1 files changed, 77 insertions, 0 deletions
diff --git a/elf/dl-hwcaps_split.c b/elf/dl-hwcaps_split.c
new file mode 100644
index 0000000000..95225e9f40
--- /dev/null
+++ b/elf/dl-hwcaps_split.c
@@ -0,0 +1,77 @@
+/* Hardware capability support for run-time dynamic loader.  String splitting.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <dl-hwcaps.h>
+#include <stdbool.h>
+#include <string.h>
+
+_Bool
+_dl_hwcaps_split (struct dl_hwcaps_split *s)
+{
+  if (s->segment == NULL)
+    return false;
+
+  /* Skip over the previous segment.   */
+  s->segment += s->length;
+
+  /* Consume delimiters.  This also avoids returning an empty
+     segment.  */
+  while (*s->segment == ':')
+    ++s->segment;
+  if (*s->segment == '\0')
+    return false;
+
+  /* This could use strchrnul, but we would have to link the function
+     into ld.so for that.  */
+  const char *colon = strchr (s->segment, ':');
+  if (colon == NULL)
+    s->length = strlen (s->segment);
+  else
+    s->length = colon - s->segment;
+  return true;
+}
+
+_Bool
+_dl_hwcaps_split_masked (struct dl_hwcaps_split_masked *s)
+{
+  while (true)
+    {
+      if (!_dl_hwcaps_split (&s->split))
+        return false;
+      bool active = s->bitmask & 1;
+      s->bitmask >>= 1;
+      if (active && _dl_hwcaps_contains (s->mask,
+                                         s->split.segment, s->split.length))
+        return true;
+    }
+}
+
+_Bool
+_dl_hwcaps_contains (const char *hwcaps, const char *name, size_t name_length)
+{
+  if (hwcaps == NULL)
+    return true;
+
+  struct dl_hwcaps_split split;
+  _dl_hwcaps_split_init (&split, hwcaps);
+  while (_dl_hwcaps_split (&split))
+    if (split.length == name_length
+        && memcmp (split.segment, name, name_length) == 0)
+      return true;
+  return false;
+}