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[PATCH 08/17] MIPS: bpf: Fix branch conditional for BPF_J{GT/GE} cases

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Subject: [PATCH 08/17] MIPS: bpf: Fix branch conditional for BPF_J{GT/GE} cases
From: Markos Chandras <markos.chandras@imgtec.com>
Date: Mon, 23 Jun 2014 10:38:51 +0100
Cc: Markos Chandras <markos.chandras@imgtec.com>, "David S. Miller" <davem@davemloft.net>, Daniel Borkmann <dborkman@redhat.com>, "Alexei Starovoitov" <ast@plumgrid.com>, <netdev@vger.kernel.org>
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The sltiu and sltu instructions will set the scratch register
to 1 if A <= X|K so fix the emitted branch conditional to check
for scratch != zero rather than scratch >= zero which would complicate
the resuling branch logic given that MIPS does not have a BGT or BGET
instructions to compare general purpose registers directly.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
---
 arch/mips/net/bpf_jit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 8cae27af03da..500f97fdc0e1 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -1127,7 +1127,7 @@ jmp_cmp:
                                }
                                /* A < (K|X) ? r_scrach = 1 */
                                b_off = b_imm(i + inst->jf + 1, ctx);
-                               emit_bcond(MIPS_COND_GT, r_s0, r_zero, b_off,
+                               emit_bcond(MIPS_COND_NE, r_s0, r_zero, b_off,
                                           ctx);
                                emit_nop(ctx);
                                /* A > (K|X) ? scratch = 0 */
-- 
2.0.0


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