Message ID | 71808d9fc272aa3cfb78c905dd5aedd39bb903f6.1651762968.git.fweimer@redhat.com |
---|---|
State | New |
Headers | show |
Series | [v4,1/3] ia64: Always define IA64_USE_NEW_STUB as a flag macro | expand |
On Mai 05 2022, Florian Weimer via Libc-alpha wrote: > +/* 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 (); \ > + } \ I think that could use _Static_assert.
* Andreas Schwab: > On Mai 05 2022, Florian Weimer via Libc-alpha wrote: > >> +/* 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 (); \ >> + } \ > > I think that could use _Static_assert. It only works for simple cases, not for arguments that require constant progagation: libc-tls.c: In function ‘__libc_setup_tls’: ../sysdeps/unix/sysv/linux/startup.h:29:23: error: expression in static assertion is not constant 29 | _Static_assert (__builtin_constant_p (__message_length), \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Thanks, Florian
On 05/05/2022 12:07, Florian Weimer via Libc-alpha wrote: > On i386 and ia64, the TCB is not available at this point. LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > v4: Unchanged. > 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 > > 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 */
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 */