libbpf: Fix build on ppc64le architecture

On ppc64le we get the following warning:

  In file included from btf_dump.c:16:0:
  btf_dump.c: In function ‘btf_dump_emit_struct_def’:
  ../include/linux/kernel.h:20:17: error: comparison of distinct pointer types lacks a cast [-Werror]
    (void) (&_max1 == &_max2);  \
                   ^
  btf_dump.c:882:11: note: in expansion of macro ‘max’
      m_sz = max(0LL, btf__resolve_size(d->btf, m->type));
             ^~~

Fix by explicitly casting to __s64, which is a return type from
btf__resolve_size().

Fixes: 702eddc77a90 ("libbpf: Handle GCC built-in types for Arm NEON")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200818164456.1181661-1-andriin@fb.com

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index fe39bd7..57c00fa 100644 (file)
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -879,7 +879,7 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
                        btf_dump_printf(d, ": %d", m_sz);
                        off = m_off + m_sz;
                } else {
-                       m_sz = max(0LL, btf__resolve_size(d->btf, m->type));
+                       m_sz = max((__s64)0, btf__resolve_size(d->btf, m->type));
                        off = m_off + m_sz * 8;
                }
                btf_dump_printf(d, ";");