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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-12-03 16:54:54 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-12-03 16:54:54 -0800 |
| commit | 015e7b0b0e8e51f7321ec2aafc1d7fc0a8a5536f (patch) | |
| tree | 258f719e59946c733dd03198eba404e85f9d0945 /tools/testing/selftests/bpf/progs/file_reader.c | |
| parent | b6d993310a65b994f37e3347419d9ed398ee37a3 (diff) | |
| parent | ff34657aa72a4dab9c2fd38e1b31a506951f4b1c (diff) | |
Merge tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Convert selftests/bpf/test_tc_edt and test_tc_tunnel from .sh to
test_progs runner (Alexis Lothoré)
- Convert selftests/bpf/test_xsk to test_progs runner (Bastien
Curutchet)
- Replace bpf memory allocator with kmalloc_nolock() in
bpf_local_storage (Amery Hung), and in bpf streams and range tree
(Puranjay Mohan)
- Introduce support for indirect jumps in BPF verifier and x86 JIT
(Anton Protopopov) and arm64 JIT (Puranjay Mohan)
- Remove runqslower bpf tool (Hoyeon Lee)
- Fix corner cases in the verifier to close several syzbot reports
(Eduard Zingerman, KaFai Wan)
- Several improvements in deadlock detection in rqspinlock (Kumar
Kartikeya Dwivedi)
- Implement "jmp" mode for BPF trampoline and corresponding
DYNAMIC_FTRACE_WITH_JMP. It improves "fexit" program type performance
from 80 M/s to 136 M/s. With Steven's Ack. (Menglong Dong)
- Add ability to test non-linear skbs in BPF_PROG_TEST_RUN (Paul
Chaignon)
- Do not let BPF_PROG_TEST_RUN emit invalid GSO types to stack (Daniel
Borkmann)
- Generalize buildid reader into bpf_dynptr (Mykyta Yatsenko)
- Optimize bpf_map_update_elem() for map-in-map types (Ritesh
Oedayrajsingh Varma)
- Introduce overwrite mode for BPF ring buffer (Xu Kuohai)
* tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (169 commits)
bpf: optimize bpf_map_update_elem() for map-in-map types
bpf: make kprobe_multi_link_prog_run always_inline
selftests/bpf: do not hardcode target rate in test_tc_edt BPF program
selftests/bpf: remove test_tc_edt.sh
selftests/bpf: integrate test_tc_edt into test_progs
selftests/bpf: rename test_tc_edt.bpf.c section to expose program type
selftests/bpf: Add success stats to rqspinlock stress test
rqspinlock: Precede non-head waiter queueing with AA check
rqspinlock: Disable spinning for trylock fallback
rqspinlock: Use trylock fallback when per-CPU rqnode is busy
rqspinlock: Perform AA checks immediately
rqspinlock: Enclose lock/unlock within lock entry acquisitions
bpf: Remove runqslower tool
selftests/bpf: Remove usage of lsm/file_alloc_security in selftest
bpf: Disable file_alloc_security hook
bpf: check for insn arrays in check_ptr_alignment
bpf: force BPF_F_RDONLY_PROG on insn array creation
bpf: Fix exclusive map memory leak
selftests/bpf: Make CS length configurable for rqspinlock stress test
selftests/bpf: Add lock wait time stats to rqspinlock stress test
...
Diffstat (limited to 'tools/testing/selftests/bpf/progs/file_reader.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/file_reader.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/file_reader.c b/tools/testing/selftests/bpf/progs/file_reader.c new file mode 100644 index 000000000000..4d756b623557 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/file_reader.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ + +#include <vmlinux.h> +#include <string.h> +#include <stdbool.h> +#include <bpf/bpf_tracing.h> +#include "bpf_misc.h" +#include "errno.h" + +char _license[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, int); + __type(value, struct elem); +} arrmap SEC(".maps"); + +struct elem { + struct file *file; + struct bpf_task_work tw; +}; + +char user_buf[256000]; +char tmp_buf[256000]; + +int pid = 0; +int err, run_success = 0; + +static int validate_file_read(struct file *file); +static int task_work_callback(struct bpf_map *map, void *key, void *value); + +SEC("lsm/file_open") +int on_open_expect_fault(void *c) +{ + struct bpf_dynptr dynptr; + struct file *file; + int local_err = 1; + __u32 user_buf_sz = sizeof(user_buf); + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + file = bpf_get_task_exe_file(bpf_get_current_task_btf()); + if (!file) + return 0; + + if (bpf_dynptr_from_file(file, 0, &dynptr)) + goto out; + + local_err = bpf_dynptr_read(tmp_buf, user_buf_sz, &dynptr, user_buf_sz, 0); + if (local_err == -EFAULT) { /* Expect page fault */ + local_err = 0; + run_success = 1; + } +out: + bpf_dynptr_file_discard(&dynptr); + if (local_err) + err = local_err; + bpf_put_file(file); + return 0; +} + +SEC("lsm/file_open") +int on_open_validate_file_read(void *c) +{ + struct task_struct *task = bpf_get_current_task_btf(); + struct elem *work; + int key = 0; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + work = bpf_map_lookup_elem(&arrmap, &key); + if (!work) { + err = 1; + return 0; + } + bpf_task_work_schedule_signal_impl(task, &work->tw, &arrmap, task_work_callback, NULL); + return 0; +} + +/* Called in a sleepable context, read 256K bytes, cross check with user space read data */ +static int task_work_callback(struct bpf_map *map, void *key, void *value) +{ + struct task_struct *task = bpf_get_current_task_btf(); + struct file *file = bpf_get_task_exe_file(task); + + if (!file) + return 0; + + err = validate_file_read(file); + if (!err) + run_success = 1; + bpf_put_file(file); + return 0; +} + +static int verify_dynptr_read(struct bpf_dynptr *ptr, u32 off, char *user_buf, u32 len) +{ + int i; + + if (bpf_dynptr_read(tmp_buf, len, ptr, off, 0)) + return 1; + + /* Verify file contents read from BPF is the same as the one read from userspace */ + bpf_for(i, 0, len) + { + if (tmp_buf[i] != user_buf[i]) + return 1; + } + return 0; +} + +static int validate_file_read(struct file *file) +{ + struct bpf_dynptr dynptr; + int loc_err = 1, off; + __u32 user_buf_sz = sizeof(user_buf); + + if (bpf_dynptr_from_file(file, 0, &dynptr)) + goto cleanup; + + loc_err = verify_dynptr_read(&dynptr, 0, user_buf, user_buf_sz); + off = 1; + loc_err = loc_err ?: verify_dynptr_read(&dynptr, off, user_buf + off, user_buf_sz - off); + off = user_buf_sz - 1; + loc_err = loc_err ?: verify_dynptr_read(&dynptr, off, user_buf + off, user_buf_sz - off); + /* Read file with random offset and length */ + off = 4097; + loc_err = loc_err ?: verify_dynptr_read(&dynptr, off, user_buf + off, 100); + + /* Adjust dynptr, verify read */ + loc_err = loc_err ?: bpf_dynptr_adjust(&dynptr, off, off + 1); + loc_err = loc_err ?: verify_dynptr_read(&dynptr, 0, user_buf + off, 1); + /* Can't read more than 1 byte */ + loc_err = loc_err ?: verify_dynptr_read(&dynptr, 0, user_buf + off, 2) == 0; + /* Can't read with far offset */ + loc_err = loc_err ?: verify_dynptr_read(&dynptr, 1, user_buf + off, 1) == 0; + +cleanup: + bpf_dynptr_file_discard(&dynptr); + return loc_err; +} |