3e689141e6
Fix all selftests to include libbpf header files with the bpf/ prefix, to
be consistent with external users of the library. Also ensure that all
includes of exported libbpf header files (those that are exported on 'make
install' of the library) use bracketed includes instead of quoted.
To not break the build, keep the old include path until everything has been
changed to the new one; a subsequent patch will remove that.
Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560568.1683545.9649335788846513446.stgit@toke.dk
102 lines
3.0 KiB
C
102 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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/* Permit pretty deep stack traces */
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#define MAX_STACK_RAWTP 100
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struct stack_trace_t {
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int pid;
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int kern_stack_size;
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int user_stack_size;
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int user_stack_buildid_size;
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__u64 kern_stack[MAX_STACK_RAWTP];
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__u64 user_stack[MAX_STACK_RAWTP];
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struct bpf_stack_build_id user_stack_buildid[MAX_STACK_RAWTP];
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};
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struct {
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__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
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__uint(max_entries, 2);
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__uint(key_size, sizeof(int));
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__uint(value_size, sizeof(__u32));
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} perfmap SEC(".maps");
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struct {
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__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
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__uint(max_entries, 1);
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__type(key, __u32);
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__type(value, struct stack_trace_t);
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} stackdata_map SEC(".maps");
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/* Allocate per-cpu space twice the needed. For the code below
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* usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
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* if (usize < 0)
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* return 0;
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* ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
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*
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* If we have value_size = MAX_STACK_RAWTP * sizeof(__u64),
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* verifier will complain that access "raw_data + usize"
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* with size "max_len - usize" may be out of bound.
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* The maximum "raw_data + usize" is "raw_data + max_len"
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* and the maximum "max_len - usize" is "max_len", verifier
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* concludes that the maximum buffer access range is
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* "raw_data[0...max_len * 2 - 1]" and hence reject the program.
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*
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* Doubling the to-be-used max buffer size can fix this verifier
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* issue and avoid complicated C programming massaging.
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* This is an acceptable workaround since there is one entry here.
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*/
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struct {
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__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
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__uint(max_entries, 1);
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__type(key, __u32);
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__type(value, __u64[2 * MAX_STACK_RAWTP]);
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} rawdata_map SEC(".maps");
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SEC("raw_tracepoint/sys_enter")
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int bpf_prog1(void *ctx)
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{
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int max_len, max_buildid_len, usize, ksize, total_size;
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struct stack_trace_t *data;
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void *raw_data;
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__u32 key = 0;
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data = bpf_map_lookup_elem(&stackdata_map, &key);
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if (!data)
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return 0;
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max_len = MAX_STACK_RAWTP * sizeof(__u64);
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max_buildid_len = MAX_STACK_RAWTP * sizeof(struct bpf_stack_build_id);
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data->pid = bpf_get_current_pid_tgid();
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data->kern_stack_size = bpf_get_stack(ctx, data->kern_stack,
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max_len, 0);
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data->user_stack_size = bpf_get_stack(ctx, data->user_stack, max_len,
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BPF_F_USER_STACK);
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data->user_stack_buildid_size = bpf_get_stack(
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ctx, data->user_stack_buildid, max_buildid_len,
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BPF_F_USER_STACK | BPF_F_USER_BUILD_ID);
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bpf_perf_event_output(ctx, &perfmap, 0, data, sizeof(*data));
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/* write both kernel and user stacks to the same buffer */
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raw_data = bpf_map_lookup_elem(&rawdata_map, &key);
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if (!raw_data)
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return 0;
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usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
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if (usize < 0)
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return 0;
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ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
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if (ksize < 0)
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return 0;
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total_size = usize + ksize;
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if (total_size > 0 && total_size <= max_len)
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bpf_perf_event_output(ctx, &perfmap, 0, raw_data, total_size);
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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