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authorLinus Torvalds <torvalds@linux-foundation.org>2025-12-03 16:54:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2025-12-03 16:54:54 -0800
commit015e7b0b0e8e51f7321ec2aafc1d7fc0a8a5536f (patch)
tree258f719e59946c733dd03198eba404e85f9d0945 /tools/testing/selftests/bpf/progs/file_reader.c
parentb6d993310a65b994f37e3347419d9ed398ee37a3 (diff)
parentff34657aa72a4dab9c2fd38e1b31a506951f4b1c (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.c145
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;
+}