Revert "bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro()"

This reverts commit 08f6c05feb which is
commit e60adf513275c3a38e5cb67f7fd12387e43a3ff5 upstream.

It is part of a series that is reported to both break the arm64 builds
and instantly crashes the powerpc systems at the first load of a bpf
program.  So revert it for now until it can come back in a safe way.

Reported-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Reported-by: Vitaly Chikunov <vt@altlinux.org>
Reported-by: WangYuli <wangyuli@uniontech.com>
Link: https://lore.kernel.org/r/5A29E00D83AB84E3+20240706031101.637601-1-wangyuli@uniontech.com
Link: https://lore.kernel.org/r/cf736c5e37489e7dc7ffd67b9de2ab47@matoro.tk
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Song Liu <song@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Kees Cook <keescook@chromium.org>
Cc: Puranjay Mohan <puranjay12@gmail.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>  # s390x
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>  # LoongArch
Cc: Johan Almbladh <johan.almbladh@anyfinetworks.com> # MIPS Part
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/net/bpf_jit_32.c

@@ -1982,21 +1982,28 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 	/* If building the body of the JITed code fails somehow,
 	 * we fall back to the interpretation.
 	 */
-	if (build_body(&ctx) < 0)
-		goto out_free;
+	if (build_body(&ctx) < 0) {
+		image_ptr = NULL;
+		bpf_jit_binary_free(header);
+		prog = orig_prog;
+		goto out_imms;
+	}
 	build_epilogue(&ctx);
 
 	/* 3.) Extra pass to validate JITed Code */
-	if (validate_code(&ctx))
-		goto out_free;
+	if (validate_code(&ctx)) {
+		image_ptr = NULL;
+		bpf_jit_binary_free(header);
+		prog = orig_prog;
+		goto out_imms;
+	}
 	flush_icache_range((u32)header, (u32)(ctx.target + ctx.idx));
 
 	if (bpf_jit_enable > 1)
 		/* there are 2 passes here */
 		bpf_jit_dump(prog->len, image_size, 2, ctx.target);
 
-	if (bpf_jit_binary_lock_ro(header))
-		goto out_free;
+	bpf_jit_binary_lock_ro(header);
 	prog->bpf_func = (void *)ctx.target;
 	prog->jited = 1;
 	prog->jited_len = image_size;
@@ -2013,11 +2020,5 @@ out:
 		bpf_jit_prog_release_other(prog, prog == orig_prog ?
 					   tmp : orig_prog);
 	return prog;
-
-out_free:
-	image_ptr = NULL;
-	bpf_jit_binary_free(header);
-	prog = orig_prog;
-	goto out_imms;
 }
 

arch/loongarch/net/bpf_jit.c

@@ -1206,19 +1206,16 @@ skip_init_ctx:
 	flush_icache_range((unsigned long)header, (unsigned long)(ctx.image + ctx.idx));
 
 	if (!prog->is_func || extra_pass) {
-		int err;
-
 		if (extra_pass && ctx.idx != jit_data->ctx.idx) {
 			pr_err_once("multi-func JIT bug %d != %d\n",
 				    ctx.idx, jit_data->ctx.idx);
-			goto out_free;
-		}
-		err = bpf_jit_binary_lock_ro(header);
-		if (err) {
-			pr_err_once("bpf_jit_binary_lock_ro() returned %d\n",
-				    err);
-			goto out_free;
+			bpf_jit_binary_free(header);
+			prog->bpf_func = NULL;
+			prog->jited = 0;
+			prog->jited_len = 0;
+			goto out_offset;
 		}
+		bpf_jit_binary_lock_ro(header);
 	} else {
 		jit_data->ctx = ctx;
 		jit_data->image = image_ptr;
@@ -1249,13 +1246,6 @@ out:
 	out_offset = -1;
 
 	return prog;
-
-out_free:
-	bpf_jit_binary_free(header);
-	prog->bpf_func = NULL;
-	prog->jited = 0;
-	prog->jited_len = 0;
-	goto out_offset;
 }
 
 /* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */

arch/mips/net/bpf_jit_comp.c

@@ -1012,8 +1012,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 	bpf_prog_fill_jited_linfo(prog, &ctx.descriptors[1]);
 
 	/* Set as read-only exec and flush instruction cache */
-	if (bpf_jit_binary_lock_ro(header))
-		goto out_err;
+	bpf_jit_binary_lock_ro(header);
 	flush_icache_range((unsigned long)header,
 			   (unsigned long)&ctx.target[ctx.jit_index]);
 

arch/parisc/net/bpf_jit_core.c

@@ -167,13 +167,7 @@ skip_init_ctx:
 	bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns);
 
 	if (!prog->is_func || extra_pass) {
-		if (bpf_jit_binary_lock_ro(jit_data->header)) {
-			bpf_jit_binary_free(jit_data->header);
-			prog->bpf_func = NULL;
-			prog->jited = 0;
-			prog->jited_len = 0;
-			goto out_offset;
-		}
+		bpf_jit_binary_lock_ro(jit_data->header);
 		prologue_len = ctx->epilogue_offset - ctx->body_len;
 		for (i = 0; i < prog->len; i++)
 			ctx->offset[i] += prologue_len;

arch/s390/net/bpf_jit_comp.c

@@ -1973,11 +1973,7 @@ skip_init_ctx:
 		print_fn_code(jit.prg_buf, jit.size_prg);
 	}
 	if (!fp->is_func || extra_pass) {
-		if (bpf_jit_binary_lock_ro(header)) {
-			bpf_jit_binary_free(header);
-			fp = orig_fp;
-			goto free_addrs;
-		}
+		bpf_jit_binary_lock_ro(header);
 	} else {
 		jit_data->header = header;
 		jit_data->ctx = jit;

arch/sparc/net/bpf_jit_comp_64.c

@@ -1602,11 +1602,7 @@ skip_init_ctx:
 	bpf_flush_icache(header, (u8 *)header + header->size);
 
 	if (!prog->is_func || extra_pass) {
-		if (bpf_jit_binary_lock_ro(header)) {
-			bpf_jit_binary_free(header);
-			prog = orig_prog;
-			goto out_off;
-		}
+		bpf_jit_binary_lock_ro(header);
 	} else {
 		jit_data->ctx = ctx;
 		jit_data->image = image_ptr;

arch/x86/net/bpf_jit_comp32.c

@@ -2600,7 +2600,8 @@ out_image:
 	if (bpf_jit_enable > 1)
 		bpf_jit_dump(prog->len, proglen, pass + 1, image);
 
-	if (image && !bpf_jit_binary_lock_ro(header)) {
+	if (image) {
+		bpf_jit_binary_lock_ro(header);
 		prog->bpf_func = (void *)image;
 		prog->jited = 1;
 		prog->jited_len = proglen;

include/linux/filter.h

@@ -853,11 +853,10 @@ static inline int __must_check bpf_prog_lock_ro(struct bpf_prog *fp)
 	return 0;
 }
 
-static inline int __must_check
-bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
+static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 {
 	set_vm_flush_reset_perms(hdr);
-	return set_memory_rox((unsigned long)hdr, hdr->size >> PAGE_SHIFT);
+	set_memory_rox((unsigned long)hdr, hdr->size >> PAGE_SHIFT);
 }
 
 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);