Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2024-03-25

The following pull-request contains BPF updates for your *net* tree.

We've added 17 non-merge commits during the last 12 day(s) which contain
a total of 19 files changed, 184 insertions(+), 61 deletions(-).

The main changes are:

1) Fix an arm64 BPF JIT bug in BPF_LDX_MEMSX implementation's offset handling
   found via test_bpf module, from Puranjay Mohan.

2) Various fixups to the BPF arena code in particular in the BPF verifier and
   around BPF selftests to match latest corresponding LLVM implementation,
   from Puranjay Mohan and Alexei Starovoitov.

3) Fix xsk to not assume that metadata is always requested in TX completion,
   from Stanislav Fomichev.

4) Fix riscv BPF JIT's kfunc parameter incompatibility between BPF and the riscv
   ABI which requires sign-extension on int/uint, from Pu Lehui.

5) Fix s390x BPF JIT's bpf_plt pointer arithmetic which triggered a crash when
   testing struct_ops, from Ilya Leoshkevich.

6) Fix libbpf's arena mmap handling which had incorrect u64-to-pointer cast on
   32-bit architectures, from Andrii Nakryiko.

7) Fix libbpf to define MFD_CLOEXEC when not available, from Arnaldo Carvalho de Melo.

8) Fix arm64 BPF JIT implementation for 32bit unconditional bswap which
   resulted in an incorrect swap as indicated by test_bpf, from Artem Savkov.

9) Fix BPF man page build script to use silent mode, from Hangbin Liu.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  riscv, bpf: Fix kfunc parameters incompatibility between bpf and riscv abi
  bpf: verifier: reject addr_space_cast insn without arena
  selftests/bpf: verifier_arena: fix mmap address for arm64
  bpf: verifier: fix addr_space_cast from as(1) to as(0)
  libbpf: Define MFD_CLOEXEC if not available
  arm64: bpf: fix 32bit unconditional bswap
  bpf, arm64: fix bug in BPF_LDX_MEMSX
  libbpf: fix u64-to-pointer cast on 32-bit arches
  s390/bpf: Fix bpf_plt pointer arithmetic
  xsk: Don't assume metadata is always requested in TX completion
  selftests/bpf: Add arena test case for 4Gbyte corner case
  selftests/bpf: Remove hard coded PAGE_SIZE macro.
  libbpf, selftests/bpf: Adjust libbpf, bpftool, selftests to match LLVM
  bpf: Clarify bpf_arena comments.
  MAINTAINERS: Update email address for Quentin Monnet
  scripts/bpf_doc: Use silent mode when exec make cmd
  bpf: Temporarily disable atomic operations in BPF arena
====================

Link: https://lore.kernel.org/r/20240325213520.26688-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

3 files changed, 38 insertions, 28 deletions

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index c5b461dda438..122021f9bdfc 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -943,7 +943,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
 			emit(A64_UXTH(is64, dst, dst), ctx);
 			break;
 		case 32:
-			emit(A64_REV32(is64, dst, dst), ctx);
+			emit(A64_REV32(0, dst, dst), ctx);
 			/* upper 32 bits already cleared */
 			break;
 		case 64:
@@ -1256,7 +1256,7 @@ emit_cond_jmp:
 			} else {
 				emit_a64_mov_i(1, tmp, off, ctx);
 				if (sign_extend)
-					emit(A64_LDRSW(dst, src_adj, off_adj), ctx);
+					emit(A64_LDRSW(dst, src, tmp), ctx);
 				else
 					emit(A64_LDR32(dst, src, tmp), ctx);
 			}
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index aac190085472..1adf2f39ce59 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -1463,6 +1463,22 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
 		if (ret < 0)
 			return ret;
 
+		if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
+			const struct btf_func_model *fm;
+			int idx;
+
+			fm = bpf_jit_find_kfunc_model(ctx->prog, insn);
+			if (!fm)
+				return -EINVAL;
+
+			for (idx = 0; idx < fm->nr_args; idx++) {
+				u8 reg = bpf_to_rv_reg(BPF_REG_1 + idx, ctx);
+
+				if (fm->arg_size[idx] == sizeof(int))
+					emit_sextw(reg, reg, ctx);
+			}
+		}
+
 		ret = emit_call(addr, fixed_addr, ctx);
 		if (ret)
 			return ret;
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index b418333bb086..5af0402e94b8 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -516,11 +516,12 @@ static void bpf_skip(struct bpf_jit *jit, int size)
  * PLT for hotpatchable calls. The calling convention is the same as for the
  * ftrace hotpatch trampolines: %r0 is return address, %r1 is clobbered.
  */
-extern const char bpf_plt[];
-extern const char bpf_plt_ret[];
-extern const char bpf_plt_target[];
-extern const char bpf_plt_end[];
-#define BPF_PLT_SIZE 32
+struct bpf_plt {
+	char code[16];
+	void *ret;
+	void *target;
+} __packed;
+extern const struct bpf_plt bpf_plt;
 asm(
 	".pushsection .rodata\n"
 	"	.balign 8\n"
@@ -531,15 +532,14 @@ asm(
 	"	.balign 8\n"
 	"bpf_plt_ret: .quad 0\n"
 	"bpf_plt_target: .quad 0\n"
-	"bpf_plt_end:\n"
 	"	.popsection\n"
 );
 
-static void bpf_jit_plt(void *plt, void *ret, void *target)
+static void bpf_jit_plt(struct bpf_plt *plt, void *ret, void *target)
 {
-	memcpy(plt, bpf_plt, BPF_PLT_SIZE);
-	*(void **)((char *)plt + (bpf_plt_ret - bpf_plt)) = ret;
-	*(void **)((char *)plt + (bpf_plt_target - bpf_plt)) = target ?: ret;
+	memcpy(plt, &bpf_plt, sizeof(*plt));
+	plt->ret = ret;
+	plt->target = target;
 }
 
 /*
@@ -662,9 +662,9 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
 	jit->prg = ALIGN(jit->prg, 8);
 	jit->prologue_plt = jit->prg;
 	if (jit->prg_buf)
-		bpf_jit_plt(jit->prg_buf + jit->prg,
+		bpf_jit_plt((struct bpf_plt *)(jit->prg_buf + jit->prg),
 			    jit->prg_buf + jit->prologue_plt_ret, NULL);
-	jit->prg += BPF_PLT_SIZE;
+	jit->prg += sizeof(struct bpf_plt);
 }
 
 static int get_probe_mem_regno(const u8 *insn)
@@ -2040,9 +2040,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	struct bpf_jit jit;
 	int pass;
 
-	if (WARN_ON_ONCE(bpf_plt_end - bpf_plt != BPF_PLT_SIZE))
-		return orig_fp;
-
 	if (!fp->jit_requested)
 		return orig_fp;
 
@@ -2148,14 +2145,11 @@ bool bpf_jit_supports_far_kfunc_call(void)
 int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
 		       void *old_addr, void *new_addr)
 {
+	struct bpf_plt expected_plt, current_plt, new_plt, *plt;
 	struct {
 		u16 opc;
 		s32 disp;
 	} __packed insn;
-	char expected_plt[BPF_PLT_SIZE];
-	char current_plt[BPF_PLT_SIZE];
-	char new_plt[BPF_PLT_SIZE];
-	char *plt;
 	char *ret;
 	int err;
 
@@ -2174,18 +2168,18 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
 		 */
 	} else {
 		/* Verify the PLT. */
-		plt = (char *)ip + (insn.disp << 1);
-		err = copy_from_kernel_nofault(current_plt, plt, BPF_PLT_SIZE);
+		plt = ip + (insn.disp << 1);
+		err = copy_from_kernel_nofault(&current_plt, plt,
+					       sizeof(current_plt));
 		if (err < 0)
 			return err;
 		ret = (char *)ip + 6;
-		bpf_jit_plt(expected_plt, ret, old_addr);
-		if (memcmp(current_plt, expected_plt, BPF_PLT_SIZE))
+		bpf_jit_plt(&expected_plt, ret, old_addr);
+		if (memcmp(&current_plt, &expected_plt, sizeof(current_plt)))
 			return -EINVAL;
 		/* Adjust the call address. */
-		bpf_jit_plt(new_plt, ret, new_addr);
-		s390_kernel_write(plt + (bpf_plt_target - bpf_plt),
-				  new_plt + (bpf_plt_target - bpf_plt),
+		bpf_jit_plt(&new_plt, ret, new_addr);
+		s390_kernel_write(&plt->target, &new_plt.target,
 				  sizeof(void *));
 	}