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Currently, for rqspinlock usage, the implementation of
smp_cond_load_acquire (and thus, atomic_cond_read_acquire) are
susceptible to stalls on arm64, because they do not guarantee that the
conditional expression will be repeatedly invoked if the address being
loaded from is not written to by other CPUs. When support for
event-streams is absent (which unblocks stuck WFE-based loops every
~100us), we may end up being stuck forever.
This causes a problem for us, as we need to repeatedly invoke the
RES_CHECK_TIMEOUT in the spin loop to break out when the timeout
expires.
Let us import the smp_cond_load_acquire_timewait implementation Ankur is
proposing in [0], and then fallback to it once it is merged.
While we rely on the implementation to amortize the cost of sampling
check_timeout for us, it will not happen when event stream support is
unavailable. This is not the common case, and it would be difficult to
fit our logic in the time_expr_ns >= time_limit_ns comparison, hence
just let it be.
[0]: https://lore.kernel.org/lkml/20250203214911.898276-1-ankur.a.arora@oracle.com
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-9-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Introduce policy macro RES_CHECK_TIMEOUT which can be used to detect
when the timeout has expired for the slow path to return an error. It
depends on being passed two variables initialized to 0: ts, ret. The
'ts' parameter is of type rqspinlock_timeout.
This macro resolves to the (ret) expression so that it can be used in
statements like smp_cond_load_acquire to break the waiting loop
condition.
The 'spin' member is used to amortize the cost of checking time by
dispatching to the implementation every 64k iterations. The
'timeout_end' member is used to keep track of the timestamp that denotes
the end of the waiting period. The 'ret' parameter denotes the status of
the timeout, and can be checked in the slow path to detect timeouts
after waiting loops.
The 'duration' member is used to store the timeout duration for each
waiting loop. The default timeout value defined in the header
(RES_DEF_TIMEOUT) is 0.25 seconds.
This macro will be used as a condition for waiting loops in the slow
path. Since each waiting loop applies a fresh timeout using the same
rqspinlock_timeout, we add a new RES_RESET_TIMEOUT as well to ensure the
values can be easily reinitialized to the default state.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Changes to rqspinlock in subsequent commits will be algorithmic
modifications, which won't remain in agreement with the implementations
of paravirt spin lock and virt_spin_lock support. These future changes
include measures for terminating waiting loops in slow path after a
certain point. While using a fair lock like qspinlock directly inside
virtual machines leads to suboptimal performance under certain
conditions, we cannot use the existing virtualization support before we
make it resilient as well. Therefore, drop it for now.
Note that we need to drop qspinlock_stat.h, as it's only relevant in
case of CONFIG_PARAVIRT_SPINLOCKS=y, but we need to keep lock_events.h
in the includes, which was indirectly pulled in before.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This header contains the public declarations usable in the rest of the
kernel for rqspinlock.
Let's also type alias qspinlock to rqspinlock_t to ensure consistent use
of the new lock type. We want to remove dependence on the qspinlock type
in later patches as we need to provide a test-and-set fallback, hence
begin abstracting away from now onwards.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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In preparation for introducing a new lock implementation, Resilient
Queued Spin Lock, or rqspinlock, we first begin our modifications by
using the existing qspinlock.c code as the base. Simply copy the code to
a new file and rename functions and variables from 'queued' to
'resilient_queued'.
Since we place the file in kernel/bpf, include needs to be relative.
This helps each subsequent commit in clearly showing how and where the
code is being changed. The only change after a literal copy in this
commit is renaming the functions where necessary, and rename qnodes to
rqnodes. Let's also use EXPORT_SYMBOL_GPL for rqspinlock slowpath.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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To support upcoming changes that require inspecting the return value
once the conditional waiting loop in arch_mcs_spin_lock_contended
terminates, modify the macro to preserve the result of
smp_cond_load_acquire. This enables checking the return value as needed,
which will help disambiguate the MCS node’s locked state in future
patches.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Move qspinlock helper functions that encode, decode tail word, set and
clear the pending and locked bits, and other miscellaneous definitions
and macros to a private header. To this end, create a qspinlock.h header
file in kernel/locking. Subsequent commits will introduce a modified
qspinlock slow path function, thus moving shared code to a private
header will help minimize unnecessary code duplication.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Move the definition of the struct mcs_spinlock from the private
mcs_spinlock.h header in kernel/locking to the mcs_spinlock.h
asm-generic header, since we will need to reference it from the
qspinlock.h header in subsequent commits.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The perf_event_read_event_output helper is currently only available to
tracing protrams, but is useful for other BPF programs like sched_ext
schedulers. When the helper is available, provide its bpf_func_proto
directly from the bpf base_proto.
Signed-off-by: Emil Tsalapatis (Meta) <emil@etsalapatis.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20250318030753.10949-1-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Jiayuan Chen says:
====================
bpftool: Using the right format specifiers
This patch adds the -Wformat-signedness compiler flag to detect and
prevent format string errors, where signed or unsigned types are
mismatched with format specifiers. Additionally, it fixes some format
string errors that were not fully addressed by the previous patch [1].
[1] https://lore.kernel.org/bpf/20250207123706.727928-1-mrpre@163.com/T/#u
---
v1->v2:
https://lore.kernel.org/bpf/20250310142037.45932-1-jiayuan.chen@linux.dev/
---
====================
Link: https://patch.msgid.link/20250311112809.81901-1-jiayuan.chen@linux.dev
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
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Fixed some formatting specifiers errors, such as using %d for int and %u
for unsigned int, as well as other byte-length types.
Perform type cast using the type derived from the data type itself, for
example, if it's originally an int, it will be cast to unsigned int if
forced to unsigned.
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250311112809.81901-3-jiayuan.chen@linux.dev
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This commit adds the -Wformat-signedness compiler flag to detect and
prevent printf format errors, where signed or unsigned types are
mismatched with format specifiers. This helps to catch potential issues at
compile-time, ensuring that our code is more robust and reliable. With
this flag, the compiler will now warn about incorrect format strings, such
as using %d with unsigned types or %u with signed types.
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250311112809.81901-2-jiayuan.chen@linux.dev
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Mykyta Yatsenko says:
====================
Support freplace prog from user namespace
From: Mykyta Yatsenko <yatsenko@meta.com>
Freplace programs can't be loaded from user namespace, as
bpf_program__set_attach_target() requires searching for target prog BTF,
which is locked under CAP_SYS_ADMIN.
This patch set enables this use case by:
1. Relaxing capable check in bpf's BPF_BTF_GET_FD_BY_ID, check for CAP_BPF
instead of CAP_SYS_ADMIN, support BPF token in attr argument.
2. Pass BPF token around libbpf from bpf_program__set_attach_target() to
bpf syscall where capable check is.
3. Validate positive/negative scenarios in selftests
This patch set is enabled by the recent libbpf change[1], that
introduced bpf_object__prepare() API. Calling bpf_object__prepare() for
freplace program before bpf_program__set_attach_target() initializes BPF
token, which is then passed to bpf syscall by libbpf.
[1] https://lore.kernel.org/all/20250303135752.158343-1-mykyta.yatsenko5@gmail.com/
====================
Link: https://patch.msgid.link/20250317174039.161275-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
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Add selftests to verify that it is possible to load freplace program
from user namespace if BPF token is initialized by bpf_object__prepare
before calling bpf_program__set_attach_target.
Negative test is added as well.
Modified type of the priv_prog to xdp, as kprobe did not work on aarch64
and s390x.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250317174039.161275-5-mykyta.yatsenko5@gmail.com
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Pass BPF token from bpf_program__set_attach_target to
BPF_BTF_GET_FD_BY_ID bpf command.
When freplace program attaches to target program, it needs to look up
for BTF of the target, this may require BPF token, if, for example,
running from user namespace.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250317174039.161275-4-mykyta.yatsenko5@gmail.com
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Return prog's btf_id from bpf_prog_get_info_by_fd regardless of capable
check. This patch enables scenario, when freplace program, running
from user namespace, requires to query target prog's btf.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250317174039.161275-3-mykyta.yatsenko5@gmail.com
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Currently BPF_BTF_GET_FD_BY_ID requires CAP_SYS_ADMIN, which does not
allow running it from user namespace. This creates a problem when
freplace program running from user namespace needs to query target
program BTF.
This patch relaxes capable check from CAP_SYS_ADMIN to CAP_BPF and adds
support for BPF token that can be passed in attributes to syscall.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250317174039.161275-2-mykyta.yatsenko5@gmail.com
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Kernel test robot reported "call without frame pointer save/setup"
warning in objtool. This will make stack traces unreliable on
CONFIG_UNWINDER_FRAME_POINTER=y, however it works on
CONFIG_UNWINDER_ORC=y. Fix this by creating a stack frame for the
function.
Fixes: 2fb761823ead ("bpf, x86: Add x86 JIT support for timed may_goto")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202503071350.QOhsHVaW-lkp@intel.com/
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250315013039.1625048-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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When there are no special fields in the map value, there is no need to
invoke bpf_obj_free_fields(). Therefore, checking the validity of
map->record in advance.
After the change, the benchmark result of the per-cpu update case in
map_perf_test increased by 40% under a 16-CPU VM.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250315150930.1511727-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The SO_RCVLOWAT option is defined as 18 in the selftest header,
which matches the generic definition. However, on powerpc,
SO_RCVLOWAT is defined as 16. This discrepancy causes
sol_socket_sockopt() to fail with the default switch case on powerpc.
This commit fixes by defining SO_RCVLOWAT as 16 for powerpc.
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20250311084647.3686544-1-skb99@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The strncmp benchmark uses the bpf_strncmp helper and a hand-written
loop to compare two strings. The values of the strings are filled from
userspace. One of the strings is non-const (in .bss) while the other is
const (in .rodata) since that is the requirement of bpf_strncmp.
The problem is that in the hand-written loop, Clang optimizes the reads
from the const string to always return 0 which breaks the benchmark.
Use barrier_var to prevent the optimization.
The effect can be seen on the strncmp-no-helper variant.
Before this change:
# ./bench strncmp-no-helper
Setting up benchmark 'strncmp-no-helper'...
Benchmark 'strncmp-no-helper' started.
Iter 0 (112.309us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 1 (-23.238us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 2 ( 58.994us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 3 (-30.466us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 4 ( 29.996us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 5 ( 16.949us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 6 (-60.035us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Summary: hits 0.000 ± 0.000M/s ( 0.000M/prod), drops 0.000 ± 0.000M/s, total operations 0.000 ± 0.000M/s
After this change:
# ./bench strncmp-no-helper
Setting up benchmark 'strncmp-no-helper'...
Benchmark 'strncmp-no-helper' started.
Iter 0 ( 77.711us): hits 5.534M/s ( 5.534M/prod), drops 0.000M/s, total operations 5.534M/s
Iter 1 ( 11.215us): hits 6.006M/s ( 6.006M/prod), drops 0.000M/s, total operations 6.006M/s
Iter 2 (-14.253us): hits 5.931M/s ( 5.931M/prod), drops 0.000M/s, total operations 5.931M/s
Iter 3 ( 59.087us): hits 6.005M/s ( 6.005M/prod), drops 0.000M/s, total operations 6.005M/s
Iter 4 (-21.379us): hits 6.010M/s ( 6.010M/prod), drops 0.000M/s, total operations 6.010M/s
Iter 5 (-20.310us): hits 5.861M/s ( 5.861M/prod), drops 0.000M/s, total operations 5.861M/s
Iter 6 ( 53.937us): hits 6.004M/s ( 6.004M/prod), drops 0.000M/s, total operations 6.004M/s
Summary: hits 5.969 ± 0.061M/s ( 5.969M/prod), drops 0.000 ± 0.000M/s, total operations 5.969 ± 0.061M/s
Fixes: 9c42652f8be3 ("selftests/bpf: Add benchmark for bpf_strncmp() helper")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/bpf/20250313122852.1365202-1-vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Venkat reported a compilation error for BPF selftests on PowerPC [0].
The crux of the error is the following message:
In file included from progs/arena_spin_lock.c:7:
/root/bpf-next/tools/testing/selftests/bpf/bpf_arena_spin_lock.h:122:8:
error: member reference base type '__attribute__((address_space(1)))
u32' (aka '__attribute__((address_space(1))) unsigned int') is not a
structure or union
122 | old = atomic_read(&lock->val);
This is because PowerPC overrides the qspinlock type changing the
lock->val member's type from atomic_t to u32.
To remedy this, import the asm-generic version in the arena spin lock
header, name it __qspinlock (since it's aliased to arena_spinlock_t, the
actual name hardly matters), and adjust the selftest to not depend on
the type in vmlinux.h.
[0]: https://lore.kernel.org/bpf/7bc80a3b-d708-4735-aa3b-6a8c21720f9d@linux.ibm.com
Fixes: 88d706ba7cc5 ("selftests/bpf: Introduce arena spin lock")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20250311154244.3775505-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Modpost complains when extra warnings are enabled:
WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/bpf/preload/bpf_preload.o
Add a description from the Kconfig help text.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250310134920.4123633-1-arnd@kernel.org
----
Not sure if that description actually fits what the module does. If not,
please add a different description instead.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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We are missing setting error code in do_loader() when
bpf_object__open_file() fails. This means the command's exit status code
will be successful, even though the operation failed. So make sure to
return the correct error code. To maintain consistency with other
locations where bpf_object__open_file() is called, return -1.
[0] Closes: https://github.com/libbpf/bpftool/issues/156
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Sewon Nam <swnam0729@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Quentin Monnet <qmo@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/d3b5b4b4-19bb-4619-b4dd-86c958c4a367@stanley.mountain/t/#u
Link: https://lore.kernel.org/bpf/20250311031238.14865-1-swnam0729@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Blaise Boscaccy says:
====================
While trying to implement an eBPF gatekeeper program, we ran into an
issue whereas the LSM hooks are missing some relevant data.
Certain subcommands passed to the bpf() syscall can be invoked from
either the kernel or userspace. Additionally, some fields in the
bpf_attr struct contain pointers, and depending on where the
subcommand was invoked, they could point to either user or kernel
memory. One example of this is the bpf_prog_load subcommand and its
fd_array. This data is made available and used by the verifier but not
made available to the LSM subsystem. This patchset simply exposes that
information to applicable LSM hooks.
Change list:
- v6 -> v7
- use gettid/pid in lieu of getpid/tgid in test condition
- v5 -> v6
- fix regression caused by is_kernel renaming
- simplify test logic
- v4 -> v5
- merge v4 selftest breakout patch back into a single patch
- change "is_kernel" to "kernel"
- add selftest using new kernel flag
- v3 -> v4
- split out selftest changes into a separate patch
- v2 -> v3
- reorder params so that the new boolean flag is the last param
- fixup function signatures in bpf selftests
- v1 -> v2
- Pass a boolean flag in lieu of bpfptr_t
Revisions:
- v6
https://lore.kernel.org/bpf/20250308013314.719150-1-bboscaccy@linux.microsoft.com/
- v5
https://lore.kernel.org/bpf/20250307213651.3065714-1-bboscaccy@linux.microsoft.com/
- v4
https://lore.kernel.org/bpf/20250304203123.3935371-1-bboscaccy@linux.microsoft.com/
- v3
https://lore.kernel.org/bpf/20250303222416.3909228-1-bboscaccy@linux.microsoft.com/
- v2
https://lore.kernel.org/bpf/20250228165322.3121535-1-bboscaccy@linux.microsoft.com/
- v1
https://lore.kernel.org/bpf/20250226003055.1654837-1-bboscaccy@linux.microsoft.com/
====================
Link: https://patch.msgid.link/20250310221737.821889-1-bboscaccy@linux.microsoft.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Replace comma between expressions with semicolons.
Using a ',' in place of a ';' can have unintended side effects.
Although that is not the case here, it is seems best to use ';'
unless ',' is intended.
Found by inspection.
No functional change intended.
Compile tested only.
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Anton Protopopov <aspsk@isovalent.com>
Link: https://lore.kernel.org/bpf/20250310032045.651068-1-nichen@iscas.ac.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This test exercises the kernel flag added to security_bpf by
effectively blocking light-skeletons from loading while allowing
normal skeletons to function as-is. Since this should work with any
arbitrary BPF program, an existing program from LSKELS_EXTRA was
used as a test payload.
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20250310221737.821889-3-bboscaccy@linux.microsoft.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The Makefile uses the exit code of the `llvm-config --link-static --libs`
command to choose between statically-linked and dynamically-linked LLVMs.
The stdout and stderr of that command are redirected to /dev/null.
To redirect the output the "&>" construction is used, which might not be
supported by /bin/sh, which is executed by make for $(shell ...) commands.
On such systems the test will fail even if static LLVM is actually
supported. Replace "&>" by ">/dev/null 2>&1" to fix this.
Fixes: 2a9d30fac818 ("selftests/bpf: Support dynamically linking LLVM if static is not available")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/bpf/20250310145112.1261241-1-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Certain bpf syscall subcommands are available for usage from both
userspace and the kernel. LSM modules or eBPF gatekeeper programs may
need to take a different course of action depending on whether or not
a BPF syscall originated from the kernel or userspace.
Additionally, some of the bpf_attr struct fields contain pointers to
arbitrary memory. Currently the functionality to determine whether or
not a pointer refers to kernel memory or userspace memory is exposed
to the bpf verifier, but that information is missing from various LSM
hooks.
Here we augment the LSM hooks to provide this data, by simply passing
a boolean flag indicating whether or not the call originated in the
kernel, in any hook that contains a bpf_attr struct that corresponds
to a subcommand that may be called from the kernel.
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250310221737.821889-2-bboscaccy@linux.microsoft.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Emil Tsalapatis says:
====================
bpf: introduce helper for populating bpf_cpumask
Some BPF programs like scx schedulers have their own internal CPU mask types,
mask types, which they must transform into struct bpf_cpumask instances
before passing them to scheduling-related kfuncs. There is currently no
way to efficiently populate the bitfield of a bpf_cpumask from BPF memory,
and programs must use multiple bpf_cpumask_[set, clear] calls to do so.
Introduce a kfunc helper to populate the bitfield of a bpf_cpumask from valid
BPF memory with a single call.
Changelog :
-----------
v6->v7
v6:https://lore.kernel.org/bpf/20250307153847.8530-1-emil@etsalapatis.com/
Addressed feedback by Hou Tao:
* Removed RUN_TESTS invocation causing tests to run twice
* Added is_test_task guard to new selftests
* Removed extraneous __success attribute from existing selftests
v5->v6
v5:https://lore.kernel.org/bpf/20250307041738.6665-1-emil@etsalapatis.com/
Addressed feedback by Hou Tao:
* Removed __success attributes from cpumask selftests
* Fixed stale patch description that used old function name
v4->v5
v4: https://lore.kernel.org/bpf/20250305211235.368399-1-emil@etsalapatis.com/
Addressed feedback by Hou Tao:
* Readded the tests in tools/selftests/bpf/prog_tests/cpumask.c,
turns out the selftest entries were not duplicates.
* Removed stray whitespace in selftest.
* Add patch the missing selftest to prog_tests/cpumask.c
* Explicitly annotate all cpumask selftests with __success
The last patch could very well be its own cleanup patch, but I rolled it into
this series because it came up in the discussion. If the last patch in the
series has any issues I'd be fine with applying the first 3 patches and dealing
with it separately.
v3->v4
v3: https://lore.kernel.org/bpf/20250305161327.203396-1-emil@etsalapatis.com/
* Removed new tests from tools/selftests/bpf/prog_tests/cpumask.c because
they were being run twice.
Addressed feedback by Alexei Starovoitov:
* Added missing return value in function kdoc
* Added an additional patch fixing some missing kdoc fields in
kernel/bpf/cpumask.c
Addressed feedback by Tejun Heo:
* Renamed the kfunc to bpf_cpumask_populate to avoid confusion
w/ bitmap_fill()
v2->v3
v2: https://lore.kernel.org/bpf/20250305021020.1004858-1-emil@etsalapatis.com/
Addressed feedback by Alexei Starovoitov:
* Added back patch descriptions dropped from v1->v2
* Elide the alignment check for archs with efficient
unaligned accesses
v1->v2
v1: https://lore.kernel.org/bpf/20250228003321.1409285-1-emil@etsalapatis.com/
Addressed feedback by Hou Tao:
* Add check that the input buffer is aligned to sizeof(long)
* Adjust input buffer size check to use bitmap_size()
* Add selftest for checking the bit pattern of the bpf_cpumask
* Moved all selftests into existing files
Signed-off-by: Emil Tsalapatis (Meta) <emil@etsalapatis.com>
====================
Link: https://patch.msgid.link/20250309230427.26603-1-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The BPF cpumask selftests are currently run twice in
test_progs/cpumask.c, once by traversing cpumask_success_testcases, and
once by invoking RUN_TESTS(cpumask_success). Remove the invocation of
RUN_TESTS to properly run the selftests only once.
Now that the tests are run only through cpumask_success_testscases, add
to it the missing test_refcount_null_tracking testcase. Also remove the
__success annotation from it, since it is now loaded and invoked by the
runner.
Signed-off-by: Emil Tsalapatis (Meta) <emil@etsalapatis.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250309230427.26603-5-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Bastien Curutchet says:
====================
This patch series continues the work to migrate the script tests into
prog_tests.
test_lwt_seg6local.sh tests some bpf_lwt_* helpers. It contains only one
test that uses a network topology quite different than the ones that
can be found in others prog_tests/lwt_*.c files so I add a new
prog_tests/lwt_seg6local.c file.
While working on the migration I noticed that some routes present in the
script weren't needed so PATCH 1 deletes them and then PATCH 2 migrates
the test into the test_progs framework.
====================
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250307-seg6local-v1-0-990fff8f180d@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Some bpf_cpumask-related kfuncs have kdoc strings that are missing
return values. Add a the missing descriptions for the return values.
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Emil Tsalapatis (Meta) <emil@etsalapatis.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250309230427.26603-4-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The caller of cap_enable_effective() expects negative error code.
Fix it.
Before:
failed to restore CAP_SYS_ADMIN: -1, Unknown error -1
After:
failed to restore CAP_SYS_ADMIN: -3, No such process
failed to restore CAP_SYS_ADMIN: -22, Invalid argument
Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250305022234.44932-1-yangfeng59949@163.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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test_lwt_seg6local.sh isn't used by the BPF CI.
Add a new file in the test_progs framework to migrate the tests done by
test_lwt_seg6local.sh. It uses the same network topology and the same BPF
programs located in progs/test_lwt_seg6local.c.
Use the network helpers instead of `nc` to exchange the final packet.
Remove test_lwt_seg6local.sh and its Makefile entry.
Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
Link: https://lore.kernel.org/r/20250307-seg6local-v1-2-990fff8f180d@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Add selftests for the bpf_cpumask_populate helper that sets a
bpf_cpumask to a bit pattern provided by a BPF program.
Signed-off-by: Emil Tsalapatis (Meta) <emil@etsalapatis.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250309230427.26603-3-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Traffic monitor thread may see dangling stdout as the main thread closes
and reassigns stdout without protection. This happens when the main thread
finishes one subtest and moves to another one in the same netns_new()
scope.
The issue can be reproduced by running test_progs repeatedly with traffic
monitor enabled:
for ((i=1;i<=100;i++)); do
./test_progs -a flow_dissector_skb* -m '*'
done
For restoring stdout in crash_handler(), since it does not really care
about closing stdout, simlpy flush stdout and restore it to the original
one.
Then, Fix the issue by consolidating stdio_restore_cleanup() and
stdio_restore(), and protecting the use/close/assignment of stdout with
a lock. The locking in the main thread is always performed regradless of
whether traffic monitor is running or not for simplicity. It won't have
any side-effect.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20250305182057.2802606-3-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Some routes in fb00:: are initialized during setup, even though they
aren't needed by the test as the UDP packets will travel through the
lightweight tunnels.
Remove these unnecessary routes.
Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
Link: https://lore.kernel.org/r/20250307-seg6local-v1-1-990fff8f180d@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Add a helper kfunc that sets the bitmap of a bpf_cpumask from BPF memory.
Signed-off-by: Emil Tsalapatis (Meta) <emil@etsalapatis.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20250309230427.26603-2-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Allow users to change traffic monitor's print function. If not provided,
traffic monitor will print to stdout by default.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250305182057.2802606-2-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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reset_affinity() and save_ns() are only called in run_one_test(). There is
no need to call stdio_restore() in reset_affinity() and save_ns() if
stdio_restore() is moved right after a test finishes in run_one_test().
Also remove an unnecessary check of env.stdout_saved in crash_handler()
by moving env.stdout_saved assignment to the beginning of main().
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20250305182057.2802606-1-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
test_lwt_ip_encap.sh isn't used by the BPF CI.
Add a new file in the test_progs framework to migrate the tests done by
test_lwt_ip_encap.sh. It uses the same network topology and the same BPF
programs located in progs/test_lwt_ip_encap.c.
Rework the GSO part to avoid using nc and dd.
Remove test_lwt_ip_encap.sh and its Makefile entry.
Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250304-lwt_ip-v1-1-8fdeb9e79a56@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Kumar Kartikeya Dwivedi says:
====================
Arena Spin Lock
This set provides an implementation of queued spin lock for arena.
There is no support for resiliency and recovering from deadlocks yet.
We will wait for the rqspinlock patch set to land before incorporating
support.
One minor change compared to the qspinlock algorithm in the kernel is
that we don't have the trylock fallback when nesting count exceeds 4.
The maximum number of supported CPUs is 1024, but this can be increased
in the future if necessary.
The API supports returning an error, so resiliency support can be added
in the future. Callers are still expected to check for and handle any
potential errors.
Errors are returned when the spin loops time out, when the number of
CPUs is greater than 1024, or when the extreme edge case of NMI
interrupting NMI interrupting HardIRQ interrupting SoftIRQ interrupting
task, all of them simultaneously in slow path, occurs, which is
unsupported.
Changelog:
----------
v4 -> v5
v4: https://lore.kernel.org/bpf/20250305045136.2614132-1-memxor@gmail.com
* Add better comment and document LLVM bug for __unqual_typeof.
* Switch to precise counting in the selftest and simplify test.
* Add comment about return value handling.
* Reduce size for 100k to 50k to cap test runtime.
v3 -> v4
v3: https://lore.kernel.org/bpf/20250305011849.1168917-1-memxor@gmail.com
* Drop extra corruption handling case in decode_tail.
* Stick to 1, 1k, 100k critical section sizes.
* Fix unqual_typeof to not cast away arena tag for pointers.
* Remove hack to skip first qnode.
* Choose 100 as repeat count, 1000 is too much for 100k size.
* Use pthread_barrier in test.
v2 -> v3
v2: https://lore.kernel.org/bpf/20250118162238.2621311-1-memxor@gmail.com
* Rename to arena_spin_lock
* Introduce cond_break_label macro to jump to label from cond_break.
* Drop trylock fallback when nesting count exceeds 4.
* Fix bug in try_cmpxchg implementation.
* Add tests with critical sections of varying lengths.
* Add comments for _Generic trick to drop __arena tag.
* Fix bug due to qnodes being placed on first page, leading to CPU 0's
node being indistinguishable from NULL.
v1 -> v2
v1: https://lore.kernel.org/bpf/20250117223754.1020174-1-memxor@gmail.com
* Fix definition of lock in selftest
====================
Link: https://patch.msgid.link/20250306035431.2186189-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
This file was renamed from bpf_iter_task_vma.c.
Fixes: 45b38941c81f ("selftests/bpf: Rename bpf_iter_task_vma.c to bpf_iter_task_vmas.c")
Signed-off-by: T.J. Mercier <tjmercier@google.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20250304204520.201115-1-tjmercier@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Add some basic selftests for qspinlock built over BPF arena using
cond_break_label macro.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250306035431.2186189-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Implement queued spin lock algorithm as BPF program for lock words
living in BPF arena.
The algorithm is copied from kernel/locking/qspinlock.c and adapted for
BPF use.
We first implement abstract helpers for portable atomics and
acquire/release load instructions, by relying on X86_64 presence to
elide expensive barriers and rely on implementation details of the JIT,
and fall back to slow but correct implementations elsewhere. When
support for acquire/release load/stores lands, we can improve this
state.
Then, the qspinlock algorithm is adapted to remove dependence on
multi-word atomics due to lack of support in BPF ISA. For instance,
xchg_tail cannot use 16-bit xchg, and needs to be a implemented as a
32-bit try_cmpxchg loop.
Loops which are seemingly infinite from verifier PoV are annotated with
cond_break_label macro to return an error. Only 1024 NR_CPUs are
supported.
Note that the slow path is a global function, hence the verifier doesn't
know the return value's precision. The recommended way of usage is to
always test against zero for success, and not ret < 0 for error, as the
verifier would assume ret > 0 has not been accounted for. Add comments
in the function documentation about this quirk.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250306035431.2186189-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Add a new cond_break_label macro that jumps to the specified label when
the cond_break termination check fires, and allows us to better handle
the uncontrolled termination of the loop.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250306035431.2186189-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
may_goto instruction does not use any registers,
but in compute_insn_live_regs() it was treated as a regular
conditional jump of kind BPF_K with r0 as source register.
Thus unnecessarily marking r0 as used.
Fixes: 14c8552db644 ("bpf: simple DFA-based live registers analysis")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250305085436.2731464-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Eduard Zingerman says:
====================
bpf: simple DFA-based live registers analysis
This patch-set introduces a simple live registers DFA analysis.
Analysis is done as a separate step before main verification pass.
Results are stored in the env->insn_aux_data for each instruction.
The change helps with iterator/callback based loops handling,
as regular register liveness marks are not finalized while
loops are processed. See veristat results in patch #2.
Note: for regular subprogram calls analysis conservatively assumes
that r1-r5 are used, and r0 is used at each 'exit' instruction.
Experiments show that adding logic handling these cases precisely has
no impact on verification performance.
The patch set was tested by disabling the current register parentage
chain liveness computation, using DFA-based liveness for registers
while assuming all stack slots as live. See discussion in [1].
Changes v2 -> v3:
- added support for BPF_LOAD_ACQ, BPF_STORE_REL atomics (Alexei);
- correct use marks for r0 for BPF_CMPXCHG.
Changes v1 -> v2:
- added a refactoring commit extracting utility functions:
jmp_offset(), verbose_insn() (Alexei);
- added a refactoring commit extracting utility function
get_call_summary() in order to share helper/kfunc related code with
mark_fastcall_pattern_for_call() (Alexei);
- comment in the compute_insn_live_regs() extended (Alexei).
Changes RFC -> v1:
- parameter count for helpers and kfuncs is taken into account;
- copy_verifier_state() bugfix had been merged as a separate
patch-set and is no longer a part of this patch set.
RFC: https://lore.kernel.org/bpf/20250122120442.3536298-1-eddyz87@gmail.com/
v1: https://lore.kernel.org/bpf/20250228060032.1425870-1-eddyz87@gmail.com/
v2: https://lore.kernel.org/bpf/20250304074239.2328752-1-eddyz87@gmail.com/
[1] https://lore.kernel.org/bpf/cc29975fbaf163d0c2ed904a9a4d6d9452177542.camel@gmail.com/
====================
Link: https://patch.msgid.link/20250304195024.2478889-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Cover instructions from each kind:
- assignment
- arithmetic
- store/load
- endian conversion
- atomics
- branches, conditional branches, may_goto, calls
- LD_ABS/LD_IND
- address_space_cast
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250304195024.2478889-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
