diff options
Diffstat (limited to 'arch/mips/kernel/signal32.c')
| -rw-r--r-- | arch/mips/kernel/signal32.c | 606 |
1 files changed, 606 insertions, 0 deletions
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c new file mode 100644 index 000000000..19a7705f2 --- /dev/null +++ b/arch/mips/kernel/signal32.c @@ -0,0 +1,606 @@ +/* + * 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, 2006 Ralf Baechle + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. + */ +#include <linux/cache.h> +#include <linux/compat.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/kernel.h> +#include <linux/signal.h> +#include <linux/syscalls.h> +#include <linux/errno.h> +#include <linux/wait.h> +#include <linux/ptrace.h> +#include <linux/suspend.h> +#include <linux/compiler.h> +#include <linux/uaccess.h> + +#include <asm/abi.h> +#include <asm/asm.h> +#include <asm/compat-signal.h> +#include <linux/bitops.h> +#include <asm/cacheflush.h> +#include <asm/sim.h> +#include <asm/ucontext.h> +#include <asm/fpu.h> +#include <asm/war.h> +#include <asm/vdso.h> +#include <asm/dsp.h> + +#include "signal-common.h" + +static int (*save_fp_context32)(struct sigcontext32 __user *sc); +static int (*restore_fp_context32)(struct sigcontext32 __user *sc); + +extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc); +extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc); + +/* + * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... + */ +#define __NR_O32_restart_syscall 4253 + +/* 32-bit compatibility types */ + +typedef unsigned int __sighandler32_t; +typedef void (*vfptr_t)(void); + +struct ucontext32 { + u32 uc_flags; + s32 uc_link; + compat_stack_t uc_stack; + struct sigcontext32 uc_mcontext; + compat_sigset_t uc_sigmask; /* mask last for extensibility */ +}; + +struct sigframe32 { + u32 sf_ass[4]; /* argument save space for o32 */ + u32 sf_pad[2]; /* Was: signal trampoline */ + struct sigcontext32 sf_sc; + compat_sigset_t sf_mask; +}; + +struct rt_sigframe32 { + u32 rs_ass[4]; /* argument save space for o32 */ + u32 rs_pad[2]; /* Was: signal trampoline */ + compat_siginfo_t rs_info; + struct ucontext32 rs_uc; +}; + +/* + * Thread saved context copy to/from a signal context presumed to be on the + * user stack, and therefore accessed with appropriate macros from uaccess.h. + */ +static int copy_fp_to_sigcontext32(struct sigcontext32 __user *sc) +{ + int i; + int err = 0; + int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1; + + for (i = 0; i < NUM_FPU_REGS; i += inc) { + err |= + __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0), + &sc->sc_fpregs[i]); + } + err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr); + + return err; +} + +static int copy_fp_from_sigcontext32(struct sigcontext32 __user *sc) +{ + int i; + int err = 0; + int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1; + u64 fpr_val; + + for (i = 0; i < NUM_FPU_REGS; i += inc) { + err |= __get_user(fpr_val, &sc->sc_fpregs[i]); + set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val); + } + err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr); + + return err; +} + +/* + * sigcontext handlers + */ +static int protected_save_fp_context32(struct sigcontext32 __user *sc) +{ + int err; + while (1) { + lock_fpu_owner(); + if (is_fpu_owner()) { + err = save_fp_context32(sc); + unlock_fpu_owner(); + } else { + unlock_fpu_owner(); + err = copy_fp_to_sigcontext32(sc); + } + if (likely(!err)) + break; + /* touch the sigcontext and try again */ + err = __put_user(0, &sc->sc_fpregs[0]) | + __put_user(0, &sc->sc_fpregs[31]) | + __put_user(0, &sc->sc_fpc_csr); + if (err) + break; /* really bad sigcontext */ + } + return err; +} + +static int protected_restore_fp_context32(struct sigcontext32 __user *sc) +{ + int err, tmp __maybe_unused; + while (1) { + lock_fpu_owner(); + if (is_fpu_owner()) { + err = restore_fp_context32(sc); + unlock_fpu_owner(); + } else { + unlock_fpu_owner(); + err = copy_fp_from_sigcontext32(sc); + } + if (likely(!err)) + break; + /* touch the sigcontext and try again */ + err = __get_user(tmp, &sc->sc_fpregs[0]) | + __get_user(tmp, &sc->sc_fpregs[31]) | + __get_user(tmp, &sc->sc_fpc_csr); + if (err) + break; /* really bad sigcontext */ + } + return err; +} + +static int setup_sigcontext32(struct pt_regs *regs, + struct sigcontext32 __user *sc) +{ + int err = 0; + int i; + u32 used_math; + + err |= __put_user(regs->cp0_epc, &sc->sc_pc); + + 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); + if (cpu_has_dsp) { + err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); + err |= __put_user(mfhi1(), &sc->sc_hi1); + err |= __put_user(mflo1(), &sc->sc_lo1); + err |= __put_user(mfhi2(), &sc->sc_hi2); + err |= __put_user(mflo2(), &sc->sc_lo2); + err |= __put_user(mfhi3(), &sc->sc_hi3); + err |= __put_user(mflo3(), &sc->sc_lo3); + } + + used_math = !!used_math(); + err |= __put_user(used_math, &sc->sc_used_math); + + if (used_math) { + /* + * Save FPU state to signal context. Signal handler + * will "inherit" current FPU state. + */ + err |= protected_save_fp_context32(sc); + } + return err; +} + +static int +check_and_restore_fp_context32(struct sigcontext32 __user *sc) +{ + int err, sig; + + err = sig = fpcsr_pending(&sc->sc_fpc_csr); + if (err > 0) + err = 0; + err |= protected_restore_fp_context32(sc); + return err ?: sig; +} + +static int restore_sigcontext32(struct pt_regs *regs, + struct sigcontext32 __user *sc) +{ + u32 used_math; + int err = 0; + s32 treg; + int i; + + /* Always make any pending restarted system calls return -EINTR */ + current->restart_block.fn = do_no_restart_syscall; + + err |= __get_user(regs->cp0_epc, &sc->sc_pc); + err |= __get_user(regs->hi, &sc->sc_mdhi); + err |= __get_user(regs->lo, &sc->sc_mdlo); + if (cpu_has_dsp) { + err |= __get_user(treg, &sc->sc_hi1); mthi1(treg); + err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg); + err |= __get_user(treg, &sc->sc_hi2); mthi2(treg); + err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg); + err |= __get_user(treg, &sc->sc_hi3); mthi3(treg); + err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg); + err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK); + } + + for (i = 1; i < 32; i++) + err |= __get_user(regs->regs[i], &sc->sc_regs[i]); + + err |= __get_user(used_math, &sc->sc_used_math); + conditional_used_math(used_math); + + if (used_math) { + /* restore fpu context if we have used it before */ + if (!err) + err = check_and_restore_fp_context32(sc); + } else { + /* signal handler may have used FPU. Give it up. */ + lose_fpu(0); + } + + return err; +} + +/* + * + */ +extern void __put_sigset_unknown_nsig(void); +extern void __get_sigset_unknown_nsig(void); + +static inline int put_sigset(const sigset_t *kbuf, compat_sigset_t __user *ubuf) +{ + int err = 0; + + if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf))) + return -EFAULT; + + switch (_NSIG_WORDS) { + default: + __put_sigset_unknown_nsig(); + case 2: + err |= __put_user(kbuf->sig[1] >> 32, &ubuf->sig[3]); + err |= __put_user(kbuf->sig[1] & 0xffffffff, &ubuf->sig[2]); + case 1: + err |= __put_user(kbuf->sig[0] >> 32, &ubuf->sig[1]); + err |= __put_user(kbuf->sig[0] & 0xffffffff, &ubuf->sig[0]); + } + + return err; +} + +static inline int get_sigset(sigset_t *kbuf, const compat_sigset_t __user *ubuf) +{ + int err = 0; + unsigned long sig[4]; + + if (!access_ok(VERIFY_READ, ubuf, sizeof(*ubuf))) + return -EFAULT; + + switch (_NSIG_WORDS) { + default: + __get_sigset_unknown_nsig(); + case 2: + err |= __get_user(sig[3], &ubuf->sig[3]); + err |= __get_user(sig[2], &ubuf->sig[2]); + kbuf->sig[1] = sig[2] | (sig[3] << 32); + case 1: + err |= __get_user(sig[1], &ubuf->sig[1]); + err |= __get_user(sig[0], &ubuf->sig[0]); + kbuf->sig[0] = sig[0] | (sig[1] << 32); + } + + return err; +} + +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ + +asmlinkage int sys32_sigsuspend(compat_sigset_t __user *uset) +{ + return compat_sys_rt_sigsuspend(uset, sizeof(compat_sigset_t)); +} + +SYSCALL_DEFINE3(32_sigaction, long, sig, const struct compat_sigaction __user *, act, + struct compat_sigaction __user *, oact) +{ + struct k_sigaction new_ka, old_ka; + int ret; + int err = 0; + + if (act) { + old_sigset_t mask; + s32 handler; + + if (!access_ok(VERIFY_READ, act, sizeof(*act))) + return -EFAULT; + err |= __get_user(handler, &act->sa_handler); + new_ka.sa.sa_handler = (void __user *)(s64)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((u32)(u64)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; +} + +int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from) +{ + int err; + + if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t))) + return -EFAULT; + + /* If you change siginfo_t structure, please be sure + this code is fixed accordingly. + It should never copy any pad contained in the structure + to avoid security leaks, but must copy the generic + 3 ints plus the relevant union member. + This routine must convert siginfo from 64bit to 32bit as well + at the same time. */ + err = __put_user(from->si_signo, &to->si_signo); + err |= __put_user(from->si_errno, &to->si_errno); + err |= __put_user((short)from->si_code, &to->si_code); + if (from->si_code < 0) + err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE); + else { + switch (from->si_code >> 16) { + case __SI_TIMER >> 16: + err |= __put_user(from->si_tid, &to->si_tid); + err |= __put_user(from->si_overrun, &to->si_overrun); + err |= __put_user(from->si_int, &to->si_int); + break; + case __SI_CHLD >> 16: + err |= __put_user(from->si_utime, &to->si_utime); + err |= __put_user(from->si_stime, &to->si_stime); + err |= __put_user(from->si_status, &to->si_status); + default: + err |= __put_user(from->si_pid, &to->si_pid); + err |= __put_user(from->si_uid, &to->si_uid); + break; + case __SI_FAULT >> 16: + err |= __put_user((unsigned long)from->si_addr, &to->si_addr); + break; + case __SI_POLL >> 16: + err |= __put_user(from->si_band, &to->si_band); + err |= __put_user(from->si_fd, &to->si_fd); + break; + case __SI_RT >> 16: /* This is not generated by the kernel as of now. */ + case __SI_MESGQ >> 16: + err |= __put_user(from->si_pid, &to->si_pid); + err |= __put_user(from->si_uid, &to->si_uid); + err |= __put_user(from->si_int, &to->si_int); + break; + } + } + return err; +} + +int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) +{ + memset(to, 0, sizeof *to); + + if (copy_from_user(to, from, 3*sizeof(int)) || + copy_from_user(to->_sifields._pad, + from->_sifields._pad, SI_PAD_SIZE32)) + return -EFAULT; + + return 0; +} + +asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs) +{ + struct sigframe32 __user *frame; + sigset_t blocked; + int sig; + + frame = (struct sigframe32 __user *) regs.regs[29]; + if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) + goto badframe; + if (__copy_conv_sigset_from_user(&blocked, &frame->sf_mask)) + goto badframe; + + set_current_blocked(&blocked); + + sig = restore_sigcontext32(®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); +} + +asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) +{ + struct rt_sigframe32 __user *frame; + sigset_t set; + int sig; + + frame = (struct rt_sigframe32 __user *) regs.regs[29]; + if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) + goto badframe; + if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask)) + goto badframe; + + set_current_blocked(&set); + + sig = restore_sigcontext32(®s, &frame->rs_uc.uc_mcontext); + if (sig < 0) + goto badframe; + else if (sig) + force_sig(sig, current); + + if (compat_restore_altstack(&frame->rs_uc.uc_stack)) + goto badframe; + + /* + * 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); +} + +static int setup_frame_32(void *sig_return, struct ksignal *ksig, + struct pt_regs *regs, sigset_t *set) +{ + struct sigframe32 __user *frame; + int err = 0; + + frame = get_sigframe(ksig, regs, sizeof(*frame)); + if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) + return -EFAULT; + + err |= setup_sigcontext32(regs, &frame->sf_sc); + err |= __copy_conv_sigset_to_user(&frame->sf_mask, set); + + if (err) + return -EFAULT; + + /* + * 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] = ksig->sig; + regs->regs[ 5] = 0; + regs->regs[ 6] = (unsigned long) &frame->sf_sc; + regs->regs[29] = (unsigned long) frame; + regs->regs[31] = (unsigned long) sig_return; + regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->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; +} + +static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig, + struct pt_regs *regs, sigset_t *set) +{ + struct rt_sigframe32 __user *frame; + int err = 0; + + frame = get_sigframe(ksig, regs, sizeof(*frame)); + if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) + return -EFAULT; + + /* Convert (siginfo_t -> compat_siginfo_t) and copy to user. */ + err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info); + + /* Create the ucontext. */ + err |= __put_user(0, &frame->rs_uc.uc_flags); + err |= __put_user(0, &frame->rs_uc.uc_link); + err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); + err |= setup_sigcontext32(regs, &frame->rs_uc.uc_mcontext); + err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set); + + if (err) + return -EFAULT; + + /* + * 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_sigframe32. + */ + regs->regs[ 4] = ksig->sig; + 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) sig_return; + regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->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; +} + +/* + * o32 compatibility on 64-bit kernels, without DSP ASE + */ +struct mips_abi mips_abi_32 = { + .setup_frame = setup_frame_32, + .signal_return_offset = + offsetof(struct mips_vdso, o32_signal_trampoline), + .setup_rt_frame = setup_rt_frame_32, + .rt_signal_return_offset = + offsetof(struct mips_vdso, o32_rt_signal_trampoline), + .restart = __NR_O32_restart_syscall +}; + +static int signal32_init(void) +{ + if (cpu_has_fpu) { + save_fp_context32 = _save_fp_context32; + restore_fp_context32 = _restore_fp_context32; + } else { + save_fp_context32 = copy_fp_to_sigcontext32; + restore_fp_context32 = copy_fp_from_sigcontext32; + } + + return 0; +} + +arch_initcall(signal32_init); |