9 files changed, 665 insertions, 0 deletions

diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
new file mode 100644
index 000000000..861c0c60a
--- /dev/null
+++ b/tools/objtool/include/objtool/arch.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+
+#ifndef _ARCH_H
+#define _ARCH_H
+
+#include <stdbool.h>
+#include <linux/list.h>
+#include <objtool/objtool.h>
+#include <objtool/cfi.h>
+
+enum insn_type {
+	INSN_JUMP_CONDITIONAL,
+	INSN_JUMP_UNCONDITIONAL,
+	INSN_JUMP_DYNAMIC,
+	INSN_JUMP_DYNAMIC_CONDITIONAL,
+	INSN_CALL,
+	INSN_CALL_DYNAMIC,
+	INSN_RETURN,
+	INSN_CONTEXT_SWITCH,
+	INSN_BUG,
+	INSN_NOP,
+	INSN_STAC,
+	INSN_CLAC,
+	INSN_STD,
+	INSN_CLD,
+	INSN_TRAP,
+	INSN_ENDBR,
+	INSN_OTHER,
+};
+
+enum op_dest_type {
+	OP_DEST_REG,
+	OP_DEST_REG_INDIRECT,
+	OP_DEST_MEM,
+	OP_DEST_PUSH,
+	OP_DEST_PUSHF,
+};
+
+struct op_dest {
+	enum op_dest_type type;
+	unsigned char reg;
+	int offset;
+};
+
+enum op_src_type {
+	OP_SRC_REG,
+	OP_SRC_REG_INDIRECT,
+	OP_SRC_CONST,
+	OP_SRC_POP,
+	OP_SRC_POPF,
+	OP_SRC_ADD,
+	OP_SRC_AND,
+};
+
+struct op_src {
+	enum op_src_type type;
+	unsigned char reg;
+	int offset;
+};
+
+struct stack_op {
+	struct op_dest dest;
+	struct op_src src;
+	struct list_head list;
+};
+
+struct instruction;
+
+void arch_initial_func_cfi_state(struct cfi_init_state *state);
+
+int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
+			    unsigned long offset, unsigned int maxlen,
+			    unsigned int *len, enum insn_type *type,
+			    unsigned long *immediate,
+			    struct list_head *ops_list);
+
+bool arch_callee_saved_reg(unsigned char reg);
+
+unsigned long arch_jump_destination(struct instruction *insn);
+
+unsigned long arch_dest_reloc_offset(int addend);
+
+const char *arch_nop_insn(int len);
+const char *arch_ret_insn(int len);
+
+int arch_decode_hint_reg(u8 sp_reg, int *base);
+
+bool arch_is_retpoline(struct symbol *sym);
+bool arch_is_rethunk(struct symbol *sym);
+bool arch_is_embedded_insn(struct symbol *sym);
+
+int arch_rewrite_retpolines(struct objtool_file *file);
+
+#endif /* _ARCH_H */
diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h
new file mode 100644
index 000000000..42a52f1a0
--- /dev/null
+++ b/tools/objtool/include/objtool/builtin.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+#ifndef _BUILTIN_H
+#define _BUILTIN_H
+
+#include <subcmd/parse-options.h>
+
+extern const struct option check_options[];
+
+struct opts {
+	/* actions: */
+	bool dump_orc;
+	bool hack_jump_label;
+	bool hack_noinstr;
+	bool ibt;
+	bool mcount;
+	bool noinstr;
+	bool orc;
+	bool retpoline;
+	bool rethunk;
+	bool unret;
+	bool sls;
+	bool stackval;
+	bool static_call;
+	bool uaccess;
+
+	/* options: */
+	bool backtrace;
+	bool backup;
+	bool dryrun;
+	bool link;
+	bool module;
+	bool no_unreachable;
+	bool sec_address;
+	bool stats;
+};
+
+extern struct opts opts;
+
+extern int cmd_parse_options(int argc, const char **argv, const char * const usage[]);
+
+extern int objtool_run(int argc, const char **argv);
+
+#endif /* _BUILTIN_H */
diff --git a/tools/objtool/include/objtool/cfi.h b/tools/objtool/include/objtool/cfi.h
new file mode 100644
index 000000000..f11d1ac1d
--- /dev/null
+++ b/tools/objtool/include/objtool/cfi.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+
+#ifndef _OBJTOOL_CFI_H
+#define _OBJTOOL_CFI_H
+
+#include <arch/cfi_regs.h>
+#include <linux/list.h>
+
+#define CFI_UNDEFINED		-1
+#define CFI_CFA			-2
+#define CFI_SP_INDIRECT		-3
+#define CFI_BP_INDIRECT		-4
+
+struct cfi_reg {
+	int base;
+	int offset;
+};
+
+struct cfi_init_state {
+	struct cfi_reg regs[CFI_NUM_REGS];
+	struct cfi_reg cfa;
+};
+
+struct cfi_state {
+	struct hlist_node hash; /* must be first, cficmp() */
+	struct cfi_reg regs[CFI_NUM_REGS];
+	struct cfi_reg vals[CFI_NUM_REGS];
+	struct cfi_reg cfa;
+	int stack_size;
+	int drap_reg, drap_offset;
+	unsigned char type;
+	bool bp_scratch;
+	bool drap;
+	bool end;
+};
+
+#endif /* _OBJTOOL_CFI_H */
diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h
new file mode 100644
index 000000000..036129ceb
--- /dev/null
+++ b/tools/objtool/include/objtool/check.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+
+#ifndef _CHECK_H
+#define _CHECK_H
+
+#include <stdbool.h>
+#include <objtool/cfi.h>
+#include <objtool/arch.h>
+
+struct insn_state {
+	struct cfi_state cfi;
+	unsigned int uaccess_stack;
+	bool uaccess;
+	bool df;
+	bool noinstr;
+	s8 instr;
+};
+
+struct alt_group {
+	/*
+	 * Pointer from a replacement group to the original group.  NULL if it
+	 * *is* the original group.
+	 */
+	struct alt_group *orig_group;
+
+	/* First and last instructions in the group */
+	struct instruction *first_insn, *last_insn;
+
+	/*
+	 * Byte-offset-addressed len-sized array of pointers to CFI structs.
+	 * This is shared with the other alt_groups in the same alternative.
+	 */
+	struct cfi_state **cfi;
+};
+
+struct instruction {
+	struct list_head list;
+	struct hlist_node hash;
+	struct list_head call_node;
+	struct section *sec;
+	unsigned long offset;
+	unsigned int len;
+	enum insn_type type;
+	unsigned long immediate;
+
+	u16 dead_end		: 1,
+	   ignore		: 1,
+	   ignore_alts		: 1,
+	   hint			: 1,
+	   save			: 1,
+	   restore		: 1,
+	   retpoline_safe	: 1,
+	   noendbr		: 1,
+	   entry		: 1;
+		/* 7 bit hole */
+
+	s8 instr;
+	u8 visited;
+
+	struct alt_group *alt_group;
+	struct symbol *call_dest;
+	struct instruction *jump_dest;
+	struct instruction *first_jump_src;
+	struct reloc *jump_table;
+	struct reloc *reloc;
+	struct list_head alts;
+	struct symbol *func;
+	struct list_head stack_ops;
+	struct cfi_state *cfi;
+};
+
+#define VISITED_BRANCH		0x01
+#define VISITED_BRANCH_UACCESS	0x02
+#define VISITED_BRANCH_MASK	0x03
+#define VISITED_ENTRY		0x04
+
+static inline bool is_static_jump(struct instruction *insn)
+{
+	return insn->type == INSN_JUMP_CONDITIONAL ||
+	       insn->type == INSN_JUMP_UNCONDITIONAL;
+}
+
+static inline bool is_dynamic_jump(struct instruction *insn)
+{
+	return insn->type == INSN_JUMP_DYNAMIC ||
+	       insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL;
+}
+
+static inline bool is_jump(struct instruction *insn)
+{
+	return is_static_jump(insn) || is_dynamic_jump(insn);
+}
+
+struct instruction *find_insn(struct objtool_file *file,
+			      struct section *sec, unsigned long offset);
+
+#define for_each_insn(file, insn)					\
+	list_for_each_entry(insn, &file->insn_list, list)
+
+#define sec_for_each_insn(file, sec, insn)				\
+	for (insn = find_insn(file, sec, 0);				\
+	     insn && &insn->list != &file->insn_list &&			\
+			insn->sec == sec;				\
+	     insn = list_next_entry(insn, list))
+
+#endif /* _CHECK_H */
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
new file mode 100644
index 000000000..5d4a841fb
--- /dev/null
+++ b/tools/objtool/include/objtool/elf.h
@@ -0,0 +1,176 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+
+#ifndef _OBJTOOL_ELF_H
+#define _OBJTOOL_ELF_H
+
+#include <stdio.h>
+#include <gelf.h>
+#include <linux/list.h>
+#include <linux/hashtable.h>
+#include <linux/rbtree.h>
+#include <linux/jhash.h>
+
+#ifdef LIBELF_USE_DEPRECATED
+# define elf_getshdrnum    elf_getshnum
+# define elf_getshdrstrndx elf_getshstrndx
+#endif
+
+/*
+ * Fallback for systems without this "read, mmaping if possible" cmd.
+ */
+#ifndef ELF_C_READ_MMAP
+#define ELF_C_READ_MMAP ELF_C_READ
+#endif
+
+struct section {
+	struct list_head list;
+	struct hlist_node hash;
+	struct hlist_node name_hash;
+	GElf_Shdr sh;
+	struct rb_root symbol_tree;
+	struct list_head symbol_list;
+	struct list_head reloc_list;
+	struct section *base, *reloc;
+	struct symbol *sym;
+	Elf_Data *data;
+	char *name;
+	int idx;
+	bool changed, text, rodata, noinstr;
+};
+
+struct symbol {
+	struct list_head list;
+	struct rb_node node;
+	struct hlist_node hash;
+	struct hlist_node name_hash;
+	GElf_Sym sym;
+	struct section *sec;
+	char *name;
+	unsigned int idx;
+	unsigned char bind, type;
+	unsigned long offset;
+	unsigned int len;
+	struct symbol *pfunc, *cfunc, *alias;
+	u8 uaccess_safe      : 1;
+	u8 static_call_tramp : 1;
+	u8 retpoline_thunk   : 1;
+	u8 return_thunk      : 1;
+	u8 fentry            : 1;
+	u8 profiling_func    : 1;
+	u8 embedded_insn     : 1;
+	struct list_head pv_target;
+};
+
+struct reloc {
+	struct list_head list;
+	struct hlist_node hash;
+	union {
+		GElf_Rela rela;
+		GElf_Rel  rel;
+	};
+	struct section *sec;
+	struct symbol *sym;
+	unsigned long offset;
+	unsigned int type;
+	s64 addend;
+	int idx;
+	bool jump_table_start;
+};
+
+#define ELF_HASH_BITS	20
+
+struct elf {
+	Elf *elf;
+	GElf_Ehdr ehdr;
+	int fd;
+	bool changed;
+	char *name;
+	unsigned int text_size, num_files;
+	struct list_head sections;
+
+	int symbol_bits;
+	int symbol_name_bits;
+	int section_bits;
+	int section_name_bits;
+	int reloc_bits;
+
+	struct hlist_head *symbol_hash;
+	struct hlist_head *symbol_name_hash;
+	struct hlist_head *section_hash;
+	struct hlist_head *section_name_hash;
+	struct hlist_head *reloc_hash;
+};
+
+#define OFFSET_STRIDE_BITS	4
+#define OFFSET_STRIDE		(1UL << OFFSET_STRIDE_BITS)
+#define OFFSET_STRIDE_MASK	(~(OFFSET_STRIDE - 1))
+
+#define for_offset_range(_offset, _start, _end)			\
+	for (_offset = ((_start) & OFFSET_STRIDE_MASK);		\
+	     _offset >= ((_start) & OFFSET_STRIDE_MASK) &&	\
+	     _offset <= ((_end) & OFFSET_STRIDE_MASK);		\
+	     _offset += OFFSET_STRIDE)
+
+static inline u32 sec_offset_hash(struct section *sec, unsigned long offset)
+{
+	u32 ol, oh, idx = sec->idx;
+
+	offset &= OFFSET_STRIDE_MASK;
+
+	ol = offset;
+	oh = (offset >> 16) >> 16;
+
+	__jhash_mix(ol, oh, idx);
+
+	return ol;
+}
+
+static inline u32 reloc_hash(struct reloc *reloc)
+{
+	return sec_offset_hash(reloc->sec, reloc->offset);
+}
+
+/*
+ * Try to see if it's a whole archive (vmlinux.o or module).
+ *
+ * Note this will miss the case where a module only has one source file.
+ */
+static inline bool has_multiple_files(struct elf *elf)
+{
+	return elf->num_files > 1;
+}
+
+struct elf *elf_open_read(const char *name, int flags);
+struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr);
+
+int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset,
+		  unsigned int type, struct symbol *sym, s64 addend);
+int elf_add_reloc_to_insn(struct elf *elf, struct section *sec,
+			  unsigned long offset, unsigned int type,
+			  struct section *insn_sec, unsigned long insn_off);
+
+int elf_write_insn(struct elf *elf, struct section *sec,
+		   unsigned long offset, unsigned int len,
+		   const char *insn);
+int elf_write_reloc(struct elf *elf, struct reloc *reloc);
+int elf_write(struct elf *elf);
+void elf_close(struct elf *elf);
+
+struct section *find_section_by_name(const struct elf *elf, const char *name);
+struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
+struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
+struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
+struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset);
+int find_symbol_hole_containing(const struct section *sec, unsigned long offset);
+struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
+struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
+				     unsigned long offset, unsigned int len);
+struct symbol *find_func_containing(struct section *sec, unsigned long offset);
+
+#define for_each_sec(file, sec)						\
+	list_for_each_entry(sec, &file->elf->sections, list)
+
+#endif /* _OBJTOOL_ELF_H */
diff --git a/tools/objtool/include/objtool/endianness.h b/tools/objtool/include/objtool/endianness.h
new file mode 100644
index 000000000..10241341e
--- /dev/null
+++ b/tools/objtool/include/objtool/endianness.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _OBJTOOL_ENDIANNESS_H
+#define _OBJTOOL_ENDIANNESS_H
+
+#include <arch/endianness.h>
+#include <linux/kernel.h>
+#include <endian.h>
+
+#ifndef __TARGET_BYTE_ORDER
+#error undefined arch __TARGET_BYTE_ORDER
+#endif
+
+#if __BYTE_ORDER != __TARGET_BYTE_ORDER
+#define __NEED_BSWAP 1
+#else
+#define __NEED_BSWAP 0
+#endif
+
+/*
+ * Does a byte swap if target endianness doesn't match the host, i.e. cross
+ * compilation for little endian on big endian and vice versa.
+ * To be used for multi-byte values conversion, which are read from / about
+ * to be written to a target native endianness ELF file.
+ */
+#define bswap_if_needed(val)						\
+({									\
+	__typeof__(val) __ret;						\
+	switch (sizeof(val)) {						\
+	case 8: __ret = __NEED_BSWAP ? bswap_64(val) : (val); break;	\
+	case 4: __ret = __NEED_BSWAP ? bswap_32(val) : (val); break;	\
+	case 2: __ret = __NEED_BSWAP ? bswap_16(val) : (val); break;	\
+	default:							\
+		BUILD_BUG(); break;					\
+	}								\
+	__ret;								\
+})
+
+#endif /* _OBJTOOL_ENDIANNESS_H */
diff --git a/tools/objtool/include/objtool/objtool.h b/tools/objtool/include/objtool/objtool.h
new file mode 100644
index 000000000..7f2d1b095
--- /dev/null
+++ b/tools/objtool/include/objtool/objtool.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020 Matt Helsley <mhelsley@vmware.com>
+ */
+
+#ifndef _OBJTOOL_H
+#define _OBJTOOL_H
+
+#include <stdbool.h>
+#include <linux/list.h>
+#include <linux/hashtable.h>
+
+#include <objtool/elf.h>
+
+#define __weak __attribute__((weak))
+
+struct pv_state {
+	bool clean;
+	struct list_head targets;
+};
+
+struct objtool_file {
+	struct elf *elf;
+	struct list_head insn_list;
+	DECLARE_HASHTABLE(insn_hash, 20);
+	struct list_head retpoline_call_list;
+	struct list_head return_thunk_list;
+	struct list_head static_call_list;
+	struct list_head mcount_loc_list;
+	struct list_head endbr_list;
+	bool ignore_unreachables, hints, rodata;
+
+	unsigned int nr_endbr;
+	unsigned int nr_endbr_int;
+
+	unsigned long jl_short, jl_long;
+	unsigned long jl_nop_short, jl_nop_long;
+
+	struct pv_state *pv_ops;
+};
+
+struct objtool_file *objtool_open_read(const char *_objname);
+
+void objtool_pv_add(struct objtool_file *file, int idx, struct symbol *func);
+
+int check(struct objtool_file *file);
+int orc_dump(const char *objname);
+int orc_create(struct objtool_file *file);
+
+#endif /* _OBJTOOL_H */
diff --git a/tools/objtool/include/objtool/special.h b/tools/objtool/include/objtool/special.h
new file mode 100644
index 000000000..dc4721e19
--- /dev/null
+++ b/tools/objtool/include/objtool/special.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+
+#ifndef _SPECIAL_H
+#define _SPECIAL_H
+
+#include <stdbool.h>
+#include <objtool/check.h>
+#include <objtool/elf.h>
+
+#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
+
+struct special_alt {
+	struct list_head list;
+
+	bool group;
+	bool skip_orig;
+	bool skip_alt;
+	bool jump_or_nop;
+
+	struct section *orig_sec;
+	unsigned long orig_off;
+
+	struct section *new_sec;
+	unsigned long new_off;
+
+	unsigned int orig_len, new_len; /* group only */
+	u8 key_addend;
+};
+
+int special_get_alts(struct elf *elf, struct list_head *alts);
+
+void arch_handle_alternative(unsigned short feature, struct special_alt *alt);
+
+bool arch_support_alt_relocation(struct special_alt *special_alt,
+				 struct instruction *insn,
+				 struct reloc *reloc);
+struct reloc *arch_find_switch_table(struct objtool_file *file,
+				    struct instruction *insn);
+#endif /* _SPECIAL_H */
diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h
new file mode 100644
index 000000000..a3e79ae75
--- /dev/null
+++ b/tools/objtool/include/objtool/warn.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+
+#ifndef _WARN_H
+#define _WARN_H
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <objtool/builtin.h>
+#include <objtool/elf.h>
+
+extern const char *objname;
+
+static inline char *offstr(struct section *sec, unsigned long offset)
+{
+	bool is_text = (sec->sh.sh_flags & SHF_EXECINSTR);
+	struct symbol *sym = NULL;
+	char *str;
+	int len;
+
+	if (is_text)
+		sym = find_func_containing(sec, offset);
+	if (!sym)
+		sym = find_symbol_containing(sec, offset);
+
+	if (sym) {
+		str = malloc(strlen(sym->name) + strlen(sec->name) + 40);
+		len = sprintf(str, "%s+0x%lx", sym->name, offset - sym->offset);
+		if (opts.sec_address)
+			sprintf(str+len, " (%s+0x%lx)", sec->name, offset);
+	} else {
+		str = malloc(strlen(sec->name) + 20);
+		sprintf(str, "%s+0x%lx", sec->name, offset);
+	}
+
+	return str;
+}
+
+#define WARN(format, ...)				\
+	fprintf(stderr,					\
+		"%s: warning: objtool: " format "\n",	\
+		objname, ##__VA_ARGS__)
+
+#define WARN_FUNC(format, sec, offset, ...)		\
+({							\
+	char *_str = offstr(sec, offset);		\
+	WARN("%s: " format, _str, ##__VA_ARGS__);	\
+	free(_str);					\
+})
+
+#define BT_FUNC(format, insn, ...)			\
+({							\
+	struct instruction *_insn = (insn);		\
+	char *_str = offstr(_insn->sec, _insn->offset); \
+	WARN("  %s: " format, _str, ##__VA_ARGS__);	\
+	free(_str);					\
+})
+
+#define WARN_ELF(format, ...)				\
+	WARN(format ": %s", ##__VA_ARGS__, elf_errmsg(-1))
+
+#endif /* _WARN_H */