Commit da9d35e2 authored by Björn Töpel's avatar Björn Töpel Committed by Alexei Starovoitov
Browse files

samples/bpf: Add BPF_ATOMIC_OP macro for BPF samples 



Brendan Jackman added extend atomic operations to the BPF instruction
set in commit 7064a734 ("Merge branch 'Atomics for eBPF'"), which
introduces the BPF_ATOMIC_OP macro. However, that macro was missing
for the BPF samples. Fix that by adding it into bpf_insn.h.

Fixes: 91c960b0 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm")
Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarBrendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/bpf/20210118091753.107572-1-bjorn.topel@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 89f479f0

samples/bpf/bpf_insn.h

+20 −4
Original line number Diff line number Diff line
@@ -134,15 +134,31 @@ struct bpf_insn; 
		.off   = OFF,					\

		.imm   = 0 })



/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */



#define BPF_STX_XADD(SIZE, DST, SRC, OFF)			\

/*

 * Atomic operations:

 *

 *   BPF_ADD                  *(uint *) (dst_reg + off16) += src_reg

 *   BPF_AND                  *(uint *) (dst_reg + off16) &= src_reg

 *   BPF_OR                   *(uint *) (dst_reg + off16) |= src_reg

 *   BPF_XOR                  *(uint *) (dst_reg + off16) ^= src_reg

 *   BPF_ADD | BPF_FETCH      src_reg = atomic_fetch_add(dst_reg + off16, src_reg);

 *   BPF_AND | BPF_FETCH      src_reg = atomic_fetch_and(dst_reg + off16, src_reg);

 *   BPF_OR | BPF_FETCH       src_reg = atomic_fetch_or(dst_reg + off16, src_reg);

 *   BPF_XOR | BPF_FETCH      src_reg = atomic_fetch_xor(dst_reg + off16, src_reg);

 *   BPF_XCHG                 src_reg = atomic_xchg(dst_reg + off16, src_reg)

 *   BPF_CMPXCHG              r0 = atomic_cmpxchg(dst_reg + off16, r0, src_reg)

 */



#define BPF_ATOMIC_OP(SIZE, OP, DST, SRC, OFF)			\

	((struct bpf_insn) {					\

		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC,	\

		.dst_reg = DST,					\

		.src_reg = SRC,					\

		.off   = OFF,					\

		.imm   = BPF_ADD })

		.imm   = OP })



/* Legacy alias */

#define BPF_STX_XADD(SIZE, DST, SRC, OFF) BPF_ATOMIC_OP(SIZE, BPF_ADD, DST, SRC, OFF)



/* Memory store, *(uint *) (dst_reg + off16) = imm32 */