bianbu-linux-6.6/arch/powerpc/include/asm/sections.h
Christophe Leroy 0dc690e4ef asm-generic: Define 'func_desc_t' to commonly describe function descriptors
We have three architectures using function descriptors, each with its
own type and name.

Add a common typedef that can be used in generic code.

Also add a stub typedef for architecture without function descriptors,
to avoid a forest of #ifdefs.

It replaces the similar 'func_desc_t' previously defined in
arch/powerpc/kernel/module_64.c

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-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/f1f91b142b3c1082bdc1586ce71c9bac1e75213c.1644928018.git.christophe.leroy@csgroup.eu
2022-02-16 23:25:11 +11:00

87 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_SECTIONS_H
#define _ASM_POWERPC_SECTIONS_H
#ifdef __KERNEL__
#include <linux/elf.h>
#include <linux/uaccess.h>
#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS
typedef struct func_desc func_desc_t;
#endif
#include <asm-generic/sections.h>
extern char __head_end[];
#ifdef __powerpc64__
extern char __start_interrupts[];
extern char __end_interrupts[];
extern char __prom_init_toc_start[];
extern char __prom_init_toc_end[];
#ifdef CONFIG_PPC_POWERNV
extern char start_real_trampolines[];
extern char end_real_trampolines[];
extern char start_virt_trampolines[];
extern char end_virt_trampolines[];
#endif
/*
* This assumes the kernel is never compiled -mcmodel=small or
* the total .toc is always less than 64k.
*/
static inline unsigned long kernel_toc_addr(void)
{
unsigned long toc_ptr;
asm volatile("mr %0, 2" : "=r" (toc_ptr));
return toc_ptr;
}
static inline int overlaps_interrupt_vector_text(unsigned long start,
unsigned long end)
{
unsigned long real_start, real_end;
real_start = __start_interrupts - _stext;
real_end = __end_interrupts - _stext;
return start < (unsigned long)__va(real_end) &&
(unsigned long)__va(real_start) < end;
}
static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
{
return start < (unsigned long)__init_end &&
(unsigned long)_stext < end;
}
#ifdef PPC64_ELF_ABI_v1
#undef dereference_function_descriptor
static inline void *dereference_function_descriptor(void *ptr)
{
struct func_desc *desc = ptr;
void *p;
if (!get_kernel_nofault(p, (void *)&desc->addr))
ptr = p;
return ptr;
}
#undef dereference_kernel_function_descriptor
static inline void *dereference_kernel_function_descriptor(void *ptr)
{
if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
return ptr;
return dereference_function_descriptor(ptr);
}
#endif /* PPC64_ELF_ABI_v1 */
#endif
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_SECTIONS_H */