diff options
Diffstat (limited to 'arch/mips/kernel/signal_o32.c')
| -rw-r--r-- | arch/mips/kernel/signal_o32.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/arch/mips/kernel/signal_o32.c b/arch/mips/kernel/signal_o32.c new file mode 100644 index 000000000..b6e3ddef4 --- /dev/null +++ b/arch/mips/kernel/signal_o32.c @@ -0,0 +1,290 @@ +/* + * 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. + * Copyright (C) 2016, Imagination Technologies Ltd. + */ +#include <linux/compiler.h> +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/sched/signal.h> +#include <linux/uaccess.h> + +#include <asm/abi.h> +#include <asm/compat-signal.h> +#include <asm/dsp.h> +#include <asm/sim.h> +#include <asm/unistd.h> + +#include "signal-common.h" + +/* + * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... + */ +#define __NR_O32_restart_syscall 4253 + +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 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 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; +}; + +static int setup_sigcontext32(struct pt_regs *regs, + struct sigcontext32 __user *sc) +{ + int err = 0; + int i; + + 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); + } + + /* + * Save FPU state to signal context. Signal handler + * will "inherit" current FPU state. + */ + err |= protected_save_fp_context(sc); + + return err; +} + +static int restore_sigcontext32(struct pt_regs *regs, + struct sigcontext32 __user *sc) +{ + 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]); + + return err ?: protected_restore_fp_context(sc); +} + +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; +} + +asmlinkage void sys32_rt_sigreturn(void) +{ + struct rt_sigframe32 __user *frame; + struct pt_regs *regs; + sigset_t set; + int sig; + + regs = current_pt_regs(); + 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(regs, &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" (regs)); + /* Unreached */ + +badframe: + force_sig(SIGSEGV, current); +} + +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, + .setup_rt_frame = setup_rt_frame_32, + .restart = __NR_O32_restart_syscall, + + .off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs), + .off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr), + .off_sc_used_math = offsetof(struct sigcontext32, sc_used_math), + + .vdso = &vdso_image_o32, +}; + + +asmlinkage void sys32_sigreturn(void) +{ + struct sigframe32 __user *frame; + struct pt_regs *regs; + sigset_t blocked; + int sig; + + regs = current_pt_regs(); + 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(regs, &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" (regs)); + /* Unreached */ + +badframe: + force_sig(SIGSEGV, current); +} |