bpf: Rename BPF_XADD and prepare to encode other atomics in .imm

A subsequent patch will add additional atomic operations. These new
operations will use the same opcode field as the existing XADD, with
the immediate discriminating different operations.

In preparation, rename the instruction mode BPF_ATOMIC and start
calling the zero immediate BPF_ADD.

This is possible (doesn't break existing valid BPF progs) because the
immediate field is currently reserved MBZ and BPF_ADD is zero.

All uses are removed from the tree but the BPF_XADD definition is
kept around to avoid breaking builds for people including kernel
headers.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com

7 files changed, 24 insertions, 24 deletions

diff --git a/tools/testing/selftests/bpf/verifier/ctx.c b/tools/testing/selftests/bpf/verifier/ctx.c
index 93d6b1641481..23080862aafd 100644
--- a/tools/testing/selftests/bpf/verifier/ctx.c
+++ b/tools/testing/selftests/bpf/verifier/ctx.c
@@ -10,14 +10,13 @@
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 },
 {
-	"context stores via XADD",
+	"context stores via BPF_ATOMIC",
 	.insns = {
 	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_W, BPF_REG_1,
-		     BPF_REG_0, offsetof(struct __sk_buff, mark), 0),
+	BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_1, BPF_REG_0, offsetof(struct __sk_buff, mark)),
 	BPF_EXIT_INSN(),
 	},
-	.errstr = "BPF_XADD stores into R1 ctx is not allowed",
+	.errstr = "BPF_ATOMIC stores into R1 ctx is not allowed",
 	.result = REJECT,
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 },
diff --git a/tools/testing/selftests/bpf/verifier/direct_packet_access.c b/tools/testing/selftests/bpf/verifier/direct_packet_access.c
index ae72536603fe..ac1e19d0f520 100644
--- a/tools/testing/selftests/bpf/verifier/direct_packet_access.c
+++ b/tools/testing/selftests/bpf/verifier/direct_packet_access.c
@@ -333,7 +333,7 @@
 	BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
 	BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
 	BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_2, 0),
-	BPF_STX_XADD(BPF_DW, BPF_REG_4, BPF_REG_5, 0),
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_4, BPF_REG_5, 0),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_4, 0),
 	BPF_STX_MEM(BPF_W, BPF_REG_2, BPF_REG_5, 0),
 	BPF_MOV64_IMM(BPF_REG_0, 0),
@@ -488,7 +488,7 @@
 	BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 11),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -8),
 	BPF_MOV64_IMM(BPF_REG_4, 0xffffffff),
-	BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_4, -8),
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_10, BPF_REG_4, -8),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_10, -8),
 	BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 49),
 	BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_2),
diff --git a/tools/testing/selftests/bpf/verifier/leak_ptr.c b/tools/testing/selftests/bpf/verifier/leak_ptr.c
index d6eec17f2cd2..73f0dea95546 100644
--- a/tools/testing/selftests/bpf/verifier/leak_ptr.c
+++ b/tools/testing/selftests/bpf/verifier/leak_ptr.c
@@ -5,7 +5,7 @@
 	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
 		    offsetof(struct __sk_buff, cb[0])),
 	BPF_LD_MAP_FD(BPF_REG_2, 0),
-	BPF_STX_XADD(BPF_DW, BPF_REG_1, BPF_REG_2,
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_1, BPF_REG_2,
 		      offsetof(struct __sk_buff, cb[0])),
 	BPF_EXIT_INSN(),
 	},
@@ -13,7 +13,7 @@
 	.errstr_unpriv = "R2 leaks addr into mem",
 	.result_unpriv = REJECT,
 	.result = REJECT,
-	.errstr = "BPF_XADD stores into R1 ctx is not allowed",
+	.errstr = "BPF_ATOMIC stores into R1 ctx is not allowed",
 },
 {
 	"leak pointer into ctx 2",
@@ -21,14 +21,14 @@
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
 		    offsetof(struct __sk_buff, cb[0])),
-	BPF_STX_XADD(BPF_DW, BPF_REG_1, BPF_REG_10,
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_1, BPF_REG_10,
 		      offsetof(struct __sk_buff, cb[0])),
 	BPF_EXIT_INSN(),
 	},
 	.errstr_unpriv = "R10 leaks addr into mem",
 	.result_unpriv = REJECT,
 	.result = REJECT,
-	.errstr = "BPF_XADD stores into R1 ctx is not allowed",
+	.errstr = "BPF_ATOMIC stores into R1 ctx is not allowed",
 },
 {
 	"leak pointer into ctx 3",
@@ -56,7 +56,7 @@
 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
 	BPF_MOV64_IMM(BPF_REG_3, 0),
 	BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_3, 0),
-	BPF_STX_XADD(BPF_DW, BPF_REG_0, BPF_REG_6, 0),
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_6, 0),
 	BPF_MOV64_IMM(BPF_REG_0, 0),
 	BPF_EXIT_INSN(),
 	},
diff --git a/tools/testing/selftests/bpf/verifier/meta_access.c b/tools/testing/selftests/bpf/verifier/meta_access.c
index 205292b8dd65..b45e8af41420 100644
--- a/tools/testing/selftests/bpf/verifier/meta_access.c
+++ b/tools/testing/selftests/bpf/verifier/meta_access.c
@@ -171,7 +171,7 @@
 	BPF_MOV64_IMM(BPF_REG_5, 42),
 	BPF_MOV64_IMM(BPF_REG_6, 24),
 	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_5, -8),
-	BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_6, -8),
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_10, BPF_REG_6, -8),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_10, -8),
 	BPF_JMP_IMM(BPF_JGT, BPF_REG_5, 100, 6),
 	BPF_ALU64_REG(BPF_ADD, BPF_REG_3, BPF_REG_5),
@@ -196,7 +196,7 @@
 	BPF_MOV64_IMM(BPF_REG_5, 42),
 	BPF_MOV64_IMM(BPF_REG_6, 24),
 	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_5, -8),
-	BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_6, -8),
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_10, BPF_REG_6, -8),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_10, -8),
 	BPF_JMP_IMM(BPF_JGT, BPF_REG_5, 100, 6),
 	BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_5),
diff --git a/tools/testing/selftests/bpf/verifier/unpriv.c b/tools/testing/selftests/bpf/verifier/unpriv.c
index a3fe0fbaed41..ee298627abae 100644
--- a/tools/testing/selftests/bpf/verifier/unpriv.c
+++ b/tools/testing/selftests/bpf/verifier/unpriv.c
@@ -207,7 +207,8 @@
 	BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
 	BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
 	BPF_MOV64_IMM(BPF_REG_0, 1),
-	BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_10, BPF_REG_0, -8, 0),
+	BPF_RAW_INSN(BPF_STX | BPF_ATOMIC | BPF_DW,
+		     BPF_REG_10, BPF_REG_0, -8, BPF_ADD),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
 	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_hash_recalc),
 	BPF_EXIT_INSN(),
diff --git a/tools/testing/selftests/bpf/verifier/value_illegal_alu.c b/tools/testing/selftests/bpf/verifier/value_illegal_alu.c
index ed1c2cea1dea..489062867218 100644
--- a/tools/testing/selftests/bpf/verifier/value_illegal_alu.c
+++ b/tools/testing/selftests/bpf/verifier/value_illegal_alu.c
@@ -82,7 +82,7 @@
 	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
 	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
 	BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, 0),
-	BPF_STX_XADD(BPF_DW, BPF_REG_2, BPF_REG_3, 0),
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_2, BPF_REG_3, 0),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 0),
 	BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 22),
 	BPF_EXIT_INSN(),
diff --git a/tools/testing/selftests/bpf/verifier/xadd.c b/tools/testing/selftests/bpf/verifier/xadd.c
index c5de2e62cc8b..b96ef3526815 100644
--- a/tools/testing/selftests/bpf/verifier/xadd.c
+++ b/tools/testing/selftests/bpf/verifier/xadd.c
@@ -3,7 +3,7 @@
 	.insns = {
 	BPF_MOV64_IMM(BPF_REG_0, 1),
 	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
-	BPF_STX_XADD(BPF_W, BPF_REG_10, BPF_REG_0, -7),
+	BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_10, BPF_REG_0, -7),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
 	BPF_EXIT_INSN(),
 	},
@@ -22,7 +22,7 @@
 	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
 	BPF_EXIT_INSN(),
 	BPF_MOV64_IMM(BPF_REG_1, 1),
-	BPF_STX_XADD(BPF_W, BPF_REG_0, BPF_REG_1, 3),
+	BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_0, BPF_REG_1, 3),
 	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 3),
 	BPF_EXIT_INSN(),
 	},
@@ -45,13 +45,13 @@
 	BPF_MOV64_IMM(BPF_REG_0, 1),
 	BPF_ST_MEM(BPF_W, BPF_REG_2, 0, 0),
 	BPF_ST_MEM(BPF_W, BPF_REG_2, 3, 0),
-	BPF_STX_XADD(BPF_W, BPF_REG_2, BPF_REG_0, 1),
-	BPF_STX_XADD(BPF_W, BPF_REG_2, BPF_REG_0, 2),
+	BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_2, BPF_REG_0, 1),
+	BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_2, BPF_REG_0, 2),
 	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 1),
 	BPF_EXIT_INSN(),
 	},
 	.result = REJECT,
-	.errstr = "BPF_XADD stores into R2 pkt is not allowed",
+	.errstr = "BPF_ATOMIC stores into R2 pkt is not allowed",
 	.prog_type = BPF_PROG_TYPE_XDP,
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
@@ -62,8 +62,8 @@
 	BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
 	BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
-	BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
-	BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_10, BPF_REG_0, -8),
+	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_10, BPF_REG_0, -8),
 	BPF_JMP_REG(BPF_JNE, BPF_REG_6, BPF_REG_0, 3),
 	BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_10, 2),
 	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
@@ -82,8 +82,8 @@
 	BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
 	BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
 	BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8),
-	BPF_STX_XADD(BPF_W, BPF_REG_10, BPF_REG_0, -8),
-	BPF_STX_XADD(BPF_W, BPF_REG_10, BPF_REG_0, -8),
+	BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_10, BPF_REG_0, -8),
+	BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_10, BPF_REG_0, -8),
 	BPF_JMP_REG(BPF_JNE, BPF_REG_6, BPF_REG_0, 3),
 	BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_10, 2),
 	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -8),