diff options
| author | Alexei Starovoitov <ast@plumgrid.com> | 2015-04-27 14:40:37 -0700 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-05-17 19:12:32 -0400 |
| commit | 2611e2418ca8be78f87cd8f727aa92f04fdcfd21 (patch) | |
| tree | ffd9ed751bbd3e4034c74cf98de13021a4fbaba9 | |
| parent | 7f1a6ae73b5c2d24b21d9a27928ceacef3a9a939 (diff) | |
bpf: fix 64-bit divide
[ Upstream commit 876a7ae65b86d8cec8efe7d15d050ac61116874e ]
ALU64_DIV instruction should be dividing 64-bit by 64-bit,
whereas do_div() does 64-bit by 32-bit divide.
x64 and arm64 JITs correctly implement 64 by 64 unsigned divide.
llvm BPF backend emits code assuming that ALU64_DIV does 64 by 64.
Fixes: 89aa075832b0 ("net: sock: allow eBPF programs to be attached to sockets")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
| -rw-r--r-- | kernel/bpf/core.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index d6594e457a25..71a9e5be6592 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -357,8 +357,8 @@ select_insn: ALU64_MOD_X: if (unlikely(SRC == 0)) return 0; - tmp = DST; - DST = do_div(tmp, SRC); + div64_u64_rem(DST, SRC, &tmp); + DST = tmp; CONT; ALU_MOD_X: if (unlikely(SRC == 0)) @@ -367,8 +367,8 @@ select_insn: DST = do_div(tmp, (u32) SRC); CONT; ALU64_MOD_K: - tmp = DST; - DST = do_div(tmp, IMM); + div64_u64_rem(DST, IMM, &tmp); + DST = tmp; CONT; ALU_MOD_K: tmp = (u32) DST; @@ -377,7 +377,7 @@ select_insn: ALU64_DIV_X: if (unlikely(SRC == 0)) return 0; - do_div(DST, SRC); + DST = div64_u64(DST, SRC); CONT; ALU_DIV_X: if (unlikely(SRC == 0)) @@ -387,7 +387,7 @@ select_insn: DST = (u32) tmp; CONT; ALU64_DIV_K: - do_div(DST, IMM); + DST = div64_u64(DST, IMM); CONT; ALU_DIV_K: tmp = (u32) DST; |