Initial import

1 files changed, 575 insertions, 0 deletions

diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c
new file mode 100644
index 000000000..dc1ea796f
--- /dev/null
+++ b/arch/parisc/kernel/signal.c
@@ -0,0 +1,575 @@
+/*
+ *  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);
+	}
+}