Hi!
libtsan only handles the standard memory model values, so I've added
just in case some new unknown memory model is used bail outs (keeping
the __atomic_* builtins instead of transforming them to __tsan_atomic*).
Except that at -O0 (or if unlucky enough otherwise) if the memory model
is variable, that means we never use __tsan_atomic*, which means libtsan
reports false positive races. We could do those checks at runtime by
performing if ((last_arg & 0x7fff) >= 6) __atomic_* else __tsan_atomic_*,
but as there are no such values yet I think it isn't worth it (the
sync/hle acq/hle rel bits which are ored are 0x8000, 0x10000 and 0x20000
and memmodel_base strips them off).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2017-03-20 Jakub Jelinek <ja...@redhat.com>
PR sanitizer/78158
* tsan.c (instrument_builtin_call): If the memory model argument
is not a constant, assume it is valid.
--- gcc/tsan.c.jj 2017-01-01 12:45:38.000000000 +0100
+++ gcc/tsan.c 2017-03-20 17:55:25.509294018 +0100
@@ -499,8 +499,8 @@ instrument_builtin_call (gimple_stmt_ite
case check_last:
case fetch_op:
last_arg = gimple_call_arg (stmt, num - 1);
- if (!tree_fits_uhwi_p (last_arg)
- || memmodel_base (tree_to_uhwi (last_arg)) >= MEMMODEL_LAST)
+ if (tree_fits_uhwi_p (last_arg)
+ && memmodel_base (tree_to_uhwi (last_arg)) >= MEMMODEL_LAST)
return;
gimple_call_set_fndecl (stmt, decl);
update_stmt (stmt);
@@ -564,11 +564,11 @@ instrument_builtin_call (gimple_stmt_ite
gcc_assert (num == 6);
for (j = 0; j < 6; j++)
args[j] = gimple_call_arg (stmt, j);
- if (!tree_fits_uhwi_p (args[4])
- || memmodel_base (tree_to_uhwi (args[4])) >= MEMMODEL_LAST)
+ if (tree_fits_uhwi_p (args[4])
+ && memmodel_base (tree_to_uhwi (args[4])) >= MEMMODEL_LAST)
return;
- if (!tree_fits_uhwi_p (args[5])
- || memmodel_base (tree_to_uhwi (args[5])) >= MEMMODEL_LAST)
+ if (tree_fits_uhwi_p (args[5])
+ && memmodel_base (tree_to_uhwi (args[5])) >= MEMMODEL_LAST)
return;
update_gimple_call (gsi, decl, 5, args[0], args[1], args[2],
args[4], args[5]);
@@ -642,8 +642,8 @@ instrument_builtin_call (gimple_stmt_ite
return;
}
last_arg = gimple_call_arg (stmt, num - 1);
- if (!tree_fits_uhwi_p (last_arg)
- || memmodel_base (tree_to_uhwi (last_arg)) >= MEMMODEL_LAST)
+ if (tree_fits_uhwi_p (last_arg)
+ && memmodel_base (tree_to_uhwi (last_arg)) >= MEMMODEL_LAST)
return;
t = TYPE_ARG_TYPES (TREE_TYPE (decl));
t = TREE_VALUE (TREE_CHAIN (t));
Jakub
