perf symbol-elf: Add support for the block argument for libbfd

James Clark caught that the BUILD_NONDISTRO=1 build with libbfd was
broken due to an update to the read_build_id function adding a
blocking argument. Add support for this argument by first opening the
file blocking or non-blocking, then switching from bfd_openr to
bfd_fdopenr and passing the opened fd. bfd_fdopenr closes the fd on
error and when bfd_close are called.

Reported-by: James Clark <[e-mail]>
Closes: https://lore.kernel.org/lkml/[e-mail]/
Fixes: 2c369d91d093 ("perf symbol: Add blocking argument to filename__read_build_id")
Signed-off-by: Ian Rogers <[e-mail]>
Reviewed-by: James Clark <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/util/symbol-elf.c

···
 
 #ifdef HAVE_LIBBFD_BUILDID_SUPPORT
 
-static int read_build_id(const char *filename, struct build_id *bid)
+static int read_build_id(const char *filename, struct build_id *bid, bool block)
 {
 	size_t size = sizeof(bid->data);
-	int err = -1;
+	int err = -1, fd;
 	bfd *abfd;
 
-	abfd = bfd_openr(filename, NULL);
+	fd = open(filename, block ? O_RDONLY : (O_RDONLY | O_NONBLOCK));
+	if (fd < 0)
+		return -1;
+
+	abfd = bfd_fdopenr(filename, /*target=*/NULL, fd);
 	if (!abfd)
 		return -1;