Fix vDSO synthetic hwcap handling so they are not masked out from ld.so.cache matching.

(cherry picked from commit 5dbc3b6cc0b759bf4b22d851ccb9cbf3e3cbc6ef)

diff --git a/ChangeLog b/ChangeLog
index 3de08e9b8e26ce90038865a0c062252334984c24..867aae45563a1285c4f69e0ef623ab756aff4633 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-07-20  Roland McGrath  <roland@redhat.com>
+
+       * elf/dl-sysdep.c (_dl_important_hwcaps): Add dsocaps mask to
+       dl_hwcap_mask as well as dl_hwcap.  Without this, dsocaps matching in
+       ld.so.cache was broken.  With it, there is no way to disable dsocaps
+       like LD_HWCAP_MASK can disable hwcaps.
+
 2010-07-05  Roland McGrath  <roland@redhat.com>
 
        * manual/arith.texi (Rounding Functions): Fix rint description

diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c
index 5700272f10c24ec8c8d849df50a80910b3ba624b..0f4970a78640ac74cf0030202fa70c2543c550c3 100644 (file)
--- a/elf/dl-sysdep.c
+++ b/elf/dl-sysdep.c
@@ -424,6 +424,11 @@ _dl_important_hwcaps (const char *platform, size_t platform_len, size_t *sz,
     {
       const ElfW(Word) mask = ((const ElfW(Word) *) dsocaps)[-1];
       GLRO(dl_hwcap) |= (uint64_t) mask << _DL_FIRST_EXTRA;
+      /* Note that we add the dsocaps to the set already chosen by the
+        LD_HWCAP_MASK environment variable (or default HWCAP_IMPORTANT).
+        So there is no way to request ignoring an OS-supplied dsocap
+        string and bit like you can ignore an OS-supplied HWCAP bit.  */
+      GLRO(dl_hwcap_mask) |= (uint64_t) mask << _DL_FIRST_EXTRA;
       size_t len;
       for (const char *p = dsocaps; p < dsocaps + dsocapslen; p += len + 1)
        {