From: Abhishek Dubey <[email protected]>
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 <[email protected]>
---
arch/powerpc/net/bpf_jit_comp.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 9ec5ab9b020e..620667c3400b 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -373,6 +373,16 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
goto out_addrs;
}
bpf_prog_fill_jited_linfo(fp, addrs);
+ /*
+ * On ABI V1, executable code starts after the function
+ * descriptor, so adjust base accordingly.
+ */
+#ifdef CONFIG_PPC64_ELF_ABI_V1
+ bpf_prog_update_insn_ptrs(fp, addrs,
+ (void *)fimage + FUNCTION_DESCR_SIZE);
+#else
+ bpf_prog_update_insn_ptrs(fp, addrs, fimage);
+#endif
out_addrs:
if (!image && priv_stack_ptr) {
fp->aux->priv_stack_ptr = NULL;
--
2.52.0
