From f9a7e025dfc28783fd2b05812e663251acf4bf21 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 21 Sep 2012 20:48:32 -0400 Subject: [PATCH] s390: switch to generic kernel_thread() Signed-off-by: Al Viro --- arch/s390/Kconfig | 1 + arch/s390/include/asm/processor.h | 1 - arch/s390/kernel/process.c | 72 ++++++++++++++----------------- 3 files changed, 34 insertions(+), 40 deletions(-) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 107610e01a29..57442393bac7 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -125,6 +125,7 @@ config S390 select GENERIC_CLOCKEVENTS select KTIME_SCALAR if 32BIT select HAVE_ARCH_SECCOMP_FILTER + select GENERIC_KERNEL_THREAD config SCHED_OMIT_FRAME_POINTER def_bool y diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 0bc77619c3a3..da6f5baeee5c 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -135,7 +135,6 @@ struct seq_file; /* Free all resources held by a thread. */ extern void release_thread(struct task_struct *); -extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); /* * Return saved PC of a blocked thread. diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 2868a364ff94..bab088de4569 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -98,25 +98,6 @@ void cpu_idle(void) extern void __kprobes kernel_thread_starter(void); -int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) -{ - struct pt_regs regs; - - memset(®s, 0, sizeof(regs)); - regs.psw.mask = psw_kernel_bits | - PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; - regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE; - regs.gprs[9] = (unsigned long) fn; - regs.gprs[10] = (unsigned long) arg; - regs.gprs[11] = (unsigned long) do_exit; - regs.orig_gpr2 = -1; - - /* Ok, create the new process.. */ - return do_fork(flags | CLONE_VM | CLONE_UNTRACED, - 0, ®s, 0, NULL, NULL); -} -EXPORT_SYMBOL(kernel_thread); - /* * Free current thread data structures etc.. */ @@ -133,7 +114,7 @@ void release_thread(struct task_struct *dead_task) } int copy_thread(unsigned long clone_flags, unsigned long new_stackp, - unsigned long unused, + unsigned long arg, struct task_struct *p, struct pt_regs *regs) { struct thread_info *ti; @@ -145,20 +126,44 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, frame = container_of(task_pt_regs(p), struct fake_frame, childregs); p->thread.ksp = (unsigned long) frame; - /* Store access registers to kernel stack of new process. */ - frame->childregs = *regs; - frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ - frame->childregs.gprs[15] = new_stackp; - frame->sf.back_chain = 0; + /* Save access registers to new thread structure. */ + save_access_regs(&p->thread.acrs[0]); + /* start new process with ar4 pointing to the correct address space */ + p->thread.mm_segment = get_fs(); + /* Don't copy debug registers */ + memset(&p->thread.per_user, 0, sizeof(p->thread.per_user)); + memset(&p->thread.per_event, 0, sizeof(p->thread.per_event)); + clear_tsk_thread_flag(p, TIF_SINGLE_STEP); + clear_tsk_thread_flag(p, TIF_PER_TRAP); + /* Initialize per thread user and system timer values */ + ti = task_thread_info(p); + ti->user_timer = 0; + ti->system_timer = 0; + frame->sf.back_chain = 0; /* new return point is ret_from_fork */ frame->sf.gprs[8] = (unsigned long) ret_from_fork; - /* fake return stack for resume(), don't go back to schedule */ frame->sf.gprs[9] = (unsigned long) frame; - /* Save access registers to new thread structure. */ - save_access_regs(&p->thread.acrs[0]); + /* Store access registers to kernel stack of new process. */ + if (unlikely(!regs)) { + /* kernel thread */ + memset(&frame->childregs, 0, sizeof(struct pt_regs)); + frame->childregs.psw.mask = psw_kernel_bits | PSW_MASK_DAT | + PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; + frame->childregs.psw.addr = PSW_ADDR_AMODE | + (unsigned long) kernel_thread_starter; + frame->childregs.gprs[9] = new_stackp; /* function */ + frame->childregs.gprs[10] = arg; + frame->childregs.gprs[11] = (unsigned long) do_exit; + frame->childregs.orig_gpr2 = -1; + + return 0; + } + frame->childregs = *regs; + frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ + frame->childregs.gprs[15] = new_stackp; #ifndef CONFIG_64BIT /* @@ -184,17 +189,6 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, } } #endif /* CONFIG_64BIT */ - /* start new process with ar4 pointing to the correct address space */ - p->thread.mm_segment = get_fs(); - /* Don't copy debug registers */ - memset(&p->thread.per_user, 0, sizeof(p->thread.per_user)); - memset(&p->thread.per_event, 0, sizeof(p->thread.per_event)); - clear_tsk_thread_flag(p, TIF_SINGLE_STEP); - clear_tsk_thread_flag(p, TIF_PER_TRAP); - /* Initialize per thread user and system timer values */ - ti = task_thread_info(p); - ti->user_timer = 0; - ti->system_timer = 0; return 0; }