[PATCH 1/4] powerpc64/bpf: Add support for instruction array

[adubey at linux.ibm.com]

From: Abhishek Dubey <adubey at linux.ibm.com>

On loading the BPF program, the verifier might adjust/omit some
instructions. The adjusted instruction offset is accounted in the
map containing original instruction -> xlated mapping. This patch
add ppc64 JIT support to additionally build the xlated->jitted
mapping for every instruction present in instruction array. This
change is needed to enable support for indirect jumps, added in a
subsequent patch.

Invoke bpf_prog_update_insn_ptrs() with offset pair of xlated_offset
and jited_offset. The offset mapping is already available, which is
being used for bpf_prog_fill_jited_linfo() and can be directly used
for bpf_prog_update_insn_ptrs() as well.

Additional details present at:

commit b4ce5923e780 ("bpf, x86: add new map type: instructions array")

Signed-off-by: Abhishek Dubey <adubey at linux.ibm.com>
---
 arch/powerpc/net/bpf_jit_comp.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index ebd21c75ce47..04f51f2c817c 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -379,6 +379,12 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 		jit_data->hdr = hdr;
 	}
 
+	/*
+	 * The bpf_prog_update_insn_ptrs function expects addrs to
+	 * point to the first byte of the jitted instruction.
+	 */
+	bpf_prog_update_insn_ptrs(fp, addrs, fimage);
+
 out:
 	if (bpf_blinded)
 		bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp);
-- 
2.52.0