linux/arch/powerpc/include/asm/module.h
Sergey Senozhatsky 5633e85b2c powerpc64: Add .opd based function descriptor dereference
We are moving towards separate kernel and module function descriptor
dereference callbacks. This patch enables it for powerpc64.

For pointers that belong to the kernel
-  Added __start_opd and __end_opd pointers, to track the kernel
   .opd section address range;

-  Added dereference_kernel_function_descriptor(). Now we
   will dereference only function pointers that are within
   [__start_opd, __end_opd);

For pointers that belong to a module
-  Added dereference_module_function_descriptor() to handle module
   function descriptor dereference. Now we will dereference only
   pointers that are within [module->opd.start, module->opd.end).

Link: http://lkml.kernel.org/r/20171109234830.5067-4-sergey.senozhatsky@gmail.com
To: Tony Luck <tony.luck@intel.com>
To: Fenghua Yu <fenghua.yu@intel.com>
To: Helge Deller <deller@gmx.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Paul Mackerras <paulus@samba.org>
To: Michael Ellerman <mpe@ellerman.id.au>
To: James Bottomley <jejb@parisc-linux.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-01-09 10:45:37 +01:00

102 lines
2.6 KiB
C

#ifndef _ASM_POWERPC_MODULE_H
#define _ASM_POWERPC_MODULE_H
#ifdef __KERNEL__
/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/list.h>
#include <asm/bug.h>
#include <asm-generic/module.h>
#ifdef CC_USING_MPROFILE_KERNEL
#define MODULE_ARCH_VERMAGIC "mprofile-kernel"
#endif
#ifndef __powerpc64__
/*
* Thanks to Paul M for explaining this.
*
* PPC can only do rel jumps += 32MB, and often the kernel and other
* modules are further away than this. So, we jump to a table of
* trampolines attached to the module (the Procedure Linkage Table)
* whenever that happens.
*/
struct ppc_plt_entry {
/* 16 byte jump instruction sequence (4 instructions) */
unsigned int jump[4];
};
#endif /* __powerpc64__ */
struct mod_arch_specific {
#ifdef __powerpc64__
unsigned int stubs_section; /* Index of stubs section in module */
unsigned int toc_section; /* What section is the TOC? */
bool toc_fixed; /* Have we fixed up .TOC.? */
#ifdef CONFIG_DYNAMIC_FTRACE
unsigned long toc;
unsigned long tramp;
#endif
/* For module function descriptor dereference */
unsigned long start_opd;
unsigned long end_opd;
#else /* powerpc64 */
/* Indices of PLT sections within module. */
unsigned int core_plt_section;
unsigned int init_plt_section;
#ifdef CONFIG_DYNAMIC_FTRACE
unsigned long tramp;
#endif
#endif /* powerpc64 */
/* List of BUG addresses, source line numbers and filenames */
struct list_head bug_list;
struct bug_entry *bug_table;
unsigned int num_bugs;
};
/*
* Select ELF headers.
* Make empty section for module_frob_arch_sections to expand.
*/
#ifdef __powerpc64__
# ifdef MODULE
asm(".section .stubs,\"ax\",@nobits; .align 3; .previous");
# endif
#else
# ifdef MODULE
asm(".section .plt,\"ax\",@nobits; .align 3; .previous");
asm(".section .init.plt,\"ax\",@nobits; .align 3; .previous");
# endif /* MODULE */
#endif
#ifdef CONFIG_DYNAMIC_FTRACE
# ifdef MODULE
asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
# endif /* MODULE */
#endif
int module_trampoline_target(struct module *mod, unsigned long trampoline,
unsigned long *target);
#ifdef CONFIG_DYNAMIC_FTRACE
int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs);
#else
static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
{
return 0;
}
#endif
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_MODULE_H */