[v3,2/3] Linux: Implement a useful version of _startup_fatal

Message ID 71808d9fc272aa3cfb78c905dd5aedd39bb903f6.1651752744.git.fweimer@redhat.com
State Committed
Commit a2a6bce7d7e52c1c34369a7da62c501cc350bc31
Headers
Series [v3,1/3] ia64: Always define IA64_USE_NEW_STUB as a flag macro |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Florian Weimer May 5, 2022, 12:14 p.m. UTC
  On i386 and ia64, the TCB is not available at this point.
---
v3: Use 2022 copyright year.  Fix “statup” typo.  Use __message_length
    local variable in _startup_fatal.
 sysdeps/unix/sysv/linux/i386/startup.h | 23 +++------------
 sysdeps/unix/sysv/linux/ia64/startup.h | 22 +++++++++++++++
 sysdeps/unix/sysv/linux/startup.h      | 39 ++++++++++++++++++++++++++
 3 files changed, 65 insertions(+), 19 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/ia64/startup.h
 create mode 100644 sysdeps/unix/sysv/linux/startup.h
  

Patch

diff --git a/sysdeps/unix/sysv/linux/i386/startup.h b/sysdeps/unix/sysv/linux/i386/startup.h
index 67c9310f3a..213805d7d2 100644
--- a/sysdeps/unix/sysv/linux/i386/startup.h
+++ b/sysdeps/unix/sysv/linux/i386/startup.h
@@ -1,5 +1,5 @@ 
 /* Linux/i386 definitions of functions used by static libc main startup.
-   Copyright (C) 2017-2022 Free Software Foundation, Inc.
+   Copyright (C) 2022 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -16,22 +16,7 @@ 
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#if BUILD_PIE_DEFAULT
-/* Can't use "call *%gs:SYSINFO_OFFSET" during statup in static PIE.  */
-# define I386_USE_SYSENTER 0
+/* Can't use "call *%gs:SYSINFO_OFFSET" during startup.  */
+#define I386_USE_SYSENTER 0
 
-# include <sysdep.h>
-# include <abort-instr.h>
-
-__attribute__ ((__noreturn__))
-static inline void
-_startup_fatal (const char *message __attribute__ ((unused)))
-{
-  /* This is only called very early during startup in static PIE.
-     FIXME: How can it be improved?  */
-  ABORT_INSTRUCTION;
-  __builtin_unreachable ();
-}
-#else
-# include_next <startup.h>
-#endif
+#include_next <startup.h>
diff --git a/sysdeps/unix/sysv/linux/ia64/startup.h b/sysdeps/unix/sysv/linux/ia64/startup.h
new file mode 100644
index 0000000000..77f29f15a2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/ia64/startup.h
@@ -0,0 +1,22 @@ 
+/* Linux/ia64 definitions of functions used by static libc main startup.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* This code is used before the TCB is set up.  */
+#define IA64_USE_NEW_STUB 0
+
+#include_next <startup.h>
diff --git a/sysdeps/unix/sysv/linux/startup.h b/sysdeps/unix/sysv/linux/startup.h
new file mode 100644
index 0000000000..39859b404a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/startup.h
@@ -0,0 +1,39 @@ 
+/* Linux definitions of functions used by static libc main startup.
+   Copyright (C) 2017-2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifdef SHARED
+# include_next <startup.h>
+#else
+# include <sysdep.h>
+
+/* Avoid a run-time invocation of strlen.  */
+#define _startup_fatal(message)                                         \
+  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);                         \
+      INTERNAL_SYSCALL_CALL (exit_group, 127);                          \
+    }                                                                   \
+  while (0)
+#endif  /* !SHARED */