glibc/include/errno.h
Florian Weimer 7d6e30b4b4 stdlib: Do not use GLIBC_PRIVATE ABI for errno in libc_nonshared.a
Using TLS directly introduces a GLIBC_PRIVATE ABI dependency
into libc_nonshared.a, and thus indirectly into applications.
Adding the !defined LIBC_NONSHARED condition deactivates direct
TLS access, and libc_nonshared.a code switches to using
__errno_location, like application code.

Currently, this has no effect because there is no code in
libc_nonshared.a that accesses errno.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-06 14:07:00 +02:00

46 lines
1.1 KiB
C

#ifndef _ERRNO_H
#include <stdlib/errno.h>
#if !defined _ISOMAC && !defined __ASSEMBLER__
# if IS_IN (rtld)
# include <dl-sysdep.h>
# ifndef RTLD_PRIVATE_ERRNO
# error "dl-sysdep.h must define RTLD_PRIVATE_ERRNO!"
# endif
# else
# define RTLD_PRIVATE_ERRNO 0
# endif
# if RTLD_PRIVATE_ERRNO
/* The dynamic linker uses its own private errno variable.
All access to errno inside the dynamic linker is serialized,
so a single (hidden) global variable is all it needs. */
# undef errno
# define errno rtld_errno
extern int rtld_errno attribute_hidden;
# elif IS_IN_LIB && !IS_IN (rtld) && !defined LIBC_NONSHARED
# undef errno
# if IS_IN (libc)
# define errno __libc_errno
# else
# define errno errno /* For #ifndef errno tests. */
# endif
extern __thread int errno attribute_tls_model_ie;
# endif /* IS_IN_LIB */
# define __set_errno(val) (errno = (val))
extern int *__errno_location (void) __THROW __attribute_const__
# if RTLD_PRIVATE_ERRNO
attribute_hidden
# endif
;
libc_hidden_proto (__errno_location)
#endif /* !_ISOMAC && !__ASSEMBLER__ */
#endif /* !_ERRNO_H */