sparc: Fix arch_fork definition

This patch fixes 3dc214977 for sparc.  Different than other architectures
SPARC kernel Kconfig does not define CONFIG_CLONE_BACKWARDS, however it
has the same ABI as if it did, implemented by sparc-specific code
(sparc_do_fork).

It also has a unique return value convention for clone:

   Parent -->  %o0 == child's  pid, %o1 == 0
   Child  -->  %o0 == parent's pid, %o1 == 1

Which required a special macro to correct issue the syscall
(INLINE_CLONE_SYSCALL).

Checked on sparc64-linux-gnu and sparcv9-linux-gnu.

	* sysdeps/unix/sysv/linux/arch-fork.h [__ASSUME_CLONE_BACKWARDS]
	(arch_fork): Issue INLINE_CLONE_SYSCALL if defined.
	* sysdeps/unix/sysv/linux/sparc/kernel-features.h
	(__ASSUME_CLONE_BACKWARDS): Define.
This commit is contained in:
Adhemerval Zanella 2018-03-27 21:23:52 -03:00
parent cc8a1620eb
commit d39c0a459e
3 changed files with 25 additions and 0 deletions

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@ -1,3 +1,10 @@
2018-03-27 Adhemerval Zanella <adhemerval.zanella@linaro.org>
* sysdeps/unix/sysv/linux/arch-fork.h [__ASSUME_CLONE_BACKWARDS]
(arch_fork): Issue INLINE_CLONE_SYSCALL if defined.
* sysdeps/unix/sysv/linux/sparc/kernel-features.h
(__ASSUME_CLONE_BACKWARDS): Define.
2018-03-27 Jesse Hathaway <jesse@mbuki-mvuki.org>
* sysdeps/unix/sysv/linux/getlogin_r.c (__getlogin_r_loginuid): Return

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@ -34,7 +34,11 @@ arch_fork (void *ctid)
const int flags = CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD;
long int ret;
#ifdef __ASSUME_CLONE_BACKWARDS
# ifdef INLINE_CLONE_SYSCALL
ret = INLINE_CLONE_SYSCALL (flags, 0, NULL, 0, ctid);
# else
ret = INLINE_SYSCALL_CALL (clone, flags, 0, NULL, 0, ctid);
# endif
#elif defined(__ASSUME_CLONE_BACKWARDS2)
ret = INLINE_SYSCALL_CALL (clone, 0, flags, NULL, ctid, 0);
#elif defined(__ASSUME_CLONE_BACKWARDS3)

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@ -40,3 +40,17 @@
/* sparc only supports ipc syscall. */
#undef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
/* SPARC kernel Kconfig does not define CONFIG_CLONE_BACKWARDS, however it
has the same ABI as if it did, implemented by sparc-specific code
(sparc_do_fork).
It also has a unique return value convention:
Parent --> %o0 == child's pid, %o1 == 0
Child --> %o0 == parent's pid, %o1 == 1
Which required a special macro to correct issue the syscall
(INLINE_CLONE_SYSCALL). */
#undef __ASSUME_CLONE_DEFAULT
#define __ASSUME_CLONE_BACKWARDS 1