diff options
author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-02-15 13:41:04 +0100 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-02-16 23:25:11 +1100 |
commit | e1478d8eaf27704db17a44dee4c53696ed01fc9c (patch) | |
tree | 7968852fd3c179c5b9311a9d70f18ed57e5b6ad8 /kernel/extable.c | |
parent | 0dc690e4ef5b901e9d4b53520854fbd5c749e09d (diff) |
asm-generic: Refactor dereference_[kernel]_function_descriptor()
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
Diffstat (limited to 'kernel/extable.c')
-rw-r--r-- | kernel/extable.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/kernel/extable.c b/kernel/extable.c index b6f330f0fe74..394c39b86e38 100644 --- 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> @@ -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; |