Merge v6.19.9linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 93 insertions, 8 deletions

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 1fe37128c876..de99f9b354ab 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -319,6 +319,83 @@ int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *
 	return 0;
 }
 
+static int zero_extend(u32 *image, struct codegen_context *ctx, u32 src_reg, u32 dst_reg, u32 size)
+{
+	switch (size) {
+	case 1:
+		 /* zero-extend 8 bits into 64 bits */
+		EMIT(PPC_RAW_RLDICL(dst_reg, src_reg, 0, 56));
+		return 0;
+	case 2:
+		 /* zero-extend 16 bits into 64 bits */
+		EMIT(PPC_RAW_RLDICL(dst_reg, src_reg, 0, 48));
+		return 0;
+	case 4:
+		 /* zero-extend 32 bits into 64 bits */
+		EMIT(PPC_RAW_RLDICL(dst_reg, src_reg, 0, 32));
+		fallthrough;
+	case 8:
+		/* Nothing to do */
+		return 0;
+	default:
+		return -1;
+	}
+}
+
+static int sign_extend(u32 *image, struct codegen_context *ctx, u32 src_reg, u32 dst_reg, u32 size)
+{
+	switch (size) {
+	case 1:
+		 /* sign-extend 8 bits into 64 bits */
+		EMIT(PPC_RAW_EXTSB(dst_reg, src_reg));
+		return 0;
+	case 2:
+		 /* sign-extend 16 bits into 64 bits */
+		EMIT(PPC_RAW_EXTSH(dst_reg, src_reg));
+		return 0;
+	case 4:
+		 /* sign-extend 32 bits into 64 bits */
+		EMIT(PPC_RAW_EXTSW(dst_reg, src_reg));
+		fallthrough;
+	case 8:
+		/* Nothing to do */
+		return 0;
+	default:
+		return -1;
+	}
+}
+
+/*
+ * Handle powerpc ABI expectations from caller:
+ *   - Unsigned arguments are zero-extended.
+ *   - Signed arguments are sign-extended.
+ */
+static int prepare_for_kfunc_call(const struct bpf_prog *fp, u32 *image,
+				  struct codegen_context *ctx,
+				  const struct bpf_insn *insn)
+{
+	const struct btf_func_model *m = bpf_jit_find_kfunc_model(fp, insn);
+	int i;
+
+	if (!m)
+		return -1;
+
+	for (i = 0; i < m->nr_args; i++) {
+		/* Note that BPF ABI only allows up to 5 args for kfuncs */
+		u32 reg = bpf_to_ppc(BPF_REG_1 + i), size = m->arg_size[i];
+
+		if (!(m->arg_flags[i] & BTF_FMODEL_SIGNED_ARG)) {
+			if (zero_extend(image, ctx, reg, reg, size))
+				return -1;
+		} else {
+			if (sign_extend(image, ctx, reg, reg, size))
+				return -1;
+		}
+	}
+
+	return 0;
+}
+
 static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
 {
 	/*
@@ -931,14 +1008,16 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code
 				/* special mov32 for zext */
 				EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
 				break;
-			} else if (off == 8) {
-				EMIT(PPC_RAW_EXTSB(dst_reg, src_reg));
-			} else if (off == 16) {
-				EMIT(PPC_RAW_EXTSH(dst_reg, src_reg));
-			} else if (off == 32) {
-				EMIT(PPC_RAW_EXTSW(dst_reg, src_reg));
-			} else if (dst_reg != src_reg)
-				EMIT(PPC_RAW_MR(dst_reg, src_reg));
+			}
+			if (off == 0) {
+				/* MOV */
+				if (dst_reg != src_reg)
+					EMIT(PPC_RAW_MR(dst_reg, src_reg));
+			} else {
+				/* MOVSX: dst = (s8,s16,s32)src (off = 8,16,32) */
+				if (sign_extend(image, ctx, src_reg, dst_reg, off / 8))
+					return -1;
+			}
 			goto bpf_alu32_trunc;
 		case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */
 		case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */
@@ -1395,6 +1474,12 @@ emit_clear:
 			if (ret < 0)
 				return ret;
 
+			/* Take care of powerpc ABI requirements before kfunc call */
+			if (insn[i].src_reg == BPF_PSEUDO_KFUNC_CALL) {
+				if (prepare_for_kfunc_call(fp, image, ctx, &insn[i]))
+					return -1;
+			}
+
 			ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr);
 			if (ret)
 				return ret;