--- /dev/null
+/*
+ * arch/sh/kernel/signal_64.c
+ *
+ * Copyright (C) 2000, 2001 Paolo Alberelli
+ * Copyright (C) 2003 - 2008 Paul Mundt
+ * Copyright (C) 2004 Richard Curnow
+ *
+ * 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.
+ */
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/personality.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/tracehook.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+#include <asm/fpu.h>
+
+#define REG_RET 9
+#define REG_ARG1 2
+#define REG_ARG2 3
+#define REG_ARG3 4
+#define REG_SP 15
+#define REG_PR 18
+#define REF_REG_RET regs->regs[REG_RET]
+#define REF_REG_SP regs->regs[REG_SP]
+#define DEREF_REG_PR regs->regs[REG_PR]
+
+#define DEBUG_SIG 0
+
+static void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs);
+
+static inline void
+handle_syscall_restart(struct pt_regs *regs, struct sigaction *sa)
+{
+ /* If we're not from a syscall, bail out */
+ if (regs->syscall_nr < 0)
+ return;
+
+ /* check for system call restart.. */
+ switch (regs->regs[REG_RET]) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ no_system_call_restart:
+ regs->regs[REG_RET] = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (!(sa->sa_flags & SA_RESTART))
+ goto no_system_call_restart;
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ /* Decode syscall # */
+ regs->regs[REG_RET] = regs->syscall_nr;
+ regs->pc -= 4;
+ break;
+ }
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ *
+ * Note that we go through the signals twice: once to check the signals that
+ * the kernel can handle, and then we build all the user-level signal handling
+ * stack-frames in one go after that.
+ */
+static void do_signal(struct pt_regs *regs)
+{
+ struct ksignal ksig;
+
+ /*
+ * 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 (get_signal(&ksig)) {
+ handle_syscall_restart(regs, &ksig.ka.sa);
+
+ /* Whee! Actually deliver the signal. */
+ handle_signal(&ksig, regs);
+ return;
+ }
+
+ /* Did we come from a system call? */
+ if (regs->syscall_nr >= 0) {
+ /* Restart the system call - no handlers present */
+ switch (regs->regs[REG_RET]) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ /* Decode Syscall # */
+ regs->regs[REG_RET] = regs->syscall_nr;
+ regs->pc -= 4;
+ break;
+
+ case -ERESTART_RESTARTBLOCK:
+ regs->regs[REG_RET] = __NR_restart_syscall;
+ regs->pc -= 4;
+ break;
+ }
+ }
+
+ /* No signal to deliver -- put the saved sigmask back */
+ restore_saved_sigmask();
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+struct sigframe {
+ struct sigcontext sc;
+ unsigned long extramask[_NSIG_WORDS-1];
+ long long retcode[2];
+};
+
+struct rt_sigframe {
+ struct siginfo __user *pinfo;
+ void *puc;
+ struct siginfo info;
+ struct ucontext uc;
+ long long retcode[2];
+};
+
+#ifdef CONFIG_SH_FPU
+static inline int
+restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ int err = 0;
+ int fpvalid;
+
+ err |= __get_user (fpvalid, &sc->sc_fpvalid);
+ conditional_used_math(fpvalid);
+ if (! fpvalid)
+ return err;
+
+ if (current == last_task_used_math) {
+ last_task_used_math = NULL;
+ regs->sr |= SR_FD;
+ }
+
+ err |= __copy_from_user(¤t->thread.xstate->hardfpu, &sc->sc_fpregs[0],
+ (sizeof(long long) * 32) + (sizeof(int) * 1));
+
+ return err;
+}
+
+static inline int
+setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ int err = 0;
+ int fpvalid;
+
+ fpvalid = !!used_math();
+ err |= __put_user(fpvalid, &sc->sc_fpvalid);
+ if (! fpvalid)
+ return err;
+
+ if (current == last_task_used_math) {
+ enable_fpu();
+ save_fpu(current);
+ disable_fpu();
+ last_task_used_math = NULL;
+ regs->sr |= SR_FD;
+ }
+
+ err |= __copy_to_user(&sc->sc_fpregs[0], ¤t->thread.xstate->hardfpu,
+ (sizeof(long long) * 32) + (sizeof(int) * 1));
+ clear_used_math();
+
+ return err;
+}
+#else
+static inline int
+restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ return 0;
+}
+static inline int
+setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ return 0;
+}
+#endif
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, long long *r2_p)
+{
+ unsigned int err = 0;
+ unsigned long long current_sr, new_sr;
+#define SR_MASK 0xffff8cfd
+
+#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
+
+ COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
+ COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
+ COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
+ COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
+ COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
+ COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
+ COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
+ COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
+ COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
+ COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
+ COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
+ COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
+ COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
+ COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
+ COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
+ COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
+ COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
+ COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
+
+ /* Prevent the signal handler manipulating SR in a way that can
+ crash the kernel. i.e. only allow S, Q, M, PR, SZ, FR to be
+ modified */
+ current_sr = regs->sr;
+ err |= __get_user(new_sr, &sc->sc_sr);
+ regs->sr &= SR_MASK;
+ regs->sr |= (new_sr & ~SR_MASK);
+
+ COPY(pc);
+
+#undef COPY
+
+ /* Must do this last in case it sets regs->sr.fd (i.e. after rest of sr
+ * has been restored above.) */
+ err |= restore_sigcontext_fpu(regs, sc);
+
+ regs->syscall_nr = -1; /* disable syscall checks */
+ err |= __get_user(*r2_p, &sc->sc_regs[REG_RET]);
+ return err;
+}
+
+asmlinkage int sys_sigreturn(unsigned long r2, unsigned long r3,
+ unsigned long r4, unsigned long r5,
+ unsigned long r6, unsigned long r7,
+ struct pt_regs * regs)
+{
+ struct sigframe __user *frame = (struct sigframe __user *) (long) REF_REG_SP;
+ sigset_t set;
+ long long ret;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+
+ if (__get_user(set.sig[0], &frame->sc.oldmask)
+ || (_NSIG_WORDS > 1
+ && __copy_from_user(&set.sig[1], &frame->extramask,
+ sizeof(frame->extramask))))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (restore_sigcontext(regs, &frame->sc, &ret))
+ goto badframe;
+ regs->pc -= 4;
+
+ return (int) ret;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+asmlinkage int sys_rt_sigreturn(unsigned long r2, unsigned long r3,
+ unsigned long r4, unsigned long r5,
+ unsigned long r6, unsigned long r7,
+ struct pt_regs * regs)
+{
+ struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (long) REF_REG_SP;
+ sigset_t set;
+ long long ret;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ret))
+ goto badframe;
+ regs->pc -= 4;
+
+ if (restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+
+ return (int) ret;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+static int
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
+ unsigned long mask)
+{
+ int err = 0;
+
+ /* Do this first, otherwise is this sets sr->fd, that value isn't preserved. */
+ err |= setup_sigcontext_fpu(regs, sc);
+
+#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
+
+ COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
+ COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
+ COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
+ COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
+ COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
+ COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
+ COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
+ COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
+ COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
+ COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
+ COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
+ COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
+ COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
+ COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
+ COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
+ COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
+ COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
+ COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
+ COPY(sr); COPY(pc);
+
+#undef COPY
+
+ err |= __put_user(mask, &sc->oldmask);
+
+ return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
+{
+ if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
+ sp = current->sas_ss_sp + current->sas_ss_size;
+
+ return (void __user *)((sp - frame_size) & -8ul);
+}
+
+void sa_default_restorer(void); /* See comments below */
+void sa_default_rt_restorer(void); /* See comments below */
+
+static int setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
+{
+ struct sigframe __user *frame;
+ int err = 0, sig = ksig->sig;
+ int signal;
+
+ frame = get_sigframe(&ksig->ka, regs->regs[REG_SP], sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
+
+ /* Give up earlier as i386, in case */
+ if (err)
+ return -EFAULT;
+
+ if (_NSIG_WORDS > 1) {
+ err |= __copy_to_user(frame->extramask, &set->sig[1],
+ sizeof(frame->extramask)); }
+
+ /* Give up earlier as i386, in case */
+ if (err)
+ return -EFAULT;
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ /*
+ * On SH5 all edited pointers are subject to NEFF
+ */
+ DEREF_REG_PR = neff_sign_extend((unsigned long)
+ ksig->ka->sa.sa_restorer | 0x1);
+ } else {
+ /*
+ * Different approach on SH5.
+ * . Endianness independent asm code gets placed in entry.S .
+ * This is limited to four ASM instructions corresponding
+ * to two long longs in size.
+ * . err checking is done on the else branch only
+ * . flush_icache_range() is called upon __put_user() only
+ * . all edited pointers are subject to NEFF
+ * . being code, linker turns ShMedia bit on, always
+ * dereference index -1.
+ */
+ DEREF_REG_PR = neff_sign_extend((unsigned long)
+ frame->retcode | 0x01);
+
+ if (__copy_to_user(frame->retcode,
+ (void *)((unsigned long)sa_default_restorer & (~1)), 16) != 0)
+ return -EFAULT;
+
+ /* Cohere the trampoline with the I-cache. */
+ flush_cache_sigtramp(DEREF_REG_PR-1);
+ }
+
+ /*
+ * Set up registers for signal handler.
+ * All edited pointers are subject to NEFF.
+ */
+ regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
+ regs->regs[REG_ARG1] = sig; /* Arg for signal handler */
+
+ /* FIXME:
+ The glibc profiling support for SH-5 needs to be passed a sigcontext
+ so it can retrieve the PC. At some point during 2003 the glibc
+ support was changed to receive the sigcontext through the 2nd
+ argument, but there are still versions of libc.so in use that use
+ the 3rd argument. Until libc.so is stabilised, pass the sigcontext
+ through both 2nd and 3rd arguments.
+ */
+
+ regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
+ regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
+
+ regs->pc = neff_sign_extend((unsigned long)ksig->ka.sa.sa_handler);
+
+ /* Broken %016Lx */
+ pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
+ sig, current->comm, current->pid, frame,
+ regs->pc >> 32, regs->pc & 0xffffffff,
+ DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
+
+ return 0;
+}
+
+static int setup_rt_frame(struct ksignal *kig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ int err = 0, sig = ksig->sig;
+
+ frame = get_sigframe(&ksig->ka, regs->regs[REG_SP], sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ err |= __put_user(&frame->info, &frame->pinfo);
+ err |= __put_user(&frame->uc, &frame->puc);
+ err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+ /* Give up earlier as i386, in case */
+ if (err)
+ return -EFAULT;
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(0, &frame->uc.uc_link);
+ err |= __save_altstack(&frame->uc.uc_stack, regs->regs[REG_SP]);
+ err |= setup_sigcontext(&frame->uc.uc_mcontext,
+ regs, set->sig[0]);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+ /* Give up earlier as i386, in case */
+ if (err)
+ return -EFAULT;
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ /*
+ * On SH5 all edited pointers are subject to NEFF
+ */
+ DEREF_REG_PR = neff_sign_extend((unsigned long)
+ ksig->ka.sa.sa_restorer | 0x1);
+ } else {
+ /*
+ * Different approach on SH5.
+ * . Endianness independent asm code gets placed in entry.S .
+ * This is limited to four ASM instructions corresponding
+ * to two long longs in size.
+ * . err checking is done on the else branch only
+ * . flush_icache_range() is called upon __put_user() only
+ * . all edited pointers are subject to NEFF
+ * . being code, linker turns ShMedia bit on, always
+ * dereference index -1.
+ */
+ DEREF_REG_PR = neff_sign_extend((unsigned long)
+ frame->retcode | 0x01);
+
+ if (__copy_to_user(frame->retcode,
+ (void *)((unsigned long)sa_default_rt_restorer & (~1)), 16) != 0)
+ return -EFAULT;
+
+ /* Cohere the trampoline with the I-cache. */
+ flush_icache_range(DEREF_REG_PR-1, DEREF_REG_PR-1+15);
+ }
+
+ /*
+ * Set up registers for signal handler.
+ * All edited pointers are subject to NEFF.
+ */
+ regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
+ regs->regs[REG_ARG1] = sig; /* Arg for signal handler */
+ regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->info;
+ regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->uc.uc_mcontext;
+ regs->pc = neff_sign_extend((unsigned long)ksig->ka.sa.sa_handler);
+
+ pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
+ sig, current->comm, current->pid, frame,
+ regs->pc >> 32, regs->pc & 0xffffffff,
+ DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
+
+ return 0;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+ sigset_t *oldset = sigmask_to_save();
+ int ret;
+
+ /* Set up the stack frame */
+ if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+ ret = setup_rt_frame(ksig, oldset, regs);
+ else
+ ret = setup_frame(ksig, oldset, regs);
+
+ signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+}
+
+asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
+{
+ 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);
+ }
+}
Code Review / kvmfornfv.git / blobdiff