aboutsummaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/progs
AgeCommit message (Collapse)AuthorFilesLines
2024-08-21selftests/bpf: validate __xlated same way as __jitedEduard Zingerman1-2/+51
Both __xlated and __jited work with disassembly. It is logical to have both work in a similar manner. This commit updates __xlated macro handling in test_loader.c by making it expect matches on sequential lines, same way as __jited operates. For example: __xlated("1: *(u64 *)(r10 -16) = r1") ;; matched on line N __xlated("3: r0 = &(void __percpu *)(r0)") ;; matched on line N+1 Also: __xlated("1: *(u64 *)(r10 -16) = r1") ;; matched on line N __xlated("...") ;; not matched __xlated("3: r0 = &(void __percpu *)(r0)") ;; mantched on any ;; line >= N Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-21selftests/bpf: validate jit behaviour for tail callsEduard Zingerman1-0/+105
A program calling sub-program which does a tail call. The idea is to verify instructions generated by jit for tail calls: - in program and sub-program prologues; - for subprogram call instruction; - for tail call itself. Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-21selftests/bpf: __jited test tag to check disassembly after jitEduard Zingerman1-0/+35
Allow to verify jit behaviour by writing tests as below: SEC("tp") __arch_x86_64 __jited(" endbr64") __jited(" nopl (%rax,%rax)") __jited(" xorq %rax, %rax") ... __naked void some_test(void) { asm volatile (... ::: __clobber_all); } Allow regular expressions in patterns, same way as in __msg. By default assume that each __jited pattern has to be matched on the next consecutive line of the disassembly, e.g.: __jited(" endbr64") # matched on line N __jited(" nopl (%rax,%rax)") # matched on line N+1 If match occurs on a wrong line an error is reported. To override this behaviour use __jited("..."), e.g.: __jited(" endbr64") # matched on line N __jited("...") # not matched __jited(" nopl (%rax,%rax)") # matched on any line >= N Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-21selftests/bpf: replace __regex macro with "{{...}}" patternsEduard Zingerman4-10/+11
Upcoming changes require a notation to specify regular expression matches for regular verifier log messages, disassembly of BPF instructions, disassembly of jited instructions. Neither basic nor extended POSIX regular expressions w/o additional escaping are good for this role because of wide use of special characters in disassembly, for example: movq -0x10(%rbp), %rax ;; () are special characters cmpq $0x21, %rax ;; $ is a special character *(u64 *)(r10 -16) = r1 ;; * and () are special characters This commit borrows syntax from LLVM's FileCheck utility. It replaces __regex macro with ability to embed regular expressions in __msg patters using "{{" "}}" pairs for escaping. Syntax for __msg patterns: pattern := (<verbatim text> | regex)* regex := "{{" <posix extended regular expression> "}}" For example, pattern "foo{{[0-9]+}}" matches strings like "foo0", "foo007", etc. Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-21selftests/bpf: fix to avoid __msg tag de-duplication by clangEduard Zingerman2-10/+13
__msg, __regex and __xlated tags are based on __attribute__((btf_decl_tag("..."))) annotations. Clang de-duplicates such annotations, e.g. the following two sequences of tags are identical in final BTF: /* seq A */ /* seq B */ __tag("foo") __tag("foo") __tag("bar") __tag("bar") __tag("foo") Fix this by adding a unique suffix for each tag using __COUNTER__ pre-processor macro. E.g. here is a new definition for __msg: #define __msg(msg) \ __attribute__((btf_decl_tag("comment:test_expect_msg=" XSTR(__COUNTER__) "=" msg))) Using this definition the "seq A" from example above is translated to BTF as follows: [..] DECL_TAG 'comment:test_expect_msg=0=foo' type_id=X component_idx=-1 [..] DECL_TAG 'comment:test_expect_msg=1=bar' type_id=X component_idx=-1 [..] DECL_TAG 'comment:test_expect_msg=2=foo' type_id=X component_idx=-1 Surprisingly, this bug affects a single existing test: verifier_spill_fill/old_stack_misc_vs_cur_ctx_ptr, where sequence of identical messages was expected in the log. Fixes: 537c3f66eac1 ("selftests/bpf: add generic BPF program tester-loader") Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-21selftests/bpf: test passing iterator to a kfuncAndrii Nakryiko1-0/+50
Define BPF iterator "getter" kfunc, which accepts iterator pointer as one of the arguments. Make sure that argument passed doesn't have to be the very first argument (unlike new-next-destroy combo). Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-19selftest/bpf: Adapt inline asm operand constraint for GCC supportCupertino Miranda2-4/+4
GCC errors when compiling tailcall_bpf2bpf_hierarchy2.c and tailcall_bpf2bpf_hierarchy3.c with the following error: progs/tailcall_bpf2bpf_hierarchy2.c: In function 'tailcall_bpf2bpf_hierarchy_2': progs/tailcall_bpf2bpf_hierarchy2.c:66:9: error: input operand constraint contains '+' 66 | asm volatile (""::"r+"(ret)); | ^~~ Changed implementation to make use of __sink macro that abstracts the desired behaviour. The proposed change seems valid for both GCC and CLANG. Signed-off-by: Cupertino Miranda <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-08-14selftests/bpf: convert test_skb_cgroup_id_user to test_progsAlexis Lothoré (eBPF Foundation)1-23/+18
test_skb_cgroup_id_user allows testing skb cgroup id retrieval at different levels, but is not integrated in test_progs, so it is not run automatically in CI. The test overlaps a bit with cgroup_skb_sk_lookup_kern, which is integrated in test_progs and test extensively skb cgroup helpers, but there is still one major difference between the two tests which justifies the conversion: cgroup_skb_sk_lookup_kern deals with a BPF_PROG_TYPE_CGROUP_SKB (attached on a cgroup), while test_skb_cgroup_id_user deals with a BPF_PROG_TYPE_SCHED_CLS (attached on a qdisc) Convert test_skb_cgroup_id_user into test_progs framework in order to run it automatically in CI. The main differences with the original test are the following: - rename the test to make it shorter and more straightforward regarding tested feature - the wrapping shell script has been dropped since every setup step is now handled in the main C test file - the test has been renamed for a shorter name and reflecting the tested API - add dedicated assert log per level to ease test failure debugging - use global variables instead of maps to access bpf prog data Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-14selftests/bpf: add proper section name to bpf prog and rename itAlexis Lothoré (eBPF Foundation)1-1/+1
test_skb_cgroup_id_kern.c is currently involved in a manual test. In its current form, it can not be used with the auto-generated skeleton APIs, because the section name is not valid to allow libbpf to deduce the program type. Update section name to allow skeleton APIs usage. Also rename the program name to make it shorter and more straighforward regarding the API it is testing. While doing so, make sure that test_skb_cgroup_id.sh passes to get a working reference before converting it to test_progs - update the obj name - fix loading issue (verifier rejecting the program when loaded through tc, because of map not found), by preloading the whole obj with bpftool Reviewed-by: Alan Maguire <[email protected]> Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-14selftests/bpf: convert test_cgroup_storage to test_progsAlexis Lothoré (eBPF Foundation)1-0/+24
test_cgroup_storage is currently a standalone program which is not run when executing test_progs. Convert it to the test_progs framework so it can be automatically executed in CI. The conversion led to the following changes: - converted the raw bpf program in the userspace test file into a dedicated test program in progs/ dir - reduced the scope of cgroup_storage test: the content from this test overlaps with some other tests already present in test_progs, most notably netcnt and cgroup_storage_multi*. Those tests already check extensively local storage, per-cpu local storage, cgroups interaction, etc. So the new test only keep the part testing that the program return code (based on map content) properly leads to packet being passed or dropped. Reviewed-by: Alan Maguire <[email protected]> Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-14selftests/bpf: convert get_current_cgroup_id_user to test_progsAlexis Lothoré (eBPF Foundation)1-22/+4
get_current_cgroup_id_user allows testing for bpf_get_current_cgroup_id() bpf API but is not integrated into test_progs, and so is not tested automatically in CI. Convert it to the test_progs framework to allow running it automatically. The most notable differences with the old test are the following: - the new test relies on autoattach instead of manually hooking/enabling the targeted tracepoint through perf_event, which reduces quite a lot the test code size - it also accesses bpf prog data through global variables instead of maps - sleep duration passed to nanosleep syscall has been reduced to its minimum to not impact overall CI duration (we only care about the syscall being properly triggered, not about the passed duration) Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-12selftests/bpf: Add a test to verify previous stacksafe() fixYonghong Song1-0/+54
A selftest is added such that without the previous patch, a crash can happen. With the previous patch, the test can run successfully. The new test is written in a way which mimics original crash case: main_prog static_prog_1 static_prog_2 where static_prog_1 has different paths to static_prog_2 and some path has stack allocated and some other path does not. A stacksafe() checking in static_prog_2() triggered the crash. Signed-off-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-08selftests/bpf: add sockopt tests for TCP_BPF_SOCK_OPS_CB_FLAGSAlan Maguire1-3/+23
Add tests to set TCP sockopt TCP_BPF_SOCK_OPS_CB_FLAGS via bpf_setsockopt() and use a cgroup/getsockopt program to retrieve the value to verify it was set. Signed-off-by: Alan Maguire <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-07selftests/bpf: Add tests for bpf_get_dentry_xattrSong Liu1-5/+32
Add test for bpf_get_dentry_xattr on hook security_inode_getxattr. Verify that the kfunc can read the xattr. Also test failing getxattr from user space by returning non-zero from the LSM bpf program. Acked-by: Christian Brauner <[email protected]> Signed-off-by: Song Liu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-06selftests/bpf: add positive tests for new VFS based BPF kfuncsMatt Bobrowski1-0/+85
Add a bunch of positive selftests which extensively cover the various contexts and parameters in which the new VFS based BPF kfuncs may be used from. Again, the following VFS based BPF kfuncs are thoroughly tested within this new selftest: * struct file *bpf_get_task_exe_file(struct task_struct *); * void bpf_put_file(struct file *); * int bpf_path_d_path(struct path *, char *, size_t); Acked-by: Christian Brauner <[email protected]> Acked-by: Song Liu <[email protected]> Signed-off-by: Matt Bobrowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-06selftests/bpf: add negative tests for new VFS based BPF kfuncsMatt Bobrowski1-0/+161
Add a bunch of negative selftests responsible for asserting that the BPF verifier successfully rejects a BPF program load when the underlying BPF program misuses one of the newly introduced VFS based BPF kfuncs. The following VFS based BPF kfuncs are extensively tested within this new selftest: * struct file *bpf_get_task_exe_file(struct task_struct *); * void bpf_put_file(struct file *); * int bpf_path_d_path(struct path *, char *, size_t); Acked-by: Christian Brauner <[email protected]> Acked-by: Song Liu <[email protected]> Signed-off-by: Matt Bobrowski <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-07-31selftests/bpf: do not disable /dev/null device access in cgroup dev testAlexis Lothoré (eBPF Foundation)1-2/+2
test_dev_cgroup currently loads a small bpf program allowing any access on urandom and zero devices, disabling access to any other device. It makes migrating this test to test_progs impossible, since this one manipulates extensively /dev/null. Allow /dev/null manipulation in dev_cgroup program to make its usage in test_progs framework possible. Update test_dev_cgroup.c as well to match this change while it has not been removed. Reviewed-by: Alan Maguire <[email protected]> Acked-by: Stanislav Fomichev <[email protected]> Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-07-29selftests/bpf: Load struct_ops map in global_maps_resize testDavid Vernet1-0/+16
In prog_tests/test_global_maps_resize.c, we test various use cases for resizing global maps. Commit 7244100e0389 ("libbpf: Don't take direct pointers into BTF data from st_ops") updated libbpf to not store pointers to volatile BTF data, which for some users, was causing a UAF when resizing a datasec array. Let's ensure we have coverage for resizing datasec arrays with struct_ops progs by also including a struct_ops map and struct_ops prog in the test_global_map_resize skeleton. The map is automatically loaded, so we don't need to do anything other than add it to the BPF prog being tested to get the coverage. Signed-off-by: David Vernet <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-29selftests/bpf: Update xdp_redirect_map prog sections for libbpfAlexis Lothoré (eBPF Foundation)1-3/+3
xdp_redirect_map.c is a bpf program used by test_xdp_veth.sh, which is not handled by the generic test runner (test_progs). To allow converting this test to test_progs, the corresponding program must be updated to allow handling it through skeletons generated by bpftool and libbpf. Update programs section names to allow to manipulate those with libbpf. Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Stanislav Fomichev <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Fix errors compiling cg_storage_multi.h with musl libcTony Ambardar1-2/+0
Remove a redundant include of '<asm/types.h>', whose needed definitions are already included (via '<linux/types.h>') in cg_storage_multi_egress_only.c, cg_storage_multi_isolated.c, and cg_storage_multi_shared.c. This avoids redefinition errors seen compiling for mips64el/musl-libc like: In file included from progs/cg_storage_multi_egress_only.c:13: In file included from progs/cg_storage_multi.h:6: In file included from /usr/mips64el-linux-gnuabi64/include/asm/types.h:23: /usr/include/asm-generic/int-l64.h:29:25: error: typedef redefinition with different types ('long' vs 'long long') 29 | typedef __signed__ long __s64; | ^ /usr/include/asm-generic/int-ll64.h:30:44: note: previous definition is here 30 | __extension__ typedef __signed__ long long __s64; | ^ Fixes: 9e5bd1f7633b ("selftests/bpf: Test CGROUP_STORAGE map can't be used by multiple progs") Signed-off-by: Tony Ambardar <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/4f4702e9f6115b7f84fea01b2326ca24c6df7ba8.1721713597.git.tony.ambardar@gmail.com
2024-07-29selftests/bpf: test no_caller_saved_registers spill/fill removalEduard Zingerman1-0/+796
Tests for no_caller_saved_registers processing logic (see verifier.c:match_and_mark_nocsr_pattern()): - a canary positive test case; - a canary test case for arm64 and riscv64; - various tests with broken patterns; - tests with read/write fixed/varying stack access that violate nocsr stack access contract; - tests with multiple subprograms; - tests using nocsr in combination with may_goto/bpf_loop, as all of these features affect stack depth; - tests for nocsr stack spills below max stack depth. Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: __arch_* macro to limit test cases to specific archsEduard Zingerman1-0/+8
Add annotations __arch_x86_64, __arch_arm64, __arch_riscv64 to specify on which architecture the test case should be tested. Several __arch_* annotations could be specified at once. When test case is not run on current arch it is marked as skipped. For example, the following would be tested only on arm64 and riscv64: SEC("raw_tp") __arch_arm64 __arch_riscv64 __xlated("1: *(u64 *)(r10 - 16) = r1") __xlated("2: call") __xlated("3: r1 = *(u64 *)(r10 - 16);") __success __naked void canary_arm64_riscv64(void) { asm volatile ( "r1 = 1;" "*(u64 *)(r10 - 16) = r1;" "call %[bpf_get_smp_processor_id];" "r1 = *(u64 *)(r10 - 16);" "exit;" : : __imm(bpf_get_smp_processor_id) : __clobber_all); } On x86 it would be skipped: #467/2 verifier_nocsr/canary_arm64_riscv64:SKIP Acked-by: Andrii Nakryiko <[email protected]> Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: allow checking xlated programs in verifier_* testsEduard Zingerman1-0/+5
Add a macro __xlated("...") for use with test_loader tests. When such annotations are present for the test case: - bpf_prog_get_info_by_fd() is used to get BPF program after all rewrites are applied by verifier. - the program is disassembled and patterns specified in __xlated are searched for in the disassembly text. __xlated matching follows the same mechanics as __msg: each subsequent pattern is matched from the point where previous pattern ended. This allows to write tests like below, where the goal is to verify the behavior of one of the of the transformations applied by verifier: SEC("raw_tp") __xlated("1: w0 = ") __xlated("2: r0 = &(void __percpu *)(r0)") __xlated("3: r0 = *(u32 *)(r0 +0)") __xlated("4: exit") __success __naked void simple(void) { asm volatile ( "call %[bpf_get_smp_processor_id];" "exit;" : : __imm(bpf_get_smp_processor_id) : __clobber_all); } Acked-by: Andrii Nakryiko <[email protected]> Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Add tests for ldsx of pkt data/data_end/data_meta accessesYonghong Song1-0/+112
The following tests are added to verifier_ldsx.c: - sign extension of data/data_end/data_meta for tcx programs. The actual checking is in bpf_skb_is_valid_access() which is called by sk_filter, cg_skb, lwt, tc(tcx) and sk_skb. - sign extension of data/data_end/data_meta for xdp programs. - sign extension of data/data_end for flow_dissector programs. All newly-added tests have verification failure with message "invalid bpf_context access". Without previous patch, all these tests succeeded verification. Acked-by: Eduard Zingerman <[email protected]> Signed-off-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Add uprobe multi consumers testJiri Olsa1-0/+39
Adding test that attaches/detaches multiple consumers on single uprobe and verifies all were hit as expected. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-29selftests/bpf: Fix compilation failure when CONFIG_NET_FOU!=yArtem Savkov1-6/+21
Without CONFIG_NET_FOU bpf selftests are unable to build because of missing definitions. Add ___local versions of struct bpf_fou_encap and enum bpf_fou_encap_type to fix the issue. Signed-off-by: Artem Savkov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-29selftests/bpf: Add a test for mmap-able map in mapSong Liu1-0/+57
Regular BPF hash map is not mmap-able from user space. However, map-in-map with outer map of type BPF_MAP_TYPE_HASH_OF_MAPS and mmap-able array as inner map can perform similar operations as a mmap-able hash map. This can be used by applications that benefit from fast accesses to some local data. Add a selftest to show this use case. Signed-off-by: Song Liu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Workaround strict bpf_lsm return value check.Alexei Starovoitov1-0/+1
test_progs-no_alu32 -t libbpf_get_fd_by_id_opts is being rejected by the verifier with the following error due to compiler optimization: 6: (67) r0 <<= 62 ; R0_w=scalar(smax=0x4000000000000000,umax=0xc000000000000000,smin32=0,smax32=umax32=0,var_off=(0x0; 0xc000000000000000)) 7: (c7) r0 s>>= 63 ; R0_w=scalar(smin=smin32=-1,smax=smax32=0) ; @ test_libbpf_get_fd_by_id_opts.c:0 8: (57) r0 &= -13 ; R0_w=scalar(smax=0x7ffffffffffffff3,umax=0xfffffffffffffff3,smax32=0x7ffffff3,umax32=0xfffffff3,var_off=(0x0; 0xfffffffffffffff3)) ; int BPF_PROG(check_access, struct bpf_map *map, fmode_t fmode) @ test_libbpf_get_fd_by_id_opts.c:27 9: (95) exit At program exit the register R0 has smax=9223372036854775795 should have been in [-4095, 0] Workaround by adding barrier(). Eventually the verifier will be able to recognize it. Fixes: 5d99e198be27 ("bpf, lsm: Add check for BPF LSM return value") Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Add verifier tests for bpf lsmXu Kuohai1-0/+162
Add verifier tests to check bpf lsm return values and disabled hooks. Signed-off-by: Xu Kuohai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Add test for lsm tail callXu Kuohai1-0/+34
Add test for lsm tail call to ensure tail call can only be used between bpf lsm progs attached to the same hook. Signed-off-by: Xu Kuohai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Add return value checks for failed testsXu Kuohai4-3/+26
The return ranges of some bpf lsm test progs can not be deduced by the verifier accurately. To avoid erroneous rejections, add explicit return value checks for these progs. Signed-off-by: Xu Kuohai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Avoid load failure for token_lsm.cXu Kuohai1-2/+2
The compiler optimized the two bpf progs in token_lsm.c to make return value from the bool variable in the "return -1" path, causing an unexpected rejection: 0: R1=ctx() R10=fp0 ; int BPF_PROG(bpf_token_capable, struct bpf_token *token, int cap) @ bpf_lsm.c:17 0: (b7) r6 = 0 ; R6_w=0 ; if (my_pid == 0 || my_pid != (bpf_get_current_pid_tgid() >> 32)) @ bpf_lsm.c:19 1: (18) r1 = 0xffffc9000102a000 ; R1_w=map_value(map=bpf_lsm.bss,ks=4,vs=5) 3: (61) r7 = *(u32 *)(r1 +0) ; R1_w=map_value(map=bpf_lsm.bss,ks=4,vs=5) R7_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) 4: (15) if r7 == 0x0 goto pc+11 ; R7_w=scalar(smin=umin=umin32=1,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) 5: (67) r7 <<= 32 ; R7_w=scalar(smax=0x7fffffff00000000,umax=0xffffffff00000000,smin32=0,smax32=umax32=0,var_off=(0x0; 0xffffffff00000000)) 6: (c7) r7 s>>= 32 ; R7_w=scalar(smin=0xffffffff80000000,smax=0x7fffffff) 7: (85) call bpf_get_current_pid_tgid#14 ; R0=scalar() 8: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) 9: (5d) if r0 != r7 goto pc+6 ; R0_w=scalar(smin=smin32=0,smax=umax=umax32=0x7fffffff,var_off=(0x0; 0x7fffffff)) R7=scalar(smin=smin32=0,smax=umax=umax32=0x7fffffff,var_off=(0x0; 0x7fffffff)) ; if (reject_capable) @ bpf_lsm.c:21 10: (18) r1 = 0xffffc9000102a004 ; R1_w=map_value(map=bpf_lsm.bss,ks=4,vs=5,off=4) 12: (71) r6 = *(u8 *)(r1 +0) ; R1_w=map_value(map=bpf_lsm.bss,ks=4,vs=5,off=4) R6_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff)) ; @ bpf_lsm.c:0 13: (87) r6 = -r6 ; R6_w=scalar() 14: (67) r6 <<= 56 ; R6_w=scalar(smax=0x7f00000000000000,umax=0xff00000000000000,smin32=0,smax32=umax32=0,var_off=(0x0; 0xff00000000000000)) 15: (c7) r6 s>>= 56 ; R6_w=scalar(smin=smin32=-128,smax=smax32=127) ; int BPF_PROG(bpf_token_capable, struct bpf_token *token, int cap) @ bpf_lsm.c:17 16: (bf) r0 = r6 ; R0_w=scalar(id=1,smin=smin32=-128,smax=smax32=127) R6_w=scalar(id=1,smin=smin32=-128,smax=smax32=127) 17: (95) exit At program exit the register R0 has smin=-128 smax=127 should have been in [-4095, 0] To avoid this failure, change the variable type from bool to int. Signed-off-by: Xu Kuohai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Ensure the unsupported struct_ops prog cannot be loadedMartin KaFai Lau1-0/+22
There is an existing "bpf_tcp_ca/unsupp_cong_op" test to ensure the unsupported tcp-cc "get_info" struct_ops prog cannot be loaded. This patch adds a new test in the bpf_testmod such that the unsupported ops test does not depend on other kernel subsystem where its supporting ops may be changed in the future. Signed-off-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Add testcases for tailcall hierarchy fixingLeon Hwang5-0/+213
Add some test cases to confirm the tailcall hierarchy issue has been fixed. On x64, the selftests result is: cd tools/testing/selftests/bpf && ./test_progs -t tailcalls 327/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK 327/19 tailcalls/tailcall_bpf2bpf_hierarchy_fentry:OK 327/20 tailcalls/tailcall_bpf2bpf_hierarchy_fexit:OK 327/21 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_fexit:OK 327/22 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_entry:OK 327/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK 327/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK 327 tailcalls:OK Summary: 1/24 PASSED, 0 SKIPPED, 0 FAILED On arm64, the selftests result is: cd tools/testing/selftests/bpf && ./test_progs -t tailcalls 327/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK 327/19 tailcalls/tailcall_bpf2bpf_hierarchy_fentry:OK 327/20 tailcalls/tailcall_bpf2bpf_hierarchy_fexit:OK 327/21 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_fexit:OK 327/22 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_entry:OK 327/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK 327/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK 327 tailcalls:OK Summary: 1/24 PASSED, 0 SKIPPED, 0 FAILED Acked-by: Eduard Zingerman <[email protected]> Signed-off-by: Leon Hwang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Update comments find_equal_scalars->sync_linked_regsEduard Zingerman1-8/+8
find_equal_scalars() is renamed to sync_linked_regs(), this commit updates existing references in the selftests comments. Signed-off-by: Eduard Zingerman <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-29selftests/bpf: Tests for per-insn sync_linked_regs() precision trackingEduard Zingerman1-0/+165
Add a few test cases to verify precision tracking for scalars gaining range because of sync_linked_regs(): - check what happens when more than 6 registers might gain range in sync_linked_regs(); - check if precision is propagated correctly when operand of conditional jump gained range in sync_linked_regs() and one of linked registers is marked precise; - check if precision is propagated correctly when operand of conditional jump gained range in sync_linked_regs() and a other-linked operand of the conditional jump is marked precise; - add a minimized reproducer for precision tracking bug reported in [0]; - Check that mark_chain_precision() for one of the conditional jump operands does not trigger equal scalars precision propagation. [0] https://lore.kernel.org/bpf/CAEf4BzZ0xidVCqB47XnkXcNhkPWF6_nTV7yt+_Lf0kcFEut2Mg@mail.gmail.com/ Signed-off-by: Eduard Zingerman <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-29bpf: Remove mark_precise_scalar_ids()Eduard Zingerman1-116/+55
Function mark_precise_scalar_ids() is superseded by bt_sync_linked_regs() and equal scalars tracking in jump history. mark_precise_scalar_ids() propagates precision over registers sharing same ID on parent/child state boundaries, while jump history records allow bt_sync_linked_regs() to propagate same information with instruction level granularity, which is strictly more precise. This commit removes mark_precise_scalar_ids() and updates test cases in progs/verifier_scalar_ids to reflect new verifier behavior. The tests are updated in the following manner: - mark_precise_scalar_ids() propagated precision regardless of presence of conditional jumps, while new jump history based logic only kicks in when conditional jumps are present. Hence test cases are augmented with conditional jumps to still trigger precision propagation. - As equal scalars tracking no longer relies on parent/child state boundaries some test cases are no longer interesting, such test cases are removed, namely: - precision_same_state and precision_cross_state are superseded by linked_regs_bpf_k; - precision_same_state_broken_link and equal_scalars_broken_link are superseded by linked_regs_broken_link. Signed-off-by: Eduard Zingerman <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-29bpf: Track equal scalars history on per-instruction levelEduard Zingerman1-1/+1
Use bpf_verifier_state->jmp_history to track which registers were updated by find_equal_scalars() (renamed to collect_linked_regs()) when conditional jump was verified. Use recorded information in backtrack_insn() to propagate precision. E.g. for the following program: while verifying instructions 1: r1 = r0 | 2: if r1 < 8 goto ... | push r0,r1 as linked registers in jmp_history 3: if r0 > 16 goto ... | push r0,r1 as linked registers in jmp_history 4: r2 = r10 | 5: r2 += r0 v mark_chain_precision(r0) while doing mark_chain_precision(r0) 5: r2 += r0 | mark r0 precise 4: r2 = r10 | 3: if r0 > 16 goto ... | mark r0,r1 as precise 2: if r1 < 8 goto ... | mark r0,r1 as precise 1: r1 = r0 v Technically, do this as follows: - Use 10 bits to identify each register that gains range because of sync_linked_regs(): - 3 bits for frame number; - 6 bits for register or stack slot number; - 1 bit to indicate if register is spilled. - Use u64 as a vector of 6 such records + 4 bits for vector length. - Augment struct bpf_jmp_history_entry with a field 'linked_regs' representing such vector. - When doing check_cond_jmp_op() remember up to 6 registers that gain range because of sync_linked_regs() in such a vector. - Don't propagate range information and reset IDs for registers that don't fit in 6-value vector. - Push a pair {instruction index, linked registers vector} to bpf_verifier_state->jmp_history. - When doing backtrack_insn() check if any of recorded linked registers is currently marked precise, if so mark all linked registers as precise. This also requires fixes for two test_verifier tests: - precise: test 1 - precise: test 2 Both tests contain the following instruction sequence: 19: (bf) r2 = r9 ; R2=scalar(id=3) R9=scalar(id=3) 20: (a5) if r2 < 0x8 goto pc+1 ; R2=scalar(id=3,umin=8) 21: (95) exit 22: (07) r2 += 1 ; R2_w=scalar(id=3+1,...) 23: (bf) r1 = r10 ; R1_w=fp0 R10=fp0 24: (07) r1 += -8 ; R1_w=fp-8 25: (b7) r3 = 0 ; R3_w=0 26: (85) call bpf_probe_read_kernel#113 The call to bpf_probe_read_kernel() at (26) forces r2 to be precise. Previously, this forced all registers with same id to become precise immediately when mark_chain_precision() is called. After this change, the precision is propagated to registers sharing same id only when 'if' instruction is backtracked. Hence verification log for both tests is changed: regs=r2,r9 -> regs=r2 for instructions 25..20. Fixes: 904e6ddf4133 ("bpf: Use scalar ids in mark_chain_precision()") Reported-by: Hao Sun <[email protected]> Suggested-by: Andrii Nakryiko <[email protected]> Signed-off-by: Eduard Zingerman <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Closes: https://lore.kernel.org/bpf/CAEf4BzZ0xidVCqB47XnkXcNhkPWF6_nTV7yt+_Lf0kcFEut2Mg@mail.gmail.com/
2024-07-25Merge tag 'for-netdev' of ↵Jakub Kicinski2-4/+4
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf Daniel Borkmann says: ==================== pull-request: bpf 2024-07-25 We've added 14 non-merge commits during the last 8 day(s) which contain a total of 19 files changed, 177 insertions(+), 70 deletions(-). The main changes are: 1) Fix af_unix to disable MSG_OOB handling for sockets in BPF sockmap and BPF sockhash. Also add test coverage for this case, from Michal Luczaj. 2) Fix a segmentation issue when downgrading gso_size in the BPF helper bpf_skb_adjust_room(), from Fred Li. 3) Fix a compiler warning in resolve_btfids due to a missing type cast, from Liwei Song. 4) Fix stack allocation for arm64 to align the stack pointer at a 16 byte boundary in the fexit_sleep BPF selftest, from Puranjay Mohan. 5) Fix a xsk regression to require a flag when actuating tx_metadata_len, from Stanislav Fomichev. 6) Fix function prototype BTF dumping in libbpf for prototypes that have no input arguments, from Andrii Nakryiko. 7) Fix stacktrace symbol resolution in perf script for BPF programs containing subprograms, from Hou Tao. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests/bpf: Add XDP_UMEM_TX_METADATA_LEN to XSK TX metadata test xsk: Require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len bpf: Fix a segment issue when downgrading gso_size tools/resolve_btfids: Fix comparison of distinct pointer types warning in resolve_btfids bpf, events: Use prog to emit ksymbol event for main program selftests/bpf: Test sockmap redirect for AF_UNIX MSG_OOB selftests/bpf: Parametrize AF_UNIX redir functions to accept send() flags selftests/bpf: Support SOCK_STREAM in unix_inet_redir_to_connected() af_unix: Disable MSG_OOB handling for sockets in sockmap/sockhash bpftool: Fix typo in usage help libbpf: Fix no-args func prototype BTF dumping syntax MAINTAINERS: Update powerpc BPF JIT maintainers MAINTAINERS: Update email address of Naveen selftests/bpf: fexit_sleep: Fix stack allocation for arm64 ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
2024-07-18Merge tag 'probes-v6.11' of ↵Linus Torvalds3-0/+128
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probes updates from Masami Hiramatsu: "Uprobes: - x86/shstk: Make return uprobe work with shadow stack - Add uretprobe syscall which speeds up the uretprobe 10-30% faster. This syscall is automatically used from user-space trampolines which are generated by the uretprobe. If this syscall is used by normal user program, it will cause SIGILL. Note that this is currently only implemented on x86_64. (This also has two fixes for adjusting the syscall number to avoid conflict with new *attrat syscalls.) - uprobes/perf: fix user stack traces in the presence of pending uretprobe. This corrects the uretprobe's trampoline address in the stacktrace with correct return address - selftests/x86: Add a return uprobe with shadow stack test - selftests/bpf: Add uretprobe syscall related tests. - test case for register integrity check - test case with register changing case - test case for uretprobe syscall without uprobes (expected to fail) - test case for uretprobe with shadow stack - selftests/bpf: add test validating uprobe/uretprobe stack traces - MAINTAINERS: Add uprobes entry. This does not specify the tree but to clarify who maintains and reviews the uprobes Kprobes: - tracing/kprobes: Test case cleanups. Replace redundant WARN_ON_ONCE() + pr_warn() with WARN_ONCE() and remove unnecessary code from selftest - tracing/kprobes: Add symbol counting check when module loads. This checks the uniqueness of the probed symbol on modules. The same check has already done for kernel symbols (This also has a fix for build error with CONFIG_MODULES=n) Cleanup: - Add MODULE_DESCRIPTION() macros for fprobe and kprobe examples" * tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: MAINTAINERS: Add uprobes entry selftests/bpf: Change uretprobe syscall number in uprobe_syscall test uprobe: Change uretprobe syscall scope and number tracing/kprobes: Fix build error when find_module() is not available tracing/kprobes: Add symbol counting check when module loads selftests/bpf: add test validating uprobe/uretprobe stack traces perf,uprobes: fix user stack traces in the presence of pending uretprobes tracing/kprobe: Remove cleanup code unrelated to selftest tracing/kprobe: Integrate test warnings into WARN_ONCE selftests/bpf: Add uretprobe shadow stack test selftests/bpf: Add uretprobe syscall call from user space test selftests/bpf: Add uretprobe syscall test for regs changes selftests/bpf: Add uretprobe syscall test for regs integrity selftests/x86: Add return uprobe shadow stack test uprobe: Add uretprobe syscall to speed up return probe uprobe: Wire up uretprobe system call x86/shstk: Make return uprobe work with shadow stack samples: kprobes: add missing MODULE_DESCRIPTION() macros fprobe: add missing MODULE_DESCRIPTION() macro
2024-07-17libbpf: Fix no-args func prototype BTF dumping syntaxAndrii Nakryiko2-4/+4
For all these years libbpf's BTF dumper has been emitting not strictly valid syntax for function prototypes that have no input arguments. Instead of `int (*blah)()` we should emit `int (*blah)(void)`. This is not normally a problem, but it manifests when we get kfuncs in vmlinux.h that have no input arguments. Due to compiler internal specifics, we get no BTF information for such kfuncs, if they are not declared with proper `(void)`. The fix is trivial. We also need to adjust a few ancient tests that happily assumed `()` is correct. Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Reported-by: Tejun Heo <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Stanislav Fomichev <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-12Merge tag 'for-netdev' of ↵Jakub Kicinski3-11/+15
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2024-07-12 We've added 23 non-merge commits during the last 3 day(s) which contain a total of 18 files changed, 234 insertions(+), 243 deletions(-). The main changes are: 1) Improve BPF verifier by utilizing overflow.h helpers to check for overflows, from Shung-Hsi Yu. 2) Fix NULL pointer dereference in resolve_prog_type() for BPF_PROG_TYPE_EXT when attr->attach_prog_fd was not specified, from Tengda Wu. 3) Fix arm64 BPF JIT when generating code for BPF trampolines with BPF_TRAMP_F_CALL_ORIG which corrupted upper address bits, from Puranjay Mohan. 4) Remove test_run callback from lwt_seg6local_prog_ops which never worked in the first place and caused syzbot reports, from Sebastian Andrzej Siewior. 5) Relax BPF verifier to accept non-zero offset on KF_TRUSTED_ARGS/ /KF_RCU-typed BPF kfuncs, from Matt Bobrowski. 6) Fix a long standing bug in libbpf with regards to handling of BPF skeleton's forward and backward compatibility, from Andrii Nakryiko. 7) Annotate btf_{seq,snprintf}_show functions with __printf, from Alan Maguire. 8) BPF selftest improvements to reuse common network helpers in sk_lookup test and dropping the open-coded inetaddr_len() and make_socket() ones, from Geliang Tang. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (23 commits) selftests/bpf: Test for null-pointer-deref bugfix in resolve_prog_type() bpf: Fix null pointer dereference in resolve_prog_type() for BPF_PROG_TYPE_EXT selftests/bpf: DENYLIST.aarch64: Skip fexit_sleep again bpf: use check_sub_overflow() to check for subtraction overflows bpf: use check_add_overflow() to check for addition overflows bpf: fix overflow check in adjust_jmp_off() bpf: Eliminate remaining "make W=1" warnings in kernel/bpf/btf.o bpf: annotate BTF show functions with __printf bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIG selftests/bpf: Close obj in error path in xdp_adjust_tail selftests/bpf: Null checks for links in bpf_tcp_ca selftests/bpf: Use connect_fd_to_fd in sk_lookup selftests/bpf: Use start_server_addr in sk_lookup selftests/bpf: Use start_server_str in sk_lookup selftests/bpf: Close fd in error path in drop_on_reuseport selftests/bpf: Add ASSERT_OK_FD macro selftests/bpf: Add backlog for network_helper_opts selftests/bpf: fix compilation failure when CONFIG_NF_FLOW_TABLE=m bpf: Remove tst_run from lwt_seg6local_prog_ops. bpf: relax zero fixed offset constraint on KF_TRUSTED_ARGS/KF_RCU ... ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
2024-07-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-0/+87
Cross-merge networking fixes after downstream PR. Conflicts: net/sched/act_ct.c 26488172b029 ("net/sched: Fix UAF when resolving a clash") 3abbd7ed8b76 ("act_ct: prepare for stolen verdict coming from conntrack and nat engine") No adjacent changes. Signed-off-by: Jakub Kicinski <[email protected]>
2024-07-11selftests/bpf: Add timer lockup selftestKumar Kartikeya Dwivedi1-0/+87
Add a selftest that tries to trigger a situation where two timer callbacks are attempting to cancel each other's timer. By running them continuously, we hit a condition where both run in parallel and cancel each other. Without the fix in the previous patch, this would cause a lockup as hrtimer_cancel on either side will wait for forward progress from the callback. Ensure that this situation leads to a EDEADLK error. Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-10selftests/bpf: fix compilation failure when CONFIG_NF_FLOW_TABLE=mAlan Maguire1-3/+7
In many cases, kernel netfilter functionality is built as modules. If CONFIG_NF_FLOW_TABLE=m in particular, progs/xdp_flowtable.c (and hence selftests) will fail to compile, so add a ___local version of "struct flow_ports". Fixes: c77e572d3a8c ("selftests/bpf: Add selftest for bpf_xdp_flow_lookup kfunc") Signed-off-by: Alan Maguire <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-07-09bpf: relax zero fixed offset constraint on KF_TRUSTED_ARGS/KF_RCUMatt Bobrowski2-8/+8
Currently, BPF kfuncs which accept trusted pointer arguments i.e. those flagged as KF_TRUSTED_ARGS, KF_RCU, or KF_RELEASE, all require an original/unmodified trusted pointer argument to be supplied to them. By original/unmodified, it means that the backing register holding the trusted pointer argument that is to be supplied to the BPF kfunc must have its fixed offset set to zero, or else the BPF verifier will outright reject the BPF program load. However, this zero fixed offset constraint that is currently enforced by the BPF verifier onto BPF kfuncs specifically flagged to accept KF_TRUSTED_ARGS or KF_RCU trusted pointer arguments is rather unnecessary, and can limit their usability in practice. Specifically, it completely eliminates the possibility of constructing a derived trusted pointer from an original trusted pointer. To put it simply, a derived pointer is a pointer which points to one of the nested member fields of the object being pointed to by the original trusted pointer. This patch relaxes the zero fixed offset constraint that is enforced upon BPF kfuncs which specifically accept KF_TRUSTED_ARGS, or KF_RCU arguments. Although, the zero fixed offset constraint technically also applies to BPF kfuncs accepting KF_RELEASE arguments, relaxing this constraint for such BPF kfuncs has subtle and unwanted side-effects. This was discovered by experimenting a little further with an initial version of this patch series [0]. The primary issue with relaxing the zero fixed offset constraint on BPF kfuncs accepting KF_RELEASE arguments is that it'd would open up the opportunity for BPF programs to supply both trusted pointers and derived trusted pointers to them. For KF_RELEASE BPF kfuncs specifically, this could be problematic as resources associated with the backing pointer could be released by the backing BPF kfunc and cause instabilities for the rest of the kernel. With this new fixed offset semantic in-place for BPF kfuncs accepting KF_TRUSTED_ARGS and KF_RCU arguments, we now have more flexibility when it comes to the BPF kfuncs that we're able to introduce moving forward. Early discussions covering the possibility of relaxing the zero fixed offset constraint can be found using the link below. This will provide more context on where all this has stemmed from [1]. Notably, pre-existing tests have been updated such that they provide coverage for the updated zero fixed offset functionality. Specifically, the nested offset test was converted from a negative to positive test as it was already designed to assert zero fixed offset semantics of a KF_TRUSTED_ARGS BPF kfunc. [0] https://lore.kernel.org/bpf/[email protected]/ [1] https://lore.kernel.org/bpf/[email protected]/ Signed-off-by: Matt Bobrowski <[email protected]> Acked-by: Kumar Kartikeya Dwivedi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-07-09Merge tag 'for-netdev' of ↵Paolo Abeni46-203/+822
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2024-07-08 The following pull-request contains BPF updates for your *net-next* tree. We've added 102 non-merge commits during the last 28 day(s) which contain a total of 127 files changed, 4606 insertions(+), 980 deletions(-). The main changes are: 1) Support resilient split BTF which cuts down on duplication and makes BTF as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman. 2) Add support for dumping kfunc prototypes from BTF which enables both detecting as well as dumping compilable prototypes for kfuncs, from Daniel Xu. 3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement support for BPF exceptions, from Ilya Leoshkevich. 4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui. 5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option for skbs and add coverage along with it, from Vadim Fedorenko. 6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan. 7) Extend the BPF verifier to track the delta between linked registers in order to better deal with recent LLVM code optimizations, from Alexei Starovoitov. 8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should have been a pointer to the map value, from Benjamin Tissoires. 9) Extend BPF selftests to add regular expression support for test output matching and adjust some of the selftest when compiled under gcc, from Cupertino Miranda. 10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always iterates exactly once anyway, from Dan Carpenter. 11) Add the capability to offload the netfilter flowtable in XDP layer through kfuncs, from Florian Westphal & Lorenzo Bianconi. 12) Various cleanups in networking helpers in BPF selftests to shave off a few lines of open-coded functions on client/server handling, from Geliang Tang. 13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so that x86 JIT does not need to implement detection, from Leon Hwang. 14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an out-of-bounds memory access for dynpointers, from Matt Bobrowski. 15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as it might lead to problems on 32-bit archs, from Jiri Olsa. 16) Enhance traffic validation and dynamic batch size support in xsk selftests, from Tushar Vyavahare. bpf-next-for-netdev * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits) selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature bpf: helpers: fix bpf_wq_set_callback_impl signature libbpf: Add NULL checks to bpf_object__{prev_map,next_map} selftests/bpf: Remove exceptions tests from DENYLIST.s390x s390/bpf: Implement exceptions s390/bpf: Change seen_reg to a mask bpf: Remove unnecessary loop in task_file_seq_get_next() riscv, bpf: Optimize stack usage of trampoline bpf, devmap: Add .map_alloc_check selftests/bpf: Remove arena tests from DENYLIST.s390x selftests/bpf: Add UAF tests for arena atomics selftests/bpf: Introduce __arena_global s390/bpf: Support arena atomics s390/bpf: Enable arena s390/bpf: Support address space cast instruction s390/bpf: Support BPF_PROBE_MEM32 s390/bpf: Land on the next JITed instruction after exception s390/bpf: Introduce pre- and post- probe functions s390/bpf: Get rid of get_probe_mem_regno() ... ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Paolo Abeni <[email protected]>
2024-07-08selftests/bpf: amend for wrong bpf_wq_set_callback_impl signatureBenjamin Tissoires2-7/+16
See the previous patch: the API was wrong, we were provided the pointer to the value, not the actual struct bpf_wq *. Signed-off-by: Benjamin Tissoires <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-07-02selftests/bpf: Add UAF tests for arena atomicsIlya Leoshkevich1-0/+76
Check that __sync_*() functions don't cause kernel panics when handling freed arena pages. x86_64 does not support some arena atomics yet, and aarch64 may or may not support them, based on the availability of LSE atomics at run time. Do not enable this test for these architectures for simplicity. Signed-off-by: Ilya Leoshkevich <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-02selftests/bpf: Introduce __arena_globalIlya Leoshkevich1-37/+30
While clang uses __attribute__((address_space(1))) both for defining arena pointers and arena globals, GCC requires different syntax for both. While __arena covers the first use case, introduce __arena_global to cover the second one. Signed-off-by: Ilya Leoshkevich <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]