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-rw-r--r--arch/parisc/kernel/ptrace.c423
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 00000000000..2937a923638
--- /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;
+ }
+}
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