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authorBrendan Jackman <jackmanb@google.com>2021-01-14 21:17:44 +0300
committerAlexei Starovoitov <ast@kernel.org>2021-01-15 05:34:29 +0300
commit91c960b0056672e74627776655c926388350fa30 (patch)
treeb15d68c17ead28b128791f8e710d9efa2a711267 /arch/powerpc/net
parente5f02caccfae94f5baf6ec6dbb57ce8a7e9a40e7 (diff)
downloadlinux-91c960b0056672e74627776655c926388350fa30.tar.xz
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 'arch/powerpc/net')
-rw-r--r--arch/powerpc/net/bpf_jit_comp64.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 022103c6a201..aaf1a887f653 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -683,10 +683,18 @@ emit_clear:
break;
/*
- * BPF_STX XADD (atomic_add)
+ * BPF_STX ATOMIC (atomic ops)
*/
- /* *(u32 *)(dst + off) += src */
- case BPF_STX | BPF_XADD | BPF_W:
+ case BPF_STX | BPF_ATOMIC | BPF_W:
+ if (insn->imm != BPF_ADD) {
+ pr_err_ratelimited(
+ "eBPF filter atomic op code %02x (@%d) unsupported\n",
+ code, i);
+ return -ENOTSUPP;
+ }
+
+ /* *(u32 *)(dst + off) += src */
+
/* Get EA into TMP_REG_1 */
EMIT(PPC_RAW_ADDI(b2p[TMP_REG_1], dst_reg, off));
tmp_idx = ctx->idx * 4;
@@ -699,8 +707,15 @@ emit_clear:
/* we're done if this succeeded */
PPC_BCC_SHORT(COND_NE, tmp_idx);
break;
- /* *(u64 *)(dst + off) += src */
- case BPF_STX | BPF_XADD | BPF_DW:
+ case BPF_STX | BPF_ATOMIC | BPF_DW:
+ if (insn->imm != BPF_ADD) {
+ pr_err_ratelimited(
+ "eBPF filter atomic op code %02x (@%d) unsupported\n",
+ code, i);
+ return -ENOTSUPP;
+ }
+ /* *(u64 *)(dst + off) += src */
+
EMIT(PPC_RAW_ADDI(b2p[TMP_REG_1], dst_reg, off));
tmp_idx = ctx->idx * 4;
EMIT(PPC_RAW_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0));