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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/cris/arch-v10/kernel/ptrace.c
downloadconfigs-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-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/cris/arch-v10/kernel/ptrace.c')
-rw-r--r--arch/cris/arch-v10/kernel/ptrace.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/kernel/ptrace.c b/arch/cris/arch-v10/kernel/ptrace.c
new file mode 100644
index 00000000000..da15db8ae48
--- /dev/null
+++ b/arch/cris/arch-v10/kernel/ptrace.c
@@ -0,0 +1,314 @@
+/*
+ * Copyright (C) 2000-2003, Axis Communications AB.
+ */
+
+#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 <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/processor.h>
+
+/*
+ * Determines which bits in DCCR the user has access to.
+ * 1 = access, 0 = no access.
+ */
+#define DCCR_MASK 0x0000001f /* XNZVC */
+
+/*
+ * Get contents of register REGNO in task TASK.
+ */
+inline long get_reg(struct task_struct *task, unsigned int regno)
+{
+ /* USP is a special case, it's not in the pt_regs struct but
+ * in the tasks thread struct
+ */
+
+ if (regno == PT_USP)
+ return task->thread.usp;
+ else if (regno < PT_MAX)
+ return ((unsigned long *)user_regs(task->thread_info))[regno];
+ else
+ return 0;
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+inline int put_reg(struct task_struct *task, unsigned int regno,
+ unsigned long data)
+{
+ if (regno == PT_USP)
+ task->thread.usp = data;
+ else if (regno < PT_MAX)
+ ((unsigned long *)user_regs(task->thread_info))[regno] = data;
+ else
+ return -1;
+ return 0;
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching.
+ *
+ * Make sure the single step bit is not set.
+ */
+void
+ptrace_disable(struct task_struct *child)
+{
+ /* Todo - pending singlesteps? */
+}
+
+/*
+ * Note that this implementation of ptrace behaves differently from vanilla
+ * ptrace. Contrary to what the man page says, in the PTRACE_PEEKTEXT,
+ * PTRACE_PEEKDATA, and PTRACE_PEEKUSER requests the data variable is not
+ * ignored. Instead, the data variable is expected to point at a location
+ * (in user space) where the result of the ptrace call is written (instead of
+ * being returned).
+ */
+asmlinkage int
+sys_ptrace(long request, long pid, long addr, long data)
+{
+ struct task_struct *child;
+ int ret;
+ unsigned long __user *datap = (unsigned long __user *)data;
+
+ lock_kernel();
+ ret = -EPERM;
+
+ if (request == PTRACE_TRACEME) {
+ if (current->ptrace & PT_PTRACED)
+ goto out;
+
+ 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) /* Leave the init process alone! */
+ 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) {
+ /* Read word at location address. */
+ case PTRACE_PEEKTEXT:
+ case PTRACE_PEEKDATA: {
+ unsigned long tmp;
+ int copied;
+
+ copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
+ ret = -EIO;
+
+ if (copied != sizeof(tmp))
+ break;
+
+ ret = put_user(tmp,datap);
+ break;
+ }
+
+ /* Read the word at location address in the USER area. */
+ case PTRACE_PEEKUSR: {
+ unsigned long tmp;
+
+ ret = -EIO;
+ if ((addr & 3) || addr < 0 || addr > PT_MAX << 2)
+ break;
+
+ tmp = get_reg(child, addr >> 2);
+ ret = put_user(tmp, datap);
+ break;
+ }
+
+ /* Write the word at location address. */
+ case PTRACE_POKETEXT:
+ case PTRACE_POKEDATA:
+ ret = 0;
+
+ if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
+ break;
+
+ ret = -EIO;
+ break;
+
+ /* Write the word at location address in the USER area. */
+ case PTRACE_POKEUSR:
+ ret = -EIO;
+ if ((addr & 3) || addr < 0 || addr > PT_MAX << 2)
+ break;
+
+ addr >>= 2;
+
+ if (addr == PT_DCCR) {
+ /* don't allow the tracing process to change stuff like
+ * interrupt enable, kernel/user bit, dma enables etc.
+ */
+ data &= DCCR_MASK;
+ data |= get_reg(child, PT_DCCR) & ~DCCR_MASK;
+ }
+ if (put_reg(child, addr, data))
+ break;
+ ret = 0;
+ break;
+
+ case PTRACE_SYSCALL:
+ case PTRACE_CONT:
+ ret = -EIO;
+
+ if ((unsigned long) data > _NSIG)
+ break;
+
+ 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;
+
+ /* TODO: make sure any pending breakpoint is killed */
+ wake_up_process(child);
+ ret = 0;
+
+ break;
+
+ /* Make the child exit by sending it a sigkill. */
+ case PTRACE_KILL:
+ ret = 0;
+
+ if (child->state == TASK_ZOMBIE)
+ break;
+
+ child->exit_code = SIGKILL;
+
+ /* TODO: make sure any pending breakpoint is killed */
+ wake_up_process(child);
+ break;
+
+ /* Set the trap flag. */
+ case PTRACE_SINGLESTEP:
+ ret = -EIO;
+
+ if ((unsigned long) data > _NSIG)
+ break;
+
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+
+ /* TODO: set some clever breakpoint mechanism... */
+
+ child->exit_code = data;
+ wake_up_process(child);
+ ret = 0;
+ break;
+
+ case PTRACE_DETACH:
+ ret = ptrace_detach(child, data);
+ break;
+
+ /* Get all GP registers from the child. */
+ case PTRACE_GETREGS: {
+ int i;
+ unsigned long tmp;
+
+ for (i = 0; i <= PT_MAX; i++) {
+ tmp = get_reg(child, i);
+
+ if (put_user(tmp, datap)) {
+ ret = -EFAULT;
+ goto out_tsk;
+ }
+
+ data += sizeof(long);
+ }
+
+ ret = 0;
+ break;
+ }
+
+ /* Set all GP registers in the child. */
+ case PTRACE_SETREGS: {
+ int i;
+ unsigned long tmp;
+
+ for (i = 0; i <= PT_MAX; i++) {
+ if (get_user(tmp, datap)) {
+ ret = -EFAULT;
+ goto out_tsk;
+ }
+
+ if (i == PT_DCCR) {
+ tmp &= DCCR_MASK;
+ tmp |= get_reg(child, PT_DCCR) & ~DCCR_MASK;
+ }
+
+ put_reg(child, i, tmp);
+ data += sizeof(long);
+ }
+
+ ret = 0;
+ break;
+ }
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+out_tsk:
+ put_task_struct(child);
+out:
+ unlock_kernel();
+ return ret;
+}
+
+void do_syscall_trace(void)
+{
+ if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ return;
+
+ if (!(current->ptrace & PT_PTRACED))
+ return;
+
+ /* the 0x80 provides a way for the tracing parent to distinguish
+ between a syscall stop and SIGTRAP delivery */
+ 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.
+ */
+ if (current->exit_code) {
+ send_sig(current->exit_code, current, 1);
+ current->exit_code = 0;
+ }
+}