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-rw-r--r--arch/mips/kernel/signal.c673
1 files changed, 673 insertions, 0 deletions
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
new file mode 100644
index 000000000..6a28c792d
--- /dev/null
+++ b/arch/mips/kernel/signal.c
@@ -0,0 +1,673 @@
+/*
+ * 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.
+ * Copyright (C) 2014, Imagination Technologies Ltd.
+ */
+#include <linux/cache.h>
+#include <linux/context_tracking.h>
+#include <linux/irqflags.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 <linux/tracehook.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/ucontext.h>
+#include <asm/cpu-features.h>
+#include <asm/war.h>
+#include <asm/vdso.h>
+#include <asm/dsp.h>
+#include <asm/inst.h>
+
+#include "signal-common.h"
+
+static int (*save_fp_context)(struct sigcontext __user *sc);
+static int (*restore_fp_context)(struct sigcontext __user *sc);
+
+extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
+extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
+
+struct sigframe {
+ u32 sf_ass[4]; /* argument save space for o32 */
+ u32 sf_pad[2]; /* Was: signal trampoline */
+ struct sigcontext sf_sc;
+ sigset_t sf_mask;
+};
+
+struct rt_sigframe {
+ u32 rs_ass[4]; /* argument save space for o32 */
+ u32 rs_pad[2]; /* Was: signal trampoline */
+ struct siginfo rs_info;
+ struct ucontext 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_sigcontext(struct sigcontext __user *sc)
+{
+ int i;
+ int err = 0;
+
+ for (i = 0; i < NUM_FPU_REGS; i++) {
+ err |=
+ __put_user(get_fpr64(&current->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_sigcontext(struct sigcontext __user *sc)
+{
+ int i;
+ int err = 0;
+ u64 fpr_val;
+
+ for (i = 0; i < NUM_FPU_REGS; i++) {
+ err |= __get_user(fpr_val, &sc->sc_fpregs[i]);
+ set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
+ }
+ err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
+
+ return err;
+}
+
+/*
+ * Helper routines
+ */
+static int protected_save_fp_context(struct sigcontext __user *sc)
+{
+ int err;
+#ifndef CONFIG_EVA
+ while (1) {
+ lock_fpu_owner();
+ if (is_fpu_owner()) {
+ err = save_fp_context(sc);
+ unlock_fpu_owner();
+ } else {
+ unlock_fpu_owner();
+ err = copy_fp_to_sigcontext(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 */
+ }
+#else
+ /*
+ * EVA does not have FPU EVA instructions so saving fpu context directly
+ * does not work.
+ */
+ lose_fpu(1);
+ err = save_fp_context(sc); /* this might fail */
+#endif
+ return err;
+}
+
+static int protected_restore_fp_context(struct sigcontext __user *sc)
+{
+ int err, tmp __maybe_unused;
+#ifndef CONFIG_EVA
+ while (1) {
+ lock_fpu_owner();
+ if (is_fpu_owner()) {
+ err = restore_fp_context(sc);
+ unlock_fpu_owner();
+ } else {
+ unlock_fpu_owner();
+ err = copy_fp_from_sigcontext(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 */
+ }
+#else
+ /*
+ * EVA does not have FPU EVA instructions so restoring fpu context
+ * directly does not work.
+ */
+ lose_fpu(0);
+ err = restore_fp_context(sc); /* this might fail */
+#endif
+ return err;
+}
+
+int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ int err = 0;
+ int i;
+ unsigned int 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]);
+
+#ifdef CONFIG_CPU_HAS_SMARTMIPS
+ err |= __put_user(regs->acx, &sc->sc_acx);
+#endif
+ err |= __put_user(regs->hi, &sc->sc_mdhi);
+ err |= __put_user(regs->lo, &sc->sc_mdlo);
+ if (cpu_has_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);
+ err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
+ }
+
+ 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_context(sc);
+ }
+ return err;
+}
+
+int fpcsr_pending(unsigned int __user *fpcsr)
+{
+ int err, sig = 0;
+ unsigned int csr, enabled;
+
+ err = __get_user(csr, fpcsr);
+ enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
+ /*
+ * If the signal handler set some FPU exceptions, clear it and
+ * send SIGFPE.
+ */
+ if (csr & enabled) {
+ csr &= ~enabled;
+ err |= __put_user(csr, fpcsr);
+ sig = SIGFPE;
+ }
+ return err ?: sig;
+}
+
+static int
+check_and_restore_fp_context(struct sigcontext __user *sc)
+{
+ int err, sig;
+
+ err = sig = fpcsr_pending(&sc->sc_fpc_csr);
+ if (err > 0)
+ err = 0;
+ err |= protected_restore_fp_context(sc);
+ return err ?: sig;
+}
+
+int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ unsigned int used_math;
+ unsigned long treg;
+ int err = 0;
+ 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);
+
+#ifdef CONFIG_CPU_HAS_SMARTMIPS
+ err |= __get_user(regs->acx, &sc->sc_acx);
+#endif
+ 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_context(sc);
+ } else {
+ /* signal handler may have used FPU. Give it up. */
+ lose_fpu(0);
+ }
+
+ return err;
+}
+
+void __user *get_sigframe(struct ksignal *ksig, 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;
+
+ sp = sigsp(sp, ksig);
+
+ return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
+}
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+
+#ifdef CONFIG_TRAD_SIGNALS
+SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
+{
+ return sys_rt_sigsuspend(uset, sizeof(sigset_t));
+}
+#endif
+
+#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
+
+#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;
+
+ set_current_blocked(&blocked);
+
+ sig = restore_sigcontext(&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);
+}
+#endif /* CONFIG_TRAD_SIGNALS */
+
+asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
+{
+ struct rt_sigframe __user *frame;
+ sigset_t set;
+ 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;
+
+ set_current_blocked(&set);
+
+ sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
+ if (sig < 0)
+ goto badframe;
+ else if (sig)
+ force_sig(sig, current);
+
+ if (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);
+}
+
+#ifdef CONFIG_TRAD_SIGNALS
+static int setup_frame(void *sig_return, struct ksignal *ksig,
+ struct pt_regs *regs, sigset_t *set)
+{
+ struct sigframe __user *frame;
+ int err = 0;
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame));
+ if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+ return -EFAULT;
+
+ err |= setup_sigcontext(regs, &frame->sf_sc);
+ err |= __copy_to_user(&frame->sf_mask, set, sizeof(*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;
+}
+#endif
+
+static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
+ struct pt_regs *regs, sigset_t *set)
+{
+ struct rt_sigframe __user *frame;
+ int err = 0;
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame));
+ if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+ return -EFAULT;
+
+ /* Create siginfo. */
+ err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->rs_uc.uc_flags);
+ err |= __put_user(NULL, &frame->rs_uc.uc_link);
+ err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
+ err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
+ err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*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_sigframe.
+ */
+ 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;
+}
+
+struct mips_abi mips_abi = {
+#ifdef CONFIG_TRAD_SIGNALS
+ .setup_frame = setup_frame,
+ .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
+#endif
+ .setup_rt_frame = setup_rt_frame,
+ .rt_signal_return_offset =
+ offsetof(struct mips_vdso, rt_signal_trampoline),
+ .restart = __NR_restart_syscall
+};
+
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+ sigset_t *oldset = sigmask_to_save();
+ int ret;
+ struct mips_abi *abi = current->thread.abi;
+#ifdef CONFIG_CPU_MICROMIPS
+ void *vdso;
+ unsigned long tmp = (unsigned long)current->mm->context.vdso;
+
+ set_isa16_mode(tmp);
+ vdso = (void *)tmp;
+#else
+ void *vdso = current->mm->context.vdso;
+#endif
+
+ if (regs->regs[0]) {
+ switch(regs->regs[2]) {
+ case ERESTART_RESTARTBLOCK:
+ case ERESTARTNOHAND:
+ regs->regs[2] = EINTR;
+ break;
+ case ERESTARTSYS:
+ if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+ regs->regs[2] = EINTR;
+ break;
+ }
+ /* fallthrough */
+ case ERESTARTNOINTR:
+ regs->regs[7] = regs->regs[26];
+ regs->regs[2] = regs->regs[0];
+ regs->cp0_epc -= 4;
+ }
+
+ regs->regs[0] = 0; /* Don't deal with this again. */
+ }
+
+ if (sig_uses_siginfo(&ksig->ka))
+ ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
+ ksig, regs, oldset);
+ else
+ ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig,
+ regs, oldset);
+
+ signal_setup_done(ret, ksig, 0);
+}
+
+static void do_signal(struct pt_regs *regs)
+{
+ struct ksignal ksig;
+
+ if (get_signal(&ksig)) {
+ /* Whee! Actually deliver the signal. */
+ handle_signal(&ksig, regs);
+ return;
+ }
+
+ if (regs->regs[0]) {
+ switch (regs->regs[2]) {
+ case ERESTARTNOHAND:
+ case ERESTARTSYS:
+ case ERESTARTNOINTR:
+ regs->regs[2] = regs->regs[0];
+ regs->regs[7] = regs->regs[26];
+ regs->cp0_epc -= 4;
+ break;
+
+ case ERESTART_RESTARTBLOCK:
+ regs->regs[2] = current->thread.abi->restart;
+ regs->regs[7] = regs->regs[26];
+ regs->cp0_epc -= 4;
+ break;
+ }
+ regs->regs[0] = 0; /* Don't deal with this again. */
+ }
+
+ /*
+ * If there's no signal to deliver, we just put the saved sigmask
+ * back
+ */
+ restore_saved_sigmask();
+}
+
+/*
+ * 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)
+{
+ local_irq_enable();
+
+ user_exit();
+
+ /* deal with pending signal delivery */
+ if (thread_info_flags & _TIF_SIGPENDING)
+ do_signal(regs);
+
+ if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+
+ user_enter();
+}
+
+#ifdef CONFIG_SMP
+#ifndef CONFIG_EVA
+static int smp_save_fp_context(struct sigcontext __user *sc)
+{
+ return raw_cpu_has_fpu
+ ? _save_fp_context(sc)
+ : copy_fp_to_sigcontext(sc);
+}
+
+static int smp_restore_fp_context(struct sigcontext __user *sc)
+{
+ return raw_cpu_has_fpu
+ ? _restore_fp_context(sc)
+ : copy_fp_from_sigcontext(sc);
+}
+#endif /* CONFIG_EVA */
+#endif
+
+static int signal_setup(void)
+{
+#ifndef CONFIG_EVA
+#ifdef CONFIG_SMP
+ /* For now just do the cpu_has_fpu check when the functions are invoked */
+ save_fp_context = smp_save_fp_context;
+ restore_fp_context = smp_restore_fp_context;
+#else
+ if (cpu_has_fpu) {
+ save_fp_context = _save_fp_context;
+ restore_fp_context = _restore_fp_context;
+ } else {
+ save_fp_context = copy_fp_to_sigcontext;
+ restore_fp_context = copy_fp_from_sigcontext;
+ }
+#endif /* CONFIG_SMP */
+#else
+ save_fp_context = copy_fp_to_sigcontext;
+ restore_fp_context = copy_fp_from_sigcontext;
+#endif
+
+ return 0;
+}
+
+arch_initcall(signal_setup);
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-28 15:15:29 +0000