From eaa6bcb71ef6ed3dc18fc525ee7e293b06b4882b Mon Sep 17 00:00:00 2001 From: Hao Luo Date: Tue, 29 Sep 2020 16:50:47 -0700 Subject: bpf: Introduce bpf_per_cpu_ptr() Add bpf_per_cpu_ptr() to help bpf programs access percpu vars. bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the kernel except that it may return NULL. This happens when the cpu parameter is out of range. So the caller must check the returned value. Signed-off-by: Hao Luo Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200929235049.2533242-5-haoluo@google.com --- kernel/trace/bpf_trace.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index e118a83439c3..364a322e2898 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1327,6 +1327,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; case BPF_FUNC_snprintf_btf: return &bpf_snprintf_btf_proto; + case BPF_FUNC_bpf_per_cpu_ptr: + return &bpf_per_cpu_ptr_proto; default: return NULL; } -- cgit v1.2.3 From 63d9b80dcf2c67bc5ade61cbbaa09d7af21f43f1 Mon Sep 17 00:00:00 2001 From: Hao Luo Date: Tue, 29 Sep 2020 16:50:48 -0700 Subject: bpf: Introducte bpf_this_cpu_ptr() Add bpf_this_cpu_ptr() to help access percpu var on this cpu. This helper always returns a valid pointer, therefore no need to check returned value for NULL. Also note that all programs run with preemption disabled, which means that the returned pointer is stable during all the execution of the program. Signed-off-by: Hao Luo Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200929235049.2533242-6-haoluo@google.com --- kernel/trace/bpf_trace.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 364a322e2898..a136a6a63a71 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1329,6 +1329,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_snprintf_btf_proto; case BPF_FUNC_bpf_per_cpu_ptr: return &bpf_per_cpu_ptr_proto; + case BPF_FUNC_bpf_this_cpu_ptr: + return &bpf_this_cpu_ptr_proto; default: return NULL; } -- cgit v1.2.3 From ebfb4d40ed9dd45d2d6780f58d0cd9336d647890 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 6 Oct 2020 23:29:33 -0700 Subject: bpf: Fix build failure for kernel/trace/bpf_trace.c with CONFIG_NET=n When CONFIG_NET is not defined, I hit the following build error: kernel/trace/bpf_trace.o:(.rodata+0x110): undefined reference to `bpf_prog_test_run_raw_tp' Commit 1b4d60ec162f ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint") added test_run support for raw_tracepoint in /kernel/trace/bpf_trace.c. But the test_run function bpf_prog_test_run_raw_tp is defined in net/bpf/test_run.c, only available with CONFIG_NET=y. Adding a CONFIG_NET guard for .test_run = bpf_prog_test_run_raw_tp; fixed the above build issue. Fixes: 1b4d60ec162f ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint") Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201007062933.3425899-1-yhs@fb.com --- kernel/trace/bpf_trace.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index a136a6a63a71..a2a4535b6277 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1780,7 +1780,9 @@ const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { }; const struct bpf_prog_ops raw_tracepoint_prog_ops = { +#ifdef CONFIG_NET .test_run = bpf_prog_test_run_raw_tp, +#endif }; const struct bpf_verifier_ops tracing_verifier_ops = { -- cgit v1.2.3