/*
* This file is part of ltrace.
- * Copyright (C) 2006,2010,2012 Petr Machata, Red Hat Inc.
+ * Copyright (C) 2006,2010,2012,2013 Petr Machata, Red Hat Inc.
* Copyright (C) 2010 Zachary T Welch
* Copyright (C) 2001,2004,2007,2009 Juan Cespedes
* Copyright (C) 2006 Ian Wienand
#include <gelf.h>
#include <stdlib.h>
-#include "sysdep.h"
+#include <callback.h>
-struct Process;
-struct library;
-struct library_symbol;
+#include "forward.h"
+#include "sysdep.h"
+#include "vect.h"
/* XXX Ok, the original idea was to separate the low-level ELF data
* from the abstract "struct library" object, but we use some of the
GElf_Addr plt_addr;
GElf_Word plt_flags;
size_t plt_size;
- Elf_Data *relplt;
Elf_Data *plt_data;
- size_t relplt_count;
+
+ /* Vector of GElf_Rela with PLT relocations. */
+ struct vect plt_relocs;
+
Elf_Data *symtab;
const char *strtab;
const char *soname;
size_t opd_size;
GElf_Addr dyn_addr;
size_t dyn_sz;
- size_t relplt_size;
GElf_Addr bias;
GElf_Addr entry_addr;
GElf_Addr base_addr;
struct arch_ltelf_data arch;
};
-int open_elf(struct ltelf *lte, const char *filename);
-void do_close_elf(struct ltelf *lte);
+int ltelf_init(struct ltelf *lte, const char *filename);
+void ltelf_destroy(struct ltelf *lte);
/* XXX is it possible to put breakpoints in VDSO and VSYSCALL
* pseudo-libraries? For now we assume that all libraries can be
* opened via a filesystem. BASE is ignored for ET_EXEC files. */
-int ltelf_read_library(struct library *lib, struct Process *proc,
+int ltelf_read_library(struct library *lib, struct process *proc,
const char *filename, GElf_Addr bias);
/* Create a library object representing the main binary. The entry
* point address is stored to *ENTRYP. */
-struct library *ltelf_read_main_binary(struct Process *proc, const char *path);
+struct library *ltelf_read_main_binary(struct process *proc, const char *path);
+
+/* This is called for every PLT relocation R in ELF file LTE, that
+ * ltrace is about to add to a library constructed in process PROC.
+ * The corresponding PLT entry is for symbol called NAME, and it's
+ * I-th relocation in the file. *RET shall be initialized and
+ * symbol(s) corresponding to the given PLT entry will be added to the
+ * front. Returns 0 for success, or a negative value for failures.
+ *
+ * This calls os_elf_add_plt_entry and arch_elf_add_plt_entry in the
+ * background (see backend.h for documentation). The arch callback is
+ * called first. If it returns PLT_DEFAULT, the os callback is called
+ * next. If that returns PLT_DEFAULT, default_elf_add_plt_entry is
+ * called. */
+int elf_add_plt_entry(struct process *proc, struct ltelf *lte,
+ const char *name, GElf_Rela *rela, size_t idx,
+ struct library_symbol **ret);
/* Create a default PLT entry. This can be used instead (or in
- * addition to) returning plt_default from arch_elf_add_plt_entry.
+ * addition to) returning PLT_DEFAULT from arch_elf_add_plt_entry.
* RET shall be initialized, the created symbol will be added to the
* beginning of the linked list at *RET. This function doesn't add
* the symbol to LTE. arch_elf_add_plt_entry has the chance to adjust
- * symbol internals to its liking, and then return either plt_default
- * or plt_ok. */
-int default_elf_add_plt_entry(struct Process *proc, struct ltelf *lte,
+ * symbol internals to its liking, and then return either PLT_DEFAULT
+ * or PLT_OK. */
+int default_elf_add_plt_entry(struct process *proc, struct ltelf *lte,
const char *a_name, GElf_Rela *rela, size_t ndx,
struct library_symbol **ret);
-/* The base implementation of backend.h (arch_get_sym_info).
- * See backend.h for details. */
-int elf_get_sym_info(struct ltelf *lte, const char *filename,
- size_t sym_index, GElf_Rela *rela, GElf_Sym *sym);
-
Elf_Data *elf_loaddata(Elf_Scn *scn, GElf_Shdr *shdr);
+
+/* The following three look for sections based on various criteria.
+ * They return 0 if there was no error, or a negative value if there
+ * was. If the section was found, it is returned in *TGT_SEC, and the
+ * header is stored to TGT_SHDR. If it wasn't found, *TGT_SEC is set
+ * to NULL. */
int elf_get_section_covering(struct ltelf *lte, GElf_Addr addr,
Elf_Scn **tgt_sec, GElf_Shdr *tgt_shdr);
int elf_get_section_type(struct ltelf *lte, GElf_Word type,
int elf_get_section_named(struct ltelf *lte, const char *name,
Elf_Scn **tgt_sec, GElf_Shdr *tgt_shdr);
-/* Read, respectively, 2, 4, or 8 bytes from Elf data at given OFFSET,
- * and store it in *RETP. Returns 0 on success or a negative value if
- * there's not enough data. */
+/* Iterate through all symbols in LTE. See callback.h for notes on
+ * iteration interfaces. START_AFTER is 0 in initial call. */
+struct elf_each_symbol_t {
+ unsigned restart;
+ int status;
+} elf_each_symbol(struct ltelf *lte, unsigned start_after,
+ enum callback_status (*cb)(GElf_Sym *symbol,
+ const char *name,
+ void *data),
+ void *data);
+
+/* Read relocations from relocation section SCN with header SHDR and
+ * add them to RELA_VEC, which is a vector of GElf_Rela. Return 0 on
+ * success, or a negative value on failure. */
+int elf_read_relocs(struct ltelf *lte, Elf_Scn *scn, GElf_Shdr *shdr,
+ struct vect *rela_vec);
+
+/* Read a given DT_ TAG from LTE. Value is returned in *VALUEP.
+ * Returns 0 on success or a negative value on failure. */
+int elf_load_dynamic_entry(struct ltelf *lte, int tag, GElf_Addr *valuep);
+
+/* Read, respectively, 1, 2, 4, or 8 bytes from Elf data at given
+ * OFFSET, and store it in *RETP. Returns 0 on success or a negative
+ * value if there's not enough data. */
+int elf_read_u8(Elf_Data *data, GElf_Xword offset, uint8_t *retp);
int elf_read_u16(Elf_Data *data, GElf_Xword offset, uint16_t *retp);
int elf_read_u32(Elf_Data *data, GElf_Xword offset, uint32_t *retp);
int elf_read_u64(Elf_Data *data, GElf_Xword offset, uint64_t *retp);
+/* Read at most 64-bit quantity recorded in an ULEB128 variable-length
+ * encoding. */
+int elf_read_uleb128(Elf_Data *data, GElf_Xword offset, uint64_t *retp);
+
+/* These are same as above, but update *OFFSET with the width
+ * of read datum. */
+int elf_read_next_u8(Elf_Data *data, GElf_Xword *offset, uint8_t *retp);
+int elf_read_next_u16(Elf_Data *data, GElf_Xword *offset, uint16_t *retp);
+int elf_read_next_u32(Elf_Data *data, GElf_Xword *offset, uint32_t *retp);
+int elf_read_next_u64(Elf_Data *data, GElf_Xword *offset, uint64_t *retp);
+int elf_read_next_uleb128(Elf_Data *data, GElf_Xword *offset, uint64_t *retp);
+
+/* Return whether there's AMOUNT more bytes after OFFSET in DATA. */
+int elf_can_read_next(Elf_Data *data, GElf_Xword offset, GElf_Xword amount);
+
#if __WORDSIZE == 32
#define PRI_ELF_ADDR PRIx32
#define GELF_ADDR_CAST(x) (void *)(uint32_t)(x)
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