7 files changed, 101 insertions, 1 deletions

diff --git a/arch/alpha/mm/extable.c b/arch/alpha/mm/extable.c
index 62dc379d301a..813c9b63c0e1 100644
--- a/arch/alpha/mm/extable.c
+++ b/arch/alpha/mm/extable.c
@@ -48,6 +48,27 @@ void sort_extable(struct exception_table_entry *start,
              cmp_ex, swap_ex);
 }
 
+#ifdef CONFIG_MODULES
+/*
+ * Any entry referring to the module init will be at the beginning or
+ * the end.
+ */
+void trim_init_extable(struct module *m)
+{
+        /*trim the beginning*/
+        while (m->num_exentries &&
+               within_module_init(ex_to_addr(&m->extable[0]), m)) {
+                m->extable++;
+                m->num_exentries--;
+        }
+        /*trim the end*/
+        while (m->num_exentries &&
+               within_module_init(ex_to_addr(&m->extable[m->num_exentries-1]),
+                                  m))
+                m->num_exentries--;
+}
+#endif /* CONFIG_MODULES */
+
 const struct exception_table_entry *
 search_extable(const struct exception_table_entry *first,
                const struct exception_table_entry *last,
diff --git a/arch/ia64/mm/extable.c b/arch/ia64/mm/extable.c
index 71c50dd8f870..e95d5ad9285d 100644
--- a/arch/ia64/mm/extable.c
+++ b/arch/ia64/mm/extable.c
@@ -53,6 +53,32 @@ void sort_extable (struct exception_table_entry *start,
              cmp_ex, swap_ex);
 }
 
+static inline unsigned long ex_to_addr(const struct exception_table_entry *x)
+{
+        return (unsigned long)&x->insn + x->insn;
+}
+
+#ifdef CONFIG_MODULES
+/*
+ * Any entry referring to the module init will be at the beginning or
+ * the end.
+ */
+void trim_init_extable(struct module *m)
+{
+        /*trim the beginning*/
+        while (m->num_exentries &&
+               within_module_init(ex_to_addr(&m->extable[0]), m)) {
+                m->extable++;
+                m->num_exentries--;
+        }
+        /*trim the end*/
+        while (m->num_exentries &&
+               within_module_init(ex_to_addr(&m->extable[m->num_exentries-1]),
+                                  m))
+                m->num_exentries--;
+}
+#endif /* CONFIG_MODULES */
+
 const struct exception_table_entry *
 search_extable (const struct exception_table_entry *first,
                 const struct exception_table_entry *last,
diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index 47d5619d43fa..8303ac481034 100644
--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h
@@ -17,6 +17,9 @@
 
 #ifndef __ASSEMBLY__
 
+#define ARCH_HAS_SORT_EXTABLE
+#define ARCH_HAS_SEARCH_EXTABLE
+
 /* Sparc is not segmented, however we need to be able to fool access_ok()
  * when doing system calls from kernel mode legitimately.
  *
diff --git a/arch/sparc/mm/extable.c b/arch/sparc/mm/extable.c
index 16cc28935e39..a61c349448e1 100644
--- a/arch/sparc/mm/extable.c
+++ b/arch/sparc/mm/extable.c
@@ -28,6 +28,10 @@ search_extable(const struct exception_table_entry *start,
          *      word 3: last insn address + 4 bytes
          *      word 4: fixup code address
          *
+         * Deleted entries are encoded as:
+         *      word 1: unused
+         *      word 2: -1
+         *
          * See asm/uaccess.h for more details.
          */
 
@@ -39,6 +43,10 @@ search_extable(const struct exception_table_entry *start,
                         continue;
                 }
 
+                /* A deleted entry; see trim_init_extable */
+                if (walk->fixup == -1)
+                        continue;
+
                 if (walk->insn == value)
                         return walk;
         }
@@ -57,6 +65,27 @@ search_extable(const struct exception_table_entry *start,
         return NULL;
 }
 
+#ifdef CONFIG_MODULES
+/* We could memmove them around; easier to mark the trimmed ones. */
+void trim_init_extable(struct module *m)
+{
+        unsigned int i;
+        bool range;
+
+        for (i = 0; i < m->num_exentries; i += range ? 2 : 1) {
+                range = m->extable[i].fixup == 0;
+
+                if (within_module_init(m->extable[i].insn, m)) {
+                        m->extable[i].fixup = -1;
+                        if (range)
+                                m->extable[i+1].fixup = -1;
+                }
+                if (range)
+                        i++;
+        }
+}
+#endif /* CONFIG_MODULES */
+
 /* Special extable search, which handles ranges.  Returns fixup */
 unsigned long search_extables_range(unsigned long addr, unsigned long *g2)
 {
diff --git a/include/linux/module.h b/include/linux/module.h
index a8f2c0aa4c32..a7bc6e7b43a7 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -77,6 +77,7 @@ search_extable(const struct exception_table_entry *first,
 void sort_extable(struct exception_table_entry *start,
                   struct exception_table_entry *finish);
 void sort_main_extable(void);
+void trim_init_extable(struct module *m);
 
 #ifdef MODULE
 #define MODULE_GENERIC_TABLE(gtype,name)                        \
diff --git a/kernel/module.c b/kernel/module.c
index 35f7de00bf0d..e4ab36ce7672 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2455,6 +2455,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
         mutex_lock(&module_mutex);
         /* Drop initial reference. */
         module_put(mod);
+        trim_init_extable(mod);
         module_free(mod, mod->module_init);
         mod->module_init = NULL;
         mod->init_size = 0;
diff --git a/lib/extable.c b/lib/extable.c
index 179c08745595..4cac81ec225e 100644
--- a/lib/extable.c
+++ b/lib/extable.c
@@ -39,7 +39,26 @@ void sort_extable(struct exception_table_entry *start,
         sort(start, finish - start, sizeof(struct exception_table_entry),
              cmp_ex, NULL);
 }
-#endif
+
+#ifdef CONFIG_MODULES
+/*
+ * If the exception table is sorted, any referring to the module init
+ * will be at the beginning or the end.
+ */
+void trim_init_extable(struct module *m)
+{
+        /*trim the beginning*/
+        while (m->num_exentries && within_module_init(m->extable[0].insn, m)) {
+                m->extable++;
+                m->num_exentries--;
+        }
+        /*trim the end*/
+        while (m->num_exentries &&
+                within_module_init(m->extable[m->num_exentries-1].insn, m))
+                m->num_exentries--;
+}
+#endif /* CONFIG_MODULES */
+#endif /* !ARCH_HAS_SORT_EXTABLE */
 
 #ifndef ARCH_HAS_SEARCH_EXTABLE
 /*