bpf: Disallow fentry/fexit/freplace for exception callbacks
During testing, it was discovered that extensions to exception callbacks
had no checks, upon running a testcase, the kernel ended up running off
the end of a program having final call as bpf_throw, and hitting int3
instructions.
The reason is that while the default exception callback would have reset
the stack frame to return back to the main program's caller, the
replacing extension program will simply return back to bpf_throw, which
will instead return back to the program and the program will continue
execution, now in an undefined state where anything could happen.
The way to support extensions to an exception callback would be to mark
the BPF_PROG_TYPE_EXT main subprog as an exception_cb, and prevent it
from calling bpf_throw. This would make the JIT produce a prologue that
restores saved registers and reset the stack frame. But let's not do
that until there is a concrete use case for this, and simply disallow
this for now.
Similar issues will exist for fentry and fexit cases, where trampoline
saves data on the stack when invoking exception callback, which however
will then end up resetting the stack frame, and on return, the fexit
program will never will invoked as the return address points to the main
program's caller in the kernel. Instead of additional complexity and
back and forth between the two stacks to enable such a use case, simply
forbid it.
One key point here to note is that currently X86_TAIL_CALL_OFFSET didn't
require any modifications, even though we emit instructions before the
corresponding endbr64 instruction. This is because we ensure that a main
subprog never serves as an exception callback, and therefore the
exception callback (which will be a global subprog) can never serve as
the tail call target, eliminating any discrepancies. However, once we
support a BPF_PROG_TYPE_EXT to also act as an exception callback, it
will end up requiring change to the tail call offset to account for the
extra instructions. For simplicitly, tail calls could be disabled for
such targets.
Noting the above, it appears better to wait for a concrete use case
before choosing to permit extension programs to replace exception
callbacks.
As a precaution, we disable fentry and fexit for exception callbacks as
well.
Now that bpf_throw kfunc is the first such call instruction that has
noreturn semantics within the verifier, this also kicks in dead code
elimination in unprecedented ways. For one, any instruction following
a bpf_throw call will never be marked as seen. Moreover, if a callchain
ends up throwing, any instructions after the call instruction to the
eventually throwing subprog in callers will also never be marked as
seen.
The tempting way to fix this would be to emit extra 'int3' instructions
which bump the jited_len of a program, and ensure that during runtime
when a program throws, we can discover its boundaries even if the call
instruction to bpf_throw (or to subprogs that always throw) is emitted
as the final instruction in the program.
An example of such a program would be this:
do_something():
...
r0 = 0
exit
foo():
r1 = 0
call bpf_throw
r0 = 0
exit
bar(cond):
if r1 != 0 goto pc+2
call do_something
exit
call foo
r0 = 0 // Never seen by verifier
exit //
main(ctx):
r1 = ...
call bar
r0 = 0
exit
Here, if we do end up throwing, the stacktrace would be the following:
bpf_throw
foo
bar
main
In bar, the final instruction emitted will be the call to foo, as such,
the return address will be the subsequent instruction (which the JIT
emits as int3 on x86). This will end up lying outside the jited_len of
the program, thus, when unwinding, we will fail to discover the return
address as belonging to any program and end up in a panic due to the
unreliable stack unwinding of BPF programs that we never expect.
To remedy this case, make bpf_prog_ksym_find treat IP == ksym.end as
part of the BPF program, so that is_bpf_text_address returns true when
such a case occurs, and we are able to unwind reliably when the final
instruction ends up being a call instruction.
The KASAN stack instrumentation when CONFIG_KASAN_STACK is true poisons
the stack of a function when it is entered and unpoisons it when
leaving. However, in the case of bpf_throw, we will never return as we
switch our stack frame to the BPF exception callback. Later, this
discrepancy will lead to confusing KASAN splats when kernel resumes
execution on return from the BPF program.
Fix this by unpoisoning everything below the stack pointer of the BPF
program, which should cover the range that would not be unpoisoned. An
example splat is below:
BUG: KASAN: stack-out-of-bounds in stack_trace_consume_entry+0x14e/0x170
Write of size 8 at addr ffffc900013af958 by task test_progs/227
mm: kasan: Declare kasan_unpoison_task_stack_below in kasan.h
We require access to this kasan helper in BPF code in the next patch
where we have to unpoison the task stack when we unwind and reset the
stack frame from bpf_throw, and it never really unpoisons the poisoned
stack slots on entry when compiler instrumentation is generated by
CONFIG_KASAN_STACK and inline instrumentation is supported.
Also, remove the declaration from mm/kasan/kasan.h as we put it in the
header file kasan.h.
bpf: Treat first argument as return value for bpf_throw
In case of the default exception callback, change the behavior of
bpf_throw, where the passed cookie value is no longer ignored, but
is instead the return value of the default exception callback. As
such, we need to place restrictions on the value being passed into
bpf_throw in such a case, only allowing those permitted by the
check_return_code function.
Thus, bpf_throw can now control the return value of the program from
each call site without having the user install a custom exception
callback just to override the return value when an exception is thrown.
We also modify the hidden subprog instructions to now move BPF_REG_1 to
BPF_REG_0, so as to set the return value before exit in the default
callback.
Since exception callbacks are not referenced using bpf_pseudo_func and
bpf_pseudo_call instructions, check_cfg traversal will never explore
instructions of the exception callback. Even after adding the subprog,
the program will then fail with a 'unreachable insn' error.
We thus need to begin walking from the start of the exception callback
again in check_cfg after a complete CFG traversal finishes, so as to
explore the CFG rooted at the exception callback.
By default, the subprog generated by the verifier to handle a thrown
exception hardcodes a return value of 0. To allow user-defined logic
and modification of the return value when an exception is thrown,
introduce the 'exception_callback:' declaration tag, which marks a
callback as the default exception handler for the program.
The format of the declaration tag is 'exception_callback:<value>', where
<value> is the name of the exception callback. Each main program can be
tagged using this BTF declaratiion tag to associate it with an exception
callback. In case the tag is absent, the default callback is used.
As such, the exception callback cannot be modified at runtime, only set
during verification.
Allowing modification of the callback for the current program execution
at runtime leads to issues when the programs begin to nest, as any
per-CPU state maintaing this information will have to be saved and
restored. We don't want it to stay in bpf_prog_aux as this takes a
global effect for all programs. An alternative solution is spilling
the callback pointer at a known location on the program stack on entry,
and then passing this location to bpf_throw as a parameter.
However, since exceptions are geared more towards a use case where they
are ideally never invoked, optimizing for this use case and adding to
the complexity has diminishing returns.
bpf: Refactor check_btf_func and split into two phases
This patch splits the check_btf_info's check_btf_func check into two
separate phases. The first phase sets up the BTF and prepares
func_info, but does not perform any validation of required invariants
for subprogs just yet. This is left to the second phase, which happens
where check_btf_info executes currently, and performs the line_info and
CO-RE relocation.
The reason to perform this split is to obtain the userspace supplied
func_info information before we perform the add_subprog call, where we
would now require finding and adding subprogs that may not have a
bpf_pseudo_call or bpf_pseudo_func instruction in the program.
We require this as we want to enable userspace to supply exception
callbacks that can override the default hidden subprogram generated by
the verifier (which performs a hardcoded action). In such a case, the
exception callback may never be referenced in an instruction, but will
still be suitably annotated (by way of BTF declaration tags). For
finding this exception callback, we would require the program's BTF
information, and the supplied func_info information which maps BTF type
IDs to subprograms.
Since the exception callback won't actually be referenced through
instructions, later checks in check_cfg and do_check_subprogs will not
verify the subprog. This means that add_subprog needs to add them in the
add_subprog_and_kfunc phase before we move forward, which is why the BTF
and func_info are required at that point.
This patch implements BPF exceptions, and introduces a bpf_throw kfunc
to allow programs to throw exceptions during their execution at runtime.
A bpf_throw invocation is treated as an immediate termination of the
program, returning back to its caller within the kernel, unwinding all
stack frames.
This allows the program to simplify its implementation, by testing for
runtime conditions which the verifier has no visibility into, and assert
that they are true. In case they are not, the program can simply throw
an exception from the other branch.
BPF exceptions are explicitly *NOT* an unlikely slowpath error handling
primitive, and this objective has guided design choices of the
implementation of the them within the kernel (with the bulk of the cost
for unwinding the stack offloaded to the bpf_throw kfunc).
The implementation of this mechanism requires use of add_hidden_subprog
mechanism introduced in the previous patch, which generates a couple of
instructions to move R1 to R0 and exit. The JIT then rewrites the
prologue of this subprog to take the stack pointer and frame pointer as
inputs and reset the stack frame, popping all callee-saved registers
saved by the main subprog. The bpf_throw function then walks the stack
at runtime, and invokes this exception subprog with the stack and frame
pointers as parameters.
Reviewers must take note that currently the main program is made to save
all callee-saved registers on x86_64 during entry into the program. This
is because we must do an equivalent of a lightweight context switch when
unwinding the stack, therefore we need the callee-saved registers of the
caller of the BPF program to be able to return with a sane state.
Note that we have to additionally handle r12, even though it is not used
by the program, because when throwing the exception the program makes an
entry into the kernel which could clobber r12 after saving it on the
stack. To be able to preserve the value we received on program entry, we
push r12 and restore it from the generated subprogram when unwinding the
stack.
For now, bpf_throw invocation fails when lingering resources or locks
exist in that path of the program. In a future followup, bpf_throw will
be extended to perform frame-by-frame unwinding to release lingering
resources for each stack frame, removing this limitation.
Introduce support in the verifier for generating a subprogram and
include it as part of a BPF program dynamically after the do_check phase
is complete. The first user will be the next patch which generates
default exception callbacks if none are set for the program. The phase
of invocation will be do_misc_fixups. Note that this is an internal
verifier function, and should be used with instruction blocks which
uphold the invariants stated in check_subprogs.
Since these subprogs are always appended to the end of the instruction
sequence of the program, it becomes relatively inexpensive to do the
related adjustments to the subprog_info of the program. Only the fake
exit subprogram is shifted forward, making room for our new subprog.
This is useful to insert a new subprogram, get it JITed, and obtain its
function pointer. The next patch will use this functionality to insert a
default exception callback which will be invoked after unwinding the
stack.
Note that these added subprograms are invisible to userspace, and never
reported in BPF_OBJ_GET_INFO_BY_ID etc. For now, only a single
subprogram is supported, but more can be easily supported in the future.
To this end, two function counts are introduced now, the existing
func_cnt, and real_func_cnt, the latter including hidden programs. This
allows us to conver the JIT code to use the real_func_cnt for management
of resources while syscall path continues working with existing
func_cnt.
The plumbing for offline unwinding when we throw an exception in
programs would require walking the stack, hence introduce a new
arch_bpf_stack_walk function. This is provided when the JIT supports
exceptions, i.e. bpf_jit_supports_exceptions is true. The arch-specific
code is really minimal, hence it should be straightforward to extend
this support to other architectures as well, as it reuses the logic of
arch_stack_walk, but allowing access to unwind_state data.
Once the stack pointer and frame pointer are known for the main subprog
during the unwinding, we know the stack layout and location of any
callee-saved registers which must be restored before we return back to
the kernel. This handling will be added in the subsequent patches.
Note that while we primarily unwind through BPF frames, which are
effectively CONFIG_UNWINDER_FRAME_POINTER, we still need one of this or
CONFIG_UNWINDER_ORC to be able to unwind through the bpf_throw frame
from which we begin walking the stack. We also require both sp and bp
(stack and frame pointers) from the unwind_state structure, which are
only available when one of these two options are enabled.
We would like to know whether a bpf_prog corresponds to the main prog or
one of the subprogs. The current JIT implementations simply check this
using the func_idx in bpf_prog->aux->func_idx. When the index is 0, it
belongs to the main program, otherwise it corresponds to some
subprogram.
This will also be necessary to halt exception propagation while walking
the stack when an exception is thrown, so we add a simple helper
function to check this, named bpf_is_subprog, and convert existing JIT
implementations to also make use of it.
====================
arm32, bpf: add support for cpuv4 insns
Changes in V2 -> V3
- Added comments at places where there could be confustion.
- In the patch for DIV64, fix the if-else case that would never run.
- In the same patch use a single instruction to POP caller saved regs.
- Add a patch to change maintainership of ARM32 BPF JIT.
Changes in V1 -> V2:
- Fix coding style issues.
- Don't use tmp variable for src in emit_ldsx_r() as it is redundant.
- Optimize emit_ldsx_r() when offset can fit in immediate.
Add the support for cpuv4 instructions for ARM32 BPF JIT. 64-bit division
was not supported earlier so this series adds 64-bit DIV, SDIV, MOD, SMOD
instructions as well.
This series needs any one of the patches from [1] to disable zero-extension
for BPF_MEMSX to support ldsx.
The relevant selftests have passed expect ldsx_insn which needs fentry:
As the selftests don't compile for 32-bit architectures without
modifications due to long being 32-bit,
I have added new tests to lib/test_bpf.c for cpuv4 insns, all are passing:
arm32, bpf: add support for 64 bit division instruction
ARM32 doesn't have instructions to do 64-bit/64-bit divisions. So, to
implement the following instructions:
BPF_ALU64 | BPF_DIV
BPF_ALU64 | BPF_MOD
BPF_ALU64 | BPF_SDIV
BPF_ALU64 | BPF_SMOD
We implement the above instructions by doing function calls to div64_u64()
and div64_u64_rem() for unsigned division/mod and calls to div64_s64()
for signed division/mod.
arm32, bpf: add support for 32-bit signed division
The cpuv4 added a new BPF_SDIV instruction that does signed division.
The encoding is similar to BPF_DIV but BPF_SDIV sets offset=1.
ARM32 already supports 32-bit BPF_DIV which can be easily extended to
support BPF_SDIV as ARM32 has the SDIV instruction. When the CPU is not
ARM-v7, we implement that SDIV/SMOD with the function call similar to
the implementation of DIV/MOD.
As we already support converting to big-endian from little-endian we can
use the same for unconditional bswap. just treat the unconditional scenario
the same as big-endian conversion.
arm32, bpf: add support for sign-extension mov instruction
The cpuv4 added a new BPF_MOVSX instruction that sign extends the src
before moving it to the destination.
BPF_ALU | BPF_MOVSX sign extends 8-bit and 16-bit operands into 32-bit
operands, and zeroes the remaining upper 32 bits.
BPF_ALU64 | BPF_MOVSX sign extends 8-bit, 16-bit, and 32-bit operands
into 64-bit operands.
The offset field of the instruction is used to tell the number of bit to
use for sign-extension. BPF_MOV and BPF_MOVSX have the same code but the
former sets offset to 0 and the later one sets the offset to 8, 16 or 32
The behaviour of this instruction is dst = (s8,s16,s32)src
On ARM32 the implementation uses LSH and ARSH to extend the 8/16 bits to
a 32-bit register and then it is sign extended to the upper 32-bit
register using ARSH. For 32-bit we just move it to the destination
register and use ARSH to extend it to the upper 32-bit register.
arm32, bpf: add support for sign-extension load instruction
The cpuv4 added the support of an instruction that is similar to load
but also sign-extends the result after the load.
BPF_MEMSX | <size> | BPF_LDX means dst = *(signed size *) (src + offset)
here <size> can be one of BPF_B, BPF_H, BPF_W.
ARM32 has instructions to load a byte or a half word with sign
extension into a 32bit register. As the JIT uses two 32 bit registers
to simulate a 64-bit BPF register, an extra instruction is emitted to
sign-extent the result up to the second register.
bpf: Allow to use kfunc XDP hints and frags together
There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints
cannot coexist in a single program.
Allow those features to be used together by modifying the flags condition
for dev-bound-only programs, segments are still prohibited for fully
offloaded programs, hence additional check.
Martin KaFai Lau [Fri, 15 Sep 2023 16:18:10 +0000 (09:18 -0700)]
Merge branch 'bpf: expose information about netdev xdp-metadata kfunc support'
Stanislav Fomichev says:
====================
Extend netdev netlink family to expose the bitmask with the
kfuncs that the device implements. The source of truth is the
device's xdp_metadata_ops. There is some amount of auto-generated
netlink boilerplate; the change itself is super minimal.
v2:
- add netdev->xdp_metadata_ops NULL check when dumping to netlink (Martin)
Cc: netdev@vger.kernel.org Cc: Willem de Bruijn <willemb@google.com>
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Stanislav Fomichev [Wed, 13 Sep 2023 17:13:50 +0000 (10:13 -0700)]
tools: ynl: extend netdev sample to dump xdp-rx-metadata-features
The tool can be used to verify that everything works end to end.
Unrelated updates:
- include tools/include/uapi to pick the latest kernel uapi headers
- print "xdp-features" and "xdp-rx-metadata-features" so it's clear
which bitmask is being dumped
Stanislav Fomichev [Wed, 13 Sep 2023 17:13:49 +0000 (10:13 -0700)]
bpf: expose information about supported xdp metadata kfunc
Add new xdp-rx-metadata-features member to netdev netlink
which exports a bitmask of supported kfuncs. Most of the patch
is autogenerated (headers), the only relevant part is netdev.yaml
and the changes in netdev-genl.c to marshal into netlink.
Example output on veth:
$ ip link add veth0 type veth peer name veth1 # ifndex == 12
$ ./tools/net/ynl/samples/netdev 12
Stanislav Fomichev [Wed, 13 Sep 2023 17:13:48 +0000 (10:13 -0700)]
bpf: make it easier to add new metadata kfunc
No functional changes.
Instead of having hand-crafted code in bpf_dev_bound_resolve_kfunc,
move kfunc <> xmo handler relationship into XDP_METADATA_KFUNC_xxx.
This way, any time new kfunc is added, we don't have to touch
bpf_dev_bound_resolve_kfunc.
Also document XDP_METADATA_KFUNC_xxx arguments since we now have
more than two and it might be confusing what is what.
xsk: add multi-buffer support for sockets sharing umem
Userspace applications indicate their multi-buffer capability to xsk
using XSK_USE_SG socket bind flag. For sockets using shared umem the
bind flag may contain XSK_USE_SG only for the first socket. For any
subsequent socket the only option supported is XDP_SHARED_UMEM.
Add option XDP_UMEM_SG_FLAG in umem config flags to store the
multi-buffer handling capability when indicated by XSK_USE_SG option in
bing flag by the first socket. Use this to derive multi-buffer capability
for subsequent sockets in xsk core.
Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com> Fixes: 81470b5c3c66 ("xsk: introduce XSK_USE_SG bind flag for xsk socket") Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/r/20230907035032.2627879-1-tirthendu.sarkar@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Song Liu [Thu, 14 Sep 2023 22:25:42 +0000 (15:25 -0700)]
bpf: Charge modmem for struct_ops trampoline
Current code charges modmem for regular trampoline, but not for struct_ops
trampoline. Add bpf_jit_[charge|uncharge]_modmem() to struct_ops so the
trampoline is charged in both cases.
====================
seltests/xsk: various improvements to xskxceiver
This patch set implements several improvements to the xsk selftests
test suite that I thought were useful while debugging the xsk
multi-buffer code and tests. The largest new feature is the ability to
be able to execute a single test instead of the whole test suite. This
required some surgery on the current code, details below.
Anatomy of the path set:
1: Print useful info on a per packet basis with the option -v
2: Add a timeout in the transmission loop too. We only used to have
one for the Rx thread, but Tx can lock up too waiting for
completions.
3: Add an option (-m) to only run the tests (or a single test with a
later patch) in a single mode: skb, drv, or zc (zero-copy).
4-5: Preparatory patches to be able to specify a test to run. Need to
define the test names in a single structure and their entry
points, so we can use this when wanting to run a specific test.
6: Adds a command line option (-l) that lists all the tests.
7: Adds a command line option (-t) that runs a specific test instead
of the whole test suite. Can be combined with -m to specify a
single mode too.
8: Use ksft_print_msg() uniformly throughout the tests. It was a mix
of printf() and ksft_print_msg() before.
9: In some places, we failed the whole test suite instead of a single
test in certain circumstances. Fix this so only the test in
question is failed and the rest of the test suite continues.
10: Display the available command line options with -h
v3 -> v4:
* Fixed another spelling error in patch #9 [Maciej]
* Only allow the actual strings for the -m command [Maciej]
* Move some code from patch #7 to #3 [Maciej]
v2 -> v3:
* Drop the support for environment variables. Probably not useful. [Maciej]
* Fixed spelling mistake in patch #9 [Maciej]
* Fail gracefully if unsupported mode is chosen [Maciej]
* Simplified test run loop [Maciej]
v1 -> v2:
* Introduce XSKTEST_MODE env variable to be able to set the mode to
use [Przemyslaw]
* Introduce XSKTEST_ETH env variable to be able to set the ethernet
interface to use by introducing a new patch (#11) [Magnus]
* Fixed spelling error in patch #5 [Przemyslaw, Maciej]
* Fixed confusing documentation in patch #10 [Przemyslaw]
* The -l option can now be used without being root [Magnus, Maciej]
* Fixed documentation error in patch #7 [Maciej]
* Added error handling to the -t option [Maciej]
* -h now displayed as an option [Maciej]
Magnus Karlsson [Thu, 14 Sep 2023 08:48:56 +0000 (10:48 +0200)]
selftests/xsk: fail single test instead of all tests
In a number of places at en error, exit_with_error() is called that
terminates the whole test suite. This is not always desirable as it
would be more logical to only fail that test and then go along with
the other ones. So change this in a number of places in which I
thought it would be more logical to just fail the test in
question. Examples of this are in code that is only used by a single
test.
Also delete a pointless if-statement in receive_pkts() that has an
exit_with_error() in it. It can never occur since the return value is
an unsigned and the test is for less than zero.
Magnus Karlsson [Thu, 14 Sep 2023 08:48:55 +0000 (10:48 +0200)]
selftests/xsk: use ksft_print_msg uniformly
Use ksft_print_msg() instead of printf() and fprintf() in all places
as the ksefltests framework is being used. There is only one exception
and that is for the list-of-tests print out option, since no tests are
run in that case.
Magnus Karlsson [Thu, 14 Sep 2023 08:48:54 +0000 (10:48 +0200)]
selftests/xsk: add option to run single test
Add a command line option to be able to run a single test. This option
(-t) takes a number from the list of tests available with the "-l"
option. Here are two examples:
Run test number 2, the "receive single packet" test in all available modes:
./test_xsk.sh -t 2
Run test number 21, the metadata copy test in skb mode only
Magnus Karlsson [Thu, 14 Sep 2023 08:48:53 +0000 (10:48 +0200)]
selftests/xsk: add option that lists all tests
Add a command line option (-l) that lists all the tests. The number
before the test will be used in the next commit for specifying a
single test to run. Here is an example of the output:
Magnus Karlsson [Thu, 14 Sep 2023 08:48:52 +0000 (10:48 +0200)]
selftests/xsk: declare test names in struct
Declare the test names statically in a struct so that we can refer to
them when adding the support to execute a single test in the next
commit. Before this patch, the names of them were not declared in a
single place which made it not possible to refer to them.
Magnus Karlsson [Thu, 14 Sep 2023 08:48:51 +0000 (10:48 +0200)]
selftests/xsk: move all tests to separate functions
Prepare for the capability to be able to run a single test by moving
all the tests to their own functions. This function can then be called
to execute that test in the next commit.
Also, the tests named RUN_TO_COMPLETION_* were not named well, so
change them to SEND_RECEIVE_* as it is just a basic send and receive
test of 4K packets.
Magnus Karlsson [Thu, 14 Sep 2023 08:48:50 +0000 (10:48 +0200)]
selftests/xsk: add option to only run tests in a single mode
Add an option -m on the command line that allows the user to run the
tests in a single mode instead of all of them. Valid modes are skb,
drv, and zc (zero-copy). An example:
Magnus Karlsson [Thu, 14 Sep 2023 08:48:49 +0000 (10:48 +0200)]
selftests/xsk: add timeout for Tx thread
Add a timeout for the transmission thread. If packets are not
completed properly, for some reason, the test harness would previously
get stuck forever in a while loop. But with this patch, this timeout
will trigger, flag the test as a failure, and continue with the next
test.
Magnus Karlsson [Thu, 14 Sep 2023 08:48:48 +0000 (10:48 +0200)]
selftests/xsk: print per packet info in verbose mode
Print info about every packet in verbose mode, both for Tx and
Rx. This is useful to have when a test fails or to validate that a
test is really doing what it was designed to do. Info on what is
supposed to be received and sent is also printed for the custom packet
streams since they differ from the base line. Here is an example:
Quan Tian [Mon, 11 Sep 2023 15:23:53 +0000 (15:23 +0000)]
docs/bpf: update out-of-date doc in BPF flow dissector
Commit a5e2151ff9d5 ("net/ipv6: SKB symmetric hash should incorporate
transport ports") removed the use of FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL
in __skb_get_hash_symmetric(), making the doc out-of-date.
This patch series fixes a tailcall infinite loop on x64.
From commit ebf7d1f508a73871 ("bpf, x64: rework pro/epilogue and tailcall
handling in JIT"), the tailcall on x64 works better than before.
From commit e411901c0b775a3a ("bpf: allow for tailcalls in BPF subprograms
for x64 JIT"), tailcall is able to run in BPF subprograms on x64.
From commit 5b92a28aae4dd0f8 ("bpf: Support attaching tracing BPF program
to other BPF programs"), BPF program is able to trace other BPF programs.
How about combining them all together?
1. FENTRY/FEXIT on a BPF subprogram.
2. A tailcall runs in the BPF subprogram.
3. The tailcall calls the subprogram's caller.
As a result, a tailcall infinite loop comes up. And the loop would halt
the machine.
As we know, in tail call context, the tail_call_cnt propagates by stack
and rax register between BPF subprograms. So do in trampolines.
How did I discover the bug?
From commit 7f6e4312e15a5c37 ("bpf: Limit caller's stack depth 256 for
subprogs with tailcalls"), the total stack size limits to around 8KiB.
Then, I write some bpf progs to validate the stack consuming, that are
tailcalls running in bpf2bpf and FENTRY/FEXIT tracing on bpf2bpf.
At that time, accidently, I made a tailcall loop. And then the loop halted
my VM. Without the loop, the bpf progs would consume over 8KiB stack size.
But the _stack-overflow_ did not halt my VM.
With bpf_printk(), I confirmed that the tailcall count limit did not work
expectedly. Next, read the code and fix it.
Thank Ilya Leoshkevich, this bug on s390x has been fixed.
Hopefully, this bug on arm64 will be fixed in near future.
====================
Leon Hwang [Tue, 12 Sep 2023 15:04:40 +0000 (23:04 +0800)]
bpf, x64: Comment tail_call_cnt initialisation
Without understanding emit_prologue(), it is really hard to figure out
where does tail_call_cnt come from, even though searching tail_call_cnt
in the whole kernel repo.
By adding these comments, it is a little bit easier to understand
tail_call_cnt initialisation.
Fixes: 79d49ba048ec ("bpf, testing: Add various tail call test cases") Fixes: 3b0379111197 ("selftests/bpf: Add tailcall_bpf2bpf tests") Fixes: 5e0b0a4c52d3 ("selftests/bpf: Test tail call counting with bpf2bpf and data on stack") Signed-off-by: Leon Hwang <hffilwlqm@gmail.com> Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/r/20230906154256.95461-1-hffilwlqm@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
This cast was made by purpose for older libbpf where the
bpf_object_skeleton field is void * instead of const void *
to eliminate a warning (as i understand
-Wincompatible-pointer-types-discards-qualifiers) but this
cast introduces another warning (-Wcast-qual) for libbpf
where data field is const void *
It makes sense for bpftool to be in sync with libbpf from
kernel sources
====================
We need to optimize the kallsyms cache, including optimizations for the
number of symbols limit, and, some test cases add new kernel symbols
(such as testmods) and we need to refresh kallsyms (reload or refresh).
====================
Static ksyms often have problems because the number of symbols exceeds the
MAX_SYMS limit. Like changing the MAX_SYMS from 300000 to 400000 in
commit e76a014334a6("selftests/bpf: Bump and validate MAX_SYMS") solves
the problem somewhat, but it's not the perfect way.
This commit uses dynamic memory allocation, which completely solves the
problem caused by the limitation of the number of kallsyms. At the same
time, add APIs:
====================
bpf: Enable IRQ after irq_work_raise() completes
From: Hou Tao <houtao1@huawei.com>
Hi,
The patchset aims to fix the problem that bpf_mem_alloc() may return
NULL unexpectedly when multiple bpf_mem_alloc() are invoked concurrently
under process context and there is still free memory available. The
problem was found when doing stress test for qp-trie but the same
problem also exists for bpf_obj_new() as demonstrated in patch #3.
As pointed out by Alexei, the patchset can only fix ENOMEM problem for
normal process context and can not fix the problem for irq-disabled
context or RT-enabled kernel.
Patch #1 fixes the race between unit_alloc() and unit_alloc(). Patch #2
fixes the race between unit_alloc() and unit_free(). And patch #3 adds
a selftest for the problem. The major change compared with v1 is using
local_irq_{save,restore)() pair to disable and enable preemption
instead of preempt_{disable,enable}_notrace pair. The main reason is to
prevent potential overhead from __preempt_schedule_notrace(). I also
run htab_mem benchmark and hash_map_perf on a 8-CPUs KVM VM to compare
the performance between local_irq_{save,restore} and
preempt_{disable,enable}_notrace(), but the results are similar as shown
below:
(1) use preempt_{disable,enable}_notrace()
[root@hello bpf]# ./map_perf_test 4 8
0:hash_map_perf kmalloc 652179 events per sec
1:hash_map_perf kmalloc 651880 events per sec
2:hash_map_perf kmalloc 651382 events per sec
3:hash_map_perf kmalloc 650791 events per sec
5:hash_map_perf kmalloc 650140 events per sec
6:hash_map_perf kmalloc 652773 events per sec
7:hash_map_perf kmalloc 652751 events per sec
4:hash_map_perf kmalloc 648199 events per sec
bpf: task_group_seq_get_next: simplify the "next tid" logic
Kill saved_tid. It looks ugly to update *tid and then restore the
previous value if __task_pid_nr_ns() returns 0. Change this code
to update *tid and common->pid_visiting once before return.
Hou Tao [Fri, 1 Sep 2023 11:19:54 +0000 (19:19 +0800)]
selftests/bpf: Test preemption between bpf_obj_new() and bpf_obj_drop()
The test case creates 4 threads and then pins these 4 threads in CPU 0.
These 4 threads will run different bpf program through
bpf_prog_test_run_opts() and these bpf program will use bpf_obj_new()
and bpf_obj_drop() to allocate and free local kptrs concurrently.
Under preemptible kernel, bpf_obj_new() and bpf_obj_drop() may preempt
each other, bpf_obj_new() may return NULL and the test will fail before
applying these fixes as shown below:
Hou Tao [Fri, 1 Sep 2023 11:19:53 +0000 (19:19 +0800)]
bpf: Enable IRQ after irq_work_raise() completes in unit_free{_rcu}()
Both unit_free() and unit_free_rcu() invoke irq_work_raise() to free
freed objects back to slab and the invocation may also be preempted by
unit_alloc() and unit_alloc() may return NULL unexpectedly as shown in
the following case:
task A task B
unit_free()
// high_watermark = 48
// free_cnt = 49 after free
irq_work_raise()
// mark irq work as IRQ_WORK_PENDING
irq_work_claim()
// task B preempts task A
unit_alloc()
// free_cnt = 48 after alloc
// does unit_alloc() 32-times
......
// free_cnt = 16
unit_alloc()
// free_cnt = 15 after alloc
// irq work is already PENDING,
// so just return
irq_work_raise()
// does unit_alloc() 15-times
......
// free_cnt = 0
unit_alloc()
// free_cnt = 0 before alloc
return NULL
Fix it by enabling IRQ after irq_work_raise() completes.
bpf: task_group_seq_get_next: cleanup the usage of get/put_task_struct
get_pid_task() makes no sense, the code does put_task_struct() soon after.
Use find_task_by_pid_ns() instead of find_pid_ns + get_pid_task and kill
put_task_struct(), this allows to do get_task_struct() only once before
return.
While at it, kill the unnecessary "if (!pid)" check in the "if (!*tid)"
block, this matches the next usage of find_pid_ns() + get_pid_task() in
this function.
bpf: task_group_seq_get_next: cleanup the usage of next_thread()
1. find_pid_ns() + get_pid_task() under rcu_read_lock() guarantees that we
can safely iterate the task->thread_group list. Even if this task exits
right after get_pid_task() (or goto retry) and pid_alive() returns 0.
====================
bpf: Add support for local percpu kptr
Patch set [1] implemented cgroup local storage BPF_MAP_TYPE_CGRP_STORAGE
similar to sk/task/inode local storage and old BPF_MAP_TYPE_CGROUP_STORAGE
map is marked as deprecated since old BPF_MAP_TYPE_CGROUP_STORAGE map can
only work with current cgroup.
Similarly, the existing BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE map
is a percpu version of BPF_MAP_TYPE_CGROUP_STORAGE and only works
with current cgroup. But there is no replacement which can work
with arbitrary cgroup.
This patch set solved this problem but adding support for local
percpu kptr. The map value can have a percpu kptr field which holds
a bpf prog allocated percpu data. The below is an example,
In the above, 'map_value_t' is the map value type for a
BPF_MAP_TYPE_CGRP_STORAGE map. User can access 'percpu_data_ptr'
and then read/write percpu data. This covers BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE
and more. So BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE map type
is marked as deprecated.
In additional, local percpu kptr supports the same map type
as other kptrs including hash, lru_hash, array, sk/inode/task/cgrp
local storage. Currently, percpu data structure does not support
non-scalars or special fields (e.g., bpf_spin_lock, bpf_rb_root, etc.).
They can be supported in the future if there exist use cases.
Changelog:
v2 -> v3:
- fix libbpf_str test failure.
v1 -> v2:
- does not support special fields in percpu data structure.
- rename __percpu attr to __percpu_kptr attr.
- rename BPF_KPTR_PERCPU_REF to BPF_KPTR_PERCPU.
- better code to handle bpf_{this,per}_cpu_ptr() helpers.
- add more negative tests.
- fix a bpftool related test failure.
====================
Hou Tao [Fri, 1 Sep 2023 11:19:52 +0000 (19:19 +0800)]
bpf: Enable IRQ after irq_work_raise() completes in unit_alloc()
When doing stress test for qp-trie, bpf_mem_alloc() returned NULL
unexpectedly because all qp-trie operations were initiated from
bpf syscalls and there was still available free memory. bpf_obj_new()
has the same problem as shown by the following selftest.
The failure is due to the preemption. irq_work_raise() will invoke
irq_work_claim() first to mark the irq work as pending and then inovke
__irq_work_queue_local() to raise an IPI. So when the current task
which is invoking irq_work_raise() is preempted by other task,
unit_alloc() may return NULL for preemption task as shown below:
task A task B
unit_alloc()
// low_watermark = 32
// free_cnt = 31 after alloc
irq_work_raise()
// mark irq work as IRQ_WORK_PENDING
irq_work_claim()
// task B preempts task A
unit_alloc()
// free_cnt = 30 after alloc
// irq work is already PENDING,
// so just return
irq_work_raise()
// does unit_alloc() 30-times
......
unit_alloc()
// free_cnt = 0 before alloc
return NULL
Fix it by enabling IRQ after irq_work_raise() completes. An alternative
fix is using preempt_{disable|enable}_notrace() pair, but it may have
extra overhead. Another feasible fix is to only disable preemption or
IRQ before invoking irq_work_queue() and enable preemption or IRQ after
the invocation completes, but it can't handle the case when
c->low_watermark is 1.
Yonghong Song [Sun, 27 Aug 2023 15:28:37 +0000 (08:28 -0700)]
bpf: Mark BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE deprecated
Now 'BPF_MAP_TYPE_CGRP_STORAGE + local percpu ptr'
can cover all BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE functionality
and more. So mark BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE deprecated.
Also make changes in selftests/bpf/test_bpftool_synctypes.py
and selftest libbpf_str to fix otherwise test errors.
Yonghong Song [Sun, 27 Aug 2023 15:28:32 +0000 (08:28 -0700)]
selftests/bpf: Add some negative tests
Add a few negative tests for common mistakes with using percpu kptr
including:
- store to percpu kptr.
- type mistach in bpf_kptr_xchg arguments.
- sleepable prog with untrusted arg for bpf_this_cpu_ptr().
- bpf_percpu_obj_new && bpf_obj_drop, and bpf_obj_new && bpf_percpu_obj_drop
- struct with ptr for bpf_percpu_obj_new
- struct with special field (e.g., bpf_spin_lock) for bpf_percpu_obj_new
Yonghong Song [Sun, 27 Aug 2023 15:28:27 +0000 (08:28 -0700)]
selftests/bpf: Add tests for cgrp_local_storage with local percpu kptr
Add a non-sleepable cgrp_local_storage test with percpu kptr. The
test does allocation of percpu data, assigning values to percpu
data and retrieval of percpu data. The de-allocation of percpu
data is done when the map is freed.
Yonghong Song [Sun, 27 Aug 2023 15:28:21 +0000 (08:28 -0700)]
selftests/bpf: Remove unnecessary direct read of local percpu kptr
For the second argument of bpf_kptr_xchg(), if the reg type contains
MEM_ALLOC and MEM_PERCPU, which means a percpu allocation,
after bpf_kptr_xchg(), the argument is marked as MEM_RCU and MEM_PERCPU
if in rcu critical section. This way, re-reading from the map value
is not needed. Remove it from the percpu_alloc_array.c selftest.
Without previous kernel change, the test will fail like below:
The R1 which gets its value from R6 is a scalar. But before insn 22, R6 is
R6=percpu_ptr_val_t(ref_obj_id=4,off=0,imm=0)
Its type is changed to a scalar at insn 22 without previous patch.
After bpf_kptr_xchg(), we need to re-read e->pc into 'p'.
This is due to that the second argument of bpf_kptr_xchg() is marked
OBJ_RELEASE and it will be marked as invalid after the call.
So after bpf_kptr_xchg(), 'p' is an unknown scalar,
and the bpf program needs to reread from the map value.
This patch checks if the 'p' has type MEM_ALLOC and MEM_PERCPU,
and if 'p' is RCU protected. If this is the case, 'p' can be marked
as MEM_RCU. MEM_ALLOC needs to be removed since 'p' is not
an owning reference any more. Such a change makes re-read
from the map value unnecessary.
Note that re-reading 'e->pc' after bpf_kptr_xchg() might get
a different value from 'p' if immediately before 'p = e->pc',
another cpu may do another bpf_kptr_xchg() and swap in another value
into 'e->pc'. If this is the case, then 'p = e->pc' may
get either 'p' or another value, and race condition already exists.
So removing direct re-reading seems fine too.
Yonghong Song [Sun, 27 Aug 2023 15:28:11 +0000 (08:28 -0700)]
selftests/bpf: Add tests for array map with local percpu kptr
Add non-sleepable and sleepable tests with percpu kptr. For
non-sleepable test, four programs are executed in the order of:
1. allocate percpu data.
2. assign values to percpu data.
3. retrieve percpu data.
4. de-allocate percpu data.
The sleepable prog tried to exercise all above 4 steps in a
single prog. Also for sleepable prog, rcu_read_lock is needed
to protect direct percpu ptr access (from map value) and
following bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers.
Andrii Nakryiko [Fri, 25 Aug 2023 20:21:52 +0000 (13:21 -0700)]
libbpf: Add basic BTF sanity validation
Implement a simple and straightforward BTF sanity check when parsing BTF
data. Right now it's very basic and just validates that all the string
offsets and type IDs are within valid range. For FUNC we also check that
it points to FUNC_PROTO kinds.
Even with such simple checks it fixes a bunch of crashes found by OSS
fuzzer ([0]-[5]) and will allow fuzzer to make further progress.
Some other invariants will be checked in follow up patches (like
ensuring there is no infinite type loops), but this seems like a good
start already.
Adding FUNC -> FUNC_PROTO check revealed that one of selftests has
a problem with FUNC pointing to VAR instead, so fix it up in the same
commit.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Song Liu <song@kernel.org> Closes: https://github.com/libbpf/libbpf/issues/617 Link: https://lore.kernel.org/bpf/20230825202152.1813394-1-andrii@kernel.org
Yonghong Song [Sun, 27 Aug 2023 15:27:49 +0000 (08:27 -0700)]
bpf: Add bpf_this_cpu_ptr/bpf_per_cpu_ptr support for allocated percpu obj
The bpf helpers bpf_this_cpu_ptr() and bpf_per_cpu_ptr() are re-purposed
for allocated percpu objects. For an allocated percpu obj,
the reg type is 'PTR_TO_BTF_ID | MEM_PERCPU | MEM_RCU'.
The return type for these two re-purposed helpera is
'PTR_TO_MEM | MEM_RCU | MEM_ALLOC'.
The MEM_ALLOC allows that the per-cpu data can be read and written.
Since the memory allocator bpf_mem_alloc() returns
a ptr to a percpu ptr for percpu data, the first argument
of bpf_this_cpu_ptr() and bpf_per_cpu_ptr() is patched
with a dereference before passing to the helper func.
Yonghong Song [Sun, 27 Aug 2023 15:27:44 +0000 (08:27 -0700)]
bpf: Add alloc/xchg/direct_access support for local percpu kptr
Add two new kfunc's, bpf_percpu_obj_new_impl() and
bpf_percpu_obj_drop_impl(), to allocate a percpu obj.
Two functions are very similar to bpf_obj_new_impl()
and bpf_obj_drop_impl(). The major difference is related
to percpu handling.
For a percpu data map_val like above 'v', the reg->type
is set as
PTR_TO_BTF_ID | MEM_PERCPU | MEM_RCU
if inside rcu critical section.
MEM_RCU marking here is similar to NON_OWN_REF as 'v'
is not a owning reference. But NON_OWN_REF is
trusted and typically inside the spinlock while
MEM_RCU is under rcu read lock. RCU is preferred here
since percpu data structures mean potential concurrent
access into its contents.
Also, bpf_percpu_obj_new_impl() is restricted such that
no pointers or special fields are allowed. Therefore,
the bpf_list_head and bpf_rb_root will not be supported
in this patch set to avoid potential memory leak issue
due to racing between bpf_obj_free_fields() and another
bpf_kptr_xchg() moving an allocated object to
bpf_list_head and bpf_rb_root.
where
#define __percpu_kptr __attribute__((btf_type_tag("percpu_kptr")))
While BPF_KPTR_REF points to a trusted kernel object or a trusted
local object, BPF_KPTR_PERCPU points to a trusted local
percpu object.
This patch added basic support for BPF_KPTR_PERCPU
related to percpu_kptr field parsing, recording and free operations.
BPF_KPTR_PERCPU also supports the same map types
as BPF_KPTR_REF does.
Note that unlike a local kptr, it is possible that
a BPF_KTPR_PERCPU struct may not contain any
special fields like other kptr, bpf_spin_lock, bpf_list_head, etc.
Yonghong Song [Sun, 27 Aug 2023 15:27:34 +0000 (08:27 -0700)]
bpf: Add support for non-fix-size percpu mem allocation
This is needed for later percpu mem allocation when the
allocation is done by bpf program. For such cases, a global
bpf_global_percpu_ma is added where a flexible allocation
size is needed.
- deal with integer overflows in kmalloc_reserve()
- use sk_forward_alloc_get() in sk_get_meminfo()
- bpf_sk_storage: fix the missing uncharge in sk_omem_alloc
- fib: avoid warn splat in flow dissector after packet mangling
- skb_segment: call zero copy functions before using skbuff frags
- eth: sfc: check for zero length in EF10 RX prefix
Previous releases - always broken:
- af_unix: fix msg_controllen test in scm_pidfd_recv() for
MSG_CMSG_COMPAT
- xsk: fix xsk_build_skb() dereferencing possible ERR_PTR()
- netfilter:
- nft_exthdr: fix non-linear header modification
- xt_u32, xt_sctp: validate user space input
- nftables: exthdr: fix 4-byte stack OOB write
- nfnetlink_osf: avoid OOB read
- one more fix for the garbage collection work from last release
- igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU
- bpf, sockmap: fix preempt_rt splat when using raw_spin_lock_t
- handshake: fix null-deref in handshake_nl_done_doit()
- ip: ignore dst hint for multipath routes to ensure packets are
hashed across the nexthops
- phy: micrel:
- correct bit assignments for cable test errata
- disable EEE according to the KSZ9477 errata
Merge tag 'pwm/for-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding:
"Various cleanups and fixes across the board"
* tag 'pwm/for-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (31 commits)
pwm: lpc32xx: Remove handling of PWM channels
pwm: atmel: Simplify using devm functions
dt-bindings: pwm: brcm,kona-pwm: convert to YAML
pwm: stmpe: Handle errors when disabling the signal
pwm: stm32: Simplify using devm_pwmchip_add()
pwm: stm32: Don't modify HW state in .remove() callback
pwm: Fix order of freeing resources in pwmchip_remove()
pwm: ntxec: Use device_set_of_node_from_dev()
pwm: ntxec: Drop a write-only variable from driver data
pwm: pxa: Don't reimplement of_device_get_match_data()
pwm: lpc18xx-sct: Simplify using devm_clk_get_enabled()
pwm: atmel-tcb: Don't track polarity in driver data
pwm: atmel-tcb: Unroll atmel_tcb_pwm_set_polarity() into only caller
pwm: atmel-tcb: Put per-channel data into driver data
pwm: atmel-tcb: Fix resource freeing in error path and remove
pwm: atmel-tcb: Harmonize resource allocation order
pwm: Drop unused #include <linux/radix-tree.h>
pwm: rz-mtu3: Fix build warning 'num_channel_ios' not described
pwm: Remove outdated documentation for pwmchip_remove()
pwm: atmel: Enable clk when pwm already enabled in bootloader
...
Merge tag 'rtc-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
"Subsystem:
- Add a way for drivers to tell the core the supported alarm range is
smaller than the date range. This is not used yet but will be
useful for the alarmtimers in the next release.
- fix Wvoid-pointer-to-enum-cast warnings
- remove redundant of_match_ptr()
- stop warning for invalid alarms when the alarm is disabled
Drivers:
- isl12022: allow setting the trip level for battery level detection
- pcf2127: add support for PCF2131 and multiple timestamps
- stm32: time precision improvement, many fixes
- twl: NVRAM support"
* tag 'rtc-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (73 commits)
dt-bindings: rtc: ds3231: Remove text binding
rtc: wm8350: remove unnecessary messages
rtc: twl: remove unnecessary messages
rtc: sun6i: remove unnecessary message
rtc: stop warning for invalid alarms when the alarm is disabled
rtc: twl: add NVRAM support
rtc: pcf85363: Allow to wake up system without IRQ
rtc: m48t86: add DT support for m48t86
dt-bindings: rtc: Add ST M48T86
rtc: pcf2127: remove useless check
rtc: rzn1: Report maximum alarm limit to rtc core
rtc: ds1305: Report maximum alarm limit to rtc core
rtc: tps6586x: Report maximum alarm limit to rtc core
rtc: cmos: Report supported alarm limit to rtc infrastructure
rtc: cros-ec: Detect and report supported alarm window size
rtc: Add support for limited alarm timer offsets
rtc: isl1208: Fix incorrect logic in isl1208_set_xtoscb()
MAINTAINERS: remove obsolete pattern in RTC SUBSYSTEM section
rtc: tps65910: Remove redundant dev_warn() and do not check for 0 return after calling platform_get_irq()
rtc: omap: Do not check for 0 return after calling platform_get_irq()
...
Merge tag 'i3c/for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux
Pull i3c updates from Alexandre Belloni:
"Core:
- Fix SETDASA when static and dynamic adress are equal
- Fix cmd_v1 DAA exit criteria
Drivers:
- svc: allow probing without any device"
* tag 'i3c/for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
i3c: master: svc: fix probe failure when no i3c device exist
i3c: master: Fix SETDASA process
dt-bindings: i3c: Fix description for assigned-address
i3c: master: svc: Describe member 'saved_regs'
i3c: master: svc: Do not check for 0 return after calling platform_get_irq()
i3c/master: cmd_v1: Fix the exit criteria for the daa procedure
i3c: Explicitly include correct DT includes
Merge tag 'regulator-fix-v6.6-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator fixes from Mark Brown:
"A couple of fixes that came in during the merge window, both driver
specific - one for a bug that came up in testing, one for a bug due
to a misreading of the datasheet"
* tag 'regulator-fix-v6.6-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: tps6594-regulator: Fix random kernel crash
regulator: tps6287x: Fix n_voltages
Merge tag 'spi-fix-v6.6-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
"A couple of fixes for the sun6i driver. The patch to reduce DMA RX to
single byte width all the time is *hopefully* excessively cautious but
it's unclear which SoCs are affected so the fix just covers everything
for safety"
* tag 'spi-fix-v6.6-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: sun6i: fix race between DMA RX transfer completion and RX FIFO drain
spi: sun6i: reduce DMA RX transfer width to single byte
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"ARM:
- Clean up vCPU targets, always returning generic v8 as the preferred
target
- Trap forwarding infrastructure for nested virtualization (used for
traps that are taken from an L2 guest and are needed by the L1
hypervisor)
- FEAT_TLBIRANGE support to only invalidate specific ranges of
addresses when collapsing a table PTE to a block PTE. This avoids
that the guest refills the TLBs again for addresses that aren't
covered by the table PTE.
- Fix vPMU issues related to handling of PMUver.
- Don't unnecessary align non-stack allocations in the EL2 VA space
- Drop HCR_VIRT_EXCP_MASK, which was never used...
- Don't use smp_processor_id() in kvm_arch_vcpu_load(), but the cpu
parameter instead
- Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort()
- Remove prototypes without implementations
RISC-V:
- Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for guest
- Added ONE_REG interface for SATP mode
- Added ONE_REG interface to enable/disable multiple ISA extensions
- Improved error codes returned by ONE_REG interfaces
- Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V
Allows a PV guest to use crypto cards. Card access is governed by
the firmware and once a crypto queue is "bound" to a PV VM every
other entity (PV or not) looses access until it is not bound
anymore. Enablement is done via flags when creating the PV VM.
- Guest debug fixes (Ilya)
x86:
- Clean up KVM's handling of Intel architectural events
- Intel bugfixes
- Add support for SEV-ES DebugSwap, allowing SEV-ES guests to use
debug registers and generate/handle #DBs
- Clean up LBR virtualization code
- Fix a bug where KVM fails to set the target pCPU during an IRTE
update
- Fix fatal bugs in SEV-ES intrahost migration
- Fix a bug where the recent (architecturally correct) change to
reinject #BP and skip INT3 broke SEV guests (can't decode INT3 to
skip it)
- Retry APIC map recalculation if a vCPU is added/enabled
- Overhaul emergency reboot code to bring SVM up to par with VMX, tie
the "emergency disabling" behavior to KVM actually being loaded,
and move all of the logic within KVM
- Fix user triggerable WARNs in SVM where KVM incorrectly assumes the
TSC ratio MSR cannot diverge from the default when TSC scaling is
disabled up related code
- Add a framework to allow "caching" feature flags so that KVM can
check if the guest can use a feature without needing to search
guest CPUID
- Rip out the ancient MMU_DEBUG crud and replace the useful bits with
CONFIG_KVM_PROVE_MMU
- Fix KVM's handling of !visible guest roots to avoid premature
triple fault injection
- Overhaul KVM's page-track APIs, and KVMGT's usage, to reduce the
API surface that is needed by external users (currently only
KVMGT), and fix a variety of issues in the process
Generic:
- Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier
events to pass action specific data without needing to constantly
update the main handlers.
- Drop unused function declarations
Selftests:
- Add testcases to x86's sync_regs_test for detecting KVM TOCTOU bugs
- Add support for printf() in guest code and covert all guest asserts
to use printf-based reporting
- Clean up the PMU event filter test and add new testcases
- Include x86 selftests in the KVM x86 MAINTAINERS entry"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (279 commits)
KVM: x86/mmu: Include mmu.h in spte.h
KVM: x86/mmu: Use dummy root, backed by zero page, for !visible guest roots
KVM: x86/mmu: Disallow guest from using !visible slots for page tables
KVM: x86/mmu: Harden TDP MMU iteration against root w/o shadow page
KVM: x86/mmu: Harden new PGD against roots without shadow pages
KVM: x86/mmu: Add helper to convert root hpa to shadow page
drm/i915/gvt: Drop final dependencies on KVM internal details
KVM: x86/mmu: Handle KVM bookkeeping in page-track APIs, not callers
KVM: x86/mmu: Drop @slot param from exported/external page-track APIs
KVM: x86/mmu: Bug the VM if write-tracking is used but not enabled
KVM: x86/mmu: Assert that correct locks are held for page write-tracking
KVM: x86/mmu: Rename page-track APIs to reflect the new reality
KVM: x86/mmu: Drop infrastructure for multiple page-track modes
KVM: x86/mmu: Use page-track notifiers iff there are external users
KVM: x86/mmu: Move KVM-only page-track declarations to internal header
KVM: x86: Remove the unused page-track hook track_flush_slot()
drm/i915/gvt: switch from ->track_flush_slot() to ->track_remove_region()
KVM: x86: Add a new page-track hook to handle memslot deletion
drm/i915/gvt: Don't bother removing write-protection on to-be-deleted slot
KVM: x86: Reject memslot MOVE operations if KVMGT is attached
...
Vladimir Oltean [Wed, 6 Sep 2023 14:16:09 +0000 (17:16 +0300)]
net: enetc: distinguish error from valid pointers in enetc_fixup_clear_rss_rfs()
enetc_psi_create() returns an ERR_PTR() or a valid station interface
pointer, but checking for the non-NULL quality of the return code blurs
that difference away. So if enetc_psi_create() fails, we call
enetc_psi_destroy() when we shouldn't. This will likely result in
crashes, since enetc_psi_create() cleans up everything after itself when
it returns an ERR_PTR().
Fixes: f0168042a212 ("net: enetc: reimplement RFS/RSS memory clearing as PCI quirk") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/netdev/582183ef-e03b-402b-8e2d-6d9bb3c83bd9@moroto.mountain/ Suggested-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20230906141609.247579-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge tag 's390-6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Heiko Carstens:
- A couple of virtual vs physical address confusion fixes
- Rework locking in dcssblk driver to address a lockdep warning
- Remove support for "noexec" kernel command line option since there is
no use case where it would make sense
- Simplify kernel mapping setup and get rid of quite a bit of code
- Add architecture specific __set_memory_yy() functions which allow us
to modify kernel mappings. Unlike the set_memory_xx() variants they
take void pointer start and end parameters, which allows using them
without the usual casts, and also to use them on areas larger than
8TB.
Note that the set_memory_xx() family comes with an int num_pages
parameter which overflows with 8TB. This could be addressed by
changing the num_pages parameter to unsigned long, however requires
to change all architectures, since the module code expects an int
parameter (see module_set_memory()).
This was indeed an issue since for debug_pagealloc() we call
set_memory_4k() on the whole identity mapping. Therefore address this
for now with the __set_memory_yy() variant, and address common code
later
- Use dev_set_name() and also fix memory leak in zcrypt driver error
handling
- Remove unused lsi_mask from airq_struct
- Add warning for invalid kernel mapping requests
* tag 's390-6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/vmem: do not silently ignore mapping limit
s390/zcrypt: utilize dev_set_name() ability to use a formatted string
s390/zcrypt: don't leak memory if dev_set_name() fails
s390/mm: fix MAX_DMA_ADDRESS physical vs virtual confusion
s390/airq: remove lsi_mask from airq_struct
s390/mm: use __set_memory() variants where useful
s390/set_memory: add __set_memory() variant
s390/set_memory: generate all set_memory() functions
s390/mm: improve description of mapping permissions of prefix pages
s390/amode31: change type of __samode31, __eamode31, etc
s390/mm: simplify kernel mapping setup
s390: remove "noexec" option
s390/vmem: fix virtual vs physical address confusion
s390/dcssblk: fix lockdep warning
s390/monreader: fix virtual vs physical address confusion
Merge tag 'xtensa-20230905' of https://github.com/jcmvbkbc/linux-xtensa
Pull xtensa updates from Max Filippov:
- enable MTD XIP support
- fix base address of the xtensa perf module in newer hardware
* tag 'xtensa-20230905' of https://github.com/jcmvbkbc/linux-xtensa:
xtensa: add XIP-aware MTD support
xtensa: PMU: fix base address for the newer hardware
Christian Brauner [Thu, 7 Sep 2023 16:03:40 +0000 (18:03 +0200)]
ntfs3: drop inode references in ntfs_put_super()
Recently we moved most cleanup from ntfs_put_super() into
ntfs3_kill_sb() as part of a bigger cleanup. This accidently also moved
dropping inode references stashed in ntfs3's sb->s_fs_info from
@sb->put_super() to @sb->kill_sb(). But generic_shutdown_super()
verifies that there are no busy inodes past sb->put_super(). Fix this
and disentangle dropping inode references from freeing @sb->s_fs_info.
Fixes: a4f64a300a29 ("ntfs3: free the sbi in ->kill_sb") # mainline only Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vfs: mostly undo glibc turning 'fstat()' into 'fstatat(AT_EMPTY_PATH)'
Mateusz reports that glibc turns 'fstat()' calls into 'fstatat()', and
that seems to have been going on for quite a long time due to glibc
having tried to simplify its stat logic into just one point.
This turns out to cause completely unnecessary overhead, where we then
go off and allocate the kernel side pathname, and actually look up the
empty path. Sure, our path lookup is quite optimized, but it still
causes a fair bit of allocation overhead and a couple of completely
unnecessary rounds of lockref accesses etc.
This is all hopefully getting fixed in user space, and there is a patch
floating around for just having glibc use the native fstat() system
call. But even with the current situation we can at least improve on
things by catching the situation and short-circuiting it.
Note that this is still measurably slower than just a plain 'fstat()',
since just checking that the filename is actually empty is somewhat
expensive due to inevitable user space access overhead from the kernel
(ie verifying pointers, and SMAP on x86). But it's still quite a bit
faster than actually looking up the path for real.
To quote numers from Mateusz:
"Sapphire Rapids, will-it-scale, ops/s
where that 'stock fstat' is the glibc translation of fstat into
fstatat() with an empty path, the 'patched fstat' is with this short
circuiting of the path lookup, and the 'real fstat' is the actual native
fstat() system call with none of this overhead.
Paolo Abeni [Thu, 7 Sep 2023 09:47:15 +0000 (11:47 +0200)]
Merge tag 'nf-23-09-06' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Florian Westphal says:
====================
netfilter updates for net
This PR contains nf_tables updates for your *net* tree.
This time almost all fixes are for old bugs:
First patch fixes a 4-byte stack OOB write, from myself.
This was broken ever since nftables was switches from 128 to 32bit
register addressing in v4.1.
2nd patch fixes an out-of-bounds read.
This has been broken ever since xt_osf got added in 2.6.31, the bug
was then just moved around during refactoring, from Wander Lairson Costa.
3rd patch adds a missing enum description, from Phil Sutter.
4th patch fixes a UaF inftables that occurs when userspace adds
elements with a timeout so small that expiration happens while the
transaction is still in progress. Fix from Pablo Neira Ayuso.
Patch 5 fixes a memory out of bounds access, this was
broken since v4.20. Patch from Kyle Zeng and Jozsef Kadlecsik.
Patch 6 fixes another bogus memory access when building audit
record. Bug added in the previous pull request, fix from Pablo.
netfilter pull request 2023-09-06
* tag 'nf-23-09-06' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nf_tables: Unbreak audit log reset
netfilter: ipset: add the missing IP_SET_HASH_WITH_NET0 macro for ip_set_hash_netportnet.c
netfilter: nft_set_rbtree: skip sync GC for new elements in this transaction
netfilter: nf_tables: uapi: Describe NFTA_RULE_CHAIN_ID
netfilter: nfnetlink_osf: avoid OOB read
netfilter: nftables: exthdr: fix 4-byte stack OOB write
====================
Jie Wang [Wed, 6 Sep 2023 07:20:18 +0000 (15:20 +0800)]
net: hns3: remove GSO partial feature bit
HNS3 NIC does not support GSO partial packets segmentation. Actually tunnel
packets for example NvGRE packets segment offload and checksum offload is
already supported. There is no need to keep gso partial feature bit. So
this patch removes it.
Fixes: 76ad4f0ee747 ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC") Signed-off-by: Jie Wang <wangjie125@huawei.com> Signed-off-by: Jijie Shao <shaojijie@huawei.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
net: hns3: fix invalid mutex between tc qdisc and dcb ets command issue
We hope that tc qdisc and dcb ets commands can not be used crosswise.
If we want to use any of the commands to configure tc,
We must use the other command to clear the existing configuration.
However, when we configure a single tc with tc qdisc,
we can still configure it with dcb ets.
Because we use mqprio_active as the tag of tc qdisc configuration,
but with dcb ets, we do not check mqprio_active.
This patch fix this issue by check mqprio_active before
executing the dcb ets command. and add dcb_ets_active to
replace HCLGE_FLAG_DCB_ENABLE and HCLGE_FLAG_MQPRIO_ENABLE
at the hclge layer,
Fixes: cacde272dd00 ("net: hns3: Add hclge_dcb module for the support of DCB feature") Signed-off-by: Jijie Shao <shaojijie@huawei.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
net: hns3: fix byte order conversion issue in hclge_dbg_fd_tcam_read()
req1->tcam_data is defined as "u8 tcam_data[8]", and we convert it as
(u32 *) without considerring byte order conversion,
it may result in printing wrong data for tcam_data.
Currently, the driver knocks the ring doorbell before updating
the ring->last_to_use in tx flow. if the hardware transmiting
packet and napi poll scheduling are fast enough, it may get
the old ring->last_to_use in drivers' napi poll.
In this case, the driver will think the tx is not completed, and
return directly without clear the flag __QUEUE_STATE_STACK_XOFF,
which may cause tx timeout.
projects / users / jedix / linux-maple.git / log