bpf: Add arch_bpf_trampoline_size()

[linux-2.6-microblaze.git] / arch / x86 / net / bpf_jit_comp.c

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 5f7528c..5d75069 100644 (file)
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -2422,10 +2422,10 @@ static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog,
  * add rsp, 8                      // skip eth_type_trans's frame
  * ret                             // return to its caller
  */
-int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end,
-                               const struct btf_func_model *m, u32 flags,
-                               struct bpf_tramp_links *tlinks,
-                               void *func_addr)
+static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end,
+                                        const struct btf_func_model *m, u32 flags,
+                                        struct bpf_tramp_links *tlinks,
+                                        void *func_addr)
 {
        int i, ret, nr_regs = m->nr_args, stack_size = 0;
        int regs_off, nregs_off, ip_off, run_ctx_off, arg_stack_off, rbx_off;
@@ -2678,6 +2678,38 @@ cleanup:
        return ret;
 }
 
+int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end,
+                               const struct btf_func_model *m, u32 flags,
+                               struct bpf_tramp_links *tlinks,
+                               void *func_addr)
+{
+       return __arch_prepare_bpf_trampoline(im, image, image_end, m, flags, tlinks, func_addr);
+}
+
+int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
+                            struct bpf_tramp_links *tlinks, void *func_addr)
+{
+       struct bpf_tramp_image im;
+       void *image;
+       int ret;
+
+       /* Allocate a temporary buffer for __arch_prepare_bpf_trampoline().
+        * This will NOT cause fragmentation in direct map, as we do not
+        * call set_memory_*() on this buffer.
+        *
+        * We cannot use kvmalloc here, because we need image to be in
+        * module memory range.
+        */
+       image = bpf_jit_alloc_exec(PAGE_SIZE);
+       if (!image)
+               return -ENOMEM;
+
+       ret = __arch_prepare_bpf_trampoline(&im, image, image + PAGE_SIZE, m, flags,
+                                           tlinks, func_addr);
+       bpf_jit_free_exec(image);
+       return ret;
+}
+
 static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs, u8 *image, u8 *buf)
 {
        u8 *jg_reloc, *prog = *pprog;