Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg...

[karo-tx-linux.git] / mm / util.c

diff --git a/mm/util.c b/mm/util.c
index a24aa22f2473690c1e2fa95514f778c6c0c616a7..d5ea733c508265aaba619248d973ec640a73d04a 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -1,6 +1,7 @@
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/compiler.h>
 #include <linux/export.h>
 #include <linux/err.h>
 #include <linux/sched.h>
@@ -9,6 +10,7 @@
 #include <linux/swapops.h>
 #include <linux/mman.h>
 #include <linux/hugetlb.h>
+#include <linux/vmalloc.h>
 
 #include <asm/uaccess.h>
 
@@ -307,7 +309,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
  * If the architecture not support this function, simply return with no
  * page pinned
  */
-int __attribute__((weak)) __get_user_pages_fast(unsigned long start,
+int __weak __get_user_pages_fast(unsigned long start,
                                 int nr_pages, int write, struct page **pages)
 {
        return 0;
@@ -338,7 +340,7 @@ EXPORT_SYMBOL_GPL(__get_user_pages_fast);
  * callers need to carefully consider what to use. On many architectures,
  * get_user_pages_fast simply falls back to get_user_pages.
  */
-int __attribute__((weak)) get_user_pages_fast(unsigned long start,
+int __weak get_user_pages_fast(unsigned long start,
                                int nr_pages, int write, struct page **pages)
 {
        struct mm_struct *mm = current->mm;
@@ -386,6 +388,15 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
 }
 EXPORT_SYMBOL(vm_mmap);
 
+void kvfree(const void *addr)
+{
+       if (is_vmalloc_addr(addr))
+               vfree(addr);
+       else
+               kfree(addr);
+}
+EXPORT_SYMBOL(kvfree);
+
 struct address_space *page_mapping(struct page *page)
 {
        struct address_space *mapping = page->mapping;
@@ -445,6 +456,54 @@ unsigned long vm_commit_limit(void)
        return allowed;
 }
 
+/**
+ * get_cmdline() - copy the cmdline value to a buffer.
+ * @task:     the task whose cmdline value to copy.
+ * @buffer:   the buffer to copy to.
+ * @buflen:   the length of the buffer. Larger cmdline values are truncated
+ *            to this length.
+ * Returns the size of the cmdline field copied. Note that the copy does
+ * not guarantee an ending NULL byte.
+ */
+int get_cmdline(struct task_struct *task, char *buffer, int buflen)
+{
+       int res = 0;
+       unsigned int len;
+       struct mm_struct *mm = get_task_mm(task);
+       if (!mm)
+               goto out;
+       if (!mm->arg_end)
+               goto out_mm;    /* Shh! No looking before we're done */
+
+       len = mm->arg_end - mm->arg_start;
+
+       if (len > buflen)
+               len = buflen;
+
+       res = access_process_vm(task, mm->arg_start, buffer, len, 0);
+
+       /*
+        * If the nul at the end of args has been overwritten, then
+        * assume application is using setproctitle(3).
+        */
+       if (res > 0 && buffer[res-1] != '\0' && len < buflen) {
+               len = strnlen(buffer, res);
+               if (len < res) {
+                       res = len;
+               } else {
+                       len = mm->env_end - mm->env_start;
+                       if (len > buflen - res)
+                               len = buflen - res;
+                       res += access_process_vm(task, mm->env_start,
+                                                buffer+res, len, 0);
+                       res = strnlen(buffer, res);
+               }
+       }
+out_mm:
+       mmput(mm);
+out:
+       return res;
+}
 
 /* Tracepoints definitions. */
 EXPORT_TRACEPOINT_SYMBOL(kmalloc);