[glibc/azanella/clang] elf: Fix _startup_fatal on clang

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=bd03225ffbbeab70a08d594cfb8d480d0771756f

commit bd03225ffbbeab70a08d594cfb8d480d0771756f
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Tue May 10 15:34:42 2022 -0300

    elf: Fix _startup_fatal on clang
    
    clang can not see that the input string is a constant one, so
    __builtin_constant_p fails and a strlen might be issue.  Instead
    change TLS_INIT_TP to return the string size.
    
    Fixed only for x86_64 and aarch64.

Diff:
---
 csu/libc-tls.c                    |  8 +++++---
 elf/rtld.c                        |  6 ++++--
 sysdeps/aarch64/nptl/tls.h        |  4 ++--
 sysdeps/unix/sysv/linux/startup.h | 10 ++--------
 sysdeps/x86_64/nptl/tls.h         |  6 ++++--
 5 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/csu/libc-tls.c b/csu/libc-tls.c
index bef92a7568..915b016bf5 100644
--- a/csu/libc-tls.c
+++ b/csu/libc-tls.c
@@ -183,18 +183,20 @@ __libc_setup_tls (void)
   /* Install the pointer to the dtv.  */
 
   /* Initialize the thread pointer.  */
+  size_t lossagelen;
 #if TLS_TCB_AT_TP
   INSTALL_DTV ((char *) tlsblock + tcb_offset, _dl_static_dtv);
 
-  const char *lossage = TLS_INIT_TP ((char *) tlsblock + tcb_offset);
+  const char *lossage = TLS_INIT_TP ((char *) tlsblock + tcb_offset,
+				     lossagelen);
 #elif TLS_DTV_AT_TP
   INSTALL_DTV (tlsblock, _dl_static_dtv);
-  const char *lossage = TLS_INIT_TP (tlsblock);
+  const char *lossage = TLS_INIT_TP (tlsblock, lossagelen);
 #else
 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
 #endif
   if (__builtin_expect (lossage != NULL, 0))
-    _startup_fatal (lossage);
+    _startup_fatal (lossage, lossagelen);
   __tls_init_tp ();
 
   /* Update the executable's link map with enough information to make
diff --git a/elf/rtld.c b/elf/rtld.c
index 3d53107504..a549afc233 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -809,7 +809,8 @@ cannot allocate TLS data structures for initial thread\n");
   GL(dl_initial_dtv) = GET_DTV (tcbp);
 
   /* And finally install it for the main thread.  */
-  const char *lossage = TLS_INIT_TP (tcbp);
+  size_t lossagelen __attribute_maybe_unused__;
+  const char *lossage = TLS_INIT_TP (tcbp, lossagelen);
   if (__glibc_unlikely (lossage != NULL))
     _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
   __tls_init_tp ();
@@ -2317,7 +2318,8 @@ dl_main (const ElfW(Phdr) *phdr,
   /* And finally install it for the main thread.  */
   if (! tls_init_tp_called)
     {
-      const char *lossage = TLS_INIT_TP (tcbp);
+      size_t lossagelen __attribute_maybe_unused__;
+      const char *lossage = TLS_INIT_TP (tcbp, lossagelen);
       if (__glibc_unlikely (lossage != NULL))
 	_dl_fatal_printf ("cannot set up thread-local storage: %s\n",
 			  lossage);
diff --git a/sysdeps/aarch64/nptl/tls.h b/sysdeps/aarch64/nptl/tls.h
index 8d62b31e23..2f8cf50b89 100644
--- a/sysdeps/aarch64/nptl/tls.h
+++ b/sysdeps/aarch64/nptl/tls.h
@@ -71,8 +71,8 @@ typedef struct
 /* Code to initially initialize the thread pointer.  This might need
    special attention since 'errno' is not yet available and if the
    operation can cause a failure 'errno' must not be touched.  */
-# define TLS_INIT_TP(tcbp) \
-  ({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); NULL; })
+# define TLS_INIT_TP(tcbp, l) \
+  ({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); l = 0, NULL; })
 
 /* Value passed to 'clone' for initialization of the thread register.  */
 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
diff --git a/sysdeps/unix/sysv/linux/startup.h b/sysdeps/unix/sysv/linux/startup.h
index 39859b404a..6f9931106a 100644
--- a/sysdeps/unix/sysv/linux/startup.h
+++ b/sysdeps/unix/sysv/linux/startup.h
@@ -22,17 +22,11 @@
 # include <sysdep.h>
 
 /* Avoid a run-time invocation of strlen.  */
-#define _startup_fatal(message)                                         \
+#define _startup_fatal(message, message_length)                         \
   do                                                                    \
     {                                                                   \
-      size_t __message_length = __builtin_strlen (message);             \
-      if (! __builtin_constant_p (__message_length))                    \
-        {                                                               \
-          extern void _startup_fatal_not_constant (void);               \
-          _startup_fatal_not_constant ();                               \
-        }                                                               \
       INTERNAL_SYSCALL_CALL (write, STDERR_FILENO, (message),           \
-                             __message_length);                         \
+                             (message_length));                         \
       INTERNAL_SYSCALL_CALL (exit_group, 127);                          \
     }                                                                   \
   while (0)
diff --git a/sysdeps/x86_64/nptl/tls.h b/sysdeps/x86_64/nptl/tls.h
index 75f8020975..57f85e78ba 100644
--- a/sysdeps/x86_64/nptl/tls.h
+++ b/sysdeps/x86_64/nptl/tls.h
@@ -132,6 +132,8 @@ _Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x80,
 # define GET_DTV(descr) \
   (((tcbhead_t *) (descr))->dtv)
 
+# define TLS_INIT_TP_ERR_MSG \
+  "cannot set %fs base address for thread-local storage"
 
 /* Code to initially initialize the thread pointer.  This might need
    special attention since 'errno' is not yet available and if the
@@ -139,7 +141,7 @@ _Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x80,
 
    We have to make the syscall for both uses of the macro since the
    address might be (and probably is) different.  */
-# define TLS_INIT_TP(thrdescr) \
+# define TLS_INIT_TP(thrdescr, l) \
   ({ void *_thrdescr = (thrdescr);					      \
      tcbhead_t *_head = _thrdescr;					      \
      int _result;							      \
@@ -156,7 +158,7 @@ _Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x80,
 		     "S" (_thrdescr)					      \
 		   : "memory", "cc", "r11", "cx");			      \
 									      \
-    _result ? "cannot set %fs base address for thread-local storage" : 0;     \
+    _result ? l = sizeof (TLS_INIT_TP_ERR_MSG) - 1, TLS_INIT_TP_ERR_MSG : 0;  \
   })
 
 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)