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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/s390/kernel/signal.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/s390/kernel/signal.c')
-rw-r--r--arch/s390/kernel/signal.c527
1 files changed, 527 insertions, 0 deletions
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
new file mode 100644
index 000000000000..610c1d03e975
--- /dev/null
+++ b/arch/s390/kernel/signal.c
@@ -0,0 +1,527 @@
+/*
+ * arch/s390/kernel/signal.c
+ *
+ * S390 version
+ * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+ *
+ * Based on Intel version
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
+ */
+
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.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 <linux/tty.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/lowcore.h>
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+
+typedef struct
+{
+ __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
+ struct sigcontext sc;
+ _sigregs sregs;
+ int signo;
+ __u8 retcode[S390_SYSCALL_SIZE];
+} sigframe;
+
+typedef struct
+{
+ __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
+ __u8 retcode[S390_SYSCALL_SIZE];
+ struct siginfo info;
+ struct ucontext uc;
+} rt_sigframe;
+
+int do_signal(struct pt_regs *regs, sigset_t *oldset);
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+asmlinkage int
+sys_sigsuspend(struct pt_regs * regs, int history0, int history1,
+ old_sigset_t mask)
+{
+ sigset_t saveset;
+
+ mask &= _BLOCKABLE;
+ spin_lock_irq(&current->sighand->siglock);
+ saveset = current->blocked;
+ siginitset(&current->blocked, mask);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+ regs->gprs[2] = -EINTR;
+
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ if (do_signal(regs, &saveset))
+ return -EINTR;
+ }
+}
+
+asmlinkage long
+sys_rt_sigsuspend(struct pt_regs *regs, sigset_t __user *unewset,
+ size_t sigsetsize)
+{
+ sigset_t saveset, newset;
+
+ /* XXX: Don't preclude handling different sized sigset_t's. */
+ if (sigsetsize != sizeof(sigset_t))
+ return -EINVAL;
+
+ if (copy_from_user(&newset, unewset, sizeof(newset)))
+ return -EFAULT;
+ sigdelsetmask(&newset, ~_BLOCKABLE);
+
+ spin_lock_irq(&current->sighand->siglock);
+ saveset = current->blocked;
+ current->blocked = newset;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+ regs->gprs[2] = -EINTR;
+
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ if (do_signal(regs, &saveset))
+ return -EINTR;
+ }
+}
+
+asmlinkage long
+sys_sigaction(int sig, const struct old_sigaction __user *act,
+ struct old_sigaction __user *oact)
+{
+ struct k_sigaction new_ka, old_ka;
+ int ret;
+
+ if (act) {
+ old_sigset_t mask;
+ if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+ __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
+ __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+ return -EFAULT;
+ __get_user(new_ka.sa.sa_flags, &act->sa_flags);
+ __get_user(mask, &act->sa_mask);
+ 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)) ||
+ __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
+ __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+ return -EFAULT;
+ __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
+ __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+ }
+
+ return ret;
+}
+
+asmlinkage long
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
+ struct pt_regs *regs)
+{
+ return do_sigaltstack(uss, uoss, regs->gprs[15]);
+}
+
+
+
+/* Returns non-zero on fault. */
+static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
+{
+ unsigned long old_mask = regs->psw.mask;
+ int err;
+
+ save_access_regs(current->thread.acrs);
+
+ /* Copy a 'clean' PSW mask to the user to avoid leaking
+ information about whether PER is currently on. */
+ regs->psw.mask = PSW_MASK_MERGE(PSW_USER_BITS, regs->psw.mask);
+ err = __copy_to_user(&sregs->regs.psw, &regs->psw,
+ sizeof(sregs->regs.psw)+sizeof(sregs->regs.gprs));
+ regs->psw.mask = old_mask;
+ if (err != 0)
+ return err;
+ err = __copy_to_user(&sregs->regs.acrs, current->thread.acrs,
+ sizeof(sregs->regs.acrs));
+ if (err != 0)
+ return err;
+ /*
+ * We have to store the fp registers to current->thread.fp_regs
+ * to merge them with the emulated registers.
+ */
+ save_fp_regs(&current->thread.fp_regs);
+ return __copy_to_user(&sregs->fpregs, &current->thread.fp_regs,
+ sizeof(s390_fp_regs));
+}
+
+/* Returns positive number on error */
+static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
+{
+ unsigned long old_mask = regs->psw.mask;
+ int err;
+
+ /* Alwys make any pending restarted system call return -EINTR */
+ current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+ err = __copy_from_user(&regs->psw, &sregs->regs.psw,
+ sizeof(sregs->regs.psw)+sizeof(sregs->regs.gprs));
+ regs->psw.mask = PSW_MASK_MERGE(old_mask, regs->psw.mask);
+ regs->psw.addr |= PSW_ADDR_AMODE;
+ if (err)
+ return err;
+ err = __copy_from_user(&current->thread.acrs, &sregs->regs.acrs,
+ sizeof(sregs->regs.acrs));
+ if (err)
+ return err;
+ restore_access_regs(current->thread.acrs);
+
+ err = __copy_from_user(&current->thread.fp_regs, &sregs->fpregs,
+ sizeof(s390_fp_regs));
+ current->thread.fp_regs.fpc &= FPC_VALID_MASK;
+ if (err)
+ return err;
+
+ restore_fp_regs(&current->thread.fp_regs);
+ regs->trap = -1; /* disable syscall checks */
+ return 0;
+}
+
+asmlinkage long sys_sigreturn(struct pt_regs *regs)
+{
+ sigframe __user *frame = (sigframe __user *)regs->gprs[15];
+ sigset_t set;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
+ goto badframe;
+
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ spin_lock_irq(&current->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ if (restore_sigregs(regs, &frame->sregs))
+ goto badframe;
+
+ return regs->gprs[2];
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+ rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
+ sigset_t set;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ spin_lock_irq(&current->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ if (restore_sigregs(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+
+ /* It is more difficult to avoid calling this function than to
+ call it and ignore errors. */
+ do_sigaltstack(&frame->uc.uc_stack, NULL, regs->gprs[15]);
+ return regs->gprs[2];
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
+{
+ unsigned long sp;
+
+ /* Default to using normal stack */
+ sp = regs->gprs[15];
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ if (ka->sa.sa_flags & SA_ONSTACK) {
+ if (! sas_ss_flags(sp))
+ sp = current->sas_ss_sp + current->sas_ss_size;
+ }
+
+ /* This is the legacy signal stack switching. */
+ else if (!user_mode(regs) &&
+ !(ka->sa.sa_flags & SA_RESTORER) &&
+ ka->sa.sa_restorer) {
+ sp = (unsigned long) ka->sa.sa_restorer;
+ }
+
+ return (void __user *)((sp - frame_size) & -8ul);
+}
+
+static inline int map_signal(int sig)
+{
+ if (current_thread_info()->exec_domain
+ && current_thread_info()->exec_domain->signal_invmap
+ && sig < 32)
+ return current_thread_info()->exec_domain->signal_invmap[sig];
+ else
+ return sig;
+}
+
+static void setup_frame(int sig, struct k_sigaction *ka,
+ sigset_t *set, struct pt_regs * regs)
+{
+ sigframe __user *frame;
+
+ frame = get_sigframe(ka, regs, sizeof(sigframe));
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
+ goto give_sigsegv;
+
+ if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
+ goto give_sigsegv;
+
+ if (save_sigregs(regs, &frame->sregs))
+ goto give_sigsegv;
+ if (__put_user(&frame->sregs, &frame->sc.sregs))
+ goto give_sigsegv;
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+ if (ka->sa.sa_flags & SA_RESTORER) {
+ regs->gprs[14] = (unsigned long)
+ ka->sa.sa_restorer | PSW_ADDR_AMODE;
+ } else {
+ regs->gprs[14] = (unsigned long)
+ frame->retcode | PSW_ADDR_AMODE;
+ if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
+ (u16 __user *)(frame->retcode)))
+ goto give_sigsegv;
+ }
+
+ /* Set up backchain. */
+ if (__put_user(regs->gprs[15], (addr_t __user *) frame))
+ goto give_sigsegv;
+
+ /* Set up registers for signal handler */
+ regs->gprs[15] = (unsigned long) frame;
+ regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
+
+ regs->gprs[2] = map_signal(sig);
+ regs->gprs[3] = (unsigned long) &frame->sc;
+
+ /* We forgot to include these in the sigcontext.
+ To avoid breaking binary compatibility, they are passed as args. */
+ regs->gprs[4] = current->thread.trap_no;
+ regs->gprs[5] = current->thread.prot_addr;
+
+ /* Place signal number on stack to allow backtrace from handler. */
+ if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
+ goto give_sigsegv;
+ return;
+
+give_sigsegv:
+ force_sigsegv(sig, current);
+}
+
+static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *set, struct pt_regs * regs)
+{
+ int err = 0;
+ rt_sigframe __user *frame;
+
+ frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
+ goto give_sigsegv;
+
+ if (copy_siginfo_to_user(&frame->info, info))
+ goto give_sigsegv;
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(0, &frame->uc.uc_link);
+ err |= __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+ err |= __put_user(sas_ss_flags(regs->gprs[15]),
+ &frame->uc.uc_stack.ss_flags);
+ err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= save_sigregs(regs, &frame->uc.uc_mcontext);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+ if (err)
+ goto give_sigsegv;
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+ if (ka->sa.sa_flags & SA_RESTORER) {
+ regs->gprs[14] = (unsigned long)
+ ka->sa.sa_restorer | PSW_ADDR_AMODE;
+ } else {
+ regs->gprs[14] = (unsigned long)
+ frame->retcode | PSW_ADDR_AMODE;
+ err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
+ (u16 __user *)(frame->retcode));
+ }
+
+ /* Set up backchain. */
+ if (__put_user(regs->gprs[15], (addr_t __user *) frame))
+ goto give_sigsegv;
+
+ /* Set up registers for signal handler */
+ regs->gprs[15] = (unsigned long) frame;
+ regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
+
+ regs->gprs[2] = map_signal(sig);
+ regs->gprs[3] = (unsigned long) &frame->info;
+ regs->gprs[4] = (unsigned long) &frame->uc;
+ return;
+
+give_sigsegv:
+ force_sigsegv(sig, current);
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+
+static void
+handle_signal(unsigned long sig, struct k_sigaction *ka,
+ siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
+{
+ /* Set up the stack frame */
+ if (ka->sa.sa_flags & SA_SIGINFO)
+ setup_rt_frame(sig, ka, info, oldset, regs);
+ else
+ setup_frame(sig, ka, oldset, regs);
+
+ if (!(ka->sa.sa_flags & SA_NODEFER)) {
+ spin_lock_irq(&current->sighand->siglock);
+ sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+ sigaddset(&current->blocked,sig);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+ }
+}
+
+/*
+ * 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.
+ */
+int do_signal(struct pt_regs *regs, sigset_t *oldset)
+{
+ unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
+ siginfo_t info;
+ int signr;
+ struct k_sigaction ka;
+
+ /*
+ * 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 1;
+
+ if (!oldset)
+ oldset = &current->blocked;
+
+ /* Are we from a system call? */
+ if (regs->trap == __LC_SVC_OLD_PSW) {
+ continue_addr = regs->psw.addr;
+ restart_addr = continue_addr - regs->ilc;
+ retval = regs->gprs[2];
+
+ /* Prepare for system call restart. We do this here so that a
+ debugger will see the already changed PSW. */
+ if (retval == -ERESTARTNOHAND ||
+ retval == -ERESTARTSYS ||
+ retval == -ERESTARTNOINTR) {
+ regs->gprs[2] = regs->orig_gpr2;
+ regs->psw.addr = restart_addr;
+ } else if (retval == -ERESTART_RESTARTBLOCK) {
+ regs->gprs[2] = -EINTR;
+ }
+ }
+
+ /* Get signal to deliver. When running under ptrace, at this point
+ the debugger may change all our registers ... */
+ signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+
+ /* Depending on the signal settings we may need to revert the
+ decision to restart the system call. */
+ if (signr > 0 && regs->psw.addr == restart_addr) {
+ if (retval == -ERESTARTNOHAND
+ || (retval == -ERESTARTSYS
+ && !(current->sighand->action[signr-1].sa.sa_flags
+ & SA_RESTART))) {
+ regs->gprs[2] = -EINTR;
+ regs->psw.addr = continue_addr;
+ }
+ }
+
+ if (signr > 0) {
+ /* Whee! Actually deliver the signal. */
+#ifdef CONFIG_S390_SUPPORT
+ if (test_thread_flag(TIF_31BIT)) {
+ extern void handle_signal32(unsigned long sig,
+ struct k_sigaction *ka,
+ siginfo_t *info,
+ sigset_t *oldset,
+ struct pt_regs *regs);
+ handle_signal32(signr, &ka, &info, oldset, regs);
+ return 1;
+ }
+#endif
+ handle_signal(signr, &ka, &info, oldset, regs);
+ return 1;
+ }
+
+ /* Restart a different system call. */
+ if (retval == -ERESTART_RESTARTBLOCK
+ && regs->psw.addr == continue_addr) {
+ regs->gprs[2] = __NR_restart_syscall;
+ set_thread_flag(TIF_RESTART_SVC);
+ }
+ return 0;
+}