X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fextable.c;h=7f8f263f85249a15ca8492fa5056c868262aa0f1;hb=af901ca181d92aac3a7dc265144a9081a86d8f39;hp=7fe2628553172eadc0d49a3cbaf9d779b80b5a7c;hpb=5e376613899076396d0c97de67ad072587267370;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/extable.c b/kernel/extable.c
index 7fe2628..7f8f263 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -15,10 +15,22 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
+#include <linux/ftrace.h>
+#include <linux/memory.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/init.h>
-#include <asm/uaccess.h>
+
 #include <asm/sections.h>
+#include <asm/uaccess.h>
+
+/*
+ * mutex protecting text section modification (dynamic code patching).
+ * some users need to sleep (allocating memory...) while they hold this lock.
+ *
+ * NOT exported to modules - patching kernel text is a really delicate matter.
+ */
+DEFINE_MUTEX(text_mutex);
 
 extern struct exception_table_entry __start___ex_table[];
 extern struct exception_table_entry __stop___ex_table[];
@@ -40,14 +52,22 @@ const struct exception_table_entry *search_exception_tables(unsigned long addr)
 	return e;
 }
 
+static inline int init_kernel_text(unsigned long addr)
+{
+	if (addr >= (unsigned long)_sinittext &&
+	    addr <= (unsigned long)_einittext)
+		return 1;
+	return 0;
+}
+
 int core_kernel_text(unsigned long addr)
 {
 	if (addr >= (unsigned long)_stext &&
 	    addr <= (unsigned long)_etext)
 		return 1;
 
-	if (addr >= (unsigned long)_sinittext &&
-	    addr <= (unsigned long)_einittext)
+	if (system_state == SYSTEM_BOOTING &&
+	    init_kernel_text(addr))
 		return 1;
 	return 0;
 }
@@ -56,12 +76,40 @@ int __kernel_text_address(unsigned long addr)
 {
 	if (core_kernel_text(addr))
 		return 1;
-	return __module_text_address(addr) != NULL;
+	if (is_module_text_address(addr))
+		return 1;
+	/*
+	 * There might be init symbols in saved stacktraces.
+	 * Give those symbols a chance to be printed in
+	 * backtraces (such as lockdep traces).
+	 *
+	 * Since we are after the module-symbols check, there's
+	 * no danger of address overlap:
+	 */
+	if (init_kernel_text(addr))
+		return 1;
+	return 0;
 }
 
 int kernel_text_address(unsigned long addr)
 {
 	if (core_kernel_text(addr))
 		return 1;
-	return module_text_address(addr) != NULL;
+	return is_module_text_address(addr);
+}
+
+/*
+ * On some architectures (PPC64, IA64) function pointers
+ * are actually only tokens to some data that then holds the
+ * real function address. As a result, to find if a function
+ * pointer is part of the kernel text, we need to do some
+ * special dereferencing first.
+ */
+int func_ptr_is_kernel_text(void *ptr)
+{
+	unsigned long addr;
+	addr = (unsigned long) dereference_function_descriptor(ptr);
+	if (core_kernel_text(addr))
+		return 1;
+	return is_module_text_address(addr);
 }