From: Naveen N. Rao naveen.n.rao@linux.vnet.ibm.com
commit fab07611fb2e6a15fac05c4583045ca5582fd826 upstream.
Pad instructions emitted for BPF_CALL so that the number of instructions generated does not change for different function addresses. This is especially important for calls to other bpf functions, whose address will only be known during extra pass.
Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Naveen N. Rao naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/52d8fe51f7620a6f27f377791564d79d75463576.164146812... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/net/bpf_jit_comp32.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -191,6 +191,9 @@ void bpf_jit_emit_func_call_rel(u32 *ima
if (image && rel < 0x2000000 && rel >= -0x2000000) { PPC_BL_ABS(func); + EMIT(PPC_RAW_NOP()); + EMIT(PPC_RAW_NOP()); + EMIT(PPC_RAW_NOP()); } else { /* Load function address into r0 */ EMIT(PPC_RAW_LIS(_R0, IMM_H(func)));