| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
Eduard Zingerman says:
====================
exact states comparison for iterator convergence checks
Iterator convergence logic in is_state_visited() uses state_equals()
for states with branches counter > 0 to check if iterator based loop
converges. This is not fully correct because state_equals() relies on
presence of read and precision marks on registers. These marks are not
guaranteed to be finalized while state has branches.
Commit message for patch #3 describes a program that exhibits such
behavior.
This patch-set aims to fix iterator convergence logic by adding notion
of exact states comparison. Exact comparison does not rely on presence
of read or precision marks and thus is more strict.
As explained in commit message for patch #3 exact comparisons require
addition of speculative register bounds widening. The end result for
BPF verifier users could be summarized as follows:
(!) After this update verifier would reject programs that conjure an
imprecise value on the first loop iteration and use it as precise
on the second (for iterator based loops).
I urge people to at least skim over the commit message for patch #3.
Patches are organized as follows:
- patches #1,2: moving/extracting utility functions;
- patch #3: introduces exact mode for states comparison and adds
widening heuristic;
- patch #4: adds test-cases that demonstrate why the series is
necessary;
- patch #5: extends patch #3 with a notion of state loop entries,
these entries have to be tracked to correctly identify that
different verifier states belong to the same states loop;
- patch #6: adds a test-case that demonstrates a program
which requires loop entry tracking for correct verification;
- patch #7: just adds a few debug prints.
The following actions are planned as a followup for this patch-set:
- implementation has to be adapted for callbacks handling logic as a
part of a fix for [1];
- it is necessary to explore ways to improve widening heuristic to
handle iters_task_vma test w/o need to insert barrier_var() calls;
- explored states eviction logic on cache miss has to be extended
to either:
- allow eviction of checkpoint states -or-
- be sped up in case if there are many active checkpoints associated
with the same instruction.
The patch-set is a followup for mailing list discussion [1].
Changelog:
- V2 [3] -> V3:
- correct check for stack spills in widen_imprecise_scalars(),
added test case progs/iters.c:widen_spill to check the behavior
(suggested by Andrii);
- allow eviction of checkpoint states in is_state_visited() to avoid
pathological verifier performance when iterator based loop does not
converge (discussion with Alexei).
- V1 [2] -> V2, applied changes suggested by Alexei offlist:
- __explored_state() function removed;
- same_callsites() function is now used in clean_live_states();
- patches #1,2 are added as preparatory code movement;
- in process_iter_next_call() a safeguard is added to verify that
cur_st->parent exists and has expected insn index / call sites.
[1] https://lore.kernel.org/bpf/97a90da09404c65c8e810cf83c94ac703705dc0e.camel@gmail.com/
[2] https://lore.kernel.org/bpf/20231021005939.1041-1-eddyz87@gmail.com/
[3] https://lore.kernel.org/bpf/20231022010812.9201-1-eddyz87@gmail.com/
====================
Link: https://lore.kernel.org/r/20231024000917.12153-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Additional logging in is_state_visited(): if infinite loop is detected
print full verifier state for both current and equivalent states.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
A convoluted test case for iterators convergence logic that
demonstrates that states with branch count equal to 0 might still be
a part of not completely explored loop.
E.g. consider the following state diagram:
initial Here state 'succ' was processed first,
| it was eventually tracked to produce a
V state identical to 'hdr'.
.---------> hdr All branches from 'succ' had been explored
| | and thus 'succ' has its .branches == 0.
| V
| .------... Suppose states 'cur' and 'succ' correspond
| | | to the same instruction + callsites.
| V V In such case it is necessary to check
| ... ... whether 'succ' and 'cur' are identical.
| | | If 'succ' and 'cur' are a part of the same loop
| V V they have to be compared exactly.
| succ <- cur
| |
| V
| ...
| |
'----'
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
It turns out that .branches > 0 in is_state_visited() is not a
sufficient condition to identify if two verifier states form a loop
when iterators convergence is computed. This commit adds logic to
distinguish situations like below:
(I) initial (II) initial
| |
V V
.---------> hdr ..
| | |
| V V
| .------... .------..
| | | | |
| V V V V
| ... ... .-> hdr ..
| | | | | |
| V V | V V
| succ <- cur | succ <- cur
| | | |
| V | V
| ... | ...
| | | |
'----' '----'
For both (I) and (II) successor 'succ' of the current state 'cur' was
previously explored and has branches count at 0. However, loop entry
'hdr' corresponding to 'succ' might be a part of current DFS path.
If that is the case 'succ' and 'cur' are members of the same loop
and have to be compared exactly.
Co-developed-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Co-developed-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
These test cases try to hide read and precision marks from loop
convergence logic: marks would only be assigned on subsequent loop
iterations or after exploring states pushed to env->head stack first.
Without verifier fix to use exact states comparison logic for
iterators convergence these tests (except 'triple_continue') would be
errorneously marked as safe.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Convergence for open coded iterators is computed in is_state_visited()
by examining states with branches count > 1 and using states_equal().
states_equal() computes sub-state relation using read and precision marks.
Read and precision marks are propagated from children states,
thus are not guaranteed to be complete inside a loop when branches
count > 1. This could be demonstrated using the following unsafe program:
1. r7 = -16
2. r6 = bpf_get_prandom_u32()
3. while (bpf_iter_num_next(&fp[-8])) {
4. if (r6 != 42) {
5. r7 = -32
6. r6 = bpf_get_prandom_u32()
7. continue
8. }
9. r0 = r10
10. r0 += r7
11. r8 = *(u64 *)(r0 + 0)
12. r6 = bpf_get_prandom_u32()
13. }
Here verifier would first visit path 1-3, create a checkpoint at 3
with r7=-16, continue to 4-7,3 with r7=-32.
Because instructions at 9-12 had not been visitied yet existing
checkpoint at 3 does not have read or precision mark for r7.
Thus states_equal() would return true and verifier would discard
current state, thus unsafe memory access at 11 would not be caught.
This commit fixes this loophole by introducing exact state comparisons
for iterator convergence logic:
- registers are compared using regs_exact() regardless of read or
precision marks;
- stack slots have to have identical type.
Unfortunately, this is too strict even for simple programs like below:
i = 0;
while(iter_next(&it))
i++;
At each iteration step i++ would produce a new distinct state and
eventually instruction processing limit would be reached.
To avoid such behavior speculatively forget (widen) range for
imprecise scalar registers, if those registers were not precise at the
end of the previous iteration and do not match exactly.
This a conservative heuristic that allows to verify wide range of
programs, however it precludes verification of programs that conjure
an imprecise value on the first loop iteration and use it as precise
on the second.
Test case iter_task_vma_for_each() presents one of such cases:
unsigned int seen = 0;
...
bpf_for_each(task_vma, vma, task, 0) {
if (seen >= 1000)
break;
...
seen++;
}
Here clang generates the following code:
<LBB0_4>:
24: r8 = r6 ; stash current value of
... body ... 'seen'
29: r1 = r10
30: r1 += -0x8
31: call bpf_iter_task_vma_next
32: r6 += 0x1 ; seen++;
33: if r0 == 0x0 goto +0x2 <LBB0_6> ; exit on next() == NULL
34: r7 += 0x10
35: if r8 < 0x3e7 goto -0xc <LBB0_4> ; loop on seen < 1000
<LBB0_6>:
... exit ...
Note that counter in r6 is copied to r8 and then incremented,
conditional jump is done using r8. Because of this precision mark for
r6 lags one state behind of precision mark on r8 and widening logic
kicks in.
Adding barrier_var(seen) after conditional is sufficient to force
clang use the same register for both counting and conditional jump.
This issue was discussed in the thread [1] which was started by
Andrew Werner <awerner32@gmail.com> demonstrating a similar bug
in callback functions handling. The callbacks would be addressed
in a followup patch.
[1] https://lore.kernel.org/bpf/97a90da09404c65c8e810cf83c94ac703705dc0e.camel@gmail.com/
Co-developed-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Co-developed-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Extract same_callsites() from clean_live_states() as a utility function.
This function would be used by the next patch in the set.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Subsequent patches would make use of explored_state() function.
Move it up to avoid adding unnecessary prototype.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Small clean up to get rid of the extra tcx_link_const() and only retain
the tcx_link().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20231023185015.21152-1-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
|
|
This modification doesn't change behaviour of the syscall_tp
But such code is often used as a reference so it should be
correct anyway
Signed-off-by: Denys Zagorui <dzagorui@cisco.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231019113521.4103825-1-dzagorui@cisco.com
|
|
Hou Tao says:
====================
bpf: Fixes for per-cpu kptr
From: Hou Tao <houtao1@huawei.com>
Hi,
The patchset aims to fix the problems found in the review of per-cpu
kptr patch-set [0]. Patch #1 moves pcpu_lock after the invocation of
pcpu_chunk_addr_search() and it is a micro-optimization for
free_percpu(). The reason includes it in the patch is that the same
logic is used in newly-added API pcpu_alloc_size(). Patch #2 introduces
pcpu_alloc_size() for dynamic per-cpu area. Patch #2 and #3 use
pcpu_alloc_size() to check whether or not unit_size matches with the
size of underlying per-cpu area and to select a matching bpf_mem_cache.
Patch #4 fixes the freeing of per-cpu kptr when these kptrs are freed by
map destruction. The last patch adds test cases for these problems.
Please see individual patches for details. And comments are always
welcome.
Change Log:
v3:
* rebased on bpf-next
* patch 2: update API document to note that pcpu_alloc_size() doesn't
support statically allocated per-cpu area. (Dennis)
* patch 1 & 2: add Acked-by from Dennis
v2: https://lore.kernel.org/bpf/20231018113343.2446300-1-houtao@huaweicloud.com/
* add a new patch "don't acquire pcpu_lock for pcpu_chunk_addr_search()"
* patch 2: change type of bit_off and end to unsigned long (Andrew)
* patch 2: rename the new API as pcpu_alloc_size and follow 80-column convention (Dennis)
* patch 5: move the common declaration into bpf.h (Stanislav, Alxei)
v1: https://lore.kernel.org/bpf/20231007135106.3031284-1-houtao@huaweicloud.com/
[0]: https://lore.kernel.org/bpf/20230827152729.1995219-1-yonghong.song@linux.dev
====================
Link: https://lore.kernel.org/r/20231020133202.4043247-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Add the following 3 test cases for bpf memory allocator:
1) Do allocation in bpf program and free through map free
2) Do batch per-cpu allocation and per-cpu free in bpf program
3) Do per-cpu allocation in bpf program and free through map free
For per-cpu allocation, because per-cpu allocation can not refill timely
sometimes, so test 2) and test 3) consider it is OK for
bpf_percpu_obj_new_impl() to return NULL.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-8-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
The following warning was reported when running "./test_progs -t
test_bpf_ma/percpu_free_through_map_free":
------------[ cut here ]------------
WARNING: CPU: 1 PID: 68 at kernel/bpf/memalloc.c:342
CPU: 1 PID: 68 Comm: kworker/u16:2 Not tainted 6.6.0-rc2+ #222
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Workqueue: events_unbound bpf_map_free_deferred
RIP: 0010:bpf_mem_refill+0x21c/0x2a0
......
Call Trace:
<IRQ>
? bpf_mem_refill+0x21c/0x2a0
irq_work_single+0x27/0x70
irq_work_run_list+0x2a/0x40
irq_work_run+0x18/0x40
__sysvec_irq_work+0x1c/0xc0
sysvec_irq_work+0x73/0x90
</IRQ>
<TASK>
asm_sysvec_irq_work+0x1b/0x20
RIP: 0010:unit_free+0x50/0x80
......
bpf_mem_free+0x46/0x60
__bpf_obj_drop_impl+0x40/0x90
bpf_obj_free_fields+0x17d/0x1a0
array_map_free+0x6b/0x170
bpf_map_free_deferred+0x54/0xa0
process_scheduled_works+0xba/0x370
worker_thread+0x16d/0x2e0
kthread+0x105/0x140
ret_from_fork+0x39/0x60
ret_from_fork_asm+0x1b/0x30
</TASK>
---[ end trace 0000000000000000 ]---
The reason is simple: __bpf_obj_drop_impl() does not know the freeing
field is a per-cpu pointer and it uses bpf_global_ma to free the
pointer. Because bpf_global_ma is not a per-cpu allocator, so ksize() is
used to select the corresponding cache. The bpf_mem_cache with 16-bytes
unit_size will always be selected to do the unmatched free and it will
trigger the warning in free_bulk() eventually.
Because per-cpu kptr doesn't support list or rb-tree now, so fix the
problem by only checking whether or not the type of kptr is per-cpu in
bpf_obj_free_fields(), and using bpf_global_percpu_ma to these kptrs.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-7-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
both syscall.c and helpers.c have the declaration of
__bpf_obj_drop_impl(), so just move it to a common header file.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
For bpf_global_percpu_ma, the pointer passed to bpf_mem_free_rcu() is
allocated by kmalloc() and its size is fixed (16-bytes on x86-64). So
no matter which cache allocates the dynamic per-cpu area, on x86-64
cache[2] will always be used to free the per-cpu area.
Fix the unbalance by checking whether the bpf memory allocator is
per-cpu or not and use pcpu_alloc_size() instead of ksize() to
find the correct cache for per-cpu free.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
With pcpu_alloc_size() in place, check whether or not the size of
the dynamic per-cpu area is matched with unit_size.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Introduce pcpu_alloc_size() to get the size of the dynamic per-cpu
area. It will be used by bpf memory allocator in the following patches.
BPF memory allocator maintains per-cpu area caches for multiple area
sizes and its free API only has the to-be-freed per-cpu pointer, so it
needs the size of dynamic per-cpu area to select the corresponding cache
when bpf program frees the dynamic per-cpu pointer.
Acked-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
There is no need to acquire pcpu_lock for pcpu_chunk_addr_search():
1) both pcpu_first_chunk & pcpu_reserved_chunk must have been
initialized before the invocation of free_percpu().
2) The dynamically-created chunk must be valid before the per-cpu
pointers allocated from it are freed.
So acquire pcpu_lock() after the invocation of pcpu_chunk_addr_search().
Acked-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
The linked list failure test 'pop_front_off' and 'pop_back_off'
currently rely on matching exact instruction and register values. The
purpose of the test is to ensure the offset is correctly incremented for
the returned pointers from list pop helpers, which can then be used with
container_of to obtain the real object. Hence, somehow obtaining the
information that the offset is 48 will work for us. Make the test more
robust by relying on verifier error string of bpf_spin_lock and remove
dependence on fragile instruction index or register number, which can be
affected by different clang versions used to build the selftests.
Fixes: 300f19dcdb99 ("selftests/bpf: Add BPF linked list API tests")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231020144839.2734006-1-memxor@gmail.com
|
|
Chuyi Zhou says:
====================
Add Open-coded task, css_task and css iters
This is version 6 of task, css_task and css iters support.
--- Changelog ---
v5 -> v6:
Patch #3:
* In bpf_iter_task_next, return pos rather than goto out. (Andrii)
Patch #2, #3, #4:
* Add the missing __diag_ignore_all to avoid kernel build warning
Patch #5, #6, #7:
* Add Andrii's ack
Patch #8:
* In BPF prog iter_css_task_for_each, return -EPERM rather than 0, and
ensure stack_mprotect() in iters.c not success. If not, it would cause
the subsequent 'test_lsm' fail, since the 'is_stack' check in
test_int_hook(lsm.c) would not be guaranteed.
(https://github.com/kernel-patches/bpf/actions/runs/6489662214/job/17624665086?pr=5790)
v4 -> v5:https://lore.kernel.org/lkml/20231007124522.34834-1-zhouchuyi@bytedance.com/
Patch 3~4:
* Relax the BUILD_BUG_ON check in bpf_iter_task_new and bpf_iter_css_new to avoid
netdev/build_32bit CI error.
(https://netdev.bots.linux.dev/static/nipa/790929/13412333/build_32bit/stderr)
Patch 8:
* Initialize skel pointer to fix the LLVM-16 build CI error
(https://github.com/kernel-patches/bpf/actions/runs/6462875618/job/17545170863)
v3 -> v4:https://lore.kernel.org/all/20230925105552.817513-1-zhouchuyi@bytedance.com/
* Address all the comments from Andrii in patch-3 ~ patch-6
* Collect Tejun's ack
* Add a extra patch to rename bpf_iter_task.c to bpf_iter_tasks.c
* Seperate three BPF program files for selftests (iters_task.c iters_css_task.c iters_css.c)
v2 -> v3:https://lore.kernel.org/lkml/20230912070149.969939-1-zhouchuyi@bytedance.com/
Patch 1 (cgroup: Prepare for using css_task_iter_*() in BPF)
* Add tj's ack and Alexei's suggest-by.
Patch 2 (bpf: Introduce css_task open-coded iterator kfuncs)
* Use bpf_mem_alloc/bpf_mem_free rather than kzalloc()
* Add KF_TRUSTED_ARGS for bpf_iter_css_task_new (Alexei)
* Move bpf_iter_css_task's definition from uapi/linux/bpf.h to
kernel/bpf/task_iter.c and we can use it from vmlinux.h
* Move bpf_iter_css_task_XXX's declaration from bpf_helpers.h to
bpf_experimental.h
Patch 3 (Introduce task open coded iterator kfuncs)
* Change th API design keep consistent with SEC("iter/task"), support
iterating all threads(BPF_TASK_ITERATE_ALL) and threads of a
specific task (BPF_TASK_ITERATE_THREAD).（Andrii)
* Move bpf_iter_task's definition from uapi/linux/bpf.h to
kernel/bpf/task_iter.c and we can use it from vmlinux.h
* Move bpf_iter_task_XXX's declaration from bpf_helpers.h to
bpf_experimental.h
Patch 4 (Introduce css open-coded iterator kfuncs)
* Change th API design keep consistent with cgroup_iters, reuse
BPF_CGROUP_ITER_DESCENDANTS_PRE/BPF_CGROUP_ITER_DESCENDANTS_POST
/BPF_CGROUP_ITER_ANCESTORS_UP(Andrii)
* Add KF_TRUSTED_ARGS for bpf_iter_css_new
* Move bpf_iter_css's definition from uapi/linux/bpf.h to
kernel/bpf/task_iter.c and we can use it from vmlinux.h
* Move bpf_iter_css_XXX's declaration from bpf_helpers.h to
bpf_experimental.h
Patch 5 (teach the verifier to enforce css_iter and task_iter in RCU CS)
* Add KF flag KF_RCU_PROTECTED to maintain kfuncs which need RCU CS.(Andrii)
* Consider STACK_ITER when using bpf_for_each_spilled_reg.
Patch 6 (Let bpf_iter_task_new accept null task ptr)
* Add this extra patch to let bpf_iter_task_new accept a 'nullable'
* task pointer(Andrii)
Patch 7 (selftests/bpf: Add tests for open-coded task and css iter)
* Add failure testcase(Alexei)
Changes from v1(https://lore.kernel.org/lkml/20230827072057.1591929-1-zhouchuyi@bytedance.com/):
- Add a pre-patch to make some preparations before supporting css_task
iters.(Alexei)
- Add an allowlist for css_task iters(Alexei)
- Let bpf progs do explicit bpf_rcu_read_lock() when using process
iters and css_descendant iters.(Alexei)
---------------------
In some BPF usage scenarios, it will be useful to iterate the process and
css directly in the BPF program. One of the expected scenarios is
customizable OOM victim selection via BPF[1].
Inspired by Dave's task_vma iter[2], this patchset adds three types of
open-coded iterator kfuncs:
1. bpf_task_iters. It can be used to
1) iterate all process in the system, like for_each_forcess() in kernel.
2) iterate all threads in the system.
3) iterate all threads of a specific task
2. bpf_css_iters. It works like css_task_iter_{start, next, end} and would
be used to iterating tasks/threads under a css.
3. css_iters. It works like css_next_descendant_{pre, post} to iterating all
descendant css.
BPF programs can use these kfuncs directly or through bpf_for_each macro.
link[1]: https://lore.kernel.org/lkml/20230810081319.65668-1-zhouchuyi@bytedance.com/
link[2]: https://lore.kernel.org/all/20230810183513.684836-1-davemarchevsky@fb.com/
====================
Link: https://lore.kernel.org/r/20231018061746.111364-1-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
This patch adds 4 subtests to demonstrate these patterns and validating
correctness.
subtest1:
1) We use task_iter to iterate all process in the system and search for the
current process with a given pid.
2) We create some threads in current process context, and use
BPF_TASK_ITER_PROC_THREADS to iterate all threads of current process. As
expected, we would find all the threads of current process.
3) We create some threads and use BPF_TASK_ITER_ALL_THREADS to iterate all
threads in the system. As expected, we would find all the threads which was
created.
subtest2:
We create a cgroup and add the current task to the cgroup. In the
BPF program, we would use bpf_for_each(css_task, task, css) to iterate all
tasks under the cgroup. As expected, we would find the current process.
subtest3:
1) We create a cgroup tree. In the BPF program, we use
bpf_for_each(css, pos, root, XXX) to iterate all descendant under the root
with pre and post order. As expected, we would find all descendant and the
last iterating cgroup in post-order is root cgroup, the first iterating
cgroup in pre-order is root cgroup.
2) We wse BPF_CGROUP_ITER_ANCESTORS_UP to traverse the cgroup tree starting
from leaf and root separately, and record the height. The diff of the
hights would be the total tree-high - 1.
subtest4:
Add some failure testcase when using css_task, task and css iters, e.g,
unlock when using task-iters to iterate tasks.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Link: https://lore.kernel.org/r/20231018061746.111364-9-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
The newly-added struct bpf_iter_task has a name collision with a selftest
for the seq_file task iter's bpf skel, so the selftests/bpf/progs file is
renamed in order to avoid the collision.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-8-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
When using task_iter to iterate all threads of a specific task, we enforce
that the user must pass a valid task pointer to ensure safety. However,
when iterating all threads/process in the system, BPF verifier still
require a valid ptr instead of "nullable" pointer, even though it's
pointless, which is a kind of surprising from usability standpoint. It
would be nice if we could let that kfunc accept a explicit null pointer
when we are using BPF_TASK_ITER_ALL_{PROCS, THREADS} and a valid pointer
when using BPF_TASK_ITER_THREAD.
Given a trival kfunc:
__bpf_kfunc void FN(struct TYPE_A *obj);
BPF Prog would reject a nullptr for obj. The error info is:
"arg#x pointer type xx xx must point to scalar, or struct with scalar"
reported by get_kfunc_ptr_arg_type(). The reg->type is SCALAR_VALUE and
the btf type of ref_t is not scalar or scalar_struct which leads to the
rejection of get_kfunc_ptr_arg_type.
This patch add "__nullable" annotation:
__bpf_kfunc void FN(struct TYPE_A *obj__nullable);
Here __nullable indicates obj can be optional, user can pass a explicit
nullptr or a normal TYPE_A pointer. In get_kfunc_ptr_arg_type(), we will
detect whether the current arg is optional and register is null, If so,
return a new kfunc_ptr_arg_type KF_ARG_PTR_TO_NULL and skip to the next
arg in check_kfunc_args().
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-7-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
css_iter and task_iter should be used in rcu section. Specifically, in
sleepable progs explicit bpf_rcu_read_lock() is needed before use these
iters. In normal bpf progs that have implicit rcu_read_lock(), it's OK to
use them directly.
This patch adds a new a KF flag KF_RCU_PROTECTED for bpf_iter_task_new and
bpf_iter_css_new. It means the kfunc should be used in RCU CS. We check
whether we are in rcu cs before we want to invoke this kfunc. If the rcu
protection is guaranteed, we would let st->type = PTR_TO_STACK | MEM_RCU.
Once user do rcu_unlock during the iteration, state MEM_RCU of regs would
be cleared. is_iter_reg_valid_init() will reject if reg->type is UNTRUSTED.
It is worth noting that currently, bpf_rcu_read_unlock does not
clear the state of the STACK_ITER reg, since bpf_for_each_spilled_reg
only considers STACK_SPILL. This patch also let bpf_for_each_spilled_reg
search STACK_ITER.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-6-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
This Patch adds kfuncs bpf_iter_css_{new,next,destroy} which allow
creation and manipulation of struct bpf_iter_css in open-coded iterator
style. These kfuncs actually wrapps css_next_descendant_{pre, post}.
css_iter can be used to:
1) iterating a sepcific cgroup tree with pre/post/up order
2) iterating cgroup_subsystem in BPF Prog, like
for_each_mem_cgroup_tree/cpuset_for_each_descendant_pre in kernel.
The API design is consistent with cgroup_iter. bpf_iter_css_new accepts
parameters defining iteration order and starting css. Here we also reuse
BPF_CGROUP_ITER_DESCENDANTS_PRE, BPF_CGROUP_ITER_DESCENDANTS_POST,
BPF_CGROUP_ITER_ANCESTORS_UP enums.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-5-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
This patch adds kfuncs bpf_iter_task_{new,next,destroy} which allow
creation and manipulation of struct bpf_iter_task in open-coded iterator
style. BPF programs can use these kfuncs or through bpf_for_each macro to
iterate all processes in the system.
The API design keep consistent with SEC("iter/task"). bpf_iter_task_new()
accepts a specific task and iterating type which allows:
1. iterating all process in the system (BPF_TASK_ITER_ALL_PROCS)
2. iterating all threads in the system (BPF_TASK_ITER_ALL_THREADS)
3. iterating all threads of a specific task (BPF_TASK_ITER_PROC_THREADS)
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Link: https://lore.kernel.org/r/20231018061746.111364-4-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
This patch adds kfuncs bpf_iter_css_task_{new,next,destroy} which allow
creation and manipulation of struct bpf_iter_css_task in open-coded
iterator style. These kfuncs actually wrapps css_task_iter_{start,next,
end}. BPF programs can use these kfuncs through bpf_for_each macro for
iteration of all tasks under a css.
css_task_iter_*() would try to get the global spin-lock *css_set_lock*, so
the bpf side has to be careful in where it allows to use this iter.
Currently we only allow it in bpf_lsm and bpf iter-s.
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-3-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
This patch makes some preparations for using css_task_iter_*() in BPF
Program.
1. Flags CSS_TASK_ITER_* are #define-s and it's not easy for bpf prog to
use them. Convert them to enum so bpf prog can take them from vmlinux.h.
2. In the next patch we will add css_task_iter_*() in common kfuncs which
is not safe. Since css_task_iter_*() does spin_unlock_irq() which might
screw up irq flags depending on the context where bpf prog is running.
So we should use irqsave/irqrestore here and the switching is harmless.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-2-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
When dumping a struct_ops, 2 dictionaries are emitted.
When using `name`, they were already wrapped in an array, but not when
using `id`. Causing `jq` to fail at parsing the payload as it reached
the comma following the first dict.
This change wraps those dictionaries in an array so valid json is emitted.
Before, jq fails to parse the output:
```
$ sudo bpftool struct_ops dump id 1523612 | jq . > /dev/null
parse error: Expected value before ',' at line 19, column 2
```
After, no error parsing the output:
```
sudo ./bpftool struct_ops dump id 1523612 | jq . > /dev/null
```
Signed-off-by: Manu Bretelle <chantr4@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20231018230133.1593152-3-chantr4@gmail.com
|
|
When printing a pointer value, "%p" will either print the hexadecimal
value of the pointer (e.g `0x1234`), or `(nil)` when NULL.
Both of those are invalid json "integer" values and need to be wrapped
in quotes.
Before:
```
$ sudo bpftool struct_ops dump name ned_dummy_cca | grep next
"next": (nil),
$ sudo bpftool struct_ops dump name ned_dummy_cca | \
jq '.[1].bpf_struct_ops_tcp_congestion_ops.data.list.next'
parse error: Invalid numeric literal at line 29, column 34
```
After:
```
$ sudo ./bpftool struct_ops dump name ned_dummy_cca | grep next
"next": "(nil)",
$ sudo ./bpftool struct_ops dump name ned_dummy_cca | \
jq '.[1].bpf_struct_ops_tcp_congestion_ops.data.list.next'
"(nil)"
```
Signed-off-by: Manu Bretelle <chantr4@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20231018230133.1593152-2-chantr4@gmail.com
|
|
There's different mathematical definitions (truncated, floored, rounded,
etc.) and different languages have chosen different definitions [0][1].
E.g., languages/libraries that follow Knuth use a different mathematical
definition than C uses. This patch specifies which definition BPF uses,
as verified by Eduard [2] and others.
[0] https://en.wikipedia.org/wiki/Modulo#Variants_of_the_definition
[1] https://torstencurdt.com/tech/posts/modulo-of-negative-numbers/
[2] https://lore.kernel.org/bpf/57e6fefadaf3b2995bb259fa8e711c7220ce5290.camel@gmail.com/
Signed-off-by: Dave Thaler <dthaler@microsoft.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20231017203020.1500-1-dthaler1968@googlemail.com
|
|
This is a follow-up to the commit 9b2b86332a9b ("bpf: Allow to use kfunc
XDP hints and frags together").
The are some possible implementations problems that may arise when providing
metadata specifically for multi-buffer packets, therefore there must be a
possibility to test such option separately.
Add an option to use multi-buffer AF_XDP xdp_hw_metadata and mark used XDP
program as capable to use frags.
As for now, xdp_hw_metadata accepts no options, so add simple option
parsing logic and a help message.
For quick reference, also add an ingress packet generation command to the
help message. The command comes from [0].
Example of output for multi-buffer packet:
xsk_ring_cons__peek: 1
0xead018: rx_desc[15]->addr=10000000000f000 addr=f100 comp_addr=f000
rx_hash: 0x5789FCBB with RSS type:0x29
rx_timestamp: 1696856851535324697 (sec:1696856851.5353)
XDP RX-time: 1696856843158256391 (sec:1696856843.1583)
delta sec:-8.3771 (-8377068.306 usec)
AF_XDP time: 1696856843158413078 (sec:1696856843.1584)
delta sec:0.0002 (156.687 usec)
0xead018: complete idx=23 addr=f000
xsk_ring_cons__peek: 1
0xead018: rx_desc[16]->addr=100000000008000 addr=8100 comp_addr=8000
0xead018: complete idx=24 addr=8000
xsk_ring_cons__peek: 1
0xead018: rx_desc[17]->addr=100000000009000 addr=9100 comp_addr=9000 EoP
0xead018: complete idx=25 addr=9000
Metadata is printed for the first packet only.
[0] https://lore.kernel.org/all/20230119221536.3349901-18-sdf@google.com/
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20231017162800.24080-1-larysa.zaremba@intel.com
|
|
Add several new test cases which assert corner cases on the mprog query
mechanism, for example, around passing in a too small or a larger array
than the current count.
./test_progs -t tc_opts
#252 tc_opts_after:OK
#253 tc_opts_append:OK
#254 tc_opts_basic:OK
#255 tc_opts_before:OK
#256 tc_opts_chain_classic:OK
#257 tc_opts_chain_mixed:OK
#258 tc_opts_delete_empty:OK
#259 tc_opts_demixed:OK
#260 tc_opts_detach:OK
#261 tc_opts_detach_after:OK
#262 tc_opts_detach_before:OK
#263 tc_opts_dev_cleanup:OK
#264 tc_opts_invalid:OK
#265 tc_opts_max:OK
#266 tc_opts_mixed:OK
#267 tc_opts_prepend:OK
#268 tc_opts_query:OK
#269 tc_opts_query_attach:OK
#270 tc_opts_replace:OK
#271 tc_opts_revision:OK
Summary: 20/0 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20231017081728.24769-1-daniel@iogearbox.net
|
|
The result is as follows:
$ tools/testing/selftests/bpf/test_progs --name=task_under_cgroup
#237 task_under_cgroup:OK
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
Without the previous patch, there will be RCU warnings in dmesg when
CONFIG_PROVE_RCU is enabled. While with the previous patch, there will
be no warnings.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20231007135945.4306-2-laoar.shao@gmail.com
|
|
When employed within a sleepable program not under RCU protection, the
use of 'bpf_task_under_cgroup()' may trigger a warning in the kernel log,
particularly when CONFIG_PROVE_RCU is enabled:
[ 1259.662357] WARNING: suspicious RCU usage
[ 1259.662358] 6.5.0+ #33 Not tainted
[ 1259.662360] -----------------------------
[ 1259.662361] include/linux/cgroup.h:423 suspicious rcu_dereference_check() usage!
Other info that might help to debug this:
[ 1259.662366] rcu_scheduler_active = 2, debug_locks = 1
[ 1259.662368] 1 lock held by trace/72954:
[ 1259.662369] #0: ffffffffb5e3eda0 (rcu_read_lock_trace){....}-{0:0}, at: __bpf_prog_enter_sleepable+0x0/0xb0
Stack backtrace:
[ 1259.662385] CPU: 50 PID: 72954 Comm: trace Kdump: loaded Not tainted 6.5.0+ #33
[ 1259.662391] Call Trace:
[ 1259.662393] <TASK>
[ 1259.662395] dump_stack_lvl+0x6e/0x90
[ 1259.662401] dump_stack+0x10/0x20
[ 1259.662404] lockdep_rcu_suspicious+0x163/0x1b0
[ 1259.662412] task_css_set.part.0+0x23/0x30
[ 1259.662417] bpf_task_under_cgroup+0xe7/0xf0
[ 1259.662422] bpf_prog_7fffba481a3bcf88_lsm_run+0x5c/0x93
[ 1259.662431] bpf_trampoline_6442505574+0x60/0x1000
[ 1259.662439] bpf_lsm_bpf+0x5/0x20
[ 1259.662443] ? security_bpf+0x32/0x50
[ 1259.662452] __sys_bpf+0xe6/0xdd0
[ 1259.662463] __x64_sys_bpf+0x1a/0x30
[ 1259.662467] do_syscall_64+0x38/0x90
[ 1259.662472] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 1259.662479] RIP: 0033:0x7f487baf8e29
[...]
[ 1259.662504] </TASK>
This issue can be reproduced by executing a straightforward program, as
demonstrated below:
SEC("lsm.s/bpf")
int BPF_PROG(lsm_run, int cmd, union bpf_attr *attr, unsigned int size)
{
struct cgroup *cgrp = NULL;
struct task_struct *task;
int ret = 0;
if (cmd != BPF_LINK_CREATE)
return 0;
// The cgroup2 should be mounted first
cgrp = bpf_cgroup_from_id(1);
if (!cgrp)
goto out;
task = bpf_get_current_task_btf();
if (bpf_task_under_cgroup(task, cgrp))
ret = -1;
bpf_cgroup_release(cgrp);
out:
return ret;
}
After running the program, if you subsequently execute another BPF program,
you will encounter the warning.
It's worth noting that task_under_cgroup_hierarchy() is also utilized by
bpf_current_task_under_cgroup(). However, bpf_current_task_under_cgroup()
doesn't exhibit this issue because it cannot be used in sleepable BPF
programs.
Fixes: b5ad4cdc46c7 ("bpf: Add bpf_task_under_cgroup() kfunc")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Cc: Feng Zhou <zhoufeng.zf@bytedance.com>
Cc: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20231007135945.4306-1-laoar.shao@gmail.com
|
|
A few drivers were missing a xdp_do_flush() invocation after
XDP_REDIRECT.
Add three helper functions each for one of the per-CPU lists. Return
true if the per-CPU list is non-empty and flush the list.
Add xdp_do_check_flushed() which invokes each helper functions and
creates a warning if one of the functions had a non-empty list.
Hide everything behind CONFIG_DEBUG_NET.
Suggested-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20231016125738.Yt79p1uF@linutronix.de
|
|
Fix too eager assumption that SHT_GNU_verdef ELF section is going to be
present whenever binary has SHT_GNU_versym section. It seems like either
SHT_GNU_verdef or SHT_GNU_verneed can be used, so failing on missing
SHT_GNU_verdef actually breaks use cases in production.
One specific reported issue, which was used to manually test this fix,
was trying to attach to `readline` function in BASH binary.
Fixes: bb7fa09399b9 ("libbpf: Support symbol versioning for uprobe")
Reported-by: Liam Wisehart <liamwisehart@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Manu Bretelle <chantr4@gmail.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/20231016182840.4033346-1-andrii@kernel.org
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2023-10-16
We've added 90 non-merge commits during the last 25 day(s) which contain
a total of 120 files changed, 3519 insertions(+), 895 deletions(-).
The main changes are:
1) Add missed stats for kprobes to retrieve the number of missed kprobe
executions and subsequent executions of BPF programs, from Jiri Olsa.
2) Add cgroup BPF sockaddr hooks for unix sockets. The use case is
for systemd to reimplement the LogNamespace feature which allows
running multiple instances of systemd-journald to process the logs
of different services, from Daan De Meyer.
3) Implement BPF CPUv4 support for s390x BPF JIT, from Ilya Leoshkevich.
4) Improve BPF verifier log output for scalar registers to better
disambiguate their internal state wrt defaults vs min/max values
matching, from Andrii Nakryiko.
5) Extend the BPF fib lookup helpers for IPv4/IPv6 to support retrieving
the source IP address with a new BPF_FIB_LOOKUP_SRC flag,
from Martynas Pumputis.
6) Add support for open-coded task_vma iterator to help with symbolization
for BPF-collected user stacks, from Dave Marchevsky.
7) Add libbpf getters for accessing individual BPF ring buffers which
is useful for polling them individually, for example, from Martin Kelly.
8) Extend AF_XDP selftests to validate the SHARED_UMEM feature,
from Tushar Vyavahare.
9) Improve BPF selftests cross-building support for riscv arch,
from Björn Töpel.
10) Add the ability to pin a BPF timer to the same calling CPU,
from David Vernet.
11) Fix libbpf's bpf_tracing.h macros for riscv to use the generic
implementation of PT_REGS_SYSCALL_REGS() to access syscall arguments,
from Alexandre Ghiti.
12) Extend libbpf to support symbol versioning for uprobes, from Hengqi Chen.
13) Fix bpftool's skeleton code generation to guarantee that ELF data
is 8 byte aligned, from Ian Rogers.
14) Inherit system-wide cpu_mitigations_off() setting for Spectre v1/v4
security mitigations in BPF verifier, from Yafang Shao.
15) Annotate struct bpf_stack_map with __counted_by attribute to prepare
BPF side for upcoming __counted_by compiler support, from Kees Cook.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (90 commits)
bpf: Ensure proper register state printing for cond jumps
bpf: Disambiguate SCALAR register state output in verifier logs
selftests/bpf: Make align selftests more robust
selftests/bpf: Improve missed_kprobe_recursion test robustness
selftests/bpf: Improve percpu_alloc test robustness
selftests/bpf: Add tests for open-coded task_vma iter
bpf: Introduce task_vma open-coded iterator kfuncs
selftests/bpf: Rename bpf_iter_task_vma.c to bpf_iter_task_vmas.c
bpf: Don't explicitly emit BTF for struct btf_iter_num
bpf: Change syscall_nr type to int in struct syscall_tp_t
net/bpf: Avoid unused "sin_addr_len" warning when CONFIG_CGROUP_BPF is not set
bpf: Avoid unnecessary audit log for CPU security mitigations
selftests/bpf: Add tests for cgroup unix socket address hooks
selftests/bpf: Make sure mount directory exists
documentation/bpf: Document cgroup unix socket address hooks
bpftool: Add support for cgroup unix socket address hooks
libbpf: Add support for cgroup unix socket address hooks
bpf: Implement cgroup sockaddr hooks for unix sockets
bpf: Add bpf_sock_addr_set_sun_path() to allow writing unix sockaddr from bpf
bpf: Propagate modified uaddrlen from cgroup sockaddr programs
...
====================
Link: https://lore.kernel.org/r/20231016204803.30153-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Currently page_pool_alloc_frag() is not supported in 32-bit
arch with 64-bit DMA because of the overlap issue between
pp_frag_count and dma_addr_upper in 'struct page' for those
arches, which seems to be quite common, see [1], which means
driver may need to handle it when using fragment API.
It is assumed that the combination of the above arch with an
address space >16TB does not exist, as all those arches have
64b equivalent, it seems logical to use the 64b version for a
system with a large address space. It is also assumed that dma
address is page aligned when we are dma mapping a page aligned
buffer, see [2].
That means we're storing 12 bits of 0 at the lower end for a
dma address, we can reuse those bits for the above arches to
support 32b+12b, which is 16TB of memory.
If we make a wrong assumption, a warning is emitted so that
user can report to us.
1. https://lore.kernel.org/all/20211117075652.58299-1-linyunsheng@huawei.com/
2. https://lore.kernel.org/all/20230818145145.4b357c89@kernel.org/
Tested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
CC: Lorenzo Bianconi <lorenzo@kernel.org>
CC: Alexander Duyck <alexander.duyck@gmail.com>
CC: Liang Chen <liangchen.linux@gmail.com>
CC: Guillaume Tucker <guillaume.tucker@collabora.com>
CC: Matthew Wilcox <willy@infradead.org>
CC: Linux-MM <linux-mm@kvack.org>
Link: https://lore.kernel.org/r/20231013064827.61135-2-linyunsheng@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
A few networking drivers including bnx2x, bnxt, qede, and idpf call
tcp_gro_complete as part of offloading TCP GRO. The function is only
defined if CONFIG_INET is true, since its TCP specific and is meaningless
if the kernel lacks IP networking support.
The combination of trying to use the complex network drivers with
CONFIG_NET but not CONFIG_INET is rather unlikely in practice: most use
cases are going to need IP networking.
The tcp_gro_complete function just sets some data in the socket buffer for
use in processing the TCP packet in the event that the GRO was offloaded to
the device. If the kernel lacks TCP support, such setup will simply go
unused.
The bnx2x, bnxt, and qede drivers wrap their TCP offload support in
CONFIG_INET checks and skip handling on such kernels.
The idpf driver did not check CONFIG_INET and thus fails to link if the
kernel is configured with CONFIG_NET=y, CONFIG_IDPF=(m|y), and
CONFIG_INET=n.
While checking CONFIG_INET does allow the driver to bypass significantly
more instructions in the event that we know TCP networking isn't supported,
the configuration is unlikely to be used widely.
Rather than require driver authors to care about this, stub the
tcp_gro_complete function when CONFIG_INET=n. This allows drivers to be
left as-is. It does mean the idpf driver will perform slightly more work
than strictly necessary when CONFIG_INET=n, since it will still execute
some of the skb setup in idpf_rx_rsc. However, that work would be performed
in the case where CONFIG_INET=y anyways.
I did not change the existing drivers, since they appear to wrap a
significant portion of code when CONFIG_INET=n. There is little benefit in
trashing these drivers just to unwrap and remove the CONFIG_INET check.
Using a stub for tcp_gro_complete is still beneficial, as it means future
drivers no longer need to worry about this case of CONFIG_NET=y and
CONFIG_INET=n, which should reduce noise from buildbots that check such a
configuration.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20231013185502.1473541-1-jacob.e.keller@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
resolved typing mistake from devce to device
Signed-off-by: Muhammad Muzammil <m.muzzammilashraf@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231013042304.7881-1-m.muzzammilashraf@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
main process.
When modifying netclassid, the command("echo 0x100001 > net_cls.classid")
will take more time on many threads of one process, because the process
create many fds.
for example, one process exists 28000 fds and 60000 threads, echo command
will task 45 seconds.
Now, we only consider the main process when exec "iterate_fd", and the
time is about 52 milliseconds.
Signed-off-by: Liansen Zhai <zhailiansen@kuaishou.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231012090330.29636-1-zhailiansen@kuaishou.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
Other implementations of .*get_drvinfo use strscpy so this patch brings
sr_get_drvinfo() in line as well:
igb/igb_ethtool.c +851
static void igb_get_drvinfo(struct net_device *netdev,
igbvf/ethtool.c
167:static void igbvf_get_drvinfo(struct net_device *netdev,
i40e/i40e_ethtool.c
1999:static void i40e_get_drvinfo(struct net_device *netdev,
e1000/e1000_ethtool.c
529:static void e1000_get_drvinfo(struct net_device *netdev,
ixgbevf/ethtool.c
211:static void ixgbevf_get_drvinfo(struct net_device *netdev,
...
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231012-strncpy-drivers-net-usb-sr9800-c-v1-1-5540832c8ec2@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
Other implementations of .*get_drvinfo use strscpy so this patch brings
lan78xx_get_drvinfo() in line as well:
igb/igb_ethtool.c +851
static void igb_get_drvinfo(struct net_device *netdev,
igbvf/ethtool.c
167:static void igbvf_get_drvinfo(struct net_device *netdev,
i40e/i40e_ethtool.c
1999:static void i40e_get_drvinfo(struct net_device *netdev,
e1000/e1000_ethtool.c
529:static void e1000_get_drvinfo(struct net_device *netdev,
ixgbevf/ethtool.c
211:static void ixgbevf_get_drvinfo(struct net_device *netdev,
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231012-strncpy-drivers-net-usb-lan78xx-c-v1-1-99d513061dfc@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
ethtool_sprintf() is designed specifically for get_strings() usage.
Let's replace strncpy in favor of this dedicated helper function.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231012-strncpy-drivers-net-phy-smsc-c-v1-1-00528f7524b3@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.
Other implementations of .*get_drvinfo also use strscpy so this patch
brings keystone_get_drvinfo() in line as well:
igb/igb_ethtool.c +851
static void igb_get_drvinfo(struct net_device *netdev,
igbvf/ethtool.c
167:static void igbvf_get_drvinfo(struct net_device *netdev,
i40e/i40e_ethtool.c
1999:static void i40e_get_drvinfo(struct net_device *netdev,
e1000/e1000_ethtool.c
529:static void e1000_get_drvinfo(struct net_device *netdev,
ixgbevf/ethtool.c
211:static void ixgbevf_get_drvinfo(struct net_device *netdev,
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20231012-strncpy-drivers-net-ethernet-ti-netcp_ethss-c-v1-1-93142e620864@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
TCP pingpong threshold is 1 by default. But some applications, like SQL DB
may prefer a higher pingpong threshold to activate delayed acks in quick
ack mode for better performance.
The pingpong threshold and related code were changed to 3 in the year
2019 in:
commit 4a41f453bedf ("tcp: change pingpong threshold to 3")
And reverted to 1 in the year 2022 in:
commit 4d8f24eeedc5 ("Revert "tcp: change pingpong threshold to 3"")
There is no single value that fits all applications.
Add net.ipv4.tcp_pingpong_thresh sysctl tunable, so it can be tuned for
optimal performance based on the application needs.
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/1697056244-21888-1-git-send-email-haiyangz@microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Add an initial user for the newly added tcf_set_drop_reason() helper to set the
drop reason for internal errors leading to TC_ACT_SHOT inside {__,}tcf_classify().
Right now this only adds a very basic SKB_DROP_REASON_TC_ERROR as a generic
fallback indicator to mark drop locations. Where needed, such locations can be
converted to more specific codes, for example, when hitting the reclassification
limit, etc.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Victor Nogueira <victor@mojatatu.com>
Link: https://lore.kernel.org/r/20231009092655.22025-2-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Currently, the kfree_skb_reason() in sch_handle_{ingress,egress}() can only
express a basic SKB_DROP_REASON_TC_INGRESS or SKB_DROP_REASON_TC_EGRESS reason.
Victor kicked-off an initial proposal to make this more flexible by disambiguating
verdict from return code by moving the verdict into struct tcf_result and
letting tcf_classify() return a negative error. If hit, then two new drop
reasons were added in the proposal, that is SKB_DROP_REASON_TC_INGRESS_ERROR
as well as SKB_DROP_REASON_TC_EGRESS_ERROR. Further analysis of the actual
error codes would have required to attach to tcf_classify via kprobe/kretprobe
to more deeply debug skb and the returned error.
In order to make the kfree_skb_reason() in sch_handle_{ingress,egress}() more
extensible, it can be addressed in a more straight forward way, that is: Instead
of placing the verdict into struct tcf_result, we can just put the drop reason
in there, which does not require changes throughout various classful schedulers
given the existing verdict logic can stay as is.
Then, SKB_DROP_REASON_TC_ERROR{,_*} can be added to the enum skb_drop_reason
to disambiguate between an error or an intentional drop. New drop reason error
codes can be added successively to the tc code base.
For internal error locations which have not yet been annotated with a
SKB_DROP_REASON_TC_ERROR{,_*}, the fallback is SKB_DROP_REASON_TC_INGRESS and
SKB_DROP_REASON_TC_EGRESS, respectively. Generic errors could be marked with a
SKB_DROP_REASON_TC_ERROR code until they are converted to more specific ones
if it is found that they would be useful for troubleshooting.
While drop reasons have infrastructure for subsystem specific error codes which
are currently used by mac80211 and ovs, Jakub mentioned that it is preferred
for tc to use the enum skb_drop_reason core codes given it is a better fit and
currently the tooling support is better, too.
With regards to the latter:
[...] I think Alastair (bpftrace) is working on auto-prettifying enums when
bpftrace outputs maps. So we can do something like:
$ bpftrace -e 'tracepoint:skb:kfree_skb { @[args->reason] = count(); }'
Attaching 1 probe...
^C
@[SKB_DROP_REASON_TC_INGRESS]: 2
@[SKB_CONSUMED]: 34
^^^^^^^^^^^^ names!!
Auto-magically. [...]
Add a small helper tcf_set_drop_reason() which can be used to set the drop reason
into the tcf_result.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Victor Nogueira <victor@mojatatu.com>
Link: https://lore.kernel.org/netdev/20231006063233.74345d36@kernel.org
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231009092655.22025-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Andrii Nakryiko says:
====================
This patch set fixes ambiguity in BPF verifier log output of SCALAR register
in the parts that emit umin/umax, smin/smax, etc ranges. See patch #4 for
details.
Also, patch #5 fixes an issue with verifier log missing instruction context
(state) output for conditionals that trigger precision marking. See details in
the patch.
First two patches are just improvements to two selftests that are very flaky
locally when run in parallel mode.
Patch #3 changes 'align' selftest to be less strict about exact verifier log
output (which patch #4 changes, breaking lots of align tests as written). Now
test does more of a register substate checks, mostly around expected var_off()
values. This 'align' selftests is one of the more brittle ones and requires
constant adjustment when verifier log output changes, without really catching
any new issues. So hopefully these changes can minimize future support efforts
for this specific set of tests.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
|
