[PATCH v4 05/13] powerpc: Prepare func_desc_t for refactorisation

Christophe Leroy
2022-02-15T12:43:36Z

In preparation of making func_desc_t generic, change the ELFv2
version to a struct containing 'addr' element.

This allows using single helpers common to ELFv1 and ELFv2 and
reduces the amount of #ifdef's

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
arch/powerpc/kernel/module_64.c | 36 ++++++++++++++++-----------------
1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 46e8eeb7c432..ff93ef4cb5a2 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -33,19 +33,17 @@
#ifdef PPC64_ELF_ABI_v2

/* An address is simply the address of the function. */
-typedef unsigned long func_desc_t;
+typedef struct {
+ unsigned long addr;
+} func_desc_t;

static func_desc_t func_desc(unsigned long addr)
{
- return addr;
-}
-static unsigned long func_addr(unsigned long addr)
-{
- return addr;
-}
-static unsigned long stub_func_addr(func_desc_t func)
-{
- return func;
+ func_desc_t desc = {
+ .addr = addr,
+ };
+
+ return desc;
}

/* PowerPC64 specific values for the Elf64_Sym st_other field. */
@@ -70,14 +68,6 @@ static func_desc_t func_desc(unsigned long addr)
{
return *(struct func_desc *)addr;
}
-static unsigned long func_addr(unsigned long addr)
-{
- return func_desc(addr).addr;
-}
-static unsigned long stub_func_addr(func_desc_t func)
-{
- return func.addr;
-}
static unsigned int local_entry_offset(const Elf64_Sym *sym)
{
return 0;
@@ -93,6 +83,16 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr)
}
#endif

+static unsigned long func_addr(unsigned long addr)
+{
+ return func_desc(addr).addr;
+}
+
+static unsigned long stub_func_addr(func_desc_t func)
+{
+ return func.addr;
+}
+
#define STUB_MAGIC 0x73747562 /* stub */

/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
--
2.34.1