| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.14 138/151] powerpc/bpf ppc32: Fix BPF_SUB when imm == 0x80000000 | Date | Mon, 11 Oct 2021 15:46:50 +0200 |
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From: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[ Upstream commit 548b762763b885b81850db676258df47c55dd5f9 ]
Special case handling of the smallest 32-bit negative number for BPF_SUB.
Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7135360a0cdf70adedbccf9863128b8daef18764.1633464148.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/powerpc/net/bpf_jit_comp32.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index c48de048c8ce..a7759aa8043d 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -355,7 +355,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * PPC_LI32(_R0, imm); EMIT(PPC_RAW_ADDC(dst_reg, dst_reg, _R0)); } - if (imm >= 0) + if (imm >= 0 || (BPF_OP(code) == BPF_SUB && imm == 0x80000000)) EMIT(PPC_RAW_ADDZE(dst_reg_h, dst_reg_h)); else EMIT(PPC_RAW_ADDME(dst_reg_h, dst_reg_h)); -- 2.33.0
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