[PATCH 5.14 138/151] powerpc/bpf ppc32: Fix BPF_SUB when imm == 0x80000000
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-10-11 14:12:50
Also in:
lkml
Subsystem:
bpf jit for powerpc (32-bit and 64-bit), bpf [general] (safe dynamic programs and tools), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Hari Bathini, Christophe Leroy, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Madhavan Srinivasan, Linus Torvalds
From: Naveen N. Rao <redacted>
[ 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 <redacted>
Reviewed-by: Christophe Leroy <redacted>
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 (local)
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