bianbu-repo-mirror/bianbu-linux-6.6
1
0
Fork 0
mirror of https://gitee.com/bianbu-linux/linux-6.6 synced 2025-04-24 14:07:52 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

asm-generic: Refactor dereference_[kernel]_function_descriptor()

Browse source 
dereference_function_descriptor() and
dereference_kernel_function_descriptor() are identical on the
three architectures implementing them.

Make them common and put them out-of-line in kernel/extable.c
which is one of the users and has similar type of functions.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/449db09b2eba57f4ab05f80102a67d8675bc8bcd.1644928018.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2022-02-15 13:41:04 +01:00 • committed by Michael Ellerman
parent 0dc690e4ef
commit e1478d8eaf
6 changed files with 24 additions and 73 deletions
Download patch file Download diff file Expand all files Collapse all files

23
kernel/extable.c
View file

@ -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>
@ -132,12 +133,32 @@ out:
}
/*
* 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;
}
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;