diff options
Diffstat (limited to 'arch/s390/kernel/process.c')
| -rw-r--r-- | arch/s390/kernel/process.c | 75 |
1 files changed, 51 insertions, 24 deletions
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 89949b9f3cf8..dd456b475861 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -30,16 +30,20 @@ #include <linux/export.h> #include <linux/init_task.h> #include <linux/entry-common.h> +#include <linux/io.h> +#include <asm/guarded_storage.h> +#include <asm/access-regs.h> +#include <asm/switch_to.h> #include <asm/cpu_mf.h> -#include <asm/io.h> #include <asm/processor.h> +#include <asm/ptrace.h> #include <asm/vtimer.h> #include <asm/exec.h> +#include <asm/fpu.h> #include <asm/irq.h> #include <asm/nmi.h> #include <asm/smp.h> #include <asm/stacktrace.h> -#include <asm/switch_to.h> #include <asm/runtime_instr.h> #include <asm/unwind.h> #include "entry.h" @@ -84,13 +88,25 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { /* * Save the floating-point or vector register state of the current - * task and set the CIF_FPU flag to lazy restore the FPU register + * task and set the TIF_FPU flag to lazy restore the FPU register * state when returning to user space. */ - save_fpu_regs(); + save_user_fpu_regs(); + + *dst = *src; + dst->thread.kfpu_flags = 0; + + /* + * 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; - memcpy(dst, src, arch_task_struct_size); - dst->thread.fpu.regs = dst->thread.fpu.fprs; return 0; } @@ -124,21 +140,19 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) 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; + frame->sf.gprs[11 - 6] = (unsigned long)&frame->childregs; + frame->sf.gprs[12 - 6] = (unsigned long)p; /* new return point is ret_from_fork */ - frame->sf.gprs[8] = (unsigned long)ret_from_fork; + frame->sf.gprs[14 - 6] = (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[15 - 6] = (unsigned long)frame; /* Store access registers to kernel stack of new process. */ 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)__ret_from_fork; + frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | + PSW_MASK_EXT | PSW_MASK_MCHECK; frame->childregs.gprs[9] = (unsigned long)args->fn; frame->childregs.gprs[10] = (unsigned long)args->fn_arg; frame->childregs.orig_gpr2 = -1; @@ -150,13 +164,11 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) 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) { @@ -178,8 +190,23 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) void execve_tail(void) { - current->thread.fpu.fpc = 0; - asm volatile("sfpc %0" : : "d" (0)); + current->thread.ufpu.fpc = 0; + fpu_sfpc(0); +} + +struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next) +{ + save_user_fpu_regs(); + save_kernel_fpu_regs(&prev->thread); + save_access_regs(&prev->thread.acrs[0]); + save_ri_cb(prev->thread.ri_cb); + save_gs_cb(prev->thread.gs_cb); + update_cr_regs(next); + restore_kernel_fpu_regs(&next->thread); + restore_access_regs(&next->thread.acrs[0]); + restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb); + restore_gs_cb(next->thread.gs_cb); + return __switch_to_asm(prev, next); } unsigned long __get_wchan(struct task_struct *p) @@ -214,13 +241,13 @@ 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 -= get_random_u32_below(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) |