1 files changed, 87 insertions, 13 deletions

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 72776dcb75aa..9e5fe2ba858f 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1250,8 +1250,8 @@ static void emit_st_r12(u8 **pprog, u32 size, u32 dst_reg, int off, int imm)
 	emit_st_index(pprog, size, dst_reg, X86_REG_R12, off, imm);
 }
 
-static int emit_atomic(u8 **pprog, u8 atomic_op,
-		       u32 dst_reg, u32 src_reg, s16 off, u8 bpf_size)
+static int emit_atomic_rmw(u8 **pprog, u32 atomic_op,
+			   u32 dst_reg, u32 src_reg, s16 off, u8 bpf_size)
 {
 	u8 *prog = *pprog;
 
@@ -1291,8 +1291,9 @@ static int emit_atomic(u8 **pprog, u8 atomic_op,
 	return 0;
 }
 
-static int emit_atomic_index(u8 **pprog, u8 atomic_op, u32 size,
-			     u32 dst_reg, u32 src_reg, u32 index_reg, int off)
+static int emit_atomic_rmw_index(u8 **pprog, u32 atomic_op, u32 size,
+				 u32 dst_reg, u32 src_reg, u32 index_reg,
+				 int off)
 {
 	u8 *prog = *pprog;
 
@@ -1305,7 +1306,7 @@ static int emit_atomic_index(u8 **pprog, u8 atomic_op, u32 size,
 		EMIT1(add_3mod(0x48, dst_reg, src_reg, index_reg));
 		break;
 	default:
-		pr_err("bpf_jit: 1 and 2 byte atomics are not supported\n");
+		pr_err("bpf_jit: 1- and 2-byte RMW atomics are not supported\n");
 		return -EFAULT;
 	}
 
@@ -1339,6 +1340,49 @@ static int emit_atomic_index(u8 **pprog, u8 atomic_op, u32 size,
 	return 0;
 }
 
+static int emit_atomic_ld_st(u8 **pprog, u32 atomic_op, u32 dst_reg,
+			     u32 src_reg, s16 off, u8 bpf_size)
+{
+	switch (atomic_op) {
+	case BPF_LOAD_ACQ:
+		/* dst_reg = smp_load_acquire(src_reg + off16) */
+		emit_ldx(pprog, bpf_size, dst_reg, src_reg, off);
+		break;
+	case BPF_STORE_REL:
+		/* smp_store_release(dst_reg + off16, src_reg) */
+		emit_stx(pprog, bpf_size, dst_reg, src_reg, off);
+		break;
+	default:
+		pr_err("bpf_jit: unknown atomic load/store opcode %02x\n",
+		       atomic_op);
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static int emit_atomic_ld_st_index(u8 **pprog, u32 atomic_op, u32 size,
+				   u32 dst_reg, u32 src_reg, u32 index_reg,
+				   int off)
+{
+	switch (atomic_op) {
+	case BPF_LOAD_ACQ:
+		/* dst_reg = smp_load_acquire(src_reg + idx_reg + off16) */
+		emit_ldx_index(pprog, size, dst_reg, src_reg, index_reg, off);
+		break;
+	case BPF_STORE_REL:
+		/* smp_store_release(dst_reg + idx_reg + off16, src_reg) */
+		emit_stx_index(pprog, size, dst_reg, src_reg, index_reg, off);
+		break;
+	default:
+		pr_err("bpf_jit: unknown atomic load/store opcode %02x\n",
+		       atomic_op);
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
 #define DONT_CLEAR 1
 
 bool ex_handler_bpf(const struct exception_table_entry *x, struct pt_regs *regs)
@@ -2121,6 +2165,13 @@ populate_extable:
 			}
 			break;
 
+		case BPF_STX | BPF_ATOMIC | BPF_B:
+		case BPF_STX | BPF_ATOMIC | BPF_H:
+			if (!bpf_atomic_is_load_store(insn)) {
+				pr_err("bpf_jit: 1- and 2-byte RMW atomics are not supported\n");
+				return -EFAULT;
+			}
+			fallthrough;
 		case BPF_STX | BPF_ATOMIC | BPF_W:
 		case BPF_STX | BPF_ATOMIC | BPF_DW:
 			if (insn->imm == (BPF_AND | BPF_FETCH) ||
@@ -2156,10 +2207,10 @@ populate_extable:
 				EMIT2(simple_alu_opcodes[BPF_OP(insn->imm)],
 				      add_2reg(0xC0, AUX_REG, real_src_reg));
 				/* Attempt to swap in new value */
-				err = emit_atomic(&prog, BPF_CMPXCHG,
-						  real_dst_reg, AUX_REG,
-						  insn->off,
-						  BPF_SIZE(insn->code));
+				err = emit_atomic_rmw(&prog, BPF_CMPXCHG,
+						      real_dst_reg, AUX_REG,
+						      insn->off,
+						      BPF_SIZE(insn->code));
 				if (WARN_ON(err))
 					return err;
 				/*
@@ -2174,17 +2225,35 @@ populate_extable:
 				break;
 			}
 
-			err = emit_atomic(&prog, insn->imm, dst_reg, src_reg,
-					  insn->off, BPF_SIZE(insn->code));
+			if (bpf_atomic_is_load_store(insn))
+				err = emit_atomic_ld_st(&prog, insn->imm, dst_reg, src_reg,
+							insn->off, BPF_SIZE(insn->code));
+			else
+				err = emit_atomic_rmw(&prog, insn->imm, dst_reg, src_reg,
+						      insn->off, BPF_SIZE(insn->code));
 			if (err)
 				return err;
 			break;
 
+		case BPF_STX | BPF_PROBE_ATOMIC | BPF_B:
+		case BPF_STX | BPF_PROBE_ATOMIC | BPF_H:
+			if (!bpf_atomic_is_load_store(insn)) {
+				pr_err("bpf_jit: 1- and 2-byte RMW atomics are not supported\n");
+				return -EFAULT;
+			}
+			fallthrough;
 		case BPF_STX | BPF_PROBE_ATOMIC | BPF_W:
 		case BPF_STX | BPF_PROBE_ATOMIC | BPF_DW:
 			start_of_ldx = prog;
-			err = emit_atomic_index(&prog, insn->imm, BPF_SIZE(insn->code),
-						dst_reg, src_reg, X86_REG_R12, insn->off);
+
+			if (bpf_atomic_is_load_store(insn))
+				err = emit_atomic_ld_st_index(&prog, insn->imm,
+							      BPF_SIZE(insn->code), dst_reg,
+							      src_reg, X86_REG_R12, insn->off);
+			else
+				err = emit_atomic_rmw_index(&prog, insn->imm, BPF_SIZE(insn->code),
+							    dst_reg, src_reg, X86_REG_R12,
+							    insn->off);
 			if (err)
 				return err;
 			goto populate_extable;
@@ -3801,3 +3870,8 @@ u64 bpf_arch_uaddress_limit(void)
 {
 	return 0;
 }
+
+bool bpf_jit_supports_timed_may_goto(void)
+{
+	return true;
+}