diff options
Diffstat (limited to 'arch/s390/kernel/process.c')
| -rw-r--r-- | arch/s390/kernel/process.c | 112 |
1 files changed, 57 insertions, 55 deletions
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 6ccef5f29761..42af4b3aa02b 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -29,6 +29,7 @@ #include <linux/random.h> #include <linux/export.h> #include <linux/init_task.h> +#include <linux/entry-common.h> #include <asm/cpu_mf.h> #include <asm/io.h> #include <asm/processor.h> @@ -43,9 +44,22 @@ #include <asm/unwind.h> #include "entry.h" -asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); +void ret_from_fork(void) asm("ret_from_fork"); -extern void kernel_thread_starter(void); +void __ret_from_fork(struct task_struct *prev, struct pt_regs *regs) +{ + void (*func)(void *arg); + + schedule_tail(prev); + + if (!user_mode(regs)) { + /* Kernel thread */ + func = (void *)regs->gprs[9]; + func((void *)regs->gprs[10]); + } + clear_pt_regs_flag(regs, PIF_SYSCALL); + syscall_exit_to_user_mode(regs); +} void flush_thread(void) { @@ -77,12 +91,26 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) memcpy(dst, src, arch_task_struct_size); dst->thread.fpu.regs = dst->thread.fpu.fprs; + + /* + * Don't transfer over the runtime instrumentation or the guarded + * storage control block pointers. These fields are cleared here instead + * of in copy_thread() to avoid premature freeing of associated memory + * on fork() failure. Wait to clear the RI flag because ->stack still + * refers to the source thread. + */ + dst->thread.ri_cb = NULL; + dst->thread.gs_cb = NULL; + dst->thread.gs_bc_cb = NULL; + return 0; } -int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp, - unsigned long arg, struct task_struct *p, unsigned long tls) +int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { + unsigned long clone_flags = args->flags; + unsigned long new_stackp = args->stack; + unsigned long tls = args->tls; struct fake_frame { struct stack_frame sf; @@ -94,7 +122,6 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp, /* 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)); @@ -106,26 +133,28 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp, p->thread.system_timer = 0; p->thread.hardirq_timer = 0; p->thread.softirq_timer = 0; + p->thread.last_break = 1; frame->sf.back_chain = 0; + frame->sf.gprs[5] = (unsigned long)frame + sizeof(struct stack_frame); + frame->sf.gprs[6] = (unsigned long)p; /* new return point is ret_from_fork */ - frame->sf.gprs[8] = (unsigned long) 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; + frame->sf.gprs[9] = (unsigned long)frame; /* Store access registers to kernel stack of new process. */ - if (unlikely(p->flags & PF_KTHREAD)) { + if (unlikely(args->fn)) { /* 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 = - (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; + (unsigned long)__ret_from_fork; + frame->childregs.gprs[9] = (unsigned long)args->fn; + frame->childregs.gprs[10] = (unsigned long)args->fn_arg; frame->childregs.orig_gpr2 = -1; - + frame->childregs.last_break = 1; return 0; } frame->childregs = *current_pt_regs(); @@ -133,13 +162,11 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp, frame->childregs.flags = 0; if (new_stackp) frame->childregs.gprs[15] = new_stackp; - - /* Don't copy runtime instrumentation info */ - p->thread.ri_cb = NULL; + /* + * Clear the runtime instrumentation flag after the above childregs + * copy. The CB pointer was already cleared in arch_dup_task_struct(). + */ frame->childregs.psw.mask &= ~PSW_MASK_RI; - /* Don't copy guarded storage control block */ - p->thread.gs_cb = NULL; - p->thread.gs_bc_cb = NULL; /* Set a new TLS ? */ if (clone_flags & CLONE_SETTLS) { @@ -150,39 +177,27 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp, p->thread.acrs[1] = (unsigned int)tls; } } + /* + * s390 stores the svc return address in arch_data when calling + * sigreturn()/restart_syscall() via vdso. 1 means no valid address + * stored. + */ + p->restart_block.arch_data = 1; return 0; } -asmlinkage void execve_tail(void) +void execve_tail(void) { current->thread.fpu.fpc = 0; asm volatile("sfpc %0" : : "d" (0)); } -/* - * fill in the FPU structure for a core dump. - */ -int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) -{ - save_fpu_regs(); - fpregs->fpc = current->thread.fpu.fpc; - fpregs->pad = 0; - if (MACHINE_HAS_VX) - convert_vx_to_fp((freg_t *)&fpregs->fprs, - current->thread.fpu.vxrs); - else - memcpy(&fpregs->fprs, current->thread.fpu.fprs, - sizeof(fpregs->fprs)); - return 1; -} -EXPORT_SYMBOL(dump_fpu); - -unsigned long get_wchan(struct task_struct *p) +unsigned long __get_wchan(struct task_struct *p) { struct unwind_state state; unsigned long ip = 0; - if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) + if (!task_stack_page(p)) return 0; if (!try_get_task_stack(p)) @@ -209,13 +224,13 @@ unsigned long get_wchan(struct task_struct *p) unsigned long arch_align_stack(unsigned long sp) { if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) - sp -= get_random_int() & ~PAGE_MASK; + sp -= prandom_u32_max(PAGE_SIZE); return sp & ~0xf; } static inline unsigned long brk_rnd(void) { - return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; + return (get_random_u16() & BRK_RND_MASK) << PAGE_SHIFT; } unsigned long arch_randomize_brk(struct mm_struct *mm) @@ -225,16 +240,3 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) ret = PAGE_ALIGN(mm->brk + brk_rnd()); return (ret > mm->brk) ? ret : mm->brk; } - -void set_fs_fixup(void) -{ - struct pt_regs *regs = current_pt_regs(); - static bool warned; - - set_fs(USER_DS); - if (warned) - return; - WARN(1, "Unbalanced set_fs - int code: 0x%x\n", regs->int_code); - show_registers(regs); - warned = true; -} |