f48cb8b48b
Impact: Allow 64 bit PowerPC to trace modules with dynamic ftrace
This adds code to handle the PPC64 module trampolines, and allows for
PPC64 to use dynamic ftrace.
Thanks to Paul Mackerras for these updates:
- fix the mod and rec->arch.mod NULL checks.
- fix to is_bl_op compare.
Thanks to Milton Miller for:
- finding the nasty race with using two nops, and recommending
instead that I use a branch 8 forward.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
89 lines
2.2 KiB
C
89 lines
2.2 KiB
C
#ifndef _ASM_POWERPC_MODULE_H
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#define _ASM_POWERPC_MODULE_H
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#ifdef __KERNEL__
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/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/list.h>
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#include <asm/bug.h>
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#ifndef __powerpc64__
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/*
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* Thanks to Paul M for explaining this.
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*
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* PPC can only do rel jumps += 32MB, and often the kernel and other
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* modules are furthur away than this. So, we jump to a table of
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* trampolines attached to the module (the Procedure Linkage Table)
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* whenever that happens.
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*/
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struct ppc_plt_entry {
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/* 16 byte jump instruction sequence (4 instructions) */
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unsigned int jump[4];
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};
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#endif /* __powerpc64__ */
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struct mod_arch_specific {
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#ifdef __powerpc64__
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unsigned int stubs_section; /* Index of stubs section in module */
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unsigned int toc_section; /* What section is the TOC? */
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#ifdef CONFIG_DYNAMIC_FTRACE
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unsigned long toc;
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unsigned long tramp;
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#endif
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#else
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/* Indices of PLT sections within module. */
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unsigned int core_plt_section;
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unsigned int init_plt_section;
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#endif
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/* List of BUG addresses, source line numbers and filenames */
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struct list_head bug_list;
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struct bug_entry *bug_table;
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unsigned int num_bugs;
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};
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/*
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* Select ELF headers.
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* Make empty section for module_frob_arch_sections to expand.
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*/
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#ifdef __powerpc64__
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# define Elf_Shdr Elf64_Shdr
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# define Elf_Sym Elf64_Sym
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# define Elf_Ehdr Elf64_Ehdr
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# ifdef MODULE
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asm(".section .stubs,\"ax\",@nobits; .align 3; .previous");
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# endif
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#else
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# define Elf_Shdr Elf32_Shdr
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# define Elf_Sym Elf32_Sym
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# define Elf_Ehdr Elf32_Ehdr
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# ifdef MODULE
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asm(".section .plt,\"ax\",@nobits; .align 3; .previous");
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asm(".section .init.plt,\"ax\",@nobits; .align 3; .previous");
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# endif /* MODULE */
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#endif
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#ifdef CONFIG_DYNAMIC_FTRACE
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# ifdef MODULE
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asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
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# endif /* MODULE */
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#endif
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struct exception_table_entry;
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void sort_ex_table(struct exception_table_entry *start,
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struct exception_table_entry *finish);
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_MODULE_H */
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