From 87f1ca8fd9f00cc024a141623d042ca4319e12c1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 21 Oct 2012 16:44:27 -0400 Subject: [PATCH] s390: switch to generic fork/vfork/clone Signed-off-by: Al Viro --- arch/s390/Kconfig | 1 + arch/s390/include/asm/unistd.h | 3 +++ arch/s390/kernel/process.c | 52 ++++++++---------------------------------- 3 files changed, 14 insertions(+), 42 deletions(-) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index a163784..3cbb875 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -141,6 +141,7 @@ config S390 select GENERIC_KERNEL_EXECVE select HAVE_MOD_ARCH_SPECIFIC select MODULES_USE_ELF_RELA + select CLONE_BACKWARDS2 config SCHED_OMIT_FRAME_POINTER def_bool y diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h index ccbcab7..086bb8e 100644 --- a/arch/s390/include/asm/unistd.h +++ b/arch/s390/include/asm/unistd.h @@ -54,6 +54,9 @@ # define __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND # endif #define __ARCH_WANT_SYS_EXECVE +#define __ARCH_WANT_SYS_FORK +#define __ARCH_WANT_SYS_VFORK +#define __ARCH_WANT_SYS_CLONE /* * "Conditional" syscalls diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index cd31ad4..e376777 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -118,7 +118,7 @@ void release_thread(struct task_struct *dead_task) int copy_thread(unsigned long clone_flags, unsigned long new_stackp, unsigned long arg, - struct task_struct *p, struct pt_regs *regs) + struct task_struct *p, struct pt_regs *unused) { struct thread_info *ti; struct fake_frame @@ -150,7 +150,7 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, frame->sf.gprs[9] = (unsigned long) frame; /* Store access registers to kernel stack of new process. */ - if (unlikely(!regs)) { + if (unlikely(p->flags & PF_KTHREAD)) { /* kernel thread */ memset(&frame->childregs, 0, sizeof(struct pt_regs)); frame->childregs.psw.mask = psw_kernel_bits | PSW_MASK_DAT | @@ -164,9 +164,10 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, return 0; } - frame->childregs = *regs; + frame->childregs = *current_pt_regs(); frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ - frame->childregs.gprs[15] = new_stackp; + if (new_stackp) + frame->childregs.gprs[15] = new_stackp; /* Don't copy runtime instrumentation info */ p->thread.ri_cb = NULL; @@ -183,57 +184,24 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, sizeof(s390_fp_regs)); /* Set a new TLS ? */ if (clone_flags & CLONE_SETTLS) - p->thread.acrs[0] = regs->gprs[6]; + p->thread.acrs[0] = frame->childregs.gprs[6]; #else /* CONFIG_64BIT */ /* Save the fpu registers to new thread structure. */ save_fp_regs(&p->thread.fp_regs); /* Set a new TLS ? */ if (clone_flags & CLONE_SETTLS) { + unsigned long tls = frame->childregs.gprs[6]; if (is_compat_task()) { - p->thread.acrs[0] = (unsigned int) regs->gprs[6]; + p->thread.acrs[0] = (unsigned int)tls; } else { - p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32); - p->thread.acrs[1] = (unsigned int) regs->gprs[6]; + p->thread.acrs[0] = (unsigned int)(tls >> 32); + p->thread.acrs[1] = (unsigned int)tls; } } #endif /* CONFIG_64BIT */ return 0; } -SYSCALL_DEFINE0(fork) -{ - struct pt_regs *regs = task_pt_regs(current); - return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL); -} - -SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags, - int __user *, parent_tidptr, int __user *, child_tidptr) -{ - struct pt_regs *regs = task_pt_regs(current); - - if (!newsp) - newsp = regs->gprs[15]; - return do_fork(clone_flags, newsp, regs, 0, - parent_tidptr, child_tidptr); -} - -/* - * This is trivial, and on the face of it looks like it - * could equally well be done in user mode. - * - * Not so, for quite unobvious reasons - register pressure. - * In user mode vfork() cannot have a stack frame, and if - * done by calling the "clone()" system call directly, you - * do not have enough call-clobbered registers to hold all - * the information you need. - */ -SYSCALL_DEFINE0(vfork) -{ - struct pt_regs *regs = task_pt_regs(current); - return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, - regs->gprs[15], regs, 0, NULL, NULL); -} - asmlinkage void execve_tail(void) { current->thread.fp_regs.fpc = 0; -- 2.7.4