mirror of git://sourceware.org/git/glibc.git
eeddfa91cb
This patch add three new macros (SYSCALL_LL, SYSCALL_LL64, and
__ASSUME_WORDSIZE64_ILP32) to use along with off_t and off64_t argument
syscalls. The rationale for this change is:
1. Remove multiple implementations for the same syscall for different
architectures (for instance, pread have 6 different implementations).
2. Also remove the requirement to use syscall wrappers for cancellable
entrypoints.
The macro usage should be used along __ALIGNMENT_ARG to follow ABI constrains
for architecture where it applies. For instance, pread can be rewritten as:
return SYSCALL_CANCEL (pread, fd, buf, count,
__ALIGNMENT_ARG SYSCALL_LL (offset));
Another macro, SYSCALL_LL64, is provided for off64_t. The macro
__ASSUME_WORDSIZE64_ILP32 is used by the ABI to define is uses 64-bit register
even if ABI is ILP32 (for instance x32 and mips64-n32).
The changes itself are not currently used in any implementation, so no
code change is expected.
* sysdeps/unix/sysv/linux/generic/sysdep.h (__ALIGNMENT_ARG): Move
definition.
(__ALIGNMENT_COUNT): Likewise.
* sysdeps/unix/sysv/linux/sysdep.h (__ALIGNMENT_ARG): To here.
(__ALIGNMENT_COUNT): Likewise.
(SYSCALL_LL): New define.
(SYSCALL_LL64): Likewise.
* sysdeps/unix/sysv/linux/mips/kernel-features.h:
[_MIPS_SIM == _ABIO32] (__ASSUME_WORDSIZE64_ILP32): Define.
* sysdeps/unix/sysv/linux/x86_64/kernel-features.h:
[ILP32] (__ASUME_WORDSIZE64_ILP32): Likewise.
|
||
|---|---|---|
| .. | ||
| bits | ||
| wordsize-32 | ||
| Makefile | ||
| README | ||
| ____longjmp_chk.c | ||
| access.c | ||
| brk.c | ||
| chmod.c | ||
| chown.c | ||
| creat.c | ||
| dl-origin.c | ||
| dup2.c | ||
| epoll_create.c | ||
| epoll_wait.c | ||
| futimesat.c | ||
| getdents.c | ||
| getdents64.c | ||
| inotify_init.c | ||
| kernel_stat.h | ||
| lchown.c | ||
| link.c | ||
| lxstat.c | ||
| mkdir.c | ||
| open.c | ||
| open64.c | ||
| pause.c | ||
| pipe.c | ||
| poll.c | ||
| readlink.c | ||
| readlink_chk.c | ||
| recv.c | ||
| rename.c | ||
| rmdir.c | ||
| select.c | ||
| send.c | ||
| symlink.c | ||
| syscalls.list | ||
| sysctl.c | ||
| sysdep.h | ||
| umount.c | ||
| unlink.c | ||
| ustat.c | ||
| utimes.c | ||
| xmknod.c | ||
| xstat.c | ||
README
This hierarchy supports Linux systems using the new asm-generic/unistd.h, which removes many familiar old syscalls. For example, to implement open(), newer Linux architectures require glibc to invoke the __NR_openat syscall with AT_FDCWD. This hierarchy provides all those implementations. It also provides support for 32-bit platforms using the 64-bit kernel syscall APIs, as the 32-bit ones are no longer provided. Note that newer ILP32 environments (x32 or AArch64:ILP32, for example) are converting to use more 64-bit types in kernel syscalls, so that aspect of this support is in more flux as of this writing.