Linux 6.9-rc4

[sfrench/cifs-2.6.git] / kernel / extable.c

diff --git a/kernel/extable.c b/kernel/extable.c
index e23cce6e6092af76569e882efdee87b10638efd9..71f482581cab4c316ed2ddd2a4eedb6771b11c37 100644 (file)
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -3,6 +3,7 @@
    Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
 
 */
+#include <linux/elf.h>
 #include <linux/ftrace.h>
 #include <linux/memory.h>
 #include <linux/extable.h>
@@ -34,58 +35,41 @@ u32 __initdata __visible main_extable_sort_needed = 1;
 /* Sort the kernel's built-in exception table */
 void __init sort_main_extable(void)
 {
-       if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) {
+       if (main_extable_sort_needed &&
+           &__stop___ex_table > &__start___ex_table) {
                pr_notice("Sorting __ex_table...\n");
                sort_extable(__start___ex_table, __stop___ex_table);
        }
 }
 
+/* Given an address, look for it in the kernel exception table */
+const
+struct exception_table_entry *search_kernel_exception_table(unsigned long addr)
+{
+       return search_extable(__start___ex_table,
+                             __stop___ex_table - __start___ex_table, addr);
+}
+
 /* Given an address, look for it in the exception tables. */
 const struct exception_table_entry *search_exception_tables(unsigned long addr)
 {
        const struct exception_table_entry *e;
 
-       e = search_extable(__start___ex_table,
-                          __stop___ex_table - __start___ex_table, addr);
+       e = search_kernel_exception_table(addr);
        if (!e)
                e = search_module_extables(addr);
+       if (!e)
+               e = search_bpf_extables(addr);
        return e;
 }
 
-int init_kernel_text(unsigned long addr)
-{
-       if (addr >= (unsigned long)_sinittext &&
-           addr < (unsigned long)_einittext)
-               return 1;
-       return 0;
-}
-
 int notrace core_kernel_text(unsigned long addr)
 {
-       if (addr >= (unsigned long)_stext &&
-           addr < (unsigned long)_etext)
+       if (is_kernel_text(addr))
                return 1;
 
-       if (system_state < SYSTEM_RUNNING &&
-           init_kernel_text(addr))
-               return 1;
-       return 0;
-}
-
-/**
- * core_kernel_data - tell if addr points to kernel data
- * @addr: address to test
- *
- * Returns true if @addr passed in is from the core kernel data
- * section.
- *
- * Note: On some archs it may return true for core RODATA, and false
- *  for others. But will always be true for core RW data.
- */
-int core_kernel_data(unsigned long addr)
-{
-       if (addr >= (unsigned long)_sdata &&
-           addr < (unsigned long)_edata)
+       if (system_state < SYSTEM_FREEING_INITMEM &&
+           is_kernel_inittext(addr))
                return 1;
        return 0;
 }
@@ -102,7 +86,7 @@ int __kernel_text_address(unsigned long addr)
         * Since we are after the module-symbols check, there's
         * no danger of address overlap:
         */
-       if (init_kernel_text(addr))
+       if (is_kernel_inittext(addr))
                return 1;
        return 0;
 }
@@ -122,14 +106,15 @@ int kernel_text_address(unsigned long addr)
         * triggers a stack trace, or a WARN() that happens during
         * coming back from idle, or cpu on or offlining.
         *
-        * is_module_text_address() as well as the kprobe slots
-        * and is_bpf_text_address() require RCU to be watching.
+        * is_module_text_address() as well as the kprobe slots,
+        * is_bpf_text_address() and is_bpf_image_address require
+        * RCU to be watching.
         */
        no_rcu = !rcu_is_watching();
 
        /* Treat this like an NMI as it can happen anywhere */
        if (no_rcu)
-               rcu_nmi_enter();
+               ct_nmi_enter();
 
        if (is_module_text_address(addr))
                goto out;
@@ -142,18 +127,39 @@ int kernel_text_address(unsigned long addr)
        ret = 0;
 out:
        if (no_rcu)
-               rcu_nmi_exit();
+               ct_nmi_exit();
 
        return ret;
 }
 
 /*
- * On some architectures (PPC64, IA64) function pointers
+ * On some architectures (PPC64, IA64, PARISC) 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.
  */
+#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
+void *dereference_function_descriptor(void *ptr)
+{
+       func_desc_t *desc = ptr;
+       void *p;
+
+       if (!get_kernel_nofault(p, (void *)&desc->addr))
+               ptr = p;
+       return ptr;
+}
+EXPORT_SYMBOL_GPL(dereference_function_descriptor);
+
+void *dereference_kernel_function_descriptor(void *ptr)
+{
+       if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
+               return ptr;
+
+       return dereference_function_descriptor(ptr);
+}
+#endif
+
 int func_ptr_is_kernel_text(void *ptr)
 {
        unsigned long addr;