string: Use tls-internal on strerror_l

The buffer allocation uses the same strategy of strsignal.

Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
and s390x-linux-gnu.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>

include/string.h

@@ -53,9 +53,6 @@ extern char *__strerror_r (int __errnum, char *__buf, size_t __buflen);
 
 extern char *__strerror_l (int __errnum, locale_t __loc);
 
-/* Called as part of the thread shutdown sequence.  */
-void __strerror_thread_freeres (void) attribute_hidden;
-
 /* Get _STRING_ARCH_unaligned.  */
 #include <string_private.h>
 #endif

malloc/thread-freeres.c

@@ -32,7 +32,6 @@ __libc_thread_freeres (void)
 {
   call_function_static_weak (__rpc_thread_destroy);
   call_function_static_weak (__res_thread_freeres);
-  call_function_static_weak (__strerror_thread_freeres);
   __glibc_tls_internal_free ();
 
   /* This should come last because it shuts down malloc for this

string/strerror_l.c

@@ -18,11 +18,8 @@
 #include <libintl.h>
 #include <locale.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
-#include <errno.h>
+#include <tls-internal.h>
-
-static __thread char *last_value;
 
 
 static const char *
@@ -43,12 +40,13 @@ __strerror_l (int errnum, locale_t loc)
   char *err = (char *) __get_errlist (errnum);
   if (__glibc_unlikely (err == NULL))
     {
-      free (last_value);
+      struct tls_internal_t *tls_internal = __glibc_tls_internal ();
-      if (__asprintf (&last_value, "%s%d",
+      free (tls_internal->strerror_l_buf);
+      if (__asprintf (&tls_internal->strerror_l_buf, "%s%d",
 		      translate ("Unknown error ", loc), errnum) == -1)
-	last_value = NULL;
+	tls_internal->strerror_l_buf = NULL;
 
-      err = last_value;
+      err = tls_internal->strerror_l_buf;
     }
   else
     err = (char *) translate (err, loc);
@@ -58,10 +56,3 @@ __strerror_l (int errnum, locale_t loc)
 }
 weak_alias (__strerror_l, strerror_l)
 libc_hidden_def (__strerror_l)
-
-void
-__strerror_thread_freeres (void)
-{
-  free (last_value);
-}
-text_set_element (__libc_subfreeres, __strerror_thread_freeres);

sysdeps/generic/tls-internal-struct.h

@@ -22,6 +22,7 @@
 struct tls_internal_t
 {
   char *strsignal_buf;
+  char *strerror_l_buf;
 };
 
 #endif

sysdeps/generic/tls-internal.h

@@ -34,6 +34,7 @@ static inline void
 __glibc_tls_internal_free (void)
 {
   free (__tls_internal.strsignal_buf);
+  free (__tls_internal.strerror_l_buf);
 }
 
 #endif

sysdeps/mach/strerror_l.c

@@ -23,11 +23,7 @@
 #include <string.h>
 #include <mach/error.h>
 #include <errorlib.h>
-#include <sys/param.h>
+#include <tls-internal.h>
-#include <libc-symbols.h>
-
-
-static __thread char *last_value;
 
 
 static const char *
@@ -58,13 +54,14 @@ __strerror_l (int errnum, locale_t loc)
 
   if (system > err_max_system || ! __mach_error_systems[system].bad_sub)
     {
-      free (last_value);
+      struct tls_internal_t *tls_internal = __glibc_tls_internal ();
-      if (__asprintf (&last_value, "%s%X",
+      free (tls_internal->strerror_l_buf);
+      if (__asprintf (&tls_internal->strerror_l_buf, "%s%X",
 		      translate ("Error in unknown error system: ", loc),
 		      errnum) == -1)
-	last_value = NULL;
+	tls_internal->strerror_l_buf = NULL;
 
-      return last_value;
+      return tls_internal->strerror_l_buf;
     }
 
   es = &__mach_error_systems[system];
@@ -74,25 +71,18 @@ __strerror_l (int errnum, locale_t loc)
 
   if (code >= es->subsystem[sub].max_code)
     {
-      free (last_value);
+      struct tls_internal_t *tls_internal = __glibc_tls_internal ();
-      if (__asprintf (&last_value, "%s%s %d",
+      free (tls_internal->strerror_l_buf);
+      if (__asprintf (&tls_internal->strerror_l_buf, "%s%s %d",
 		      translate ("Unknown error ", loc),
 		      translate (es->subsystem[sub].subsys_name, loc),
 		      errnum) == -1)
-	last_value = NULL;
+	tls_internal->strerror_l_buf = NULL;
 
-      return last_value;
+      return tls_internal->strerror_l_buf;
     }
 
   return (char *) translate (es->subsystem[sub].codes[code], loc);
 }
 weak_alias (__strerror_l, strerror_l)
 libc_hidden_def (__strerror_l)
-
-/* This is called when a thread is exiting to free the last_value string.  */
-void
-__strerror_thread_freeres (void)
-{
-  free (last_value);
-}
-text_set_element (__libc_subfreeres, __strerror_thread_freeres);

sysdeps/unix/sysv/linux/tls-internal.h

@@ -32,6 +32,7 @@ static inline void
 __glibc_tls_internal_free (void)
 {
   free (THREAD_SELF->tls_state.strsignal_buf);
+  free (THREAD_SELF->tls_state.strerror_l_buf);
 }
 
 #endif