--- /dev/null
+/*
+ * linux/arch/parisc/kernel/signal.c: Architecture-specific signal
+ * handling support.
+ *
+ * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
+ * Copyright (C) 2000 Linuxcare, Inc.
+ *
+ * Based on the ia64, i386, and alpha versions.
+ *
+ * Like the IA-64, we are a recent enough port (we are *starting*
+ * with glibc2.2) that we do not need to support the old non-realtime
+ * Linux signals. Therefore we don't.
+ */
+
+#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/tracehook.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/compat.h>
+#include <linux/elf.h>
+#include <asm/ucontext.h>
+#include <asm/rt_sigframe.h>
+#include <asm/uaccess.h>
+#include <asm/pgalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/asm-offsets.h>
+
+#ifdef CONFIG_COMPAT
+#include "signal32.h"
+#endif
+
+#define DEBUG_SIG 0
+#define DEBUG_SIG_LEVEL 2
+
+#if DEBUG_SIG
+#define DBG(LEVEL, ...) \
+ ((DEBUG_SIG_LEVEL >= LEVEL) \
+ ? printk(__VA_ARGS__) : (void) 0)
+#else
+#define DBG(LEVEL, ...)
+#endif
+
+/* gcc will complain if a pointer is cast to an integer of different
+ * size. If you really need to do this (and we do for an ELF32 user
+ * application in an ELF64 kernel) then you have to do a cast to an
+ * integer of the same size first. The A() macro accomplishes
+ * this. */
+#define A(__x) ((unsigned long)(__x))
+
+/*
+ * Do a signal return - restore sigcontext.
+ */
+
+/* Trampoline for calling rt_sigreturn() */
+#define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */
+#define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */
+#define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */
+#define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
+#define INSN_NOP 0x08000240 /* nop */
+/* For debugging */
+#define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
+
+static long
+restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
+{
+ long err = 0;
+
+ err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
+ err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
+ err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
+ err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
+ err |= __get_user(regs->sar, &sc->sc_sar);
+ DBG(2,"restore_sigcontext: iaoq is %#lx / %#lx\n",
+ regs->iaoq[0],regs->iaoq[1]);
+ DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]);
+ return err;
+}
+
+void
+sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
+{
+ struct rt_sigframe __user *frame;
+ sigset_t set;
+ unsigned long usp = (regs->gr[30] & ~(0x01UL));
+ unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
+#ifdef CONFIG_64BIT
+ compat_sigset_t compat_set;
+ struct compat_rt_sigframe __user * compat_frame;
+
+ if (is_compat_task())
+ sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
+#endif
+
+ current->restart_block.fn = do_no_restart_syscall;
+
+ /* Unwind the user stack to get the rt_sigframe structure. */
+ frame = (struct rt_sigframe __user *)
+ (usp - sigframe_size);
+ DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
+
+ regs->orig_r28 = 1; /* no restarts for sigreturn */
+
+#ifdef CONFIG_64BIT
+ compat_frame = (struct compat_rt_sigframe __user *)frame;
+
+ if (is_compat_task()) {
+ DBG(2,"sys_rt_sigreturn: ELF32 process.\n");
+ if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set)))
+ goto give_sigsegv;
+ sigset_32to64(&set,&compat_set);
+ } else
+#endif
+ {
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto give_sigsegv;
+ }
+
+ set_current_blocked(&set);
+
+ /* Good thing we saved the old gr[30], eh? */
+#ifdef CONFIG_64BIT
+ if (is_compat_task()) {
+ DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
+ &compat_frame->uc.uc_mcontext);
+// FIXME: Load upper half from register file
+ if (restore_sigcontext32(&compat_frame->uc.uc_mcontext,
+ &compat_frame->regs, regs))
+ goto give_sigsegv;
+ DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
+ usp, &compat_frame->uc.uc_stack);
+ if (compat_restore_altstack(&compat_frame->uc.uc_stack))
+ goto give_sigsegv;
+ } else
+#endif
+ {
+ DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
+ &frame->uc.uc_mcontext);
+ if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
+ goto give_sigsegv;
+ DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
+ usp, &frame->uc.uc_stack);
+ if (restore_altstack(&frame->uc.uc_stack))
+ goto give_sigsegv;
+ }
+
+
+
+ /* If we are on the syscall path IAOQ will not be restored, and
+ * if we are on the interrupt path we must not corrupt gr31.
+ */
+ if (in_syscall)
+ regs->gr[31] = regs->iaoq[0];
+#if DEBUG_SIG
+ DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
+ show_regs(regs);
+#endif
+ return;
+
+give_sigsegv:
+ DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
+ force_sig(SIGSEGV, current);
+ return;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
+{
+ /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
+ don't use the parameter it doesn't matter */
+
+ DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
+ (unsigned long)ka, sp, frame_size);
+
+ /* Align alternate stack and reserve 64 bytes for the signal
+ handler's frame marker. */
+ if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
+ sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */
+
+ DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
+ return (void __user *) sp; /* Stacks grow up. Fun. */
+}
+
+static long
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
+
+{
+ unsigned long flags = 0;
+ long err = 0;
+
+ if (on_sig_stack((unsigned long) sc))
+ flags |= PARISC_SC_FLAG_ONSTACK;
+ if (in_syscall) {
+ flags |= PARISC_SC_FLAG_IN_SYSCALL;
+ /* regs->iaoq is undefined in the syscall return path */
+ err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
+ err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
+ err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
+ err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
+ DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
+ regs->gr[31], regs->gr[31]+4);
+ } else {
+ err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
+ err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
+ DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n",
+ regs->iaoq[0], regs->iaoq[1]);
+ }
+
+ err |= __put_user(flags, &sc->sc_flags);
+ err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
+ err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
+ err |= __put_user(regs->sar, &sc->sc_sar);
+ DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
+
+ return err;
+}
+
+static long
+setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
+ int in_syscall)
+{
+ struct rt_sigframe __user *frame;
+ unsigned long rp, usp;
+ unsigned long haddr, sigframe_size;
+ int err = 0;
+#ifdef CONFIG_64BIT
+ struct compat_rt_sigframe __user * compat_frame;
+ compat_sigset_t compat_set;
+#endif
+
+ usp = (regs->gr[30] & ~(0x01UL));
+ /*FIXME: frame_size parameter is unused, remove it. */
+ frame = get_sigframe(&ksig->ka, usp, sizeof(*frame));
+
+ DBG(1,"SETUP_RT_FRAME: START\n");
+ DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info);
+
+
+#ifdef CONFIG_64BIT
+
+ compat_frame = (struct compat_rt_sigframe __user *)frame;
+
+ if (is_compat_task()) {
+ DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
+ err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info);
+ err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]);
+ DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
+ DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
+ err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext,
+ &compat_frame->regs, regs, in_syscall);
+ sigset_64to32(&compat_set,set);
+ err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set));
+ } else
+#endif
+ {
+ DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
+ err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+ err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]);
+ DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
+ DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
+ err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
+ /* FIXME: Should probably be converted as well for the compat case */
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+ }
+
+ if (err)
+ return -EFAULT;
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. The first words of tramp are used to
+ save the previous sigrestartblock trampoline that might be
+ on the stack. We start the sigreturn trampoline at
+ SIGRESTARTBLOCK_TRAMP+X. */
+ err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
+ &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
+ err |= __put_user(INSN_LDI_R20,
+ &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
+ err |= __put_user(INSN_BLE_SR2_R0,
+ &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
+ err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
+
+#if DEBUG_SIG
+ /* Assert that we're flushing in the correct space... */
+ {
+ unsigned long sid;
+ asm ("mfsp %%sr3,%0" : "=r" (sid));
+ DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
+ sid, frame->tramp);
+ }
+#endif
+
+ flush_user_dcache_range((unsigned long) &frame->tramp[0],
+ (unsigned long) &frame->tramp[TRAMP_SIZE]);
+ flush_user_icache_range((unsigned long) &frame->tramp[0],
+ (unsigned long) &frame->tramp[TRAMP_SIZE]);
+
+ /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
+ * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
+ * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
+ */
+ rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
+
+ if (err)
+ return -EFAULT;
+
+ haddr = A(ksig->ka.sa.sa_handler);
+ /* The sa_handler may be a pointer to a function descriptor */
+#ifdef CONFIG_64BIT
+ if (is_compat_task()) {
+#endif
+ if (haddr & PA_PLABEL_FDESC) {
+ Elf32_Fdesc fdesc;
+ Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
+
+ err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
+
+ if (err)
+ return -EFAULT;
+
+ haddr = fdesc.addr;
+ regs->gr[19] = fdesc.gp;
+ }
+#ifdef CONFIG_64BIT
+ } else {
+ Elf64_Fdesc fdesc;
+ Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
+
+ err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
+
+ if (err)
+ return -EFAULT;
+
+ haddr = fdesc.addr;
+ regs->gr[19] = fdesc.gp;
+ DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
+ haddr, regs->gr[19], in_syscall);
+ }
+#endif
+
+ /* The syscall return path will create IAOQ values from r31.
+ */
+ sigframe_size = PARISC_RT_SIGFRAME_SIZE;
+#ifdef CONFIG_64BIT
+ if (is_compat_task())
+ sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
+#endif
+ if (in_syscall) {
+ regs->gr[31] = haddr;
+#ifdef CONFIG_64BIT
+ if (!test_thread_flag(TIF_32BIT))
+ sigframe_size |= 1;
+#endif
+ } else {
+ unsigned long psw = USER_PSW;
+#ifdef CONFIG_64BIT
+ if (!test_thread_flag(TIF_32BIT))
+ psw |= PSW_W;
+#endif
+
+ /* If we are singlestepping, arrange a trap to be delivered
+ when we return to userspace. Note the semantics -- we
+ should trap before the first insn in the handler is
+ executed. Ref:
+ http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
+ */
+ if (pa_psw(current)->r) {
+ pa_psw(current)->r = 0;
+ psw |= PSW_R;
+ mtctl(-1, 0);
+ }
+
+ regs->gr[0] = psw;
+ regs->iaoq[0] = haddr | 3;
+ regs->iaoq[1] = regs->iaoq[0] + 4;
+ }
+
+ regs->gr[2] = rp; /* userland return pointer */
+ regs->gr[26] = ksig->sig; /* signal number */
+
+#ifdef CONFIG_64BIT
+ if (is_compat_task()) {
+ regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
+ regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */
+ } else
+#endif
+ {
+ regs->gr[25] = A(&frame->info); /* siginfo pointer */
+ regs->gr[24] = A(&frame->uc); /* ucontext pointer */
+ }
+
+ DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
+ regs->gr[30], sigframe_size,
+ regs->gr[30] + sigframe_size);
+ /* Raise the user stack pointer to make a proper call frame. */
+ regs->gr[30] = (A(frame) + sigframe_size);
+
+
+ DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
+ current->comm, current->pid, frame, regs->gr[30],
+ regs->iaoq[0], regs->iaoq[1], rp);
+
+ return 0;
+}
+
+/*
+ * OK, we're invoking a handler.
+ */
+
+static void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall)
+{
+ int ret;
+ sigset_t *oldset = sigmask_to_save();
+
+ DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
+ ksig->sig, ksig->ka, ksig->info, oldset, regs);
+
+ /* Set up the stack frame */
+ ret = setup_rt_frame(ksig, oldset, regs, in_syscall);
+
+ signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) ||
+ test_thread_flag(TIF_BLOCKSTEP));
+
+ DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
+ regs->gr[28]);
+}
+
+static inline void
+syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
+{
+ if (regs->orig_r28)
+ return;
+ regs->orig_r28 = 1; /* no more restarts */
+ /* Check the return code */
+ switch (regs->gr[28]) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
+ regs->gr[28] = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (!(ka->sa.sa_flags & SA_RESTART)) {
+ DBG(1,"ERESTARTSYS: putting -EINTR\n");
+ regs->gr[28] = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ /* A syscall is just a branch, so all
+ * we have to do is fiddle the return pointer.
+ */
+ regs->gr[31] -= 8; /* delayed branching */
+ break;
+ }
+}
+
+static inline void
+insert_restart_trampoline(struct pt_regs *regs)
+{
+ if (regs->orig_r28)
+ return;
+ regs->orig_r28 = 1; /* no more restarts */
+ switch(regs->gr[28]) {
+ case -ERESTART_RESTARTBLOCK: {
+ /* Restart the system call - no handlers present */
+ unsigned int *usp = (unsigned int *)regs->gr[30];
+ unsigned long start = (unsigned long) &usp[2];
+ unsigned long end = (unsigned long) &usp[5];
+ long err = 0;
+
+ /* Setup a trampoline to restart the syscall
+ * with __NR_restart_syscall
+ *
+ * 0: <return address (orig r31)>
+ * 4: <2nd half for 64-bit>
+ * 8: ldw 0(%sp), %r31
+ * 12: be 0x100(%sr2, %r0)
+ * 16: ldi __NR_restart_syscall, %r20
+ */
+#ifdef CONFIG_64BIT
+ err |= put_user(regs->gr[31] >> 32, &usp[0]);
+ err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]);
+ err |= put_user(0x0fc010df, &usp[2]);
+#else
+ err |= put_user(regs->gr[31], &usp[0]);
+ err |= put_user(0x0fc0109f, &usp[2]);
+#endif
+ err |= put_user(0xe0008200, &usp[3]);
+ err |= put_user(0x34140000, &usp[4]);
+
+ WARN_ON(err);
+
+ /* flush data/instruction cache for new insns */
+ flush_user_dcache_range(start, end);
+ flush_user_icache_range(start, end);
+
+ regs->gr[31] = regs->gr[30] + 8;
+ return;
+ }
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR: {
+ /* Hooray for delayed branching. We don't
+ * have to restore %r20 (the system call
+ * number) because it gets loaded in the delay
+ * slot of the branch external instruction.
+ */
+ regs->gr[31] -= 8;
+ return;
+ }
+ default:
+ 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.
+ *
+ * We need to be able to restore the syscall arguments (r21-r26) to
+ * restart syscalls. Thus, the syscall path should save them in the
+ * pt_regs structure (it's okay to do so since they are caller-save
+ * registers). As noted below, the syscall number gets restored for
+ * us due to the magic of delayed branching.
+ */
+asmlinkage void
+do_signal(struct pt_regs *regs, long in_syscall)
+{
+ struct ksignal ksig;
+
+ DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
+ regs, regs->sr[7], in_syscall);
+
+ if (get_signal(&ksig)) {
+ DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
+ /* Restart a system call if necessary. */
+ if (in_syscall)
+ syscall_restart(regs, &ksig.ka);
+
+ handle_signal(&ksig, regs, in_syscall);
+ return;
+ }
+
+ /* Did we come from a system call? */
+ if (in_syscall)
+ insert_restart_trampoline(regs);
+
+ DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n",
+ regs->gr[28]);
+
+ restore_saved_sigmask();
+}
+
+void do_notify_resume(struct pt_regs *regs, long in_syscall)
+{
+ if (test_thread_flag(TIF_SIGPENDING))
+ do_signal(regs, in_syscall);
+
+ if (test_thread_flag(TIF_NOTIFY_RESUME)) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+}
Code Review / kvmfornfv.git / blobdiff