| Message ID | 5654DA50.5060002@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 24-11-2015 19:44, Florian Weimer wrote: > Since GCC 4.0, GCC will put zero-initialized variables into .bss. > This makes the macro suitable for automatic variables, too. > > On x86_64-redhat-linux-gnu, all DSOs except libc.so.6 are unchanged. > The differences for libc.so.6 are harmless, the symbols still end up in > .bss: > > <https://gcc.gnu.org/ml/gcc-help/2015-11/msg00211.html> > > I think this change is still worthwhile because it removes a nasty > source of errors, a macro with “initialized” in the name which does not > actually initialize anything. > > Florian > LGTM. Since you touching this, I think it is worthwhile to cleanup the LLL_LOCK_INITIALIZER{_LOCKED,_WAITERS} definition (i386, sparc, and x86_64 redefines it to same value).
On 25-11-2015 17:24, Florian Weimer wrote: > On 11/25/2015 07:43 PM, Adhemerval Zanella wrote: > >> LGTM. Since you touching this, I think it is worthwhile to cleanup the >> LLL_LOCK_INITIALIZER{_LOCKED,_WAITERS} definition (i386, sparc, and >> x86_64 redefines it to same value). > > Do you suggest to remove the architecture-specific #defines? Yes, since right now they are equal to default one at sysdeps/nptl/lowlevellock.h, and I see not reason to have different definition for each architecture. > > Thanks, > Florian >
2015-11-24 Florian Weimer <fweimer@redhat.com> * sysdeps/nptl/libc-lockP.h (__libc_lock_define_initialized): Always initialize the lock. diff --git a/sysdeps/nptl/libc-lockP.h b/sysdeps/nptl/libc-lockP.h index 3881b45..2a4809f 100644 --- a/sysdeps/nptl/libc-lockP.h +++ b/sysdeps/nptl/libc-lockP.h @@ -66,27 +66,15 @@ typedef pthread_key_t __libc_key_t; #define __rtld_lock_define_recursive(CLASS,NAME) \ CLASS __rtld_lock_recursive_t NAME; -/* Define an initialized lock variable NAME with storage class CLASS. - - For the C library we take a deeper look at the initializer. For - this implementation all fields are initialized to zero. Therefore - we don't initialize the variable which allows putting it into the - BSS section. (Except on PA-RISC and other odd architectures, where - initialized locks must be set to one due to the lack of normal - atomic operations.) */ +/* Define an initialized lock variable NAME with storage class CLASS. */ #define _LIBC_LOCK_INITIALIZER LLL_LOCK_INITIALIZER #if IS_IN (libc) || IS_IN (libpthread) -# if LLL_LOCK_INITIALIZER == 0 -# define __libc_lock_define_initialized(CLASS,NAME) \ - CLASS __libc_lock_t NAME; -# else -# define __libc_lock_define_initialized(CLASS,NAME) \ +# define __libc_lock_define_initialized(CLASS,NAME) \ CLASS __libc_lock_t NAME = LLL_LOCK_INITIALIZER; -# endif #else # define __libc_lock_define_initialized(CLASS,NAME) \ - CLASS __libc_lock_t NAME; + CLASS __libc_lock_t NAME = PTHREAD_MUTEX_INITIALIZER; #endif #define __libc_rwlock_define_initialized(CLASS,NAME) \