linux/tools/testing/selftests/bpf/bpf_testmod, branch master

selftests/bpf: Consolidate kernel modules into common directory

2024-12-06T18:44:10Z

The selftests build four kernel modules which use copy-pasted Makefile targets. This is a bit messy, and doesn't scale so well when we add more modules, so let's consolidate these rules into a single rule generated for each module name, and move the module sources into a single directory. To avoid parallel builds of the different modules stepping on each other's toes during the 'modpost' phase of the Kbuild 'make modules', the module files should really be a grouped target. However, make only added explicit support for grouped targets in version 4.3, which is newer than the minimum version supported by the kernel. However, make implicitly treats pattern matching rules with multiple targets as a grouped target, so we can work around this by turning the rule into a pattern matching target. We do this by replacing '.ko' with '%ko' in the targets with subst(). Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Andrii Nakryiko Acked-by: Viktor Malik Link: https://lore.kernel.org/bpf/20241204-bpf-selftests-mod-compile-v5-1-b96231134a49@redhat.com

selftests/bpf: Add struct_ops prog private stack tests

2024-11-13T00:26:25Z

Add three tests for struct_ops using private stack. ./test_progs -t struct_ops_private_stack #336/1 struct_ops_private_stack/private_stack:OK #336/2 struct_ops_private_stack/private_stack_fail:OK #336/3 struct_ops_private_stack/private_stack_recur:OK #336 struct_ops_private_stack:OK The following is a snippet of a struct_ops check_member() implementation: u32 moff = __btf_member_bit_offset(t, member) / 8; switch (moff) { case offsetof(struct bpf_testmod_ops3, test_1): prog->aux->priv_stack_requested = true; prog->aux->recursion_detected = test_1_recursion_detected; fallthrough; default: break; } return 0; The first test is with nested two different callback functions where the first prog has more than 512 byte stack size (including subprogs) with private stack enabled. The second test is a negative test where the second prog has more than 512 byte stack size without private stack enabled. The third test is the same callback function recursing itself. At run time, the jit trampoline recursion check kicks in to prevent the recursion. The recursion_detected() callback function is implemented by the bpf_testmod, the following message in dmesg bpf_testmod: oh no, recursing into test_1, recursion_misses 1 demonstrates the callback function is indeed triggered when recursion miss happens. Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20241112163938.2225528-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov

Merge tag 'perf-core-for-bpf-next' from tip tree

2024-11-06T16:13:03Z

Stable tag for bpf-next's uprobe work. Signed-off-by: Andrii Nakryiko

selftests/bpf: Add tests for raw_tp null handling

2024-11-04T19:37:36Z

Ensure that trusted PTR_TO_BTF_ID accesses perform PROBE_MEM handling in raw_tp program. Without the previous fix, this selftest crashes the kernel due to a NULL-pointer dereference. Also ensure that dead code elimination does not kick in for checks on the pointer. Reviewed-by: Jiri Olsa Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20241104171959.2938862-4-memxor@gmail.com Signed-off-by: Alexei Starovoitov

uprobe: Add data pointer to consumer handlers

2024-10-23T18:52:27Z

Adding data pointer to both entry and exit consumer handlers and all its users. The functionality itself is coming in following change. Signed-off-by: Jiri Olsa Signed-off-by: Peter Zijlstra (Intel) Acked-by: Oleg Nesterov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20241018202252.693462-2-jolsa@kernel.org

Merge tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2024-09-21T16:27:50Z

Pull bpf updates from Alexei Starovoitov: - Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with corresponding support in LLVM. It is similar to existing 'no_caller_saved_registers' attribute in GCC/LLVM with a provision for backward compatibility. It allows compilers generate more efficient BPF code assuming the verifier or JITs will inline or partially inline a helper/kfunc with such attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast, bpf_get_smp_processor_id are the first set of such helpers. - Harden and extend ELF build ID parsing logic. When called from sleepable context the relevants parts of ELF file will be read to find and fetch .note.gnu.build-id information. Also harden the logic to avoid TOCTOU, overflow, out-of-bounds problems. - Improvements and fixes for sched-ext: - Allow passing BPF iterators as kfunc arguments - Make the pointer returned from iter_next method trusted - Fix x86 JIT convergence issue due to growing/shrinking conditional jumps in variable length encoding - BPF_LSM related: - Introduce few VFS kfuncs and consolidate them in fs/bpf_fs_kfuncs.c - Enforce correct range of return values from certain LSM hooks - Disallow attaching to other LSM hooks - Prerequisite work for upcoming Qdisc in BPF: - Allow kptrs in program provided structs - Support for gen_epilogue in verifier_ops - Important fixes: - Fix uprobe multi pid filter check - Fix bpf_strtol and bpf_strtoul helpers - Track equal scalars history on per-instruction level - Fix tailcall hierarchy on x86 and arm64 - Fix signed division overflow to prevent INT_MIN/-1 trap on x86 - Fix get kernel stack in BPF progs attached to tracepoint:syscall - Selftests: - Add uprobe bench/stress tool - Generate file dependencies to drastically improve re-build time - Match JIT-ed and BPF asm with __xlated/__jited keywords - Convert older tests to test_progs framework - Add support for RISC-V - Few fixes when BPF programs are compiled with GCC-BPF backend (support for GCC-BPF in BPF CI is ongoing in parallel) - Add traffic monitor - Enable cross compile and musl libc * tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits) btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh bpf: Call the missed kfree() when there is no special field in btf bpf: Call the missed btf_record_free() when map creation fails selftests/bpf: Add a test case to write mtu result into .rodata selftests/bpf: Add a test case to write strtol result into .rodata selftests/bpf: Rename ARG_PTR_TO_LONG test description selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types bpf: Fix helper writes to read-only maps bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit selftests/bpf: Add tests for sdiv/smod overflow cases bpf: Fix a sdiv overflow issue libbpf: Add bpf_object__token_fd accessor docs/bpf: Add missing BPF program types to docs docs/bpf: Add constant values for linkages bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing ...

Merge tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-09-18T13:03:58Z

Pull perf events updates from Ingo Molnar: - Implement per-PMU context rescheduling to significantly improve single-PMU performance, and related cleanups/fixes (Peter Zijlstra and Namhyung Kim) - Fix ancient bug resulting in a lot of events being dropped erroneously at higher sampling frequencies (Luo Gengkun) - uprobes enhancements: - Implement RCU-protected hot path optimizations for better performance: "For baseline vs SRCU, peak througput increased from 3.7 M/s (million uprobe triggerings per second) up to about 8 M/s. For uretprobes it's a bit more modest with bump from 2.4 M/s to 5 M/s. For SRCU vs RCU Tasks Trace, peak throughput for uprobes increases further from 8 M/s to 10.3 M/s (+28%!), and for uretprobes from 5.3 M/s to 5.8 M/s (+11%), as we have more work to do on uretprobes side. Even single-thread (no contention) performance is slightly better: 3.276 M/s to 3.396 M/s (+3.5%) for uprobes, and 2.055 M/s to 2.174 M/s (+5.8%) for uretprobes." (Andrii Nakryiko et al) - Document mmap_lock, don't abuse get_user_pages_remote() (Oleg Nesterov) - Cleanups & fixes to prepare for future work: - Remove uprobe_register_refctr() - Simplify error handling for alloc_uprobe() - Make uprobe_register() return struct uprobe * - Fold __uprobe_unregister() into uprobe_unregister() - Shift put_uprobe() from delete_uprobe() to uprobe_unregister() - BPF: Fix use-after-free in bpf_uprobe_multi_link_attach() (Oleg Nesterov) - New feature & ABI extension: allow events to use PERF_SAMPLE READ with inheritance, enabling sample based profiling of a group of counters over a hierarchy of processes or threads (Ben Gainey) - Intel uncore & power events updates: - Add Arrow Lake and Lunar Lake support - Add PERF_EV_CAP_READ_SCOPE - Clean up and enhance cpumask and hotplug support (Kan Liang) - Add LNL uncore iMC freerunning support - Use D0:F0 as a default device (Zhenyu Wang) - Intel PT: fix AUX snapshot handling race (Adrian Hunter) - Misc fixes and cleanups (James Clark, Jiri Olsa, Oleg Nesterov and Peter Zijlstra) * tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) dmaengine: idxd: Clean up cpumask and hotplug for perfmon iommu/vt-d: Clean up cpumask and hotplug for perfmon perf/x86/intel/cstate: Clean up cpumask and hotplug perf: Add PERF_EV_CAP_READ_SCOPE perf: Generic hotplug support for a PMU with a scope uprobes: perform lockless SRCU-protected uprobes_tree lookup rbtree: provide rb_find_rcu() / rb_find_add_rcu() perf/uprobe: split uprobe_unregister() uprobes: travers uprobe's consumer list locklessly under SRCU protection uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks uprobes: protected uprobe lifetime with SRCU uprobes: revamp uprobe refcounting and lifetime management bpf: Fix use-after-free in bpf_uprobe_multi_link_attach() perf/core: Fix small negative period being ignored perf: Really fix event_function_call() locking perf: Optimize __pmu_ctx_sched_out() perf: Add context time freeze perf: Fix event_function_call() locking perf: Extract a few helpers perf: Optimize context reschedule for single PMU cases ...

selftests/bpf: Add test for __nullable suffix in tp_btf

2024-09-11T15:56:42Z

Add a tracepoint with __nullable suffix in bpf_testmod, and add cases for it: $ ./test_progs -t "tp_btf_nullable" #406/1 tp_btf_nullable/handle_tp_btf_nullable_bare1:OK #406/2 tp_btf_nullable/handle_tp_btf_nullable_bare2:OK #406 tp_btf_nullable:OK Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Philo Lu Link: https://lore.kernel.org/r/20240911033719.91468-3-lulie@linux.alibaba.com Signed-off-by: Martin KaFai Lau

perf/uprobe: split uprobe_unregister()

2024-09-05T14:56:14Z

With uprobe_unregister() having grown a synchronize_srcu(), it becomes fairly slow to call. Esp. since both users of this API call it in a loop. Peel off the sync_srcu() and do it once, after the loop. We also need to add uprobe_unregister_sync() into uprobe_register()'s error handling path, as we need to be careful about returning to the caller before we have a guarantee that partially attached consumer won't be called anymore. This is an unlikely slow path and this should be totally fine to be slow in the case of a failed attach. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: "Peter Zijlstra (Intel)" Co-developed-by: Andrii Nakryiko Signed-off-by: Andrii Nakryiko Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Oleg Nesterov Link: https://lore.kernel.org/r/20240903174603.3554182-6-andrii@kernel.org

selftests/bpf: Add tests for iter next method returning valid pointer

2024-08-30T01:52:16Z

This patch adds test cases for iter next method returning valid pointer, which can also used as usage examples. Currently iter next method should return valid pointer. iter_next_trusted is the correct usage and test if iter next method return valid pointer. bpf_iter_task_vma_next has KF_RET_NULL flag, so the returned pointer may be NULL. We need to check if the pointer is NULL before using it. iter_next_trusted_or_null is the incorrect usage. There is no checking before using the pointer, so it will be rejected by the verifier. iter_next_rcu and iter_next_rcu_or_null are similar test cases for KF_RCU_PROTECTED iterators. iter_next_rcu_not_trusted is used to test that the pointer returned by iter next method of KF_RCU_PROTECTED iterator cannot be passed in KF_TRUSTED_ARGS kfuncs. iter_next_ptr_mem_not_trusted is used to test that base type PTR_TO_MEM should not be combined with type flag PTR_TRUSTED. Signed-off-by: Juntong Deng Link: https://lore.kernel.org/r/AM6PR03MB5848709758F6922F02AF9F1F99962@AM6PR03MB5848.eurprd03.prod.outlook.com Signed-off-by: Alexei Starovoitov