diff options
Diffstat (limited to 'ltrace-elf.h')
| -rw-r--r-- | ltrace-elf.h | 104 |
1 files changed, 80 insertions, 24 deletions
diff --git a/ltrace-elf.h b/ltrace-elf.h index 1a1321e..4a824c4 100644 --- a/ltrace-elf.h +++ b/ltrace-elf.h @@ -1,6 +1,6 @@ /* * 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 @@ -26,11 +26,11 @@ #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 @@ -48,9 +48,11 @@ struct ltelf { 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; @@ -60,43 +62,59 @@ struct ltelf { 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, @@ -104,13 +122,51 @@ 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); + +void delete_symbol_chain(struct library_symbol *); #if __WORDSIZE == 32 #define PRI_ELF_ADDR PRIx32 #define GELF_ADDR_CAST(x) (void *)(uint32_t)(x) |