elf: Use C11 atomics on _dl_mcount

All atomic operation are counters, so relaxed MO should be suffice.

Checked on x86_64-linux-gnu.
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>

diff --git a/elf/dl-profile.c b/elf/dl-profile.c
index ec57e3a96552ae6460c22a0fcc819b85d486c0da..96ba6067240f2a2fec905442647b04272db523df 100644 (file)
--- a/elf/dl-profile.c
+++ b/elf/dl-profile.c
@@ -548,7 +548,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
              size_t newfromidx;
              to_index = (data[narcs].self_pc
                          / (HASHFRACTION * sizeof (*tos)));
-             newfromidx = catomic_exchange_and_add (&fromidx, 1) + 1;
+             newfromidx = atomic_fetch_add_relaxed (&fromidx, 1) + 1;
              froms[newfromidx].here = &data[narcs];
              froms[newfromidx].link = tos[to_index];
              tos[to_index] = newfromidx;
@@ -558,14 +558,14 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
          /* If we still have no entry stop searching and insert.  */
          if (*topcindex == 0)
            {
-             unsigned int newarc = catomic_exchange_and_add (narcsp, 1);
+             unsigned int newarc = atomic_fetch_add_relaxed (narcsp, 1);
 
              /* In rare cases it could happen that all entries in FROMS are
                 occupied.  So we cannot count this anymore.  */
              if (newarc >= fromlimit)
                goto done;
 
-             *topcindex = catomic_exchange_and_add (&fromidx, 1) + 1;
+             *topcindex = atomic_fetch_add_relaxed (&fromidx, 1) + 1;
              fromp = &froms[*topcindex];
 
              fromp->here = &data[newarc];
@@ -573,7 +573,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
              data[newarc].self_pc = selfpc;
              data[newarc].count = 0;
              fromp->link = 0;
-             catomic_increment (&narcs);
+             atomic_fetch_add_relaxed (&narcs, 1);
 
              break;
            }
@@ -586,7 +586,7 @@ _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc)
     }
 
   /* Increment the counter.  */
-  catomic_increment (&fromp->here->count);
+  atomic_fetch_add_relaxed (&fromp->here->count, 1);
 
  done:
   ;