3.19.8-ckt2 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Alexei Starovoitov <[email protected]> commit 343f845b375989f1753f605902931fa939aa2223 upstream. FROM_BE16: 'ror %reg, 8' doesn't clear upper bits of the register, so use additional 'movzwl' insn to zero extend 16 bits into 64 FROM_LE16: should zero extend lower 16 bits into 64 bit FROM_LE32: should zero extend lower 32 bits into 64 bit Fixes: 89aa075832b0 ("net: sock: allow eBPF programs to be attached to sockets") Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- arch/x86/net/bpf_jit_comp.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 9875143..99f7610 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -559,6 +559,13 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, if (is_ereg(dst_reg)) EMIT1(0x41); EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); + + /* emit 'movzwl eax, ax' */ + if (is_ereg(dst_reg)) + EMIT3(0x45, 0x0F, 0xB7); + else + EMIT2(0x0F, 0xB7); + EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); break; case 32: /* emit 'bswap eax' to swap lower 4 bytes */ @@ -577,6 +584,27 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, break; case BPF_ALU | BPF_END | BPF_FROM_LE: + switch (imm32) { + case 16: + /* emit 'movzwl eax, ax' to zero extend 16-bit + * into 64 bit + */ + if (is_ereg(dst_reg)) + EMIT3(0x45, 0x0F, 0xB7); + else + EMIT2(0x0F, 0xB7); + EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); + break; + case 32: + /* emit 'mov eax, eax' to clear upper 32-bits */ + if (is_ereg(dst_reg)) + EMIT1(0x45); + EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); + break; + case 64: + /* nop */ + break; + } break; /* ST: *(u8*)(dst_reg + off) = imm */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
