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!

1 files changed, 389 insertions, 0 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
new file mode 100644
index 000000000000..88b306c4e841
--- /dev/null
+++ b/kernel/ptrace.c
@@ -0,0 +1,389 @@
+/*
+ * linux/kernel/ptrace.c
+ *
+ * (C) Copyright 1999 Linus Torvalds
+ *
+ * Common interfaces for "ptrace()" which we do not want
+ * to continually duplicate across every architecture.
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/smp_lock.h>
+#include <linux/ptrace.h>
+#include <linux/security.h>
+
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+
+/*
+ * ptrace a task: make the debugger its new parent and
+ * move it to the ptrace list.
+ *
+ * Must be called with the tasklist lock write-held.
+ */
+void __ptrace_link(task_t *child, task_t *new_parent)
+{
+        if (!list_empty(&child->ptrace_list))
+                BUG();
+        if (child->parent == new_parent)
+                return;
+        list_add(&child->ptrace_list, &child->parent->ptrace_children);
+        REMOVE_LINKS(child);
+        child->parent = new_parent;
+        SET_LINKS(child);
+}
+ 
+/*
+ * Turn a tracing stop into a normal stop now, since with no tracer there
+ * would be no way to wake it up with SIGCONT or SIGKILL.  If there was a
+ * signal sent that would resume the child, but didn't because it was in
+ * TASK_TRACED, resume it now.
+ * Requires that irqs be disabled.
+ */
+void ptrace_untrace(task_t *child)
+{
+        spin_lock(&child->sighand->siglock);
+        if (child->state == TASK_TRACED) {
+                if (child->signal->flags & SIGNAL_STOP_STOPPED) {
+                        child->state = TASK_STOPPED;
+                } else {
+                        signal_wake_up(child, 1);
+                }
+        }
+        spin_unlock(&child->sighand->siglock);
+}
+
+/*
+ * unptrace a task: move it back to its original parent and
+ * remove it from the ptrace list.
+ *
+ * Must be called with the tasklist lock write-held.
+ */
+void __ptrace_unlink(task_t *child)
+{
+        if (!child->ptrace)
+                BUG();
+        child->ptrace = 0;
+        if (!list_empty(&child->ptrace_list)) {
+                list_del_init(&child->ptrace_list);
+                REMOVE_LINKS(child);
+                child->parent = child->real_parent;
+                SET_LINKS(child);
+        }
+
+        if (child->state == TASK_TRACED)
+                ptrace_untrace(child);
+}
+
+/*
+ * Check that we have indeed attached to the thing..
+ */
+int ptrace_check_attach(struct task_struct *child, int kill)
+{
+        int ret = -ESRCH;
+
+        /*
+         * We take the read lock around doing both checks to close a
+         * possible race where someone else was tracing our child and
+         * detached between these two checks.  After this locked check,
+         * we are sure that this is our traced child and that can only
+         * be changed by us so it's not changing right after this.
+         */
+        read_lock(&tasklist_lock);
+        if ((child->ptrace & PT_PTRACED) && child->parent == current &&
+            (!(child->ptrace & PT_ATTACHED) || child->real_parent != current)
+            && child->signal != NULL) {
+                ret = 0;
+                spin_lock_irq(&child->sighand->siglock);
+                if (child->state == TASK_STOPPED) {
+                        child->state = TASK_TRACED;
+                } else if (child->state != TASK_TRACED && !kill) {
+                        ret = -ESRCH;
+                }
+                spin_unlock_irq(&child->sighand->siglock);
+        }
+        read_unlock(&tasklist_lock);
+
+        if (!ret && !kill) {
+                wait_task_inactive(child);
+        }
+
+        /* All systems go.. */
+        return ret;
+}
+
+int ptrace_attach(struct task_struct *task)
+{
+        int retval;
+        task_lock(task);
+        retval = -EPERM;
+        if (task->pid <= 1)
+                goto bad;
+        if (task == current)
+                goto bad;
+        if (!task->mm)
+                goto bad;
+        if(((current->uid != task->euid) ||
+            (current->uid != task->suid) ||
+            (current->uid != task->uid) ||
+            (current->gid != task->egid) ||
+            (current->gid != task->sgid) ||
+            (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE))
+                goto bad;
+        rmb();
+        if (!task->mm->dumpable && !capable(CAP_SYS_PTRACE))
+                goto bad;
+        /* the same process cannot be attached many times */
+        if (task->ptrace & PT_PTRACED)
+                goto bad;
+        retval = security_ptrace(current, task);
+        if (retval)
+                goto bad;
+
+        /* Go */
+        task->ptrace |= PT_PTRACED | ((task->real_parent != current)
+                                      ? PT_ATTACHED : 0);
+        if (capable(CAP_SYS_PTRACE))
+                task->ptrace |= PT_PTRACE_CAP;
+        task_unlock(task);
+
+        write_lock_irq(&tasklist_lock);
+        __ptrace_link(task, current);
+        write_unlock_irq(&tasklist_lock);
+
+        force_sig_specific(SIGSTOP, task);
+        return 0;
+
+bad:
+        task_unlock(task);
+        return retval;
+}
+
+int ptrace_detach(struct task_struct *child, unsigned int data)
+{
+        if ((unsigned long) data > _NSIG)
+                return  -EIO;
+
+        /* Architecture-specific hardware disable .. */
+        ptrace_disable(child);
+
+        /* .. re-parent .. */
+        child->exit_code = data;
+
+        write_lock_irq(&tasklist_lock);
+        __ptrace_unlink(child);
+        /* .. and wake it up. */
+        if (child->exit_state != EXIT_ZOMBIE)
+                wake_up_process(child);
+        write_unlock_irq(&tasklist_lock);
+
+        return 0;
+}
+
+/*
+ * Access another process' address space.
+ * Source/target buffer must be kernel space, 
+ * Do not walk the page table directly, use get_user_pages
+ */
+
+int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write)
+{
+        struct mm_struct *mm;
+        struct vm_area_struct *vma;
+        struct page *page;
+        void *old_buf = buf;
+
+        mm = get_task_mm(tsk);
+        if (!mm)
+                return 0;
+
+        down_read(&mm->mmap_sem);
+        /* ignore errors, just check how much was sucessfully transfered */
+        while (len) {
+                int bytes, ret, offset;
+                void *maddr;
+
+                ret = get_user_pages(tsk, mm, addr, 1,
+                                write, 1, &page, &vma);
+                if (ret <= 0)
+                        break;
+
+                bytes = len;
+                offset = addr & (PAGE_SIZE-1);
+                if (bytes > PAGE_SIZE-offset)
+                        bytes = PAGE_SIZE-offset;
+
+                maddr = kmap(page);
+                if (write) {
+                        copy_to_user_page(vma, page, addr,
+                                          maddr + offset, buf, bytes);
+                        set_page_dirty_lock(page);
+                } else {
+                        copy_from_user_page(vma, page, addr,
+                                            buf, maddr + offset, bytes);
+                }
+                kunmap(page);
+                page_cache_release(page);
+                len -= bytes;
+                buf += bytes;
+                addr += bytes;
+        }
+        up_read(&mm->mmap_sem);
+        mmput(mm);
+        
+        return buf - old_buf;
+}
+
+int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
+{
+        int copied = 0;
+
+        while (len > 0) {
+                char buf[128];
+                int this_len, retval;
+
+                this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
+                retval = access_process_vm(tsk, src, buf, this_len, 0);
+                if (!retval) {
+                        if (copied)
+                                break;
+                        return -EIO;
+                }
+                if (copy_to_user(dst, buf, retval))
+                        return -EFAULT;
+                copied += retval;
+                src += retval;
+                dst += retval;
+                len -= retval;                  
+        }
+        return copied;
+}
+
+int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
+{
+        int copied = 0;
+
+        while (len > 0) {
+                char buf[128];
+                int this_len, retval;
+
+                this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
+                if (copy_from_user(buf, src, this_len))
+                        return -EFAULT;
+                retval = access_process_vm(tsk, dst, buf, this_len, 1);
+                if (!retval) {
+                        if (copied)
+                                break;
+                        return -EIO;
+                }
+                copied += retval;
+                src += retval;
+                dst += retval;
+                len -= retval;                  
+        }
+        return copied;
+}
+
+static int ptrace_setoptions(struct task_struct *child, long data)
+{
+        child->ptrace &= ~PT_TRACE_MASK;
+
+        if (data & PTRACE_O_TRACESYSGOOD)
+                child->ptrace |= PT_TRACESYSGOOD;
+
+        if (data & PTRACE_O_TRACEFORK)
+                child->ptrace |= PT_TRACE_FORK;
+
+        if (data & PTRACE_O_TRACEVFORK)
+                child->ptrace |= PT_TRACE_VFORK;
+
+        if (data & PTRACE_O_TRACECLONE)
+                child->ptrace |= PT_TRACE_CLONE;
+
+        if (data & PTRACE_O_TRACEEXEC)
+                child->ptrace |= PT_TRACE_EXEC;
+
+        if (data & PTRACE_O_TRACEVFORKDONE)
+                child->ptrace |= PT_TRACE_VFORK_DONE;
+
+        if (data & PTRACE_O_TRACEEXIT)
+                child->ptrace |= PT_TRACE_EXIT;
+
+        return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
+}
+
+static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data)
+{
+        siginfo_t lastinfo;
+        int error = -ESRCH;
+
+        read_lock(&tasklist_lock);
+        if (likely(child->sighand != NULL)) {
+                error = -EINVAL;
+                spin_lock_irq(&child->sighand->siglock);
+                if (likely(child->last_siginfo != NULL)) {
+                        lastinfo = *child->last_siginfo;
+                        error = 0;
+                }
+                spin_unlock_irq(&child->sighand->siglock);
+        }
+        read_unlock(&tasklist_lock);
+        if (!error)
+                return copy_siginfo_to_user(data, &lastinfo);
+        return error;
+}
+
+static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data)
+{
+        siginfo_t newinfo;
+        int error = -ESRCH;
+
+        if (copy_from_user(&newinfo, data, sizeof (siginfo_t)))
+                return -EFAULT;
+
+        read_lock(&tasklist_lock);
+        if (likely(child->sighand != NULL)) {
+                error = -EINVAL;
+                spin_lock_irq(&child->sighand->siglock);
+                if (likely(child->last_siginfo != NULL)) {
+                        *child->last_siginfo = newinfo;
+                        error = 0;
+                }
+                spin_unlock_irq(&child->sighand->siglock);
+        }
+        read_unlock(&tasklist_lock);
+        return error;
+}
+
+int ptrace_request(struct task_struct *child, long request,
+                   long addr, long data)
+{
+        int ret = -EIO;
+
+        switch (request) {
+#ifdef PTRACE_OLDSETOPTIONS
+        case PTRACE_OLDSETOPTIONS:
+#endif
+        case PTRACE_SETOPTIONS:
+                ret = ptrace_setoptions(child, data);
+                break;
+        case PTRACE_GETEVENTMSG:
+                ret = put_user(child->ptrace_message, (unsigned long __user *) data);
+                break;
+        case PTRACE_GETSIGINFO:
+                ret = ptrace_getsiginfo(child, (siginfo_t __user *) data);
+                break;
+        case PTRACE_SETSIGINFO:
+                ret = ptrace_setsiginfo(child, (siginfo_t __user *) data);
+                break;
+        default:
+                break;
+        }
+
+        return ret;
+}