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Diffstat (limited to 'arch/cris/arch-v10/kernel/signal.c')
-rw-r--r--arch/cris/arch-v10/kernel/signal.c438
1 files changed, 438 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/kernel/signal.c b/arch/cris/arch-v10/kernel/signal.c
new file mode 100644
index 000000000..7122d9773
--- /dev/null
+++ b/arch/cris/arch-v10/kernel/signal.c
@@ -0,0 +1,438 @@
+/*
+ * linux/arch/cris/kernel/signal.c
+ *
+ * Based on arch/i386/kernel/signal.c by
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson *
+ *
+ * Ideas also taken from arch/arm.
+ *
+ * Copyright (C) 2000-2007 Axis Communications AB
+ *
+ * Authors: Bjorn Wesen (bjornw@axis.com)
+ *
+ */
+
+#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/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+
+#include <asm/processor.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <arch/system.h>
+
+#define DEBUG_SIG 0
+
+/* a syscall in Linux/CRIS is a break 13 instruction which is 2 bytes */
+/* manipulate regs so that upon return, it will be re-executed */
+
+/* We rely on that pc points to the instruction after "break 13", so the
+ * library must never do strange things like putting it in a delay slot.
+ */
+#define RESTART_CRIS_SYS(regs) regs->r10 = regs->orig_r10; regs->irp -= 2;
+
+void do_signal(int canrestart, struct pt_regs *regs);
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+struct sigframe {
+ struct sigcontext sc;
+ unsigned long extramask[_NSIG_WORDS-1];
+ unsigned char retcode[8]; /* trampoline code */
+};
+
+struct rt_sigframe {
+ struct siginfo *pinfo;
+ void *puc;
+ struct siginfo info;
+ struct ucontext uc;
+ unsigned char retcode[8]; /* trampoline code */
+};
+
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ unsigned int err = 0;
+ unsigned long old_usp;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ /* restore the regs from &sc->regs (same as sc, since regs is first)
+ * (sc is already checked for VERIFY_READ since the sigframe was
+ * checked in sys_sigreturn previously)
+ */
+
+ if (__copy_from_user(regs, sc, sizeof(struct pt_regs)))
+ goto badframe;
+
+ /* make sure the U-flag is set so user-mode cannot fool us */
+
+ regs->dccr |= 1 << 8;
+
+ /* restore the old USP as it was before we stacked the sc etc.
+ * (we cannot just pop the sigcontext since we aligned the sp and
+ * stuff after pushing it)
+ */
+
+ err |= __get_user(old_usp, &sc->usp);
+
+ wrusp(old_usp);
+
+ /* TODO: the other ports use regs->orig_XX to disable syscall checks
+ * after this completes, but we don't use that mechanism. maybe we can
+ * use it now ?
+ */
+
+ return err;
+
+badframe:
+ return 1;
+}
+
+asmlinkage int sys_sigreturn(void)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct sigframe __user *frame = (struct sigframe *)rdusp();
+ sigset_t set;
+
+ /*
+ * Since we stacked the signal on a dword boundary,
+ * then frame should be dword aligned here. If it's
+ * not, then the user is trying to mess with us.
+ */
+ if (((long)frame) & 3)
+ goto badframe;
+
+ 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))
+ goto badframe;
+
+ /* TODO: SIGTRAP when single-stepping as in arm ? */
+
+ return regs->r10;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+asmlinkage int sys_rt_sigreturn(void)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct rt_sigframe __user *frame = (struct rt_sigframe *)rdusp();
+ sigset_t set;
+
+ /*
+ * Since we stacked the signal on a dword boundary,
+ * then frame should be dword aligned here. If it's
+ * not, then the user is trying to mess with us.
+ */
+ if (((long)frame) & 3)
+ goto badframe;
+
+ 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))
+ goto badframe;
+
+ if (restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+
+ return regs->r10;
+
+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;
+ unsigned long usp = rdusp();
+
+ /* copy the regs. they are first in sc so we can use sc directly */
+
+ err |= __copy_to_user(sc, regs, sizeof(struct pt_regs));
+
+ /* Set the frametype to CRIS_FRAME_NORMAL for the execution of
+ the signal handler. The frametype will be restored to its previous
+ value in restore_sigcontext. */
+ regs->frametype = CRIS_FRAME_NORMAL;
+
+ /* then some other stuff */
+
+ err |= __put_user(mask, &sc->oldmask);
+
+ err |= __put_user(usp, &sc->usp);
+
+ return err;
+}
+
+/* Figure out where we want to put the new signal frame
+ * - usually on the stack. */
+
+static inline void __user *
+get_sigframe(struct ksignal *ksig, size_t frame_size)
+{
+ unsigned long sp = sigsp(rdusp(), ksig);
+
+ /* make sure the frame is dword-aligned */
+
+ sp &= ~3;
+
+ return (void __user*)(sp - frame_size);
+}
+
+/* grab and setup a signal frame.
+ *
+ * basically we stack a lot of state info, and arrange for the
+ * user-mode program to return to the kernel using either a
+ * trampoline which performs the syscall sigreturn, or a provided
+ * user-mode trampoline.
+ */
+
+static int setup_frame(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ struct sigframe __user *frame;
+ unsigned long return_ip;
+ int err = 0;
+
+ frame = get_sigframe(ksig, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
+ if (err)
+ return -EFAULT;
+
+ if (_NSIG_WORDS > 1) {
+ err |= __copy_to_user(frame->extramask, &set->sig[1],
+ sizeof(frame->extramask));
+ }
+ 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) {
+ return_ip = (unsigned long)ksig->ka.sa.sa_restorer;
+ } else {
+ /* trampoline - the desired return ip is the retcode itself */
+ return_ip = (unsigned long)&frame->retcode;
+ /* This is movu.w __NR_sigreturn, r9; break 13; */
+ err |= __put_user(0x9c5f, (short __user*)(frame->retcode+0));
+ err |= __put_user(__NR_sigreturn, (short __user*)(frame->retcode+2));
+ err |= __put_user(0xe93d, (short __user*)(frame->retcode+4));
+ }
+
+ if (err)
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+
+ regs->irp = (unsigned long) ksig->ka.sa.sa_handler; /* what we enter NOW */
+ regs->srp = return_ip; /* what we enter LATER */
+ regs->r10 = ksig->sig; /* first argument is signo */
+
+ /* actually move the usp to reflect the stacked frame */
+
+ wrusp((unsigned long)frame);
+
+ return 0;
+}
+
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ unsigned long return_ip;
+ int err = 0;
+
+ frame = get_sigframe(ksig, 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);
+ if (err)
+ return -EFAULT;
+
+ /* Clear all the bits of the ucontext we don't use. */
+ err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
+
+ err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
+
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+ err |= __save_altstack(&frame->uc.uc_stack, rdusp());
+
+ 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) {
+ return_ip = (unsigned long)ksig->ka.sa.sa_restorer;
+ } else {
+ /* trampoline - the desired return ip is the retcode itself */
+ return_ip = (unsigned long)&frame->retcode;
+ /* This is movu.w __NR_rt_sigreturn, r9; break 13; */
+ err |= __put_user(0x9c5f, (short __user *)(frame->retcode+0));
+ err |= __put_user(__NR_rt_sigreturn,
+ (short __user *)(frame->retcode+2));
+ err |= __put_user(0xe93d, (short __user *)(frame->retcode+4));
+ }
+
+ if (err)
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+
+ /* What we enter NOW */
+ regs->irp = (unsigned long) ksig->ka.sa.sa_handler;
+ /* What we enter LATER */
+ regs->srp = return_ip;
+ /* First argument is signo */
+ regs->r10 = ksig->sig;
+ /* Second argument is (siginfo_t *) */
+ regs->r11 = (unsigned long)&frame->info;
+ /* Third argument is unused */
+ regs->r12 = 0;
+
+ /* Actually move the usp to reflect the stacked frame */
+ wrusp((unsigned long)frame);
+
+ return 0;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+
+static inline void handle_signal(int canrestart, struct ksignal *ksig,
+ struct pt_regs *regs)
+{
+ sigset_t *oldset = sigmask_to_save();
+ int ret;
+
+ /* Are we from a system call? */
+ if (canrestart) {
+ /* If so, check system call restarting.. */
+ switch (regs->r10) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ /* ERESTARTNOHAND means that the syscall should
+ * only be restarted if there was no handler for
+ * the signal, and since we only get here if there
+ * is a handler, we don't restart */
+ regs->r10 = -EINTR;
+ break;
+ case -ERESTARTSYS:
+ /* ERESTARTSYS means to restart the syscall if
+ * there is no handler or the handler was
+ * registered with SA_RESTART */
+ if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+ regs->r10 = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ /* ERESTARTNOINTR means that the syscall should
+ * be called again after the signal handler returns. */
+ RESTART_CRIS_SYS(regs);
+ }
+ }
+
+ /* 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, 0);
+}
+
+/*
+ * 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.
+ *
+ * Also note that the regs structure given here as an argument, is the latest
+ * pushed pt_regs. It may or may not be the same as the first pushed registers
+ * when the initial usermode->kernelmode transition took place. Therefore
+ * we can use user_mode(regs) to see if we came directly from kernel or user
+ * mode below.
+ */
+
+void do_signal(int canrestart, 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)) {
+ /* Whee! Actually deliver the signal. */
+ handle_signal(canrestart, &ksig, regs);
+ return;
+ }
+
+ /* Did we come from a system call? */
+ if (canrestart) {
+ /* Restart the system call - no handlers present */
+ if (regs->r10 == -ERESTARTNOHAND ||
+ regs->r10 == -ERESTARTSYS ||
+ regs->r10 == -ERESTARTNOINTR) {
+ RESTART_CRIS_SYS(regs);
+ }
+ if (regs->r10 == -ERESTART_RESTARTBLOCK) {
+ regs->r9 = __NR_restart_syscall;
+ regs->irp -= 2;
+ }
+ }
+
+ /* if there's no signal to deliver, we just put the saved sigmask
+ * back */
+ restore_saved_sigmask();
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-05 18:01:44 +0000