Merge branch 'fixes for bpf_prog_pack'

Song Liu says:

====================

Changes v1 => v2:
1. Rephrase comments in 2/2. (Yonghong)

Two fixes for bpf_prog_pack.
====================

Signed-off-by: Alexei Starovoitov <[email protected]>

Author: Alexei Starovoitov

arch/x86/Kconfig

@@ -158,7 +158,7 @@ config X86
 	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
-	select HAVE_ARCH_HUGE_VMALLOC		if HAVE_ARCH_HUGE_VMAP
+	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_ARCH_JUMP_LABEL_RELATIVE
 	select HAVE_ARCH_KASAN			if X86_64

arch/x86/net/bpf_jit_comp.c

@@ -2330,8 +2330,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 		if (proglen <= 0) {
 out_image:
 			image = NULL;
-			if (header)
+			if (header) {
+				bpf_arch_text_copy(&header->size, &rw_header->size,
+						   sizeof(rw_header->size));
 				bpf_jit_binary_pack_free(header, rw_header);
+			}
 			prog = orig_prog;
 			goto out_addrs;
 		}

kernel/bpf/core.c

@@ -1112,13 +1112,16 @@ int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
  *   1) when the program is freed after;
  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
  * For case 2), we need to free both the RO memory and the RW buffer.
- * Also, ro_header->size in 2) is not properly set yet, so rw_header->size
- * is used for uncharge.
+ *
+ * bpf_jit_binary_pack_free requires proper ro_header->size. However,
+ * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
+ * must be set with either bpf_jit_binary_pack_finalize (normal path) or
+ * bpf_arch_text_copy (when jit fails).
  */
 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
 			      struct bpf_binary_header *rw_header)
 {
-	u32 size = rw_header ? rw_header->size : ro_header->size;
+	u32 size = ro_header->size;
 
 	bpf_prog_pack_free(ro_header);
 	kvfree(rw_header);