1 files changed, 423 insertions, 0 deletions

diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
new file mode 100644
index 000000000000..2937a9236384
--- /dev/null
+++ b/arch/parisc/kernel/ptrace.c
@@ -0,0 +1,423 @@
+/*
+ * Kernel support for the ptrace() and syscall tracing interfaces.
+ *
+ * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc.
+ * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx>
+ * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/personality.h>
+#include <linux/security.h>
+#include <linux/compat.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/offsets.h>
+
+/* PSW bits we allow the debugger to modify */
+#define USER_PSW_BITS   (PSW_N | PSW_V | PSW_CB)
+
+#undef DEBUG_PTRACE
+
+#ifdef DEBUG_PTRACE
+#define DBG(x...)       printk(x)
+#else
+#define DBG(x...)
+#endif
+
+#ifdef __LP64__
+
+/* This function is needed to translate 32 bit pt_regs offsets in to
+ * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
+ * will request offset 12 if it wants gr3, but the lower 32 bits of
+ * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
+ * This code relies on a 32 bit pt_regs being comprised of 32 bit values
+ * except for the fp registers which (a) are 64 bits, and (b) follow
+ * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
+ * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
+ * being 64 bit in both cases.
+ */
+
+static long translate_usr_offset(long offset)
+{
+        if (offset < 0)
+                return -1;
+        else if (offset <= 32*4)        /* gr[0..31] */
+                return offset * 2 + 4;
+        else if (offset <= 32*4+32*8)   /* gr[0..31] + fr[0..31] */
+                return offset + 32*4;
+        else if (offset < sizeof(struct pt_regs)/2 + 32*4)
+                return offset * 2 + 4 - 32*8;
+        else
+                return -1;
+}
+#endif
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure single step bits etc are not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+        /* make sure the trap bits are not set */
+        pa_psw(child)->r = 0;
+        pa_psw(child)->t = 0;
+        pa_psw(child)->h = 0;
+        pa_psw(child)->l = 0;
+}
+
+long sys_ptrace(long request, pid_t pid, long addr, long data)
+{
+        struct task_struct *child;
+        long ret;
+#ifdef DEBUG_PTRACE
+        long oaddr=addr, odata=data;
+#endif
+
+        lock_kernel();
+        ret = -EPERM;
+        if (request == PTRACE_TRACEME) {
+                /* are we already being traced? */
+                if (current->ptrace & PT_PTRACED)
+                        goto out;
+
+                ret = security_ptrace(current->parent, current);
+                if (ret) 
+                        goto out;
+
+                /* set the ptrace bit in the process flags. */
+                current->ptrace |= PT_PTRACED;
+                ret = 0;
+                goto out;
+        }
+
+        ret = -ESRCH;
+        read_lock(&tasklist_lock);
+        child = find_task_by_pid(pid);
+        if (child)
+                get_task_struct(child);
+        read_unlock(&tasklist_lock);
+        if (!child)
+                goto out;
+        ret = -EPERM;
+        if (pid == 1)           /* no messing around with init! */
+                goto out_tsk;
+
+        if (request == PTRACE_ATTACH) {
+                ret = ptrace_attach(child);
+                goto out_tsk;
+        }
+
+        ret = ptrace_check_attach(child, request == PTRACE_KILL);
+        if (ret < 0)
+                goto out_tsk;
+
+        switch (request) {
+        case PTRACE_PEEKTEXT: /* read word at location addr. */ 
+        case PTRACE_PEEKDATA: {
+                int copied;
+
+#ifdef __LP64__
+                if (is_compat_task(child)) {
+                        unsigned int tmp;
+
+                        addr &= 0xffffffffL;
+                        copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+                        ret = -EIO;
+                        if (copied != sizeof(tmp))
+                                goto out_tsk;
+                        ret = put_user(tmp,(unsigned int *) data);
+                        DBG("sys_ptrace(PEEK%s, %d, %lx, %lx) returning %ld, data %x\n",
+                                request == PTRACE_PEEKTEXT ? "TEXT" : "DATA",
+                                pid, oaddr, odata, ret, tmp);
+                }
+                else
+#endif
+                {
+                        unsigned long tmp;
+
+                        copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+                        ret = -EIO;
+                        if (copied != sizeof(tmp))
+                                goto out_tsk;
+                        ret = put_user(tmp,(unsigned long *) data);
+                }
+                goto out_tsk;
+        }
+
+        /* when I and D space are separate, this will have to be fixed. */
+        case PTRACE_POKETEXT: /* write the word at location addr. */
+        case PTRACE_POKEDATA:
+                ret = 0;
+#ifdef __LP64__
+                if (is_compat_task(child)) {
+                        unsigned int tmp = (unsigned int)data;
+                        DBG("sys_ptrace(POKE%s, %d, %lx, %lx)\n",
+                                request == PTRACE_POKETEXT ? "TEXT" : "DATA",
+                                pid, oaddr, odata);
+                        addr &= 0xffffffffL;
+                        if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1) == sizeof(tmp))
+                                goto out_tsk;
+                }
+                else
+#endif
+                {
+                        if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
+                                goto out_tsk;
+                }
+                ret = -EIO;
+                goto out_tsk;
+
+        /* Read the word at location addr in the USER area.  For ptraced
+           processes, the kernel saves all regs on a syscall. */
+        case PTRACE_PEEKUSR: {
+                ret = -EIO;
+#ifdef __LP64__
+                if (is_compat_task(child)) {
+                        unsigned int tmp;
+
+                        if (addr & (sizeof(int)-1))
+                                goto out_tsk;
+                        if ((addr = translate_usr_offset(addr)) < 0)
+                                goto out_tsk;
+
+                        tmp = *(unsigned int *) ((char *) task_regs(child) + addr);
+                        ret = put_user(tmp, (unsigned int *) data);
+                        DBG("sys_ptrace(PEEKUSR, %d, %lx, %lx) returning %ld, addr %lx, data %x\n",
+                                pid, oaddr, odata, ret, addr, tmp);
+                }
+                else
+#endif
+                {
+                        unsigned long tmp;
+
+                        if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs))
+                                goto out_tsk;
+                        tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
+                        ret = put_user(tmp, (unsigned long *) data);
+                }
+                goto out_tsk;
+        }
+
+        /* Write the word at location addr in the USER area.  This will need
+           to change when the kernel no longer saves all regs on a syscall.
+           FIXME.  There is a problem at the moment in that r3-r18 are only
+           saved if the process is ptraced on syscall entry, and even then
+           those values are overwritten by actual register values on syscall
+           exit. */
+        case PTRACE_POKEUSR:
+                ret = -EIO;
+                /* Some register values written here may be ignored in
+                 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
+                 * r31/r31+4, and not with the values in pt_regs.
+                 */
+                 /* PT_PSW=0, so this is valid for 32 bit processes under 64
+                 * bit kernels.
+                 */
+                if (addr == PT_PSW) {
+                        /* PT_PSW=0, so this is valid for 32 bit processes
+                         * under 64 bit kernels.
+                         *
+                         * Allow writing to Nullify, Divide-step-correction,
+                         * and carry/borrow bits.
+                         * BEWARE, if you set N, and then single step, it won't
+                         * stop on the nullified instruction.
+                         */
+                        DBG("sys_ptrace(POKEUSR, %d, %lx, %lx)\n",
+                                pid, oaddr, odata);
+                        data &= USER_PSW_BITS;
+                        task_regs(child)->gr[0] &= ~USER_PSW_BITS;
+                        task_regs(child)->gr[0] |= data;
+                        ret = 0;
+                        goto out_tsk;
+                }
+#ifdef __LP64__
+                if (is_compat_task(child)) {
+                        if (addr & (sizeof(int)-1))
+                                goto out_tsk;
+                        if ((addr = translate_usr_offset(addr)) < 0)
+                                goto out_tsk;
+                        DBG("sys_ptrace(POKEUSR, %d, %lx, %lx) addr %lx\n",
+                                pid, oaddr, odata, addr);
+                        if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
+                                /* Special case, fp regs are 64 bits anyway */
+                                *(unsigned int *) ((char *) task_regs(child) + addr) = data;
+                                ret = 0;
+                        }
+                        else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
+                                        addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
+                                        addr == PT_SAR+4) {
+                                /* Zero the top 32 bits */
+                                *(unsigned int *) ((char *) task_regs(child) + addr - 4) = 0;
+                                *(unsigned int *) ((char *) task_regs(child) + addr) = data;
+                                ret = 0;
+                        }
+                        goto out_tsk;
+                }
+                else
+#endif
+                {
+                        if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs))
+                                goto out_tsk;
+                        if ((addr >= PT_GR1 && addr <= PT_GR31) ||
+                                        addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
+                                        (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
+                                        addr == PT_SAR) {
+                                *(unsigned long *) ((char *) task_regs(child) + addr) = data;
+                                ret = 0;
+                        }
+                        goto out_tsk;
+                }
+
+        case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
+        case PTRACE_CONT:
+                ret = -EIO;
+                DBG("sys_ptrace(%s)\n",
+                        request == PTRACE_SYSCALL ? "SYSCALL" : "CONT");
+                if ((unsigned long) data > _NSIG)
+                        goto out_tsk;
+                child->ptrace &= ~(PT_SINGLESTEP|PT_BLOCKSTEP);
+                if (request == PTRACE_SYSCALL) {
+                        set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+                } else {
+                        clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+                }               
+                child->exit_code = data;
+                goto out_wake_notrap;
+
+        case PTRACE_KILL:
+                /*
+                 * make the child exit.  Best I can do is send it a
+                 * sigkill.  perhaps it should be put in the status
+                 * that it wants to exit.
+                 */
+                DBG("sys_ptrace(KILL)\n");
+                if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
+                        goto out_tsk;
+                child->exit_code = SIGKILL;
+                goto out_wake_notrap;
+
+        case PTRACE_SINGLEBLOCK:
+                DBG("sys_ptrace(SINGLEBLOCK)\n");
+                ret = -EIO;
+                if ((unsigned long) data > _NSIG)
+                        goto out_tsk;
+                clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+                child->ptrace &= ~PT_SINGLESTEP;
+                child->ptrace |= PT_BLOCKSTEP;
+                child->exit_code = data;
+
+                /* Enable taken branch trap. */
+                pa_psw(child)->r = 0;
+                pa_psw(child)->t = 1;
+                pa_psw(child)->h = 0;
+                pa_psw(child)->l = 0;
+                goto out_wake;
+
+        case PTRACE_SINGLESTEP:
+                DBG("sys_ptrace(SINGLESTEP)\n");
+                ret = -EIO;
+                if ((unsigned long) data > _NSIG)
+                        goto out_tsk;
+
+                clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+                child->ptrace &= ~PT_BLOCKSTEP;
+                child->ptrace |= PT_SINGLESTEP;
+                child->exit_code = data;
+
+                if (pa_psw(child)->n) {
+                        struct siginfo si;
+
+                        /* Nullified, just crank over the queue. */
+                        task_regs(child)->iaoq[0] = task_regs(child)->iaoq[1];
+                        task_regs(child)->iasq[0] = task_regs(child)->iasq[1];
+                        task_regs(child)->iaoq[1] = task_regs(child)->iaoq[0] + 4;
+                        pa_psw(child)->n = 0;
+                        pa_psw(child)->x = 0;
+                        pa_psw(child)->y = 0;
+                        pa_psw(child)->z = 0;
+                        pa_psw(child)->b = 0;
+                        ptrace_disable(child);
+                        /* Don't wake up the child, but let the
+                           parent know something happened. */
+                        si.si_code = TRAP_TRACE;
+                        si.si_addr = (void __user *) (task_regs(child)->iaoq[0] & ~3);
+                        si.si_signo = SIGTRAP;
+                        si.si_errno = 0;
+                        force_sig_info(SIGTRAP, &si, child);
+                        //notify_parent(child, SIGCHLD);
+                        //ret = 0;
+                        goto out_wake;
+                }
+
+                /* Enable recovery counter traps.  The recovery counter
+                 * itself will be set to zero on a task switch.  If the
+                 * task is suspended on a syscall then the syscall return
+                 * path will overwrite the recovery counter with a suitable
+                 * value such that it traps once back in user space.  We
+                 * disable interrupts in the childs PSW here also, to avoid
+                 * interrupts while the recovery counter is decrementing.
+                 */
+                pa_psw(child)->r = 1;
+                pa_psw(child)->t = 0;
+                pa_psw(child)->h = 0;
+                pa_psw(child)->l = 0;
+                /* give it a chance to run. */
+                goto out_wake;
+
+        case PTRACE_DETACH:
+                ret = ptrace_detach(child, data);
+                goto out_tsk;
+
+        case PTRACE_GETEVENTMSG:
+                ret = put_user(child->ptrace_message, (unsigned int __user *) data);
+                goto out_tsk;
+
+        default:
+                ret = ptrace_request(child, request, addr, data);
+                goto out_tsk;
+        }
+
+out_wake_notrap:
+        ptrace_disable(child);
+out_wake:
+        wake_up_process(child);
+        ret = 0;
+out_tsk:
+        put_task_struct(child);
+out:
+        unlock_kernel();
+        DBG("sys_ptrace(%ld, %d, %lx, %lx) returning %ld\n",
+                request, pid, oaddr, odata, ret);
+        return ret;
+}
+
+void syscall_trace(void)
+{
+        if (!test_thread_flag(TIF_SYSCALL_TRACE))
+                return;
+        if (!(current->ptrace & PT_PTRACED))
+                return;
+        ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
+                                 ? 0x80 : 0));
+        /*
+         * this isn't the same as continuing with a signal, but it will do
+         * for normal use.  strace only continues with a signal if the
+         * stopping signal is not SIGTRAP.  -brl
+         */
+        if (current->exit_code) {
+                send_sig(current->exit_code, current, 1);
+                current->exit_code = 0;
+        }
+}