diff options
Diffstat (limited to 'target/linux/realtek/files/arch/rlx/kernel/signal.c')
| -rw-r--r-- | target/linux/realtek/files/arch/rlx/kernel/signal.c | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/target/linux/realtek/files/arch/rlx/kernel/signal.c b/target/linux/realtek/files/arch/rlx/kernel/signal.c new file mode 100644 index 000000000..93aca32a3 --- /dev/null +++ b/target/linux/realtek/files/arch/rlx/kernel/signal.c @@ -0,0 +1,550 @@ +/* + * 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/cache.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/personality.h> +#include <linux/smp.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 <linux/syscalls.h> +#include <linux/uaccess.h> + +#include <asm/abi.h> +#include <asm/asm.h> +#include <linux/bitops.h> +#include <asm/cacheflush.h> +#include <asm/sim.h> +#include <asm/ucontext.h> +#include <asm/cpu-features.h> + +#include "signal-common.h" + +/* + * 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. + */ +struct sigframe { + u32 sf_ass[4]; /* argument save space for o32 */ + u32 sf_code[2]; /* signal trampoline */ + struct sigcontext sf_sc; + sigset_t sf_mask; +}; + +struct rt_sigframe { + u32 rs_ass[4]; /* argument save space for o32 */ + u32 rs_code[2]; /* signal trampoline */ + struct siginfo rs_info; + struct ucontext rs_uc; +}; + +/* + * Helper routines + */ +int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) +{ + int err = 0; + int i; + + err |= __put_user(0, &sc->sc_regs[0]); + for (i = 1; i < 32; i++) + err |= __put_user(regs->regs[i], &sc->sc_regs[i]); + + err |= __put_user(regs->hi, &sc->sc_mdhi); + err |= __put_user(regs->lo, &sc->sc_mdlo); + err |= __put_user(regs->cp0_epc, &sc->sc_pc); + + return err; +} + +int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) +{ + int err = 0; + int i; + + /* Always make any pending restarted system calls return -EINTR */ + current_thread_info()->restart_block.fn = do_no_restart_syscall; + + err |= __get_user(regs->cp0_epc, &sc->sc_pc); + err |= __get_user(regs->lo, &sc->sc_mdlo); + err |= __get_user(regs->hi, &sc->sc_mdhi); + + for (i = 1; i < 32; i++) + err |= __get_user(regs->regs[i], &sc->sc_regs[i]); + + return err; +} + +void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, + size_t frame_size) +{ + unsigned long sp; + + /* Default to using normal stack */ + sp = regs->regs[29]; + + /* + * FPU emulator may have it's own trampoline active just + * above the user stack, 16-bytes before the next lowest + * 16 byte boundary. Try to avoid trashing it. + */ + sp -= 32; + + /* This is the X/Open sanctioned signal stack switching. */ + if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0)) + sp = current->sas_ss_sp + current->sas_ss_size; + + return (void __user *)((sp - frame_size) & ALMASK); +} + +int install_sigtramp(unsigned int __user *tramp, unsigned int syscall) +{ + int err; + + /* + * Set up the return code ... + * + * li v0, __NR__foo_sigreturn + * syscall + */ + + err = __put_user(0x24020000 + syscall, tramp + 0); + err |= __put_user(0x0000000c , tramp + 1); + + flush_cache_sigtramp((unsigned long) tramp); + + return err; +} + +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ + +#ifdef CONFIG_TRAD_SIGNALS +asmlinkage int sys_sigsuspend(nabi_no_regargs struct pt_regs regs) +{ + sigset_t 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); + current->saved_sigmask = current->blocked; + current->blocked = newset; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + current->state = TASK_INTERRUPTIBLE; + schedule(); + set_thread_flag(TIF_RESTORE_SIGMASK); + return -ERESTARTNOHAND; +} +#endif + +asmlinkage int sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs) +{ + sigset_t 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); + current->saved_sigmask = current->blocked; + current->blocked = newset; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + current->state = TASK_INTERRUPTIBLE; + schedule(); + set_thread_flag(TIF_RESTORE_SIGMASK); + return -ERESTARTNOHAND; +} + +#ifdef CONFIG_TRAD_SIGNALS +SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act, + struct sigaction __user *, 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); +} + +#ifdef CONFIG_TRAD_SIGNALS +asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs) +{ + struct sigframe __user *frame; + sigset_t blocked; + int sig; + + frame = (struct sigframe __user *) 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); + + sig = restore_sigcontext(®s, &frame->sf_sc); + if (sig < 0) + goto badframe; + else if (sig) + force_sig(sig, current); + + /* + * 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); +} +#endif /* CONFIG_TRAD_SIGNALS */ + +asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs) +{ + struct rt_sigframe __user *frame; + sigset_t set; + stack_t st; + int sig; + + frame = (struct rt_sigframe __user *) 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); + + sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext); + if (sig < 0) + goto badframe; + else if (sig) + force_sig(sig, current); + + 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((stack_t __user *)&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 +static int setup_frame(struct k_sigaction * ka, struct pt_regs *regs, + int signr, sigset_t *set) +{ + struct sigframe __user *frame; + int err = 0; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) + goto give_sigsegv; + + err |= 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; + + DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", + current->comm, current->pid, + frame, regs->cp0_epc, regs->regs[31]); + return 0; + +give_sigsegv: + force_sigsegv(signr, current); + return -EFAULT; +} +#endif + +static int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs, + int signr, sigset_t *set, siginfo_t *info) +{ + struct rt_sigframe __user *frame; + int err = 0; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) + goto give_sigsegv; + + err |= 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(NULL, &frame->rs_uc.uc_link); + err |= __put_user((void __user *)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; + + DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", + current->comm, current->pid, + frame, regs->cp0_epc, regs->regs[31]); + + return 0; + +give_sigsegv: + force_sigsegv(signr, current); + return -EFAULT; +} + +struct mips_abi mips_abi = { +#ifdef CONFIG_TRAD_SIGNALS + .setup_frame = setup_frame, +#endif + .setup_rt_frame = setup_rt_frame, + .restart = __NR_restart_syscall +}; + +static 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; +} + +static void do_signal(struct pt_regs *regs) +{ + struct k_sigaction ka; + sigset_t *oldset; + 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; + + if (test_thread_flag(TIF_RESTORE_SIGMASK)) + oldset = ¤t->saved_sigmask; + else + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + /* Whee! Actually deliver the signal. */ + if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { + /* + * A signal was successfully delivered; the saved + * sigmask will have been stored in the signal frame, + * and will be restored by sigreturn, so we can simply + * clear the TIF_RESTORE_SIGMASK flag. + */ + if (test_thread_flag(TIF_RESTORE_SIGMASK)) + clear_thread_flag(TIF_RESTORE_SIGMASK); + } + + return; + } + + /* + * 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] = current->thread.abi->restart; + regs->regs[7] = regs->regs[26]; + regs->cp0_epc -= 4; + } + regs->regs[0] = 0; /* Don't deal with this again. */ + } + + /* + * If there's no signal to deliver, we just put the saved sigmask + * back + */ + if (test_thread_flag(TIF_RESTORE_SIGMASK)) { + clear_thread_flag(TIF_RESTORE_SIGMASK); + sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); + } +} + +/* + * notification of userspace execution resumption + * - triggered by the TIF_WORK_MASK flags + */ +asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, + __u32 thread_info_flags) +{ + /* deal with pending signal delivery */ + if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) + do_signal(regs); +} |