From fab07611fb2e6a15fac05c4583045ca5582fd826 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Thu, 6 Jan 2022 17:15:06 +0530 Subject: [PATCH] powerpc32/bpf: Fix codegen for bpf-to-bpf calls 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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/52d8fe51f7620a6f27f377791564d79d75463576.1641468127.git.naveen.n.rao@linux.vnet.ibm.com --- arch/powerpc/net/bpf_jit_comp32.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index faaebd4..c20b49b 100644 --- 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 *image, struct codegen_context *ctx, u64 fun 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))); -- 2.7.4