Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2019-11-02

The following pull-request contains BPF updates for your *net* tree.

We've added 6 non-merge commits during the last 6 day(s) which contain
a total of 8 files changed, 35 insertions(+), 9 deletions(-).

The main changes are:

1) Fix ppc BPF JIT's tail call implementation by performing a second pass
   to gather a stable JIT context before opcode emission, from Eric Dumazet.

2) Fix build of BPF samples sys_perf_event_open() usage to compiled out
   unavailable test_attr__{enabled,open} checks. Also fix potential overflows
   in bpf_map_{area_alloc,charge_init} on 32 bit archs, from Björn Töpel.

3) Fix narrow loads of bpf_sysctl context fields with offset > 0 on big endian
   archs like s390x and also improve the test coverage, from Ilya Leoshkevich.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 0 deletions

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 02a59946a78a..be3517ef0574 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -1142,6 +1142,19 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	}
 
 	/*
+	 * If we have seen a tail call, we need a second pass.
+	 * This is because bpf_jit_emit_common_epilogue() is called
+	 * from bpf_jit_emit_tail_call() with a not yet stable ctx->seen.
+	 */
+	if (cgctx.seen & SEEN_TAILCALL) {
+		cgctx.idx = 0;
+		if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) {
+			fp = org_fp;
+			goto out_addrs;
+		}
+	}
+
+	/*
 	 * Pretend to build prologue, given the features we've seen.  This will
 	 * update ctgtx.idx as it pretends to output instructions, then we can
 	 * calculate total size from idx.