Commit fab07611 authored by Naveen N. Rao's avatar Naveen N. Rao Committed by Michael Ellerman
Browse files

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: 51c66ad8 ("powerpc/bpf: Implement extended BPF on PPC32")
Cc: stable@vger.kernel.org # v5.13+
Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/52d8fe51f7620a6f27f377791564d79d75463576.1641468127.git.naveen.n.rao@linux.vnet.ibm.com
parent b992f01e

arch/powerpc/net/bpf_jit_comp32.c

+3 −0
Original line number Diff line number Diff line
@@ -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)));