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2023-01-18fs: port vfs_*() helpers to struct mnt_idmapChristian Brauner1-1/+1
Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Christian Brauner (Microsoft) <[email protected]>
2023-01-17bpf/selftests: Add verifier tests for loading sleepable programsJiri Olsa1-0/+91
Adding verifier tests for loading all types od allowed sleepable programs plus reject for tp_btf type. Acked-by: Song Liu <[email protected]> Signed-off-by: Jiri Olsa <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-15selftests/bpf: add ipip6 and ip6ip decap to test_tc_tunnelZiyang Xuan2-8/+98
Add ipip6 and ip6ip decap testcases. Verify that bpf_skb_adjust_room() correctly decapsulate ipip6 and ip6ip tunnel packets. Signed-off-by: Ziyang Xuan <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Link: https://lore.kernel.org/r/dfd2d8cfdf9111bd129170d4345296f53bee6a67.1673574419.git.william.xuanziyang@huawei.com Signed-off-by: Martin KaFai Lau <[email protected]>
2023-01-13selftests/bpf: Fix missing space errorRoberto Valenzuela1-1/+1
Add the missing space after 'dest' variable assignment. This change will resolve the following checkpatch.pl script error: ERROR: spaces required around that '+=' (ctx:VxW) Signed-off-by: Roberto Valenzuela <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2023-01-11selftests/xsk: automatically switch XDP programsMagnus Karlsson4-68/+96
Implement automatic switching of XDP programs and execution modes if needed by a test. This makes it much simpler to write a test as it only has to say what XDP program it needs if it is not the default one. This also makes it possible to remove the initial explicit attachment of the XDP program as well as the explicit mode switch in the code. These are now handled by the same code that just checks if a switch is necessary, so no special cases are needed. The default XDP program for all tests is one that sends all packets to the AF_XDP socket. If you need another one, please use the new function test_spec_set_xdp_prog() to specify what XDP programs and maps to use for this test. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: automatically restore packet streamMagnus Karlsson1-14/+1
Automatically restore the default packet stream if needed at the end of each test. This so that test writers do not forget to do this. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: merge dual and single thread dispatchersMagnus Karlsson1-66/+54
Make the thread dispatching code common by unifying the dual and single thread dispatcher code. This so we do not have to add code in two places in upcoming commits. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: add test when some packets are XDP_DROPedMagnus Karlsson3-0/+43
Add a new test where some of the packets are not passed to the AF_XDP socket and instead get a XDP_DROP verdict. This is important as it tests the recycling mechanism of the buffer pool. If a packet is not sent to the AF_XDP socket, the buffer the packet resides in is instead recycled so it can be used again without the round-trip to user space. The test introduces a new XDP program that drops every other packet. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: get rid of built-in XDP programMagnus Karlsson6-106/+92
Get rid of the built-in XDP program that was part of the old libbpf code in xsk.c and replace it with an eBPF program build using the framework by all the other bpf selftests. This will form the base for adding more programs in later commits. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: remove unnecessary code in control pathMagnus Karlsson3-631/+3
Remove unnecessary code in the control path. This is located in the file xsk.c that was moved from libbpf when the xsk support there was deprecated. Some of the code there is not needed anymore as the selftests are only guaranteed to run on the kernel it is shipped with. Therefore, all the code that has to deal with compatibility of older kernels can be dropped and also any other function that is not of any use for the tests. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: load and attach XDP program only once per modeMagnus Karlsson4-87/+162
Load and attach the XDP program only once per XDP mode that is being executed. Today, the XDP program is loaded and attached for every test, then unloaded, which takes a long time on real NICs, since they have to reconfigure their HW, in contrast to veth. The test suite now completes in 21 seconds, instead of 207 seconds previously on my machine. This is a speed-up of around 10x. This is accomplished by moving the XDP loading from the worker threads to the main thread and replacing the XDP loading interfaces of xsk.c that was taken from the xsk support in libbpf, with something more explicit that is more useful for these tests. Instead, the relevant file descriptors and ifindexes are just passed down to the new functions. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: remove namespacesMagnus Karlsson4-74/+20
Remove the namespaces used as they fill no function. This will simplify the code for speeding up the tests in the following commits. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: replace asm acquire/release implementationsMagnus Karlsson1-76/+4
Replace our own homegrown assembly store/release and load/acquire implementations with the HW agnositic atomic APIs C11 offers. This to make the code more portable, easier to read, and reduce the maintenance burden. The original code used load-acquire and store-release barriers hand-coded in assembly. Since C11, these kind of operations are offered as built-ins in gcc and llvm. The load-acquire operation prevents hoisting of non-atomic memory operations to before this operation and it corresponds to the __ATOMIC_ACQUIRE operation in the built-in atomics. The store-release operation prevents hoisting of non-atomic memory operations to after this operation and it corresponds to the __ATOMIC_RELEASE operation in the built-in atomics. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: add debug option for creating netdevsMagnus Karlsson1-1/+10
Add a new option to the test_xsk.sh script that only creates the two veth netdevs and the extra namespace, then exits without running any tests. The failed test can then be executed in the debugger without having to create the netdevs and namespace manually. For ease-of-use, the veth netdevs to use are printed so they can be copied into the debugger. Here is an example how to use it: > sudo ./test_xsk.sh -d veth10 veth11 > gdb xskxceiver In gdb: run -i veth10 -i veth11 And now the test cases can be debugged with gdb. If you want to debug the test suite on a real NIC in loopback mode, there is no need to use this feature as you already know the netdev of your NIC. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: remove unused variable outstanding_txMagnus Karlsson1-2/+0
Remove the unused variable outstanding_tx. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: print correct error codes when exitingMagnus Karlsson1-9/+9
Print the correct error codes when exiting the test suite due to some terminal error. Some of these had a switched sign and some of them printed zero instead of errno. Fixes: facb7cb2e909 ("selftests/bpf: Xsk selftests - SKB POLL, NOPOLL") Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: submit correct number of frames in populate_fill_ringMagnus Karlsson1-1/+1
Submit the correct number of frames in the function xsk_populate_fill_ring(). For the tests that set the flag use_addr_for_fill, uninitialized buffers were sent to the fill ring following the correct ones. This has no impact on the tests, since they only use the ones that were initialized. But for correctness, this should be fixed. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: do not close unused file descriptorsMagnus Karlsson1-2/+11
Do not close descriptors that have never been used. File descriptor fields that are not in use are erroneously marked with the number 0, which is a valid fd. Mark unused fds with -1 instead and do not close these when deleting the socket. Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-11selftests/xsk: print correct payload for packet dumpMagnus Karlsson1-2/+2
Print the correct payload when the packet dump option is selected. The network to host conversion was forgotten and the payload was erronously declared to be an int instead of an unsigned int. Fixes: facb7cb2e909 ("selftests/bpf: Xsk selftests - SKB POLL, NOPOLL") Signed-off-by: Magnus Karlsson <[email protected]> Acked-by: Maciej Fijalkowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-01-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski9-1/+286
No conflicts. Signed-off-by: Jakub Kicinski <[email protected]>
2023-01-04Merge tag 'for-netdev' of ↵Jakub Kicinski10-23/+411
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== bpf-next 2023-01-04 We've added 45 non-merge commits during the last 21 day(s) which contain a total of 50 files changed, 1454 insertions(+), 375 deletions(-). The main changes are: 1) Fixes, improvements and refactoring of parts of BPF verifier's state equivalence checks, from Andrii Nakryiko. 2) Fix a few corner cases in libbpf's BTF-to-C converter in particular around padding handling and enums, also from Andrii Nakryiko. 3) Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata, from Christian Ehrig. 4) Improve x86 JIT's codegen for PROBE_MEM runtime error checks, from Dave Marchevsky. 5) Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers, from Jiri Olsa. 6) Add proper documentation for BPF_MAP_TYPE_SOCK{MAP,HASH} maps, from Maryam Tahhan. 7) Improvements in libbpf's btf_parse_elf error handling, from Changbin Du. 8) Bigger batch of improvements to BPF tracing code samples, from Daniel T. Lee. 9) Add LoongArch support to libbpf's bpf_tracing helper header, from Hengqi Chen. 10) Fix a libbpf compiler warning in perf_event_open_probe on arm32, from Khem Raj. 11) Optimize bpf_local_storage_elem by removing 56 bytes of padding, from Martin KaFai Lau. 12) Use pkg-config to locate libelf for resolve_btfids build, from Shen Jiamin. 13) Various libbpf improvements around API documentation and errno handling, from Xin Liu. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (45 commits) libbpf: Return -ENODATA for missing btf section libbpf: Add LoongArch support to bpf_tracing.h libbpf: Restore errno after pr_warn. libbpf: Added the description of some API functions libbpf: Fix invalid return address register in s390 samples/bpf: Use BPF_KSYSCALL macro in syscall tracing programs samples/bpf: Fix tracex2 by using BPF_KSYSCALL macro samples/bpf: Change _kern suffix to .bpf with syscall tracing program samples/bpf: Use vmlinux.h instead of implicit headers in syscall tracing program samples/bpf: Use kyscall instead of kprobe in syscall tracing program bpf: rename list_head -> graph_root in field info types libbpf: fix errno is overwritten after being closed. bpf: fix regs_exact() logic in regsafe() to remap IDs correctly bpf: perform byte-by-byte comparison only when necessary in regsafe() bpf: reject non-exact register type matches in regsafe() bpf: generalize MAYBE_NULL vs non-MAYBE_NULL rule bpf: reorganize struct bpf_reg_state fields bpf: teach refsafe() to take into account ID remapping bpf: Remove unused field initialization in bpf's ctl_table selftests/bpf: Add jit probe_mem corner case tests to s390x denylist ... ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
2022-12-28selftests/bpf: add a test for iter/task_vma for short-lived processesKui-Feng Lee1-0/+73
When a task iterator traverses vma(s), it is possible task->mm might become invalid in the middle of traversal and this may cause kernel misbehave (e.g., crash) This test case creates iterators repeatedly and forks short-lived processes in the background to detect this bug. The test will last for 3 seconds to get the chance to trigger the issue. Signed-off-by: Kui-Feng Lee <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-28selftests/bpf: Temporarily disable part of btf_dump:var_data test.Alexei Starovoitov1-1/+1
Commit 7443b296e699 ("x86/percpu: Move cpu_number next to current_task") moved global per_cpu variable 'cpu_number' into pcpu_hot structure. Therefore this part of var_data test is no longer valid. Disable it until better solution is found. Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-23selftests/bpf: Add host-tools to gitignoreStanislav Fomichev1-0/+1
Shows up when cross-compiling: HOST_SCRATCH_DIR := $(OUTPUT)/host-tools vs SCRATCH_DIR := $(OUTPUT)/tools HOST_SCRATCH_DIR := $(SCRATCH_DIR) Reported-by: John Sperbeck <[email protected]> Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-22selftests/bpf: check null propagation only neither reg is PTR_TO_BTF_IDHao Sun2-0/+51
Verify that nullness information is not porpagated in the branches of register to register JEQ and JNE operations if one of them is PTR_TO_BTF_ID. Implement this in C level so we can use CO-RE. Signed-off-by: Hao Sun <[email protected]> Suggested-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2022-12-22selftests/bpf: Add jit probe_mem corner case tests to s390x denylistDaniel Borkmann1-0/+1
BPF CI fails for s390x with the following result: [...] All error logs: libbpf: prog 'test_jit_probe_mem': BPF program load failed: ERROR: strerror_r(524)=22 libbpf: prog 'test_jit_probe_mem': -- BEGIN PROG LOAD LOG -- JIT does not support calling kernel function processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 -- END PROG LOAD LOG -- libbpf: prog 'test_jit_probe_mem': failed to load: -524 libbpf: failed to load object 'jit_probe_mem' libbpf: failed to load BPF skeleton 'jit_probe_mem': -524 test_jit_probe_mem:FAIL:jit_probe_mem__open_and_load unexpected error: -524 #89 jit_probe_mem:FAIL [...] Add the test to the deny list. Fixes: 59fe41b5255f ("selftests/bpf: Add verifier test exercising jit PROBE_MEM logic") Signed-off-by: Daniel Borkmann <[email protected]>
2022-12-22selftests/bpf: Test bpf_skb_adjust_room on CHECKSUM_PARTIALMartin KaFai Lau4-0/+160
When the bpf_skb_adjust_room() shrinks the skb such that its csum_start is invalid, the skb->ip_summed should be reset from CHECKSUM_PARTIAL to CHECKSUM_NONE. The commit 54c3f1a81421 ("bpf: pull before calling skb_postpull_rcsum()") fixed it. This patch adds a test to ensure the skb->ip_summed changed from CHECKSUM_PARTIAL to CHECKSUM_NONE after bpf_skb_adjust_room(). Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Stanislav Fomichev <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-22selftests/bpf: Add verifier test exercising jit PROBE_MEM logicDave Marchevsky2-0/+89
This patch adds a test exercising logic that was fixed / improved in the previous patch in the series, as well as general sanity checking for jit's PROBE_MEM logic which should've been unaffected by the previous patch. The added verifier test does the following: * Acquire a referenced kptr to struct prog_test_ref_kfunc using existing net/bpf/test_run.c kfunc * Helper returns ptr to a specific prog_test_ref_kfunc whose first two fields - both ints - have been prepopulated w/ vals 42 and 108, respectively * kptr_xchg the acquired ptr into an arraymap * Do a direct map_value load of the just-added ptr * Goal of all this setup is to get an unreferenced kptr pointing to struct with ints of known value, which is the result of this step * Using unreferenced kptr obtained in previous step, do loads of prog_test_ref_kfunc.a (offset 0) and .b (offset 4) * Then incr the kptr by 8 and load prog_test_ref_kfunc.a again (this time at offset -8) * Add all the loaded ints together and return Before the PROBE_MEM fixes in previous patch, the loads at offset 0 and 4 would succeed, while the load at offset -8 would incorrectly fail runtime check emitted by the JIT and 0 out dst reg as a result. This confirmed by retval of 150 for this test before previous patch - since second .a read is 0'd out - and a retval of 192 with the fixed logic. The test exercises the two optimizations to fixed logic added in last patch as well: * First load, with insn "r8 = *(u32 *)(r9 + 0)" exercises "insn->off is 0, no need to add / sub from src_reg" optimization * Third load, with insn "r9 = *(u32 *)(r9 - 8)" exercises "src_reg == dst_reg, no need to restore src_reg after load" optimization Signed-off-by: Dave Marchevsky <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-20bpf: makefiles: Do not generate empty vmlinux.hChangbin Du1-0/+3
Remove the empty vmlinux.h if bpftool failed to dump btf info. The empty vmlinux.h can hide real error when reading output of make. This is done by adding .DELETE_ON_ERROR special target in related makefiles. Signed-off-by: Changbin Du <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Quentin Monnet <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-19selftests/bpf: Add BPF_F_NO_TUNNEL_KEY testChristian Ehrig2-3/+58
This patch adds a selftest simulating a GRE sender and receiver using tunnel headers without tunnel keys. It validates if packets encapsulated using BPF_F_NO_TUNNEL_KEY are decapsulated by a GRE receiver not configured with tunnel keys. Signed-off-by: Christian Ehrig <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Reviewed-by: Jakub Sitnicki <[email protected]> Acked-by: Stanislav Fomichev <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-15libbpf: Fix btf_dump's packed struct determinationAndrii Nakryiko1-0/+19
Fix bug in btf_dump's logic of determining if a given struct type is packed or not. The notion of "natural alignment" is not needed and is even harmful in this case, so drop it altogether. The biggest difference in btf_is_struct_packed() compared to its original implementation is that we don't really use btf__align_of() to determine overall alignment of a struct type (because it could be 1 for both packed and non-packed struct, depending on specifci field definitions), and just use field's actual alignment to calculate whether any field is requiring packing or struct's size overall necessitates packing. Add two simple test cases that demonstrate the difference this change would make. Fixes: ea2ce1ba99aa ("libbpf: Fix BTF-to-C converter's padding logic") Reported-by: Eduard Zingerman <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-14selftests/bpf: Add a test for using a cpumap from an freplace-to-XDP programToke Høiland-Jørgensen2-0/+72
This adds a simple test for inserting an XDP program into a cpumap that is "owned" by an XDP program that was loaded as PROG_TYPE_EXT (as libxdp does). Prior to the kernel fix this would fail because the map type ownership would be set to PROG_TYPE_EXT instead of being resolved to PROG_TYPE_XDP. v5: - Fix a few nits from Andrii, add his ACK v4: - Use skeletons for selftest v3: - Update comment to better explain the cause - Add Yonghong's ACK Acked-by: Yonghong Song <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Signed-off-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2022-12-15selftests/bpf: Add few corner cases to test padding handling of btf_dumpAndrii Nakryiko2-1/+164
Add few hand-crafted cases and few randomized cases found using script from [0] that tests btf_dump's padding logic. [0] https://lore.kernel.org/bpf/[email protected]/ Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-15libbpf: Fix BTF-to-C converter's padding logicAndrii Nakryiko2-19/+41
Turns out that btf_dump API doesn't handle a bunch of tricky corner cases, as reported by Per, and further discovered using his testing Python script ([0]). This patch revamps btf_dump's padding logic significantly, making it more correct and also avoiding unnecessary explicit padding, where compiler would pad naturally. This overall topic turned out to be very tricky and subtle, there are lots of subtle corner cases. The comments in the code tries to give some clues, but comments themselves are supposed to be paired with good understanding of C alignment and padding rules. Plus some experimentation to figure out subtle things like whether `long :0;` means that struct is now forced to be long-aligned (no, it's not, turns out). Anyways, Per's script, while not completely correct in some known situations, doesn't show any obvious cases where this logic breaks, so this is a nice improvement over the previous state of this logic. Some selftests had to be adjusted to accommodate better use of natural alignment rules, eliminating some unnecessary padding, or changing it to `type: 0;` alignment markers. Note also that for when we are in between bitfields, we emit explicit bit size, while otherwise we use `: 0`, this feels much more natural in practice. Next patch will add few more test cases, found through randomized Per's script. [0] https://lore.kernel.org/bpf/[email protected]/ Reported-by: Per Sundström XP <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-15selftests/bpf: Add non-standardly sized enum tests for btf_dumpAndrii Nakryiko1-0/+36
Add few custom enum definitions testing mode(byte) and mode(word) attributes. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-14selftests/bpf: Select CONFIG_FUNCTION_ERROR_INJECTIONSong Liu1-0/+1
BPF selftests require CONFIG_FUNCTION_ERROR_INJECTION to work. However, CONFIG_FUNCTION_ERROR_INJECTION is no longer 'y' by default after recent changes. As a result, we are seeing errors like the following from BPF CI: bpf_testmod_test_read() is not modifiable __x64_sys_setdomainname is not sleepable __x64_sys_getpgid is not sleepable Fix this by explicitly selecting CONFIG_FUNCTION_ERROR_INJECTION in the selftest config. Fixes: a4412fdd49dc ("error-injection: Add prompt for function error injection") Reported-by: Daniel Müller <[email protected]> Signed-off-by: Song Liu <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Daniel Müller <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-14selftests/bpf: Fix a selftest compilation error with CONFIG_SMP=nYonghong Song2-5/+5
Kernel test robot reported bpf selftest build failure when CONFIG_SMP is not set. The error message looks below: >> progs/rcu_read_lock.c:256:34: error: no member named 'last_wakee' in 'struct task_struct' last_wakee = task->real_parent->last_wakee; ~~~~~~~~~~~~~~~~~ ^ 1 error generated. When CONFIG_SMP is not set, the field 'last_wakee' is not available in struct 'task_struct'. Hence the above compilation failure. To fix the issue, let us choose another field 'group_leader' which is available regardless of CONFIG_SMP set or not. Fixes: fe147956fca4 ("bpf/selftests: Add selftests for new task kfuncs") Fixes: 48671232fcb8 ("selftests/bpf: Add tests for bpf_rcu_read_lock()") Reported-by: kernel test robot <[email protected]> Signed-off-by: David Vernet <[email protected]> Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: David Vernet <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-10selftests/bpf: test case for relaxed prunning of active_lock.idEduard Zingerman1-0/+75
Check that verifier.c:states_equal() uses check_ids() to match consistent active_lock/map_value configurations. This allows to prune states with active spin locks even if numerical values of active_lock ids do not match across compared states. Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-10selftests/bpf: Add pruning test case for bpf_spin_lockKumar Kartikeya Dwivedi1-0/+39
Test that when reg->id is not same for the same register of type PTR_TO_MAP_VALUE between current and old explored state, we currently return false from regsafe and continue exploring. Without the fix in prior commit, the test case fails. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-10selftests/bpf: verify states_equal() maintains idmap across all framesEduard Zingerman1-0/+82
A test case that would erroneously pass verification if verifier.c:states_equal() maintains separate register ID mappings for call frames. Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-10selftests/bpf: test cases for regsafe() bug skipping check_id()Eduard Zingerman2-0/+103
Under certain conditions it was possible for verifier.c:regsafe() to skip check_id() call. This commit adds negative test cases previously errorneously accepted as safe. Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-08selftests/bpf: Add test for dynptr reinit in user_ringbuf callbackKumar Kartikeya Dwivedi2-8/+45
The original support for bpf_user_ringbuf_drain callbacks simply short-circuited checks for the dynptr state, allowing users to pass PTR_TO_DYNPTR (now CONST_PTR_TO_DYNPTR) to helpers that initialize a dynptr. This bug would have also surfaced with other dynptr helpers in the future that changed dynptr view or modified it in some way. Include test cases for all cases, i.e. both bpf_dynptr_from_mem and bpf_ringbuf_reserve_dynptr, and ensure verifier rejects both of them. Without the fix, both of these programs load and pass verification. While at it, remove sys_nanosleep target from failure cases' SEC definition, as there is no such tracepoint. Acked-by: David Vernet <[email protected]> Acked-by: Joanne Koong <[email protected]> Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-08bpf: Rework check_func_arg_reg_offKumar Kartikeya Dwivedi2-2/+2
While check_func_arg_reg_off is the place which performs generic checks needed by various candidates of reg->type, there is some handling for special cases, like ARG_PTR_TO_DYNPTR, OBJ_RELEASE, and ARG_PTR_TO_RINGBUF_MEM. This commit aims to streamline these special cases and instead leave other things up to argument type specific code to handle. The function will be restrictive by default, and cover all possible cases when OBJ_RELEASE is set, without having to update the function again (and missing to do that being a bug). This is done primarily for two reasons: associating back reg->type to its argument leaves room for the list getting out of sync when a new reg->type is supported by an arg_type. The other case is ARG_PTR_TO_RINGBUF_MEM. The problem there is something we already handle, whenever a release argument is expected, it should be passed as the pointer that was received from the acquire function. Hence zero fixed and variable offset. There is nothing special about ARG_PTR_TO_RINGBUF_MEM, where technically its target register type PTR_TO_MEM | MEM_RINGBUF can already be passed with non-zero offset to other helper functions, which makes sense. Hence, lift the arg_type_is_release check for reg->off and cover all possible register types, instead of duplicating the same kind of check twice for current OBJ_RELEASE arg_types (alloc_mem and ptr_to_btf_id). For the release argument, arg_type_is_dynptr is the special case, where we go to actual object being freed through the dynptr, so the offset of the pointer still needs to allow fixed and variable offset and process_dynptr_func will verify them later for the release argument case as well. This is not specific to ARG_PTR_TO_DYNPTR though, we will need to make this exception for any future object on the stack that needs to be released. In this sense, PTR_TO_STACK as a candidate for object on stack argument is a special case for release offset checks, and they need to be done by the helper releasing the object on stack. Since the check has been lifted above all register type checks, remove the duplicated check that is being done for PTR_TO_BTF_ID. Acked-by: Joanne Koong <[email protected]> Acked-by: David Vernet <[email protected]> Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-08bpf: Rework process_dynptr_funcKumar Kartikeya Dwivedi1-2/+2
Recently, user ringbuf support introduced a PTR_TO_DYNPTR register type for use in callback state, because in case of user ringbuf helpers, there is no dynptr on the stack that is passed into the callback. To reflect such a state, a special register type was created. However, some checks have been bypassed incorrectly during the addition of this feature. First, for arg_type with MEM_UNINIT flag which initialize a dynptr, they must be rejected for such register type. Secondly, in the future, there are plans to add dynptr helpers that operate on the dynptr itself and may change its offset and other properties. In all of these cases, PTR_TO_DYNPTR shouldn't be allowed to be passed to such helpers, however the current code simply returns 0. The rejection for helpers that release the dynptr is already handled. For fixing this, we take a step back and rework existing code in a way that will allow fitting in all classes of helpers and have a coherent model for dealing with the variety of use cases in which dynptr is used. First, for ARG_PTR_TO_DYNPTR, it can either be set alone or together with a DYNPTR_TYPE_* constant that denotes the only type it accepts. Next, helpers which initialize a dynptr use MEM_UNINIT to indicate this fact. To make the distinction clear, use MEM_RDONLY flag to indicate that the helper only operates on the memory pointed to by the dynptr, not the dynptr itself. In C parlance, it would be equivalent to taking the dynptr as a point to const argument. When either of these flags are not present, the helper is allowed to mutate both the dynptr itself and also the memory it points to. Currently, the read only status of the memory is not tracked in the dynptr, but it would be trivial to add this support inside dynptr state of the register. With these changes and renaming PTR_TO_DYNPTR to CONST_PTR_TO_DYNPTR to better reflect its usage, it can no longer be passed to helpers that initialize a dynptr, i.e. bpf_dynptr_from_mem, bpf_ringbuf_reserve_dynptr. A note to reviewers is that in code that does mark_stack_slots_dynptr, and unmark_stack_slots_dynptr, we implicitly rely on the fact that PTR_TO_STACK reg is the only case that can reach that code path, as one cannot pass CONST_PTR_TO_DYNPTR to helpers that don't set MEM_RDONLY. In both cases such helpers won't be setting that flag. The next patch will add a couple of selftest cases to make sure this doesn't break. Fixes: 205715673844 ("bpf: Add bpf_user_ringbuf_drain() helper") Acked-by: Joanne Koong <[email protected]> Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-08bpf: Refactor ARG_PTR_TO_DYNPTR checks into process_dynptr_funcKumar Kartikeya Dwivedi2-17/+2
ARG_PTR_TO_DYNPTR is akin to ARG_PTR_TO_TIMER, ARG_PTR_TO_KPTR, where the underlying register type is subjected to more special checks to determine the type of object represented by the pointer and its state consistency. Move dynptr checks to their own 'process_dynptr_func' function so that is consistent and in-line with existing code. This also makes it easier to reuse this code for kfunc handling. Then, reuse this consolidated function in kfunc dynptr handling too. Note that for kfuncs, the arg_type constraint of DYNPTR_TYPE_LOCAL has been lifted. Acked-by: David Vernet <[email protected]> Acked-by: Joanne Koong <[email protected]> Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-08selftests/bpf: Bring test_offload.py back to lifeStanislav Fomichev1-3/+5
Bpftool has new extra libbpf_det_bind probing map we need to exclude. Also skip trying to load netdevsim modules if it's already loaded (builtin). v2: - drop iproute2->bpftool changes (Toke) Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-12-07selftests/bpf: convert dynptr_fail and map_kptr_fail subtests to generic testerAndrii Nakryiko5-155/+64
Convert big chunks of dynptr and map_kptr subtests to use generic verification_tester. They are switched from using manually maintained tables of test cases, specifying program name and expected error verifier message, to btf_decl_tag-based annotations directly on corresponding BPF programs: __failure to specify that BPF program is expected to fail verification, and __msg() to specify expected log message. Acked-by: John Fastabend <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Kumar Kartikeya Dwivedi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-07selftests/bpf: add generic BPF program tester-loaderAndrii Nakryiko4-1/+272
It's become a common pattern to have a collection of small BPF programs in one BPF object file, each representing one test case. On user-space side of such tests we maintain a table of program names and expected failure or success, along with optional expected verifier log message. This works, but each set of tests reimplement this mundane code over and over again, which is a waste of time for anyone trying to add a new set of tests. Furthermore, it's quite error prone as it's way too easy to miss some entries in these manually maintained test tables (as evidences by dynptr_fail tests, in which ringbuf_release_uninit_dynptr subtest was accidentally missed; this is fixed in next patch). So this patch implements generic test_loader, which accepts skeleton name and handles the rest of details: opens and loads BPF object file, making sure each program is tested in isolation. Optionally each test case can specify expected BPF verifier log message. In case of failure, tester makes sure to report verifier log, but it also reports verifier log in verbose mode unconditionally. Now, the interesting deviation from existing custom implementations is the use of btf_decl_tag attribute to specify expected-to-fail vs expected-to-succeed markers and, optionally, expected log message directly next to BPF program source code, eliminating the need to manually create and update table of tests. We define few macros wrapping btf_decl_tag with a convention that all values of btf_decl_tag start with "comment:" prefix, and then utilizing a very simple "just_some_text_tag" or "some_key_name=<value>" pattern to define things like expected success/failure, expected verifier message, extra verifier log level (if necessary). This approach is demonstrated by next patch in which two existing sets of failure tests are converted. Tester supports both expected-to-fail and expected-to-succeed programs, though this patch set didn't convert any existing expected-to-succeed programs yet, as existing tests couple BPF program loading with their further execution through attach or test_prog_run. One way to allow testing scenarios like this would be ability to specify custom callback, executed for each successfully loaded BPF program. This is left for follow up patches, after some more analysis of existing test cases. This test_loader is, hopefully, a start of a test_verifier-like runner, but integrated into test_progs infrastructure. It will allow much better "user experience" of defining low-level verification tests that can take advantage of all the libbpf-provided nicety features on BPF side: global variables, declarative maps, etc. All while having a choice of defining it in C or as BPF assembly (through __attribute__((naked)) functions and using embedded asm), depending on what makes most sense in each particular case. This will be explored in follow up patches as well. Acked-by: John Fastabend <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-06bpf: Don't use rcu_users to refcount in task kfuncsDavid Vernet2-2/+12
A series of prior patches added some kfuncs that allow struct task_struct * objects to be used as kptrs. These kfuncs leveraged the 'refcount_t rcu_users' field of the task for performing refcounting. This field was used instead of 'refcount_t usage', as we wanted to leverage the safety provided by RCU for ensuring a task's lifetime. A struct task_struct is refcounted by two different refcount_t fields: 1. p->usage: The "true" refcount field which task lifetime. The task is freed as soon as this refcount drops to 0. 2. p->rcu_users: An "RCU users" refcount field which is statically initialized to 2, and is co-located in a union with a struct rcu_head field (p->rcu). p->rcu_users essentially encapsulates a single p->usage refcount, and when p->rcu_users goes to 0, an RCU callback is scheduled on the struct rcu_head which decrements the p->usage refcount. Our logic was that by using p->rcu_users, we would be able to use RCU to safely issue refcount_inc_not_zero() a task's rcu_users field to determine if a task could still be acquired, or was exiting. Unfortunately, this does not work due to p->rcu_users and p->rcu sharing a union. When p->rcu_users goes to 0, an RCU callback is scheduled to drop a single p->usage refcount, and because the fields share a union, the refcount immediately becomes nonzero again after the callback is scheduled. If we were to split the fields out of the union, this wouldn't be a problem. Doing so should also be rather non-controversial, as there are a number of places in struct task_struct that have padding which we could use to avoid growing the structure by splitting up the fields. For now, so as to fix the kfuncs to be correct, this patch instead updates bpf_task_acquire() and bpf_task_release() to use the p->usage field for refcounting via the get_task_struct() and put_task_struct() functions. Because we can no longer rely on RCU, the change also guts the bpf_task_acquire_not_zero() and bpf_task_kptr_get() functions pending a resolution on the above problem. In addition, the task fixes the kfunc and rcu_read_lock selftests to expect this new behavior. Fixes: 90660309b0c7 ("bpf: Add kfuncs for storing struct task_struct * as a kptr") Fixes: fca1aa75518c ("bpf: Handle MEM_RCU type properly") Reported-by: Matus Jokay <[email protected]> Signed-off-by: David Vernet <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-12-06selftests/bpf: Use CONFIG_TEST_BPF=m instead of CONFIG_TEST_BPF=yDaan De Meyer1-1/+1
CONFIG_TEST_BPF can only be a module, so let's indicate it as such in the selftests config. Signed-off-by: Daan De Meyer <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]