilo Krummrich:
- Do not register imx_clk_scu_driver in imx8qxp_clk_probe(); besides
fixing two other issues, this avoids a deadlock in combination with
commit dc23806a7c ("driver core: enforce device_lock for
driver_match_device()")
- Move secondary node lookup from device_get_next_child_node() to
fwnode_get_next_child_node(); this avoids issues when users switch
from the device API to the fwnode API
- Export io_define_{read,write}!() to avoid unused import warnings when
CONFIG_PCI=n
* tag 'driver-core-7.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
clk: scu/imx8qxp: do not register driver in probe()
rust: io: macro_export io_define_read!() and io_define_write!()
device property: Allow secondary lookup in fwnode_get_next_child_node()
Pull smb client fixes from Steve French:
- Two multichannel fixes
- Locking fix for superblock flags
- Fix to remove debug message that could log password
- Cleanup fix for setting credentials
* tag 'v7.0rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb: client: Use snprintf in cifs_set_cifscreds
smb: client: Don't log plaintext credentials in cifs_set_cifscreds
smb: client: fix broken multichannel with krb5+signing
smb: client: use atomic_t for mnt_cifs_flags
smb: client: fix cifs_pick_channel when channels are equally loaded
Pull spi fixes from Mark Brown:
"One fix for the stm32 driver which got broken for DMA chaining cases,
plus a removal of some straggling bindings for the Bikal SoC which has
been pulled out of the kernel"
* tag 'spi-fix-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: stm32: fix missing pointer assignment in case of dma chaining
spi: dt-bindings: snps,dw-abp-ssi: Remove unused bindings
Pull regulator fixes from Mark Brown:
"A small pile of fixes, none of which are super major - the code fixes
are improved error handling and fixing a leak of a device node.
We also have a typo fix and an improvement to make the binding example
for mt6359 more directly usable"
* tag 'regulator-fix-v7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: Kconfig: fix a typo
regulator: bq257xx: Fix device node reference leak in bq257xx_reg_dt_parse_gpio()
regulator: fp9931: Fix PM runtime reference leak in fp9931_hwmon_read()
regulator: tps65185: check devm_kzalloc() result in probe
regulator: dt-bindings: mt6359: make regulator names unique
Pull s390 fixes from Vasily Gorbik:
- Fix guest pfault init to pass a physical address to DIAG 0x258,
restoring pfault interrupts and avoiding vCPU stalls during host
page-in
- Fix kexec/kdump hangs with stack protector by marking
s390_reset_system() __no_stack_protector; set_prefix(0) switches
lowcore and the canary no longer matches
- Fix idle/vtime cputime accounting (idle-exit ordering, vtimer
double-forwarding) and small cleanups
* tag 's390-7.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/pfault: Fix virtual vs physical address confusion
s390/kexec: Disable stack protector in s390_reset_system()
s390/idle: Remove psw_idle() prototype
s390/vtime: Use lockdep_assert_irqs_disabled() instead of BUG_ON()
s390/vtime: Use __this_cpu_read() / get rid of READ_ONCE()
s390/irq/idle: Remove psw bits early
s390/idle: Inline update_timer_idle()
s390/idle: Slightly optimize idle time accounting
s390/idle: Add comment for non obvious code
s390/vtime: Fix virtual timer forwarding
s390/idle: Fix cpu idle exit cpu time accounting
KVM/arm64 fixes for 7.0, take #1
- Make sure we don't leak any S1POE state from guest to guest when
the feature is supported on the HW, but not enabled on the host
- Propagate the ID registers from the host into non-protected VMs
managed by pKVM, ensuring that the guest sees the intended feature set
- Drop double kern_hyp_va() from unpin_host_sve_state(), which could
bite us if we were to change kern_hyp_va() to not being idempotent
- Don't leak stage-2 mappings in protected mode
- Correctly align the faulting address when dealing with single page
stage-2 mappings for PAGE_SIZE > 4kB
- Fix detection of virtualisation-capable GICv5 IRS, due to the
maintainer being obviously fat fingered...
- Remove duplication of code retrieving the ASID for the purpose of
S1 PT handling
- Fix slightly abusive const-ification in vgic_set_kvm_info()
KVM_CAP_SYNC_MMU is provided by KVM's MMU notifiers, which are now always
available. Move the definition from individual architectures to common
code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All architectures now use MMU notifier for KVM page table management.
Remove the Kconfig symbol and the code that is used when it is
disabled.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paul Chaignon says:
====================
Fix invariant violation for single-value tnums
We're hitting an invariant violation in Cilium that sometimes leads to
BPF programs being rejected and Cilium failing to start [1]. As far as
I know this is the first case of invariant violation found in a real
program (i.e., not by a fuzzer). The following extract from verifier
logs shows what's happening:
from 201 to 236: R1=0 R6=ctx() R7=1 R9=scalar(smin=umin=smin32=umin32=3584,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100)) R10=fp0
236: R1=0 R6=ctx() R7=1 R9=scalar(smin=umin=smin32=umin32=3584,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100)) R10=fp0
; if (magic == MARK_MAGIC_HOST || magic == MARK_MAGIC_OVERLAY || magic == MARK_MAGIC_ENCRYPT) @ bpf_host.c:1337
236: (16) if w9 == 0xe00 goto pc+45 ; R9=scalar(smin=umin=smin32=umin32=3585,smax=umax=smax32=umax32=3840,var_off=(0xe00; 0x100))
237: (16) if w9 == 0xf00 goto pc+1
verifier bug: REG INVARIANTS VIOLATION (false_reg1): range bounds violation u64=[0xe01, 0xe00] s64=[0xe01, 0xe00] u32=[0xe01, 0xe00] s32=[0xe01, 0xe00] var_off=(0xe00, 0x0)
More details are given in the second patch, but in short, the verifier
should be able to detect that the false branch of instruction 237 is
never true. After instruction 236, the u64 range and the tnum overlap
in a single value, 0xf00.
The long-term solution to invariant violation is likely to rely on the
refinement + invariant violation check to detect dead branches, as
started by Eduard. To fix the current issue, we need something with
less refactoring that we can backport to affected kernels.
The solution implemented in the second patch is to improve the bounds
refinement to avoid this case. It relies on a new tnum helper,
tnum_step, first sent as an RFC in [2]. The last two patches extend and
update the selftests.
Link: https://github.com/cilium/cilium/issues/44216 [1]
Link: https://lore.kernel.org/bpf/20251107192328.2190680-2-harishankar.vishwanathan@gmail.com/ [2]
Changes in v3:
- Fix commit description error spotted by AI bot.
- Simplify constants in first two tests (Eduard).
- Rework comment on third test (Eduard).
- Add two new negative test cases (Eduard).
- Rebased.
Changes in v2:
- Add guard suggested by Hari in tnum_step, to avoid undefined
behavior spotted by AI code review.
- Add explanation diagrams in code as suggested by Eduard.
- Rework conditions for readability as suggested by Eduard.
- Updated reference to SMT formula.
- Rebased.
====================
Link: https://patch.msgid.link/cover.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The reg_bounds_crafted tests validate the verifier's range analysis
logic. They focus on the actual ranges and thus ignore the tnum. As a
consequence, they carry the assumption that the tested cases can be
reproduced in userspace without using the tnum information.
Unfortunately, the previous change the refinement logic breaks that
assumption for one test case:
(u64)2147483648 (u32)<op> [4294967294; 0x100000000]
The tested bytecode is shown below. Without our previous improvement, on
the false branch of the condition, R7 is only known to have u64 range
[0xfffffffe; 0x100000000]. With our improvement, and using the tnum
information, we can deduce that R7 equals 0x100000000.
19: (bc) w0 = w6 ; R6=0x80000000
20: (bc) w0 = w7 ; R7=scalar(smin=umin=0xfffffffe,smax=umax=0x100000000,smin32=-2,smax32=0,var_off=(0x0; 0x1ffffffff))
21: (be) if w6 <= w7 goto pc+3 ; R6=0x80000000 R7=0x100000000
R7's tnum is (0; 0x1ffffffff). On the false branch, regs_refine_cond_op
refines R7's u32 range to [0; 0x7fffffff]. Then, __reg32_deduce_bounds
refines the s32 range to 0 using u32 and finally also sets u32=0.
From this, __reg_bound_offset improves the tnum to (0; 0x100000000).
Finally, our previous patch uses this new tnum to deduce that it only
intersect with u64=[0xfffffffe; 0x100000000] in a single value:
0x100000000.
Because the verifier uses the tnum to reach this constant value, the
selftest is unable to reproduce it by only simulating ranges. The
solution implemented in this patch is to change the test case such that
there is more than one overlap value between u64 and the tnum. The max.
u64 value is thus changed from 0x100000000 to 0x300000000.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/50641c6a7ef39520595dcafa605692427c1006ec.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Alain Volmat
Svyatoslav Ryhel
Krzysztof Kozlowski
Tomi Valkeinen
Yemike Abhilash Chandra
Jai Luthra
Wenmeng Liu
Mauro Carvalho Chehab
Linus Torvalds
Takashi Sakamoto
Paolo Bonzini
Alexei Starovoitov
Paul Chaignon