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authorYonghong Song <yonghong.song@linux.dev>2023-07-28 04:12:13 +0300
committerAlexei Starovoitov <ast@kernel.org>2023-07-28 04:52:33 +0300
commit0845c3db7bf5c4ceb7100bcd8fd594d9ccf3c29a (patch)
treef60e9cb2004b103c0ab01257bdb9952d06df292d /kernel
parent1f1e864b65554e33fe74e3377e58b12f4302f2eb (diff)
downloadlinux-0845c3db7bf5c4ceb7100bcd8fd594d9ccf3c29a.tar.xz
bpf: Support new unconditional bswap instruction
The existing 'be' and 'le' insns will do conditional bswap depends on host endianness. This patch implements unconditional bswap insns. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728011213.3712808-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/core.c14
-rw-r--r--kernel/bpf/verifier.c7
2 files changed, 19 insertions, 2 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index c37c454b09eb..ad58697cec4b 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1524,6 +1524,7 @@ EXPORT_SYMBOL_GPL(__bpf_call_base);
INSN_3(ALU64, DIV, X), \
INSN_3(ALU64, MOD, X), \
INSN_2(ALU64, NEG), \
+ INSN_3(ALU64, END, TO_LE), \
/* Immediate based. */ \
INSN_3(ALU64, ADD, K), \
INSN_3(ALU64, SUB, K), \
@@ -1848,6 +1849,19 @@ select_insn:
break;
}
CONT;
+ ALU64_END_TO_LE:
+ switch (IMM) {
+ case 16:
+ DST = (__force u16) __swab16(DST);
+ break;
+ case 32:
+ DST = (__force u32) __swab32(DST);
+ break;
+ case 64:
+ DST = (__force u64) __swab64(DST);
+ break;
+ }
+ CONT;
/* CALL */
JMP_CALL:
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 7a6945be07e3..a3dcaeed8217 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3012,8 +3012,10 @@ static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn,
}
}
+ if (class == BPF_ALU64 && op == BPF_END && (insn->imm == 16 || insn->imm == 32))
+ return false;
+
if (class == BPF_ALU64 || class == BPF_JMP ||
- /* BPF_END always use BPF_ALU class. */
(class == BPF_ALU && op == BPF_END && insn->imm == 64))
return true;
@@ -13076,7 +13078,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
} else {
if (insn->src_reg != BPF_REG_0 || insn->off != 0 ||
(insn->imm != 16 && insn->imm != 32 && insn->imm != 64) ||
- BPF_CLASS(insn->code) == BPF_ALU64) {
+ (BPF_CLASS(insn->code) == BPF_ALU64 &&
+ BPF_SRC(insn->code) != BPF_TO_LE)) {
verbose(env, "BPF_END uses reserved fields\n");
return -EINVAL;
}