[PATCH 5.14 136/151] powerpc/bpf ppc32: Fix JMP32_JSET_K

From: Greg Kroah-Hartman
Date: Mon Oct 11 2021 - 10:12:31 EST


From: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>

[ Upstream commit e8278d44443207bb6609c7b064073f353e6f4978 ]

'andi' only takes an unsigned 16-bit value. Correct the imm range used
when emitting andi.

Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32")
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/b94489f52831305ec15aca4dd04a3527236be7e8.1633464148.git.naveen.n.rao@xxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 faef4a1598fd..ae3a31cb7b7e 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c
@@ -1073,7 +1073,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *
break;
case BPF_JMP32 | BPF_JSET | BPF_K:
/* andi does not sign-extend the immediate */
- if (imm >= -32768 && imm < 32768) {
+ if (imm >= 0 && imm < 32768) {
/* PPC_ANDI is _only/always_ dot-form */
EMIT(PPC_RAW_ANDI(_R0, dst_reg, imm));
} else {
--
2.33.0