| // SPDX-License-Identifier: GPL-2.0 |
| /* linux/arch/sparc/kernel/signal.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) |
| * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx) |
| * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be) |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/signal.h> |
| #include <linux/errno.h> |
| #include <linux/wait.h> |
| #include <linux/ptrace.h> |
| #include <linux/unistd.h> |
| #include <linux/mm.h> |
| #include <linux/tty.h> |
| #include <linux/smp.h> |
| #include <linux/binfmts.h> /* do_coredum */ |
| #include <linux/bitops.h> |
| #include <linux/tracehook.h> |
| |
| #include <linux/uaccess.h> |
| #include <asm/ptrace.h> |
| #include <asm/cacheflush.h> /* flush_sig_insns */ |
| #include <asm/switch_to.h> |
| |
| #include "sigutil.h" |
| #include "kernel.h" |
| |
| extern void fpsave(unsigned long *fpregs, unsigned long *fsr, |
| void *fpqueue, unsigned long *fpqdepth); |
| extern void fpload(unsigned long *fpregs, unsigned long *fsr); |
| |
| struct signal_frame { |
| struct sparc_stackf ss; |
| __siginfo32_t info; |
| __siginfo_fpu_t __user *fpu_save; |
| unsigned long insns[2] __attribute__ ((aligned (8))); |
| unsigned int extramask[_NSIG_WORDS - 1]; |
| unsigned int extra_size; /* Should be 0 */ |
| __siginfo_rwin_t __user *rwin_save; |
| } __attribute__((aligned(8))); |
| |
| struct rt_signal_frame { |
| struct sparc_stackf ss; |
| siginfo_t info; |
| struct pt_regs regs; |
| sigset_t mask; |
| __siginfo_fpu_t __user *fpu_save; |
| unsigned int insns[2]; |
| stack_t stack; |
| unsigned int extra_size; /* Should be 0 */ |
| __siginfo_rwin_t __user *rwin_save; |
| } __attribute__((aligned(8))); |
| |
| /* Align macros */ |
| #define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7))) |
| #define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7))) |
| |
| /* Checks if the fp is valid. We always build signal frames which are |
| * 16-byte aligned, therefore we can always enforce that the restore |
| * frame has that property as well. |
| */ |
| static inline bool invalid_frame_pointer(void __user *fp, int fplen) |
| { |
| if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen)) |
| return true; |
| |
| return false; |
| } |
| |
| asmlinkage void do_sigreturn(struct pt_regs *regs) |
| { |
| unsigned long up_psr, pc, npc, ufp; |
| struct signal_frame __user *sf; |
| sigset_t set; |
| __siginfo_fpu_t __user *fpu_save; |
| __siginfo_rwin_t __user *rwin_save; |
| int err; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current->restart_block.fn = do_no_restart_syscall; |
| |
| synchronize_user_stack(); |
| |
| sf = (struct signal_frame __user *) regs->u_regs[UREG_FP]; |
| |
| /* 1. Make sure we are not getting garbage from the user */ |
| if (invalid_frame_pointer(sf, sizeof(*sf))) |
| goto segv_and_exit; |
| |
| if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP])) |
| goto segv_and_exit; |
| |
| if (ufp & 0x7) |
| goto segv_and_exit; |
| |
| err = __get_user(pc, &sf->info.si_regs.pc); |
| err |= __get_user(npc, &sf->info.si_regs.npc); |
| |
| if ((pc | npc) & 3) |
| goto segv_and_exit; |
| |
| /* 2. Restore the state */ |
| up_psr = regs->psr; |
| err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs)); |
| |
| /* User can only change condition codes and FPU enabling in %psr. */ |
| regs->psr = (up_psr & ~(PSR_ICC | PSR_EF)) |
| | (regs->psr & (PSR_ICC | PSR_EF)); |
| |
| /* Prevent syscall restart. */ |
| pt_regs_clear_syscall(regs); |
| |
| err |= __get_user(fpu_save, &sf->fpu_save); |
| if (fpu_save) |
| err |= restore_fpu_state(regs, fpu_save); |
| err |= __get_user(rwin_save, &sf->rwin_save); |
| if (rwin_save) |
| err |= restore_rwin_state(rwin_save); |
| |
| /* This is pretty much atomic, no amount locking would prevent |
| * the races which exist anyways. |
| */ |
| err |= __get_user(set.sig[0], &sf->info.si_mask); |
| err |= __copy_from_user(&set.sig[1], &sf->extramask, |
| (_NSIG_WORDS-1) * sizeof(unsigned int)); |
| |
| if (err) |
| goto segv_and_exit; |
| |
| set_current_blocked(&set); |
| return; |
| |
| segv_and_exit: |
| force_sig(SIGSEGV); |
| } |
| |
| asmlinkage void do_rt_sigreturn(struct pt_regs *regs) |
| { |
| struct rt_signal_frame __user *sf; |
| unsigned int psr, pc, npc, ufp; |
| __siginfo_fpu_t __user *fpu_save; |
| __siginfo_rwin_t __user *rwin_save; |
| sigset_t set; |
| int err; |
| |
| synchronize_user_stack(); |
| sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP]; |
| if (invalid_frame_pointer(sf, sizeof(*sf))) |
| goto segv; |
| |
| if (get_user(ufp, &sf->regs.u_regs[UREG_FP])) |
| goto segv; |
| |
| if (ufp & 0x7) |
| goto segv; |
| |
| err = __get_user(pc, &sf->regs.pc); |
| err |= __get_user(npc, &sf->regs.npc); |
| err |= ((pc | npc) & 0x03); |
| |
| err |= __get_user(regs->y, &sf->regs.y); |
| err |= __get_user(psr, &sf->regs.psr); |
| |
| err |= __copy_from_user(®s->u_regs[UREG_G1], |
| &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32)); |
| |
| regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC); |
| |
| /* Prevent syscall restart. */ |
| pt_regs_clear_syscall(regs); |
| |
| err |= __get_user(fpu_save, &sf->fpu_save); |
| if (!err && fpu_save) |
| err |= restore_fpu_state(regs, fpu_save); |
| err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t)); |
| err |= restore_altstack(&sf->stack); |
| |
| if (err) |
| goto segv; |
| |
| regs->pc = pc; |
| regs->npc = npc; |
| |
| err |= __get_user(rwin_save, &sf->rwin_save); |
| if (!err && rwin_save) { |
| if (restore_rwin_state(rwin_save)) |
| goto segv; |
| } |
| |
| set_current_blocked(&set); |
| return; |
| segv: |
| force_sig(SIGSEGV); |
| } |
| |
| static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize) |
| { |
| unsigned long sp = regs->u_regs[UREG_FP]; |
| |
| /* |
| * If we are on the alternate signal stack and would overflow it, don't. |
| * Return an always-bogus address instead so we will die with SIGSEGV. |
| */ |
| if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize))) |
| return (void __user *) -1L; |
| |
| /* This is the X/Open sanctioned signal stack switching. */ |
| sp = sigsp(sp, ksig) - framesize; |
| |
| /* Always align the stack frame. This handles two cases. First, |
| * sigaltstack need not be mindful of platform specific stack |
| * alignment. Second, if we took this signal because the stack |
| * is not aligned properly, we'd like to take the signal cleanly |
| * and report that. |
| */ |
| sp &= ~15UL; |
| |
| return (void __user *) sp; |
| } |
| |
| static int setup_frame(struct ksignal *ksig, struct pt_regs *regs, |
| sigset_t *oldset) |
| { |
| struct signal_frame __user *sf; |
| int sigframe_size, err, wsaved; |
| void __user *tail; |
| |
| /* 1. Make sure everything is clean */ |
| synchronize_user_stack(); |
| |
| wsaved = current_thread_info()->w_saved; |
| |
| sigframe_size = sizeof(*sf); |
| if (used_math()) |
| sigframe_size += sizeof(__siginfo_fpu_t); |
| if (wsaved) |
| sigframe_size += sizeof(__siginfo_rwin_t); |
| |
| sf = (struct signal_frame __user *) |
| get_sigframe(ksig, regs, sigframe_size); |
| |
| if (invalid_frame_pointer(sf, sigframe_size)) { |
| force_exit_sig(SIGILL); |
| return -EINVAL; |
| } |
| |
| tail = sf + 1; |
| |
| /* 2. Save the current process state */ |
| err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs)); |
| |
| err |= __put_user(0, &sf->extra_size); |
| |
| if (used_math()) { |
| __siginfo_fpu_t __user *fp = tail; |
| tail += sizeof(*fp); |
| err |= save_fpu_state(regs, fp); |
| err |= __put_user(fp, &sf->fpu_save); |
| } else { |
| err |= __put_user(0, &sf->fpu_save); |
| } |
| if (wsaved) { |
| __siginfo_rwin_t __user *rwp = tail; |
| tail += sizeof(*rwp); |
| err |= save_rwin_state(wsaved, rwp); |
| err |= __put_user(rwp, &sf->rwin_save); |
| } else { |
| err |= __put_user(0, &sf->rwin_save); |
| } |
| |
| err |= __put_user(oldset->sig[0], &sf->info.si_mask); |
| err |= __copy_to_user(sf->extramask, &oldset->sig[1], |
| (_NSIG_WORDS - 1) * sizeof(unsigned int)); |
| if (!wsaved) { |
| err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP], |
| sizeof(struct reg_window32)); |
| } else { |
| struct reg_window32 *rp; |
| |
| rp = ¤t_thread_info()->reg_window[wsaved - 1]; |
| err |= __copy_to_user(sf, rp, sizeof(struct reg_window32)); |
| } |
| if (err) |
| return err; |
| |
| /* 3. signal handler back-trampoline and parameters */ |
| regs->u_regs[UREG_FP] = (unsigned long) sf; |
| regs->u_regs[UREG_I0] = ksig->sig; |
| regs->u_regs[UREG_I1] = (unsigned long) &sf->info; |
| regs->u_regs[UREG_I2] = (unsigned long) &sf->info; |
| |
| /* 4. signal handler */ |
| regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
| regs->npc = (regs->pc + 4); |
| |
| /* 5. return to kernel instructions */ |
| if (ksig->ka.ka_restorer) |
| regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; |
| else { |
| regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2); |
| |
| /* mov __NR_sigreturn, %g1 */ |
| err |= __put_user(0x821020d8, &sf->insns[0]); |
| |
| /* t 0x10 */ |
| err |= __put_user(0x91d02010, &sf->insns[1]); |
| if (err) |
| return err; |
| |
| /* Flush instruction space. */ |
| flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0])); |
| } |
| return 0; |
| } |
| |
| static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs, |
| sigset_t *oldset) |
| { |
| struct rt_signal_frame __user *sf; |
| int sigframe_size, wsaved; |
| void __user *tail; |
| unsigned int psr; |
| int err; |
| |
| synchronize_user_stack(); |
| wsaved = current_thread_info()->w_saved; |
| sigframe_size = sizeof(*sf); |
| if (used_math()) |
| sigframe_size += sizeof(__siginfo_fpu_t); |
| if (wsaved) |
| sigframe_size += sizeof(__siginfo_rwin_t); |
| sf = (struct rt_signal_frame __user *) |
| get_sigframe(ksig, regs, sigframe_size); |
| if (invalid_frame_pointer(sf, sigframe_size)) { |
| force_exit_sig(SIGILL); |
| return -EINVAL; |
| } |
| |
| tail = sf + 1; |
| err = __put_user(regs->pc, &sf->regs.pc); |
| err |= __put_user(regs->npc, &sf->regs.npc); |
| err |= __put_user(regs->y, &sf->regs.y); |
| psr = regs->psr; |
| if (used_math()) |
| psr |= PSR_EF; |
| err |= __put_user(psr, &sf->regs.psr); |
| err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs)); |
| err |= __put_user(0, &sf->extra_size); |
| |
| if (psr & PSR_EF) { |
| __siginfo_fpu_t __user *fp = tail; |
| tail += sizeof(*fp); |
| err |= save_fpu_state(regs, fp); |
| err |= __put_user(fp, &sf->fpu_save); |
| } else { |
| err |= __put_user(0, &sf->fpu_save); |
| } |
| if (wsaved) { |
| __siginfo_rwin_t __user *rwp = tail; |
| tail += sizeof(*rwp); |
| err |= save_rwin_state(wsaved, rwp); |
| err |= __put_user(rwp, &sf->rwin_save); |
| } else { |
| err |= __put_user(0, &sf->rwin_save); |
| } |
| err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t)); |
| |
| /* Setup sigaltstack */ |
| err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]); |
| |
| if (!wsaved) { |
| err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP], |
| sizeof(struct reg_window32)); |
| } else { |
| struct reg_window32 *rp; |
| |
| rp = ¤t_thread_info()->reg_window[wsaved - 1]; |
| err |= __copy_to_user(sf, rp, sizeof(struct reg_window32)); |
| } |
| |
| err |= copy_siginfo_to_user(&sf->info, &ksig->info); |
| |
| if (err) |
| return err; |
| |
| regs->u_regs[UREG_FP] = (unsigned long) sf; |
| regs->u_regs[UREG_I0] = ksig->sig; |
| regs->u_regs[UREG_I1] = (unsigned long) &sf->info; |
| regs->u_regs[UREG_I2] = (unsigned long) &sf->regs; |
| |
| regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
| regs->npc = (regs->pc + 4); |
| |
| if (ksig->ka.ka_restorer) |
| regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer; |
| else { |
| regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2); |
| |
| /* mov __NR_rt_sigreturn, %g1 */ |
| err |= __put_user(0x82102065, &sf->insns[0]); |
| |
| /* t 0x10 */ |
| err |= __put_user(0x91d02010, &sf->insns[1]); |
| if (err) |
| return err; |
| |
| /* Flush instruction space. */ |
| flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0])); |
| } |
| return 0; |
| } |
| |
| static inline void |
| handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
| { |
| sigset_t *oldset = sigmask_to_save(); |
| int err; |
| |
| if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
| err = setup_rt_frame(ksig, regs, oldset); |
| else |
| err = setup_frame(ksig, regs, oldset); |
| signal_setup_done(err, ksig, 0); |
| } |
| |
| static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs, |
| struct sigaction *sa) |
| { |
| switch(regs->u_regs[UREG_I0]) { |
| case ERESTART_RESTARTBLOCK: |
| case ERESTARTNOHAND: |
| no_system_call_restart: |
| regs->u_regs[UREG_I0] = EINTR; |
| regs->psr |= PSR_C; |
| break; |
| case ERESTARTSYS: |
| if (!(sa->sa_flags & SA_RESTART)) |
| goto no_system_call_restart; |
| fallthrough; |
| case ERESTARTNOINTR: |
| regs->u_regs[UREG_I0] = orig_i0; |
| regs->pc -= 4; |
| regs->npc -= 4; |
| } |
| } |
| |
| /* Note that 'init' is a special process: it doesn't get signals it doesn't |
| * want to handle. Thus you cannot kill init even with a SIGKILL even by |
| * mistake. |
| */ |
| static void do_signal(struct pt_regs *regs, unsigned long orig_i0) |
| { |
| struct ksignal ksig; |
| int restart_syscall; |
| bool has_handler; |
| |
| /* It's a lot of work and synchronization to add a new ptrace |
| * register for GDB to save and restore in order to get |
| * orig_i0 correct for syscall restarts when debugging. |
| * |
| * Although it should be the case that most of the global |
| * registers are volatile across a system call, glibc already |
| * depends upon that fact that we preserve them. So we can't |
| * just use any global register to save away the orig_i0 value. |
| * |
| * In particular %g2, %g3, %g4, and %g5 are all assumed to be |
| * preserved across a system call trap by various pieces of |
| * code in glibc. |
| * |
| * %g7 is used as the "thread register". %g6 is not used in |
| * any fixed manner. %g6 is used as a scratch register and |
| * a compiler temporary, but it's value is never used across |
| * a system call. Therefore %g6 is usable for orig_i0 storage. |
| */ |
| if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) |
| regs->u_regs[UREG_G6] = orig_i0; |
| |
| has_handler = get_signal(&ksig); |
| |
| /* If the debugger messes with the program counter, it clears |
| * the software "in syscall" bit, directing us to not perform |
| * a syscall restart. |
| */ |
| restart_syscall = 0; |
| if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) { |
| restart_syscall = 1; |
| orig_i0 = regs->u_regs[UREG_G6]; |
| } |
| |
| if (has_handler) { |
| if (restart_syscall) |
| syscall_restart(orig_i0, regs, &ksig.ka.sa); |
| handle_signal(&ksig, regs); |
| } else { |
| if (restart_syscall) { |
| switch (regs->u_regs[UREG_I0]) { |
| case ERESTARTNOHAND: |
| case ERESTARTSYS: |
| case ERESTARTNOINTR: |
| /* replay the system call when we are done */ |
| regs->u_regs[UREG_I0] = orig_i0; |
| regs->pc -= 4; |
| regs->npc -= 4; |
| pt_regs_clear_syscall(regs); |
| fallthrough; |
| case ERESTART_RESTARTBLOCK: |
| regs->u_regs[UREG_G1] = __NR_restart_syscall; |
| regs->pc -= 4; |
| regs->npc -= 4; |
| pt_regs_clear_syscall(regs); |
| } |
| } |
| restore_saved_sigmask(); |
| } |
| } |
| |
| void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, |
| unsigned long thread_info_flags) |
| { |
| if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) |
| do_signal(regs, orig_i0); |
| if (thread_info_flags & _TIF_NOTIFY_RESUME) |
| tracehook_notify_resume(regs); |
| } |
| |
| asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr, |
| struct sigstack __user *ossptr, |
| unsigned long sp) |
| { |
| int ret = -EFAULT; |
| |
| /* First see if old state is wanted. */ |
| if (ossptr) { |
| if (put_user(current->sas_ss_sp + current->sas_ss_size, |
| &ossptr->the_stack) || |
| __put_user(on_sig_stack(sp), &ossptr->cur_status)) |
| goto out; |
| } |
| |
| /* Now see if we want to update the new state. */ |
| if (ssptr) { |
| char *ss_sp; |
| |
| if (get_user(ss_sp, &ssptr->the_stack)) |
| goto out; |
| /* If the current stack was set with sigaltstack, don't |
| swap stacks while we are on it. */ |
| ret = -EPERM; |
| if (current->sas_ss_sp && on_sig_stack(sp)) |
| goto out; |
| |
| /* Since we don't know the extent of the stack, and we don't |
| track onstack-ness, but rather calculate it, we must |
| presume a size. Ho hum this interface is lossy. */ |
| current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ; |
| current->sas_ss_size = SIGSTKSZ; |
| } |
| ret = 0; |
| out: |
| return ret; |
| } |