forked from Minki/linux
1e7e478838
Add the inline static call implementation for x86-64. The generated code is identical to the out-of-line case, except we move the trampoline into it's own section. Objtool uses the trampoline naming convention to detect all the call sites. It then annotates those call sites in the .static_call_sites section. During boot (and module init), the call sites are patched to call directly into the destination function. The temporary trampoline is then no longer used. [peterz: merged trampolines, put trampoline in section] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20200818135804.864271425@infradead.org
149 lines
4.0 KiB
C
149 lines
4.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
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*/
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#ifndef _OBJTOOL_ELF_H
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#define _OBJTOOL_ELF_H
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#include <stdio.h>
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#include <gelf.h>
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#include <linux/list.h>
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#include <linux/hashtable.h>
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#include <linux/rbtree.h>
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#include <linux/jhash.h>
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#ifdef LIBELF_USE_DEPRECATED
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# define elf_getshdrnum elf_getshnum
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# define elf_getshdrstrndx elf_getshstrndx
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#endif
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/*
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* Fallback for systems without this "read, mmaping if possible" cmd.
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*/
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#ifndef ELF_C_READ_MMAP
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#define ELF_C_READ_MMAP ELF_C_READ
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#endif
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struct section {
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struct list_head list;
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struct hlist_node hash;
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struct hlist_node name_hash;
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GElf_Shdr sh;
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struct rb_root symbol_tree;
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struct list_head symbol_list;
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struct list_head reloc_list;
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struct section *base, *reloc;
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struct symbol *sym;
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Elf_Data *data;
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char *name;
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int idx;
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unsigned int len;
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bool changed, text, rodata, noinstr;
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};
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struct symbol {
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struct list_head list;
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struct rb_node node;
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struct hlist_node hash;
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struct hlist_node name_hash;
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GElf_Sym sym;
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struct section *sec;
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char *name;
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unsigned int idx;
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unsigned char bind, type;
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unsigned long offset;
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unsigned int len;
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struct symbol *pfunc, *cfunc, *alias;
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bool uaccess_safe;
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bool static_call_tramp;
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};
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struct reloc {
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struct list_head list;
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struct hlist_node hash;
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union {
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GElf_Rela rela;
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GElf_Rel rel;
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};
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struct section *sec;
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struct symbol *sym;
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unsigned long offset;
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unsigned int type;
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int addend;
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int idx;
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bool jump_table_start;
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};
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#define ELF_HASH_BITS 20
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struct elf {
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Elf *elf;
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GElf_Ehdr ehdr;
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int fd;
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bool changed;
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char *name;
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struct list_head sections;
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DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
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DECLARE_HASHTABLE(symbol_name_hash, ELF_HASH_BITS);
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DECLARE_HASHTABLE(section_hash, ELF_HASH_BITS);
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DECLARE_HASHTABLE(section_name_hash, ELF_HASH_BITS);
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DECLARE_HASHTABLE(reloc_hash, ELF_HASH_BITS);
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};
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#define OFFSET_STRIDE_BITS 4
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#define OFFSET_STRIDE (1UL << OFFSET_STRIDE_BITS)
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#define OFFSET_STRIDE_MASK (~(OFFSET_STRIDE - 1))
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#define for_offset_range(_offset, _start, _end) \
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for (_offset = ((_start) & OFFSET_STRIDE_MASK); \
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_offset >= ((_start) & OFFSET_STRIDE_MASK) && \
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_offset <= ((_end) & OFFSET_STRIDE_MASK); \
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_offset += OFFSET_STRIDE)
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static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
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{
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u32 ol, oh, idx = sec->idx;
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offset &= OFFSET_STRIDE_MASK;
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ol = offset;
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oh = (offset >> 16) >> 16;
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__jhash_mix(ol, oh, idx);
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return ol;
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}
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static inline u32 reloc_hash(struct reloc *reloc)
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{
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return sec_offset_hash(reloc->sec, reloc->offset);
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}
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struct elf *elf_open_read(const char *name, int flags);
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struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr);
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struct section *elf_create_reloc_section(struct elf *elf, struct section *base, int reltype);
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void elf_add_reloc(struct elf *elf, struct reloc *reloc);
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int elf_write_insn(struct elf *elf, struct section *sec,
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unsigned long offset, unsigned int len,
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const char *insn);
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int elf_write_reloc(struct elf *elf, struct reloc *reloc);
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int elf_write(struct elf *elf);
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void elf_close(struct elf *elf);
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struct section *find_section_by_name(const struct elf *elf, const char *name);
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struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
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struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
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struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
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struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset);
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struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
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struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
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unsigned long offset, unsigned int len);
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struct symbol *find_func_containing(struct section *sec, unsigned long offset);
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int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);
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#define for_each_sec(file, sec) \
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list_for_each_entry(sec, &file->elf->sections, list)
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#endif /* _OBJTOOL_ELF_H */
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