mirror of
https://gitee.com/bianbu-linux/linux-6.6
synced 2025-04-24 14:07:52 -04:00
77e69ee7ce
Build modules using PCREL addressing when CONFIG_PPC_KERNEL_PCREL=y.
- The module loader must handle several new relocation types:
* R_PPC64_REL24_NOTOC is a function call handled like R_PPC_REL24, but
does not restore r2 upon return. The external function call stub is
changed to use pcrel addressing to load the function pointer rather
than based on the module TOC.
* R_PPC64_GOT_PCREL34 is a reference to external data. A GOT table
must be built by hand, because the linker adds this during the final
link (which is not done for kernel modules). The GOT table is built
similarly to the way the external function call stub table is. This
section is called .mygot because .got has a special meaning for the
linker and can become upset.
* R_PPC64_PCREL34 is used for local data addressing, but there is a
special case where the percpu section is moved at load-time to the
percpu area which is out of range of this relocation. This requires
the PCREL34 relocations are converted to use GOT_PCREL34 addressing.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Some coding style & formatting fixups]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-7-npiggin@gmail.com
93 lines
2.5 KiB
C
93 lines
2.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
#ifndef _ASM_POWERPC_MODULE_H
|
|
#define _ASM_POWERPC_MODULE_H
|
|
#ifdef __KERNEL__
|
|
|
|
#include <linux/list.h>
|
|
#include <asm/bug.h>
|
|
#include <asm-generic/module.h>
|
|
|
|
#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 */
|
|
#ifdef CONFIG_PPC_KERNEL_PCREL
|
|
unsigned int got_section; /* What section is the GOT? */
|
|
unsigned int pcpu_section; /* .data..percpu section */
|
|
#else
|
|
unsigned int toc_section; /* What section is the TOC? */
|
|
bool toc_fixed; /* Have we fixed up .TOC.? */
|
|
#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;
|
|
#endif /* powerpc64 */
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
unsigned long tramp;
|
|
unsigned long tramp_regs;
|
|
#endif
|
|
|
|
/* 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 sections for module_frob_arch_sections to expand.
|
|
*/
|
|
|
|
#ifdef __powerpc64__
|
|
# ifdef MODULE
|
|
asm(".section .stubs,\"ax\",@nobits; .align 3; .previous");
|
|
# ifdef CONFIG_PPC_KERNEL_PCREL
|
|
asm(".section .mygot,\"a\",@nobits; .align 3; .previous");
|
|
# endif
|
|
# 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 */
|
|
|
|
int module_trampoline_target(struct module *mod, unsigned long trampoline,
|
|
unsigned long *target);
|
|
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 */
|