Use devm_clk_get_optional() instead of hand writing it.
This saves some loC and improves the semantic.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
When an async notifier is unregistered, the async sub-devices in the
notifier's done list will disappear with the notifier. However this is
currently also done to the sub-notifiers that remain registered. Their
sub-devices only need to be unbound while the async sub-devices themselves
need to be returned to the sub-notifier's waiting list. Do this now.
Fixes: 2cab00bb07 ("media: v4l: async: Allow binding notifiers to sub-devices")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
* Update my email address in the MAINTAINERS file.
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Merge tag 'ata-6.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata
Pull ata fix from Damien Le Moal:
- Update my email address in the MAINTAINERS file
* tag 'ata-6.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
MAINTAINERS: Change ata maintainer email addresses
There is no need to declare an extra tables to just create directory,
this can be easily be done with a prefix path with register_sysctl().
Simplify this registration.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
No need to do a forward declaration for sunrpc_table, just move
the sysctls up as everyone else does it. This will make the next
change easier to read. This change produces no functional changes.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
There is no need to declare an extra tables to just create directory,
this can be easily be done with a prefix path with register_sysctl().
Simplify this registration.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
There is no need to declare an extra tables to just create directory,
this can be easily be done with a prefix path with register_sysctl().
Simplify this registration.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
In prepration for adding the IOMMUs and LARBs of this SoC, add the
VDECSYS and VENCSYS clock controller nodes, providing clocks for the
vcodec stateful decoder and stateful decoder hardware.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230327083647.22017-11-angelogioacchino.delregno@collabora.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
* Ensure the guest PMU context is restored before the first KVM_RUN,
fixing an issue where EL0 event counting is broken after vCPU
save/restore
* Actually initialize ID_AA64PFR0_EL1.{CSV2,CSV3} based on the
sanitized, system-wide values for protected VMs
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Two ARM fixes:
- Ensure the guest PMU context is restored before the first KVM_RUN,
fixing an issue where EL0 event counting is broken after vCPU
save/restore
- Actually initialize ID_AA64PFR0_EL1.{CSV2,CSV3} based on the
sanitized, system-wide values for protected VMs"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: arm64: Advertise ID_AA64PFR0_EL1.CSV2/3 to protected VMs
KVM: arm64: PMU: Restore the guest's EL0 event counting after migration
Extend VMX's nested intercept logic for emulated instructions to handle
"pause" interception, in quotes because KVM's emulator doesn't filter out
NOPs when checking for nested intercepts. Failure to allow emulation of
NOPs results in KVM injecting a #UD into L2 on any NOP that collides with
the emulator's definition of PAUSE, i.e. on all single-byte NOPs.
For PAUSE itself, honor L1's PAUSE-exiting control, but ignore PLE to
avoid unnecessarily injecting a #UD into L2. Per the SDM, the first
execution of PAUSE after VM-Entry is treated as the beginning of a new
loop, i.e. will never trigger a PLE VM-Exit, and so L1 can't expect any
given execution of PAUSE to deterministically exit.
... the processor considers this execution to be the first execution of
PAUSE in a loop. (It also does so for the first execution of PAUSE at
CPL 0 after VM entry.)
All that said, the PLE side of things is currently a moot point, as KVM
doesn't expose PLE to L1.
Note, vmx_check_intercept() is still wildly broken when L1 wants to
intercept an instruction, as KVM injects a #UD instead of synthesizing a
nested VM-Exit. That issue extends far beyond NOP/PAUSE and needs far
more effort to fix, i.e. is a problem for the future.
Fixes: 07721feee4 ("KVM: nVMX: Don't emulate instructions in guest mode")
Cc: Mathias Krause <minipli@grsecurity.net>
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20230405002359.418138-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Legacy Display Unit (LDU) fb dirty support used a custom fb dirty callback. Latter
handled only the DIRTYFB IOCTL presentation path but not the ADDFB2/PAGE_FLIP/RMFB
IOCTL path, common for Wayland compositors.
Get rid of the custom callback in favor of drm_atomic_helper_dirtyfb and unify the
handling of the presentation paths inside of vmw_ldu_primary_plane_atomic_update.
This also homogenizes the fb dirty callbacks across all DUs: LDU, SOU and STDU.
Signed-off-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Fixes: 2f5544ff03 ("drm/vmwgfx: Use atomic helper function for dirty fb IOCTL")
Cc: <stable@vger.kernel.org> # v5.0+
Signed-off-by: Zack Rusin <zackr@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230321020949.335012-3-zack@kde.org
virtualbox implemented an incomplete version of the svga device which
they decided to drop soon after the initial release. The device was
always broken in various ways and never supported by vmwgfx.
vmwgfx should refuse to load on those configurations but currently
drm has no way of reloading fbdev when the specific pci driver refuses
to load, which would leave users without a usable fb. Instead of
refusing to load print an error and disable a bunch of functionality
that virtualbox never implemented to at least get fb to work on their
setup.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230321020949.335012-2-zack@kde.org
This internal helper handles a type of mksstat event counter
which is currently unused. Remove the routine to avoid compile
warnings.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230321020949.335012-1-zack@kde.org
Some older processors don't allow BIT(13) and BIT(15) in the current
mask set by "THERM_STATUS_CLEAR_CORE_MASK". This results in:
unchecked MSR access error: WRMSR to 0x19c (tried to
write 0x000000000000aaa8) at rIP: 0xffffffff816f66a6
(throttle_active_work+0xa6/0x1d0)
To avoid unchecked MSR issues, check CPUID for each relevant feature and
use that information to set the supported feature bits only in the
"clear" mask for cores. Do the same for the analogous package mask set
by "THERM_STATUS_CLEAR_PKG_MASK".
Introduce functions thermal_intr_init_core_clear_mask() and
thermal_intr_init_pkg_clear_mask() to set core and package mask bits,
respectively. These functions are called during initialization.
Fixes: 6fe1e64b60 ("thermal: intel: Prevent accidental clearing of HFI status")
Reported-by: Rui Salvaterra <rsalvaterra@gmail.com>
Link: https://lore.kernel.org/lkml/cdf43fb423368ee3994124a9e8c9b4f8d00712c6.camel@linux.intel.com/T/
Tested-by: Rui Salvaterra <rsalvaterra@gmail.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 6.2+ <stable@kernel.org> # 6.2+
[ rjw: Renamed 2 funtions and 2 static variables, edited subject and
changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The imx_media_of_add_csi() function is only called in its compilation
unit. Make it static and don't export it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
The imx_media_find_subdev_by_fwnode(),
imx_media_find_subdev_by_devname(), imx_media_pipeline_csi2_channel()
and imx_media_pipeline_video_device() helper functions are not used.
Drop them.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
The IMX_MEDIA_GRP_ID_CSI group ID isn't used anymore. Drop it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
The imx_media_subdev_bound() function is a no-op, and the async notifier
.bound() operation is optional. Drop it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Clean up the driver a bit by inlining the imx8mq_mipi_csi_system_enable()
function to the callsites and removing the hs_settle variable from the
driver state.
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Simplify the driver by using the V4L2 subdev active state API to store
the active format.
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
This device only supports video capture, so bail out if invalid
selection type is passed.
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
'field' is zero-initialized to V4L2_FIELD_ANY, which is an invalid value
to return to userspace. Instead default to non-interleaving.
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
The CSI requires a connected source subdev to operate. If
fwnode_graph_get_endpoint_by_id() fails and returns NULL, there is no
point in going on. Print an error message and abort instead.
Also we don't need to check for an existing asd. Any failure of
v4l2_async_nf_add_fwnode_remote() should abort the probe.
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Eliminate duplicate boilerplate code for simple modules that contain
a single DM target driver without any additional setup code.
Add a new module_dm() macro, which replaces the module_init() and
module_exit() with template functions that call dm_register_target()
and dm_unregister_target() respectively.
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Andrii Nakryiko says:
====================
This patch set changes BPF verifier log behavior to behave as a rotating log,
by default. If user-supplied log buffer is big enough to contain entire
verifier log output, there is no effective difference. But where previously
user supplied too small log buffer and would get -ENOSPC error result and the
beginning part of the verifier log, now there will be no error and user will
get ending part of verifier log filling up user-supplied log buffer. Which
is, in absolute majority of cases, is exactly what's useful, relevant, and
what users want and need, as the ending of the verifier log is containing
details of verifier failure and relevant state that got us to that failure.
So this rotating mode is made default, but for some niche advanced debugging
scenarios it's possible to request old behavior by specifying additional
BPF_LOG_FIXED (8) flag.
This patch set adjusts libbpf to allow specifying flags beyond 1 | 2 | 4. We
also add --log-size and --log-fixed options to veristat to be able to both
test this functionality manually, but also to be used in various debugging
scenarios. We also add selftests that tries many variants of log buffer size
to stress-test correctness of internal verifier log bookkeeping code.
Further, this patch set is merged with log_size_actual v1 patchset ([0]),
which adds ability to get required log buffer size to fit entire verifier
log output.
This addresses a long-standing limitation, which causes users and BPF loader
library writers to guess and pre-size log buffer, often allocating unnecessary
extra memory for this or doing extra program verifications just to size logs
better, ultimately wasting resources. This was requested most recently by Go
BPF library maintainers ([1]).
See respective patches for details. A bunch of them some drive-by fixes
detecting during working with the code. Some other further refactor and
compratmentalize verifier log handling code into kernel/bpf/log.c, which
should also make it simpler to integrate such verbose log for other
complicated bpf() syscall commands, if necessary. The rest are actual logic
to calculate maximum log buffer size needed and return it to user-space.
Few patches wire this on libbpf side, and the rest add selftests to test
proper log truncation and log_buf==NULL handling.
This turned into a pretty sizable patch set with lots of arithmetics, but
hopefully the set of features added to verifier log in this patch set are
both useful for BPF users and are self-contained and isolated enough to not
cause troubles going forward.
v3->v4:
- s/log_size_actual/log_true_size/ (Alexei);
- log_buf==NULL && log_size==0 don't trigger -ENOSPC (Lorenz);
- added WARN_ON_ONCE if we try bpf_vlog_reset() forward (Lorenz);
- added selftests for truncation in BPF_LOG_FIXED mode;
- fixed edge case in BPF_LOG_FIXED when log_size==1, leaving buf not zero
terminated;
v2->v3:
- typos and comment improvement (Lorenz);
- merged with log_size_actual v1 ([0]) patch set (Alexei);
- added log_buf==NULL condition allowed (Lorenz);
- added BPF_BTF_LOAD logs tests (Lorenz);
- more clean up and refactoring of internal verifier log API;
v1->v2:
- return -ENOSPC even in rotating log mode for preserving backwards
compatibility (Lorenz);
[0] https://patchwork.kernel.org/project/netdevbpf/list/?series=735213&state=*
[1] https://lore.kernel.org/bpf/CAN+4W8iNoEbQzQVbB_o1W0MWBDV4xCJAq7K3f6psVE-kkCfMqg@mail.gmail.com/
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add verifier log tests for BPF_BTF_LOAD command, which are very similar,
conceptually, to BPF_PROG_LOAD tests. These are two separate commands
dealing with verbose verifier log, so should be both tested separately.
Test that log_buf==NULL condition *does not* return -ENOSPC.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-20-andrii@kernel.org
Add few extra test conditions to validate that it's ok to pass
log_buf==NULL and log_size==0 to BPF_PROG_LOAD command with the intent
to get log_true_size without providing a buffer.
Test that log_buf==NULL condition *does not* return -ENOSPC.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-19-andrii@kernel.org
Add additional test cases validating that log_true_size is consistent
between fixed and rotating log modes, and that log_true_size can be
used *exactly* without causing -ENOSPC, while using just 1 byte shorter
log buffer would cause -ENOSPC.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-18-andrii@kernel.org
Similar to what we did for bpf_prog_load() in previous patch, wire
returning of log_true_size value from kernel back to the user through
OPTS out field.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230406234205.323208-17-andrii@kernel.org
Add output-only log_true_size field to bpf_prog_load_opts to return
bpf_attr->log_true_size value back from bpf() syscall.
Note, that we have to drop const modifier from opts in bpf_prog_load().
This could potentially cause compilation error for some users. But
the usual practice is to define bpf_prog_load_ops
as a local variable next to bpf_prog_load() call and pass pointer to it,
so const vs non-const makes no difference and won't even come up in most
(if not all) cases.
There are no runtime and ABI backwards/forward compatibility issues at all.
If user provides old struct bpf_prog_load_opts, libbpf won't set new
fields. If old libbpf is provided new bpf_prog_load_opts, nothing will
happen either as old libbpf doesn't yet know about this new field.
Adding a new variant of bpf_prog_load() just for this seems like a big
and unnecessary overkill. As a corroborating evidence is the fact that
entire selftests/bpf code base required not adjustment whatsoever.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230406234205.323208-16-andrii@kernel.org
Drop the log_size>0 and log_buf!=NULL condition when log_level>0. This
allows users to request log_true_size of a full log without providing
actual (even if small) log buffer. Verifier log handling code was mostly
ready to handle NULL log->ubuf, so only few small changes were necessary
to prevent NULL log->ubuf from causing problems.
Note, that if user provided NULL log_buf with log_level>0 we don't
consider this a log truncation, and thus won't return -ENOSPC.
We also enforce that either (log_buf==NULL && log_size==0) or
(log_buf!=NULL && log_size>0).
Suggested-by: Lorenz Bauer <lmb@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-15-andrii@kernel.org
Simplify internal verifier log API down to bpf_vlog_init() and
bpf_vlog_finalize(). The former handles input arguments validation in
one place and makes it easier to change it. The latter subsumes -ENOSPC
(truncation) and -EFAULT handling and simplifies both caller's code
(bpf_check() and btf_parse()).
For btf_parse(), this patch also makes sure that verifier log
finalization happens even if there is some error condition during BTF
verification process prior to normal finalization step.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-14-andrii@kernel.org
Add output-only log_true_size and btf_log_true_size field to
BPF_PROG_LOAD and BPF_BTF_LOAD commands, respectively. It will return
the size of log buffer necessary to fit in all the log contents at
specified log_level. This is very useful for BPF loader libraries like
libbpf to be able to size log buffer correctly, but could be used by
users directly, if necessary, as well.
This patch plumbs all this through the code, taking into account actual
bpf_attr size provided by user to determine if these new fields are
expected by users. And if they are, set them from kernel on return.
We refactory btf_parse() function to accommodate this, moving attr and
uattr handling inside it. The rest is very straightforward code, which
is split from the logging accounting changes in the previous patch to
make it simpler to review logic vs UAPI changes.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-13-andrii@kernel.org
Change how we do accounting in BPF_LOG_FIXED mode and adopt log->end_pos
as *logical* log position. This means that we can go beyond physical log
buffer size now and be able to tell what log buffer size should be to
fit entire log contents without -ENOSPC.
To do this for BPF_LOG_FIXED mode, we need to remove a short-circuiting
logic of not vsnprintf()'ing further log content once we filled up
user-provided buffer, which is done by bpf_verifier_log_needed() checks.
We modify these checks to always keep going if log->level is non-zero
(i.e., log is requested), even if log->ubuf was NULL'ed out due to
copying data to user-space, or if entire log buffer is physically full.
We adopt bpf_verifier_vlog() routine to work correctly with
log->ubuf == NULL condition, performing log formatting into temporary
kernel buffer, doing all the necessary accounting, but just avoiding
copying data out if buffer is full or NULL'ed out.
With these changes, it's now possible to do this sort of determination of
log contents size in both BPF_LOG_FIXED and default rolling log mode.
We need to keep in mind bpf_vlog_reset(), though, which shrinks log
contents after successful verification of a particular code path. This
log reset means that log->end_pos isn't always increasing, so to return
back to users what should be the log buffer size to fit all log content
without causing -ENOSPC even in the presence of log resetting, we need
to keep maximum over "lifetime" of logging. We do this accounting in
bpf_vlog_update_len_max() helper.
A related and subtle aspect is that with this logical log->end_pos even in
BPF_LOG_FIXED mode we could temporary "overflow" buffer, but then reset
it back with bpf_vlog_reset() to a position inside user-supplied
log_buf. In such situation we still want to properly maintain
terminating zero. We will eventually return -ENOSPC even if final log
buffer is small (we detect this through log->len_max check). This
behavior is simpler to reason about and is consistent with current
behavior of verifier log. Handling of this required a small addition to
bpf_vlog_reset() logic to avoid doing put_user() beyond physical log
buffer dimensions.
Another issue to keep in mind is that we limit log buffer size to 32-bit
value and keep such log length as u32, but theoretically verifier could
produce huge log stretching beyond 4GB. Instead of keeping (and later
returning) 64-bit log length, we cap it at UINT_MAX. Current UAPI makes
it impossible to specify log buffer size bigger than 4GB anyways, so we
don't really loose anything here and keep everything consistently 32-bit
in UAPI. This property will be utilized in next patch.
Doing the same determination of maximum log buffer for rolling mode is
trivial, as log->end_pos and log->start_pos are already logical
positions, so there is nothing new there.
These changes do incidentally fix one small issue with previous logging
logic. Previously, if use provided log buffer of size N, and actual log
output was exactly N-1 bytes + terminating \0, kernel logic coun't
distinguish this condition from log truncation scenario which would end
up with truncated log contents of N-1 bytes + terminating \0 as well.
But now with log->end_pos being logical position that could go beyond
actual log buffer size, we can distinguish these two conditions, which
we do in this patch. This plays nicely with returning log_size_actual
(implemented in UAPI in the next patch), as we can now guarantee that if
user takes such log_size_actual and provides log buffer of that exact
size, they will not get -ENOSPC in return.
All in all, all these changes do conceptually unify fixed and rolling
log modes much better, and allow a nice feature requested by users:
knowing what should be the size of the buffer to avoid -ENOSPC.
We'll plumb this through the UAPI and the code in the next patch.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-12-andrii@kernel.org
If verifier log is in BPF_LOG_KERNEL mode, no log->ubuf is expected and
it stays NULL throughout entire verification process. Don't erroneously
return -EFAULT in such case.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-10-andrii@kernel.org
btf_parse() is missing -EFAULT error return if log->ubuf was NULL-ed out
due to error while copying data into user-provided buffer. Add it, but
handle a special case of BPF_LOG_KERNEL in which log->ubuf is always NULL.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-9-andrii@kernel.org
Verifier log position reset is meaningless in BPF_LOG_KERNEL mode, so
just exit early in bpf_vlog_reset() if log->level is BPF_LOG_KERNEL.
This avoid meaningless put_user() into NULL log->ubuf.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-8-andrii@kernel.org
Add selftests validating BPF_LOG_FIXED behavior, which used to be the
only behavior, and now default rotating BPF verifier log, which returns
just up to last N bytes of full verifier log, instead of returning
-ENOSPC.
To stress test correctness of in-kernel verifier log logic, we force it
to truncate program's verifier log to all lengths from 1 all the way to
its full size (about 450 bytes today). This was a useful stress test
while developing the feature.
For both fixed and rotating log modes we expect -ENOSPC if log contents
doesn't fit in user-supplied log buffer.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-7-andrii@kernel.org
Add --log-size to be able to customize log buffer sent to bpf() syscall
for BPF program verification logging.
Add --log-fixed to enforce BPF_LOG_FIXED behavior for BPF verifier log.
This is useful in unlikely event that beginning of truncated verifier
log is more important than the end of it (which with rotating verifier
log behavior is the default now).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230406234205.323208-6-andrii@kernel.org
This basically prevents any forward compatibility. And we either way
just return -EINVAL, which would otherwise be returned from bpf()
syscall anyways.
Similarly, drop enforcement of non-NULL log_buf when log_level > 0. This
won't be true anymore soon.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-5-andrii@kernel.org
Currently, if user-supplied log buffer to collect BPF verifier log turns
out to be too small to contain full log, bpf() syscall returns -ENOSPC,
fails BPF program verification/load, and preserves first N-1 bytes of
the verifier log (where N is the size of user-supplied buffer).
This is problematic in a bunch of common scenarios, especially when
working with real-world BPF programs that tend to be pretty complex as
far as verification goes and require big log buffers. Typically, it's
when debugging tricky cases at log level 2 (verbose). Also, when BPF program
is successfully validated, log level 2 is the only way to actually see
verifier state progression and all the important details.
Even with log level 1, it's possible to get -ENOSPC even if the final
verifier log fits in log buffer, if there is a code path that's deep
enough to fill up entire log, even if normally it would be reset later
on (there is a logic to chop off successfully validated portions of BPF
verifier log).
In short, it's not always possible to pre-size log buffer. Also, what's
worse, in practice, the end of the log most often is way more important
than the beginning, but verifier stops emitting log as soon as initial
log buffer is filled up.
This patch switches BPF verifier log behavior to effectively behave as
rotating log. That is, if user-supplied log buffer turns out to be too
short, verifier will keep overwriting previously written log,
effectively treating user's log buffer as a ring buffer. -ENOSPC is
still going to be returned at the end, to notify user that log contents
was truncated, but the important last N bytes of the log would be
returned, which might be all that user really needs. This consistent
-ENOSPC behavior, regardless of rotating or fixed log behavior, allows
to prevent backwards compatibility breakage. The only user-visible
change is which portion of verifier log user ends up seeing *if buffer
is too small*. Given contents of verifier log itself is not an ABI,
there is no breakage due to this behavior change. Specialized tools that
rely on specific contents of verifier log in -ENOSPC scenario are
expected to be easily adapted to accommodate old and new behaviors.
Importantly, though, to preserve good user experience and not require
every user-space application to adopt to this new behavior, before
exiting to user-space verifier will rotate log (in place) to make it
start at the very beginning of user buffer as a continuous
zero-terminated string. The contents will be a chopped off N-1 last
bytes of full verifier log, of course.
Given beginning of log is sometimes important as well, we add
BPF_LOG_FIXED (which equals 8) flag to force old behavior, which allows
tools like veristat to request first part of verifier log, if necessary.
BPF_LOG_FIXED flag is also a simple and straightforward way to check if
BPF verifier supports rotating behavior.
On the implementation side, conceptually, it's all simple. We maintain
64-bit logical start and end positions. If we need to truncate the log,
start position will be adjusted accordingly to lag end position by
N bytes. We then use those logical positions to calculate their matching
actual positions in user buffer and handle wrap around the end of the
buffer properly. Finally, right before returning from bpf_check(), we
rotate user log buffer contents in-place as necessary, to make log
contents contiguous. See comments in relevant functions for details.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-4-andrii@kernel.org
It's not clear why we have 128 as minimum size, but it makes testing
harder and seems unnecessary, as we carefully handle truncation
scenarios and use proper snprintf variants. So remove this limitation
and just enforce positive length for log buffer.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-3-andrii@kernel.org
kernel/bpf/verifier.c file is large and growing larger all the time. So
it's good to start splitting off more or less self-contained parts into
separate files to keep source code size (somewhat) somewhat under
control.
This patch is a one step in this direction, moving some of BPF verifier log
routines into a separate kernel/bpf/log.c. Right now it's most low-level
and isolated routines to append data to log, reset log to previous
position, etc. Eventually we could probably move verifier state
printing logic here as well, but this patch doesn't attempt to do that
yet.
Subsequent patches will add more logic to verifier log management, so
having basics in a separate file will make sure verifier.c doesn't grow
more with new changes.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-2-andrii@kernel.org
