m68k: Wire up clone3() syscall

Wire up the clone3() syscall for m68k. The special entry point is done in
assembler as was done for clone() as well. This is needed because all
registers need to be saved. The C wrapper then calls the generic
sys_clone3() with the correct arguments.

Tested on A1200 using the simple test program from:

  https://lore.kernel.org/lkml/20190716130631.tohj4ub54md25dys@brauner.io/

Signed-off-by: Kars de Jong <jongk@linux-m68k.org>
Link: https://lore.kernel.org/r/20191124195225.31230-1-jongk@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
This commit is contained in:
Kars de Jong 2019-11-24 20:52:25 +01:00 committed by Geert Uytterhoeven
parent 46cf053efe
commit e8bb2a2a1d
4 changed files with 21 additions and 2 deletions

View File

@ -30,5 +30,6 @@
#define __ARCH_WANT_SYS_SIGPROCMASK
#define __ARCH_WANT_SYS_FORK
#define __ARCH_WANT_SYS_VFORK
#define __ARCH_WANT_SYS_CLONE3
#endif /* _ASM_M68K_UNISTD_H_ */

View File

@ -69,6 +69,13 @@ ENTRY(__sys_vfork)
lea %sp@(24),%sp
rts
ENTRY(__sys_clone3)
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jbsr m68k_clone3
lea %sp@(28),%sp
rts
ENTRY(sys_sigreturn)
SAVE_SWITCH_STACK
movel %sp,%sp@- | switch_stack pointer

View File

@ -30,8 +30,9 @@
#include <linux/init_task.h>
#include <linux/mqueue.h>
#include <linux/rcupdate.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/traps.h>
#include <asm/machdep.h>
#include <asm/setup.h>
@ -119,6 +120,16 @@ asmlinkage int m68k_clone(struct pt_regs *regs)
(int __user *)regs->d3, (int __user *)regs->d4);
}
/*
* Because extra registers are saved on the stack after the sys_clone3()
* arguments, this C wrapper extracts them from pt_regs * and then calls the
* generic sys_clone3() implementation.
*/
asmlinkage int m68k_clone3(struct pt_regs *regs)
{
return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{

View File

@ -434,4 +434,4 @@
432 common fsmount sys_fsmount
433 common fspick sys_fspick
434 common pidfd_open sys_pidfd_open
# 435 reserved for clone3
435 common clone3 __sys_clone3