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-rw-r--r--kernel/extable.c48
1 files changed, 39 insertions, 9 deletions
diff --git a/kernel/extable.c b/kernel/extable.c
index e136ed8d82b..7f8f263f852 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -15,11 +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 <linux/ftrace.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[];
@@ -41,31 +52,50 @@ const struct exception_table_entry *search_exception_tables(unsigned long addr)
return e;
}
-__notrace_funcgraph int core_kernel_text(unsigned long addr)
+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 (system_state == SYSTEM_BOOTING &&
- addr >= (unsigned long)_sinittext &&
- addr <= (unsigned long)_einittext)
+ init_kernel_text(addr))
return 1;
return 0;
}
-__notrace_funcgraph int __kernel_text_address(unsigned long addr)
+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);
}
/*
@@ -81,5 +111,5 @@ int func_ptr_is_kernel_text(void *ptr)
addr = (unsigned long) dereference_function_descriptor(ptr);
if (core_kernel_text(addr))
return 1;
- return module_text_address(addr) != NULL;
+ return is_module_text_address(addr);
}