| Message ID | 20170320212224.GP11094@tucnak |
|---|---|
| State | New |
| Headers | show |
On Mon, 20 Mar 2017, Jakub Jelinek wrote: > 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? Ok. Richard. > 2017-03-20 Jakub Jelinek <jakub@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 > >
--- 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));