diff options
| author | Brendan Jackman <jackmanb@google.com> | 2021-01-14 18:17:44 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-01-14 18:34:29 -0800 |
| commit | 91c960b0056672e74627776655c926388350fa30 (patch) | |
| tree | b15d68c17ead28b128791f8e710d9efa2a711267 /samples | |
| parent | e5f02caccfae94f5baf6ec6dbb57ce8a7e9a40e7 (diff) | |
| download | lwn-91c960b0056672e74627776655c926388350fa30.tar.gz lwn-91c960b0056672e74627776655c926388350fa30.zip | |
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
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/bpf/bpf_insn.h | 4 | ||||
| -rw-r--r-- | samples/bpf/cookie_uid_helper_example.c | 8 | ||||
| -rw-r--r-- | samples/bpf/sock_example.c | 2 | ||||
| -rw-r--r-- | samples/bpf/test_cgrp2_attach.c | 5 |
4 files changed, 10 insertions, 9 deletions
diff --git a/samples/bpf/bpf_insn.h b/samples/bpf/bpf_insn.h index 544237980582..db67a2847395 100644 --- a/samples/bpf/bpf_insn.h +++ b/samples/bpf/bpf_insn.h @@ -138,11 +138,11 @@ struct bpf_insn; #define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ ((struct bpf_insn) { \ - .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC, \ .dst_reg = DST, \ .src_reg = SRC, \ .off = OFF, \ - .imm = 0 }) + .imm = BPF_ADD }) /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ diff --git a/samples/bpf/cookie_uid_helper_example.c b/samples/bpf/cookie_uid_helper_example.c index deb0e3e0324d..c5ff7a13918c 100644 --- a/samples/bpf/cookie_uid_helper_example.c +++ b/samples/bpf/cookie_uid_helper_example.c @@ -147,12 +147,12 @@ static void prog_load(void) */ BPF_MOV64_REG(BPF_REG_9, BPF_REG_0), BPF_MOV64_IMM(BPF_REG_1, 1), - BPF_STX_XADD(BPF_DW, BPF_REG_9, BPF_REG_1, - offsetof(struct stats, packets)), + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_9, BPF_REG_1, + offsetof(struct stats, packets)), BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, offsetof(struct __sk_buff, len)), - BPF_STX_XADD(BPF_DW, BPF_REG_9, BPF_REG_1, - offsetof(struct stats, bytes)), + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_9, BPF_REG_1, + offsetof(struct stats, bytes)), BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, offsetof(struct __sk_buff, len)), BPF_EXIT_INSN(), diff --git a/samples/bpf/sock_example.c b/samples/bpf/sock_example.c index 00aae1d33fca..23d1930e1927 100644 --- a/samples/bpf/sock_example.c +++ b/samples/bpf/sock_example.c @@ -54,7 +54,7 @@ static int test_sock(void) BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */ - BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */ + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_1, 0), BPF_MOV64_IMM(BPF_REG_0, 0), /* r0 = 0 */ BPF_EXIT_INSN(), }; diff --git a/samples/bpf/test_cgrp2_attach.c b/samples/bpf/test_cgrp2_attach.c index 20fbd1241db3..390ff38d2ac6 100644 --- a/samples/bpf/test_cgrp2_attach.c +++ b/samples/bpf/test_cgrp2_attach.c @@ -53,7 +53,7 @@ static int prog_load(int map_fd, int verdict) BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */ - BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */ + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_1, 0), /* Count bytes */ BPF_MOV64_IMM(BPF_REG_0, MAP_KEY_BYTES), /* r0 = 1 */ @@ -64,7 +64,8 @@ static int prog_load(int map_fd, int verdict) BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, offsetof(struct __sk_buff, len)), /* r1 = skb->len */ - BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */ + + BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_1, 0), BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */ BPF_EXIT_INSN(), |