diff options
Diffstat (limited to 'arch/s390/kernel/signal.c')
| -rw-r--r-- | arch/s390/kernel/signal.c | 296 |
1 files changed, 231 insertions, 65 deletions
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c index 469c4c6d9182..0c1a0ff0a558 100644 --- a/arch/s390/kernel/signal.c +++ b/arch/s390/kernel/signal.c @@ -31,30 +31,117 @@ #include <asm/switch_to.h> #include "entry.h" -typedef struct +/* + * Layout of an old-style signal-frame: + * ----------------------------------------- + * | save area (_SIGNAL_FRAMESIZE) | + * ----------------------------------------- + * | struct sigcontext | + * | oldmask | + * | _sigregs * | + * ----------------------------------------- + * | _sigregs with | + * | _s390_regs_common | + * | _s390_fp_regs | + * ----------------------------------------- + * | int signo | + * ----------------------------------------- + * | _sigregs_ext with | + * | gprs_high 64 byte (opt) | + * | vxrs_low 128 byte (opt) | + * | vxrs_high 256 byte (opt) | + * | reserved 128 byte (opt) | + * ----------------------------------------- + * | __u16 svc_insn | + * ----------------------------------------- + * The svc_insn entry with the sigreturn system call opcode does not + * have a fixed position and moves if gprs_high or vxrs exist. + * Future extensions will be added to _sigregs_ext. + */ +struct sigframe { __u8 callee_used_stack[__SIGNAL_FRAMESIZE]; struct sigcontext sc; _sigregs sregs; int signo; - __u8 retcode[S390_SYSCALL_SIZE]; -} sigframe; + _sigregs_ext sregs_ext; + __u16 svc_insn; /* Offset of svc_insn is NOT fixed! */ +}; -typedef struct +/* + * Layout of an rt signal-frame: + * ----------------------------------------- + * | save area (_SIGNAL_FRAMESIZE) | + * ----------------------------------------- + * | svc __NR_rt_sigreturn 2 byte | + * ----------------------------------------- + * | struct siginfo | + * ----------------------------------------- + * | struct ucontext_extended with | + * | unsigned long uc_flags | + * | struct ucontext *uc_link | + * | stack_t uc_stack | + * | _sigregs uc_mcontext with | + * | _s390_regs_common | + * | _s390_fp_regs | + * | sigset_t uc_sigmask | + * | _sigregs_ext uc_mcontext_ext | + * | gprs_high 64 byte (opt) | + * | vxrs_low 128 byte (opt) | + * | vxrs_high 256 byte (opt)| + * | reserved 128 byte (opt) | + * ----------------------------------------- + * Future extensions will be added to _sigregs_ext. + */ +struct rt_sigframe { __u8 callee_used_stack[__SIGNAL_FRAMESIZE]; - __u8 retcode[S390_SYSCALL_SIZE]; + __u16 svc_insn; struct siginfo info; - struct ucontext uc; -} rt_sigframe; + struct ucontext_extended uc; +}; + +/* Store registers needed to create the signal frame */ +static void store_sigregs(void) +{ + save_access_regs(current->thread.acrs); + save_fp_ctl(¤t->thread.fp_regs.fpc); +#ifdef CONFIG_64BIT + if (current->thread.vxrs) { + int i; + + save_vx_regs(current->thread.vxrs); + for (i = 0; i < __NUM_FPRS; i++) + current->thread.fp_regs.fprs[i] = + *(freg_t *)(current->thread.vxrs + i); + } else +#endif + save_fp_regs(current->thread.fp_regs.fprs); +} + +/* Load registers after signal return */ +static void load_sigregs(void) +{ + restore_access_regs(current->thread.acrs); + /* restore_fp_ctl is done in restore_sigregs */ +#ifdef CONFIG_64BIT + if (current->thread.vxrs) { + int i; + + for (i = 0; i < __NUM_FPRS; i++) + *(freg_t *)(current->thread.vxrs + i) = + current->thread.fp_regs.fprs[i]; + restore_vx_regs(current->thread.vxrs); + } else +#endif + restore_fp_regs(current->thread.fp_regs.fprs); +} /* Returns non-zero on fault. */ static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs) { _sigregs user_sregs; - save_access_regs(current->thread.acrs); - /* Copy a 'clean' PSW mask to the user to avoid leaking information about whether PER is currently on. */ user_sregs.regs.psw.mask = PSW_USER_BITS | @@ -63,12 +150,6 @@ static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs) memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs)); memcpy(&user_sregs.regs.acrs, current->thread.acrs, sizeof(user_sregs.regs.acrs)); - /* - * We have to store the fp registers to current->thread.fp_regs - * to merge them with the emulated registers. - */ - save_fp_ctl(¤t->thread.fp_regs.fpc); - save_fp_regs(current->thread.fp_regs.fprs); memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs, sizeof(user_sregs.fpregs)); if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs))) @@ -107,20 +188,64 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs) memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs)); memcpy(¤t->thread.acrs, &user_sregs.regs.acrs, sizeof(current->thread.acrs)); - restore_access_regs(current->thread.acrs); memcpy(¤t->thread.fp_regs, &user_sregs.fpregs, sizeof(current->thread.fp_regs)); - restore_fp_regs(current->thread.fp_regs.fprs); clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */ return 0; } +/* Returns non-zero on fault. */ +static int save_sigregs_ext(struct pt_regs *regs, + _sigregs_ext __user *sregs_ext) +{ +#ifdef CONFIG_64BIT + __u64 vxrs[__NUM_VXRS_LOW]; + int i; + + /* Save vector registers to signal stack */ + if (current->thread.vxrs) { + for (i = 0; i < __NUM_VXRS_LOW; i++) + vxrs[i] = *((__u64 *)(current->thread.vxrs + i) + 1); + if (__copy_to_user(&sregs_ext->vxrs_low, vxrs, + sizeof(sregs_ext->vxrs_low)) || + __copy_to_user(&sregs_ext->vxrs_high, + current->thread.vxrs + __NUM_VXRS_LOW, + sizeof(sregs_ext->vxrs_high))) + return -EFAULT; + } +#endif + return 0; +} + +static int restore_sigregs_ext(struct pt_regs *regs, + _sigregs_ext __user *sregs_ext) +{ +#ifdef CONFIG_64BIT + __u64 vxrs[__NUM_VXRS_LOW]; + int i; + + /* Restore vector registers from signal stack */ + if (current->thread.vxrs) { + if (__copy_from_user(vxrs, &sregs_ext->vxrs_low, + sizeof(sregs_ext->vxrs_low)) || + __copy_from_user(current->thread.vxrs + __NUM_VXRS_LOW, + &sregs_ext->vxrs_high, + sizeof(sregs_ext->vxrs_high))) + return -EFAULT; + for (i = 0; i < __NUM_VXRS_LOW; i++) + *((__u64 *)(current->thread.vxrs + i) + 1) = vxrs[i]; + } +#endif + return 0; +} + SYSCALL_DEFINE0(sigreturn) { struct pt_regs *regs = task_pt_regs(current); - sigframe __user *frame = (sigframe __user *)regs->gprs[15]; + struct sigframe __user *frame = + (struct sigframe __user *) regs->gprs[15]; sigset_t set; if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE)) @@ -128,6 +253,9 @@ SYSCALL_DEFINE0(sigreturn) set_current_blocked(&set); if (restore_sigregs(regs, &frame->sregs)) goto badframe; + if (restore_sigregs_ext(regs, &frame->sregs_ext)) + goto badframe; + load_sigregs(); return regs->gprs[2]; badframe: force_sig(SIGSEGV, current); @@ -137,16 +265,20 @@ badframe: SYSCALL_DEFINE0(rt_sigreturn) { struct pt_regs *regs = task_pt_regs(current); - rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15]; + struct rt_sigframe __user *frame = + (struct rt_sigframe __user *)regs->gprs[15]; sigset_t set; if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set))) goto badframe; set_current_blocked(&set); + if (restore_altstack(&frame->uc.uc_stack)) + goto badframe; if (restore_sigregs(regs, &frame->uc.uc_mcontext)) goto badframe; - if (restore_altstack(&frame->uc.uc_stack)) + if (restore_sigregs_ext(regs, &frame->uc.uc_mcontext_ext)) goto badframe; + load_sigregs(); return regs->gprs[2]; badframe: force_sig(SIGSEGV, current); @@ -154,11 +286,6 @@ badframe: } /* - * Set up a signal frame. - */ - - -/* * Determine which stack to use.. */ static inline void __user * @@ -195,39 +322,63 @@ static inline int map_signal(int sig) static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs) { - sigframe __user *frame; - - frame = get_sigframe(ka, regs, sizeof(sigframe)); + struct sigframe __user *frame; + struct sigcontext sc; + unsigned long restorer; + size_t frame_size; + /* + * gprs_high are only present for a 31-bit task running on + * a 64-bit kernel (see compat_signal.c) but the space for + * gprs_high need to be allocated if vector registers are + * included in the signal frame on a 31-bit system. + */ + frame_size = sizeof(*frame) - sizeof(frame->sregs_ext); + if (MACHINE_HAS_VX) + frame_size += sizeof(frame->sregs_ext); + frame = get_sigframe(ka, regs, frame_size); if (frame == (void __user *) -1UL) return -EFAULT; - if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE)) + /* Set up backchain. */ + if (__put_user(regs->gprs[15], (addr_t __user *) frame)) return -EFAULT; + /* Create struct sigcontext on the signal stack */ + memcpy(&sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE); + sc.sregs = (_sigregs __user __force *) &frame->sregs; + if (__copy_to_user(&frame->sc, &sc, sizeof(frame->sc))) + return -EFAULT; + + /* Store registers needed to create the signal frame */ + store_sigregs(); + + /* Create _sigregs on the signal stack */ if (save_sigregs(regs, &frame->sregs)) return -EFAULT; - if (__put_user(&frame->sregs, &frame->sc.sregs)) + + /* Place signal number on stack to allow backtrace from handler. */ + if (__put_user(regs->gprs[2], (int __user *) &frame->signo)) + return -EFAULT; + + /* Create _sigregs_ext on the signal stack */ + if (save_sigregs_ext(regs, &frame->sregs_ext)) return -EFAULT; /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ka->sa.sa_flags & SA_RESTORER) { - regs->gprs[14] = (unsigned long) - ka->sa.sa_restorer | PSW_ADDR_AMODE; + restorer = (unsigned long) ka->sa.sa_restorer | PSW_ADDR_AMODE; } else { - regs->gprs[14] = (unsigned long) - frame->retcode | PSW_ADDR_AMODE; - if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, - (u16 __user *)(frame->retcode))) + /* Signal frame without vector registers are short ! */ + __u16 __user *svc = (void *) frame + frame_size - 2; + if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc)) return -EFAULT; + restorer = (unsigned long) svc | PSW_ADDR_AMODE; } - /* Set up backchain. */ - if (__put_user(regs->gprs[15], (addr_t __user *) frame)) - return -EFAULT; - /* Set up registers for signal handler */ + regs->gprs[14] = restorer; regs->gprs[15] = (unsigned long) frame; /* Force default amode and default user address space control. */ regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA | @@ -247,54 +398,69 @@ static int setup_frame(int sig, struct k_sigaction *ka, regs->gprs[5] = regs->int_parm_long; regs->gprs[6] = task_thread_info(current)->last_break; } - - /* Place signal number on stack to allow backtrace from handler. */ - if (__put_user(regs->gprs[2], (int __user *) &frame->signo)) - return -EFAULT; return 0; } static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { - int err = 0; - rt_sigframe __user *frame; - - frame = get_sigframe(&ksig->ka, regs, sizeof(rt_sigframe)); + struct rt_sigframe __user *frame; + unsigned long uc_flags, restorer; + size_t frame_size; + frame_size = sizeof(struct rt_sigframe) - sizeof(_sigregs_ext); + /* + * gprs_high are only present for a 31-bit task running on + * a 64-bit kernel (see compat_signal.c) but the space for + * gprs_high need to be allocated if vector registers are + * included in the signal frame on a 31-bit system. + */ + uc_flags = 0; +#ifdef CONFIG_64BIT + if (MACHINE_HAS_VX) { + frame_size += sizeof(_sigregs_ext); + if (current->thread.vxrs) + uc_flags |= UC_VXRS; + } +#endif + frame = get_sigframe(&ksig->ka, regs, frame_size); if (frame == (void __user *) -1UL) return -EFAULT; - if (copy_siginfo_to_user(&frame->info, &ksig->info)) - return -EFAULT; - - /* Create the ucontext. */ - err |= __put_user(0, &frame->uc.uc_flags); - err |= __put_user(NULL, &frame->uc.uc_link); - err |= __save_altstack(&frame->uc.uc_stack, regs->gprs[15]); - err |= save_sigregs(regs, &frame->uc.uc_mcontext); - err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); - if (err) + /* Set up backchain. */ + if (__put_user(regs->gprs[15], (addr_t __user *) frame)) return -EFAULT; /* Set up to return from userspace. If provided, use a stub already in userspace. */ if (ksig->ka.sa.sa_flags & SA_RESTORER) { - regs->gprs[14] = (unsigned long) + restorer = (unsigned long) ksig->ka.sa.sa_restorer | PSW_ADDR_AMODE; } else { - regs->gprs[14] = (unsigned long) - frame->retcode | PSW_ADDR_AMODE; - if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, - (u16 __user *)(frame->retcode))) + __u16 __user *svc = &frame->svc_insn; + if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc)) return -EFAULT; + restorer = (unsigned long) svc | PSW_ADDR_AMODE; } - /* Set up backchain. */ - if (__put_user(regs->gprs[15], (addr_t __user *) frame)) + /* Create siginfo on the signal stack */ + if (copy_siginfo_to_user(&frame->info, &ksig->info)) + return -EFAULT; + + /* Store registers needed to create the signal frame */ + store_sigregs(); + + /* Create ucontext on the signal stack. */ + if (__put_user(uc_flags, &frame->uc.uc_flags) || + __put_user(NULL, &frame->uc.uc_link) || + __save_altstack(&frame->uc.uc_stack, regs->gprs[15]) || + save_sigregs(regs, &frame->uc.uc_mcontext) || + __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)) || + save_sigregs_ext(regs, &frame->uc.uc_mcontext_ext)) return -EFAULT; /* Set up registers for signal handler */ + regs->gprs[14] = restorer; regs->gprs[15] = (unsigned long) frame; /* Force default amode and default user address space control. */ regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA | |