/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 1994 - 2000 Ralf Baechle * Copyright (C) 1999, 2000 Silicon Graphics, Inc. */ #include <linux/config.h> #include <linux/cache.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/personality.h> #include <linux/smp.h> #include <linux/smp_lock.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/compiler.h> #include <asm/abi.h> #include <asm/asm.h> #include <linux/bitops.h> #include <asm/cacheflush.h> #include <asm/fpu.h> #include <asm/sim.h> #include <asm/uaccess.h> #include <asm/ucontext.h> #include <asm/cpu-features.h> #include <asm/war.h> #include "signal-common.h" #define DEBUG_SIG 0 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) int do_signal(sigset_t *oldset, struct pt_regs *regs); /* * Atomically swap in the new signal mask, and wait for a signal. */ #ifdef CONFIG_TRAD_SIGNALS save_static_function(sys_sigsuspend); __attribute_used__ noinline static int _sys_sigsuspend(nabi_no_regargs struct pt_regs regs) { sigset_t saveset, newset; sigset_t __user *uset; uset = (sigset_t __user *) regs.regs[4]; if (copy_from_user(&newset, uset, sizeof(sigset_t))) return -EFAULT; sigdelsetmask(&newset, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); saveset = current->blocked; current->blocked = newset; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); regs.regs[2] = EINTR; regs.regs[7] = 1; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(&saveset, ®s)) return -EINTR; } } #endif save_static_function(sys_rt_sigsuspend); __attribute_used__ noinline static int _sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs) { sigset_t saveset, newset; sigset_t __user *unewset; size_t sigsetsize; /* XXX Don't preclude handling different sized sigset_t's. */ sigsetsize = regs.regs[5]; if (sigsetsize != sizeof(sigset_t)) return -EINVAL; unewset = (sigset_t __user *) regs.regs[4]; if (copy_from_user(&newset, unewset, sizeof(newset))) return -EFAULT; sigdelsetmask(&newset, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); saveset = current->blocked; current->blocked = newset; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); regs.regs[2] = EINTR; regs.regs[7] = 1; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(&saveset, ®s)) return -EINTR; } } #ifdef CONFIG_TRAD_SIGNALS asmlinkage int sys_sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { struct k_sigaction new_ka, old_ka; int ret; int err = 0; if (act) { old_sigset_t mask; if (!access_ok(VERIFY_READ, act, sizeof(*act))) return -EFAULT; err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler); err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); err |= __get_user(mask, &act->sa_mask.sig[0]); if (err) return -EFAULT; siginitset(&new_ka.sa.sa_mask, mask); } ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); if (!ret && oact) { if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact))) return -EFAULT; err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler); err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig); err |= __put_user(0, &oact->sa_mask.sig[1]); err |= __put_user(0, &oact->sa_mask.sig[2]); err |= __put_user(0, &oact->sa_mask.sig[3]); if (err) return -EFAULT; } return ret; } #endif asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs) { const stack_t __user *uss = (const stack_t __user *) regs.regs[4]; stack_t __user *uoss = (stack_t __user *) regs.regs[5]; unsigned long usp = regs.regs[29]; return do_sigaltstack(uss, uoss, usp); } /* * Horribly complicated - with the bloody RM9000 workarounds enabled * the signal trampolines is moving to the end of the structure so we can * increase the alignment without breaking software compatibility. */ #ifdef CONFIG_TRAD_SIGNALS struct sigframe { u32 sf_ass[4]; /* argument save space for o32 */ #if ICACHE_REFILLS_WORKAROUND_WAR u32 sf_pad[2]; #else u32 sf_code[2]; /* signal trampoline */ #endif struct sigcontext sf_sc; sigset_t sf_mask; #if ICACHE_REFILLS_WORKAROUND_WAR u32 sf_code[8] ____cacheline_aligned; /* signal trampoline */ #endif }; #endif struct rt_sigframe { u32 rs_ass[4]; /* argument save space for o32 */ #if ICACHE_REFILLS_WORKAROUND_WAR u32 rs_pad[2]; #else u32 rs_code[2]; /* signal trampoline */ #endif struct siginfo rs_info; struct ucontext rs_uc; #if ICACHE_REFILLS_WORKAROUND_WAR u32 rs_code[8] ____cacheline_aligned; /* signal trampoline */ #endif }; #ifdef CONFIG_TRAD_SIGNALS save_static_function(sys_sigreturn); __attribute_used__ noinline static void _sys_sigreturn(nabi_no_regargs struct pt_regs regs) { struct sigframe *frame; sigset_t blocked; frame = (struct sigframe *) regs.regs[29]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked))) goto badframe; sigdelsetmask(&blocked, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = blocked; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (restore_sigcontext(®s, &frame->sf_sc)) goto badframe; /* * Don't let your children do this ... */ if (current_thread_info()->flags & TIF_SYSCALL_TRACE) do_syscall_trace(®s, 1); __asm__ __volatile__( "move\t$29, %0\n\t" "j\tsyscall_exit" :/* no outputs */ :"r" (®s)); /* Unreached */ badframe: force_sig(SIGSEGV, current); } #endif /* CONFIG_TRAD_SIGNALS */ save_static_function(sys_rt_sigreturn); __attribute_used__ noinline static void _sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs) { struct rt_sigframe *frame; sigset_t set; stack_t st; frame = (struct rt_sigframe *) regs.regs[29]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set))) goto badframe; sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (restore_sigcontext(®s, &frame->rs_uc.uc_mcontext)) goto badframe; if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st))) goto badframe; /* It is more difficult to avoid calling this function than to call it and ignore errors. */ do_sigaltstack(&st, NULL, regs.regs[29]); /* * Don't let your children do this ... */ __asm__ __volatile__( "move\t$29, %0\n\t" "j\tsyscall_exit" :/* no outputs */ :"r" (®s)); /* Unreached */ badframe: force_sig(SIGSEGV, current); } #ifdef CONFIG_TRAD_SIGNALS int setup_frame(struct k_sigaction * ka, struct pt_regs *regs, int signr, sigset_t *set) { struct sigframe *frame; int err = 0; frame = get_sigframe(ka, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) goto give_sigsegv; install_sigtramp(frame->sf_code, __NR_sigreturn); err |= setup_sigcontext(regs, &frame->sf_sc); err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set)); if (err) goto give_sigsegv; /* * Arguments to signal handler: * * a0 = signal number * a1 = 0 (should be cause) * a2 = pointer to struct sigcontext * * $25 and c0_epc point to the signal handler, $29 points to the * struct sigframe. */ regs->regs[ 4] = signr; regs->regs[ 5] = 0; regs->regs[ 6] = (unsigned long) &frame->sf_sc; regs->regs[29] = (unsigned long) frame; regs->regs[31] = (unsigned long) frame->sf_code; regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler; #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n", current->comm, current->pid, frame, regs->cp0_epc, frame->regs[31]); #endif return 1; give_sigsegv: force_sigsegv(signr, current); return 0; } #endif int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info) { struct rt_sigframe *frame; int err = 0; frame = get_sigframe(ka, regs, sizeof(*frame)); if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) goto give_sigsegv; install_sigtramp(frame->rs_code, __NR_rt_sigreturn); /* Create siginfo. */ err |= copy_siginfo_to_user(&frame->rs_info, info); /* Create the ucontext. */ err |= __put_user(0, &frame->rs_uc.uc_flags); err |= __put_user(0, &frame->rs_uc.uc_link); err |= __put_user((void *)current->sas_ss_sp, &frame->rs_uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(regs->regs[29]), &frame->rs_uc.uc_stack.ss_flags); err |= __put_user(current->sas_ss_size, &frame->rs_uc.uc_stack.ss_size); err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set)); if (err) goto give_sigsegv; /* * Arguments to signal handler: * * a0 = signal number * a1 = 0 (should be cause) * a2 = pointer to ucontext * * $25 and c0_epc point to the signal handler, $29 points to * the struct rt_sigframe. */ regs->regs[ 4] = signr; regs->regs[ 5] = (unsigned long) &frame->rs_info; regs->regs[ 6] = (unsigned long) &frame->rs_uc; regs->regs[29] = (unsigned long) frame; regs->regs[31] = (unsigned long) frame->rs_code; regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler; #if DEBUG_SIG printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n", current->comm, current->pid, frame, regs->cp0_epc, regs->regs[31]); #endif return 1; give_sigsegv: force_sigsegv(signr, current); return 0; } extern void setup_rt_frame_n32(struct k_sigaction * ka, struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info); static inline int handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs) { int ret; switch(regs->regs[0]) { case ERESTART_RESTARTBLOCK: case ERESTARTNOHAND: regs->regs[2] = EINTR; break; case ERESTARTSYS: if(!(ka->sa.sa_flags & SA_RESTART)) { regs->regs[2] = EINTR; break; } /* fallthrough */ case ERESTARTNOINTR: /* Userland will reload $v0. */ regs->regs[7] = regs->regs[26]; regs->cp0_epc -= 8; } regs->regs[0] = 0; /* Don't deal with this again. */ if (sig_uses_siginfo(ka)) ret = current->thread.abi->setup_rt_frame(ka, regs, sig, oldset, info); else ret = current->thread.abi->setup_frame(ka, regs, sig, oldset); spin_lock_irq(¤t->sighand->siglock); sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); if (!(ka->sa.sa_flags & SA_NODEFER)) sigaddset(¤t->blocked,sig); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); return ret; } int do_signal(sigset_t *oldset, struct pt_regs *regs) { struct k_sigaction ka; siginfo_t info; int signr; /* * We want the common case to go fast, which is why we may in certain * cases get here from kernel mode. Just return without doing anything * if so. */ if (!user_mode(regs)) return 1; if (try_to_freeze()) goto no_signal; if (!oldset) oldset = ¤t->blocked; signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) return handle_signal(signr, &info, &ka, oldset, regs); no_signal: /* * Who's code doesn't conform to the restartable syscall convention * dies here!!! The li instruction, a single machine instruction, * must directly be followed by the syscall instruction. */ if (regs->regs[0]) { if (regs->regs[2] == ERESTARTNOHAND || regs->regs[2] == ERESTARTSYS || regs->regs[2] == ERESTARTNOINTR) { regs->regs[7] = regs->regs[26]; regs->cp0_epc -= 8; } if (regs->regs[2] == ERESTART_RESTARTBLOCK) { regs->regs[2] = __NR_restart_syscall; regs->regs[7] = regs->regs[26]; regs->cp0_epc -= 4; } } return 0; } /* * notification of userspace execution resumption * - triggered by current->work.notify_resume */ asmlinkage void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, __u32 thread_info_flags) { /* deal with pending signal delivery */ if (thread_info_flags & _TIF_SIGPENDING) { current->thread.abi->do_signal(oldset, regs); } }