bpf: tracing session supporting

arch/arm64/net/bpf_jit_comp.c

@@ -2788,6 +2788,9 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *ro_image,
 	void *image, *tmp;
 	int ret;
 
+	if (tlinks[BPF_TRAMP_SESSION].nr_links)
+		return -EOPNOTSUPP;
+
 	/* image doesn't need to be in module memory range, so we can
 	 * use kvmalloc.
 	 */

arch/loongarch/net/bpf_jit.c

@@ -1739,6 +1739,9 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *ro_image,
 	void *image, *tmp;
 	struct jit_ctx ctx;
 
+	if (tlinks[BPF_TRAMP_SESSION].nr_links)
+		return -EOPNOTSUPP;
+
 	size = ro_image_end - ro_image;
 	image = kvmalloc(size, GFP_KERNEL);
 	if (!image)

arch/powerpc/net/bpf_jit_comp.c

@@ -1017,6 +1017,9 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i
 	void *rw_image, *tmp;
 	int ret;
 
+	if (tlinks[BPF_TRAMP_SESSION].nr_links)
+		return -EOPNOTSUPP;
+
 	/*
 	 * rw_image doesn't need to be in module memory range, so we can
 	 * use kvmalloc.

arch/riscv/net/bpf_jit_comp64.c

@@ -1286,6 +1286,9 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *ro_image,
 	struct rv_jit_context ctx;
 	u32 size = ro_image_end - ro_image;
 
+	if (tlinks[BPF_TRAMP_SESSION].nr_links)
+		return -EOPNOTSUPP;
+
 	image = kvmalloc(size, GFP_KERNEL);
 	if (!image)
 		return -ENOMEM;

arch/s390/net/bpf_jit_comp.c

@@ -2924,6 +2924,9 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image,
 	struct bpf_tramp_jit tjit;
 	int ret;
 
+	if (tlinks[BPF_TRAMP_SESSION].nr_links)
+		return -EOPNOTSUPP;
+
 	/* Compute offsets, check whether the code fits. */
 	memset(&tjit, 0, sizeof(tjit));
 	ret = __arch_prepare_bpf_trampoline(im, &tjit, m, flags,