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-rw-r--r--arch/alpha/mm/extable.c21
-rw-r--r--arch/ia64/mm/extable.c26
-rw-r--r--arch/sparc/include/asm/uaccess_32.h3
-rw-r--r--arch/sparc/mm/extable.c29
-rw-r--r--include/linux/module.h1
-rw-r--r--kernel/module.c1
-rw-r--r--lib/extable.c21
7 files changed, 101 insertions, 1 deletions
diff --git a/arch/alpha/mm/extable.c b/arch/alpha/mm/extable.c
index 62dc379..813c9b6 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 71c50dd..e95d5ad 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 47d5619..8303ac4 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 16cc289..a61c349 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 a8f2c0a..a7bc6e7b 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 35f7de0..e4ab36c 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 179c087..4cac81e 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
/*
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