| /* Report a module to libdwfl based on ELF program headers. |
| Copyright (C) 2005 Red Hat, Inc. |
| |
| This program is Open Source software; you can redistribute it and/or |
| modify it under the terms of the Open Software License version 1.0 as |
| published by the Open Source Initiative. |
| |
| You should have received a copy of the Open Software License along |
| with this program; if not, you may obtain a copy of the Open Software |
| License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 3001 King Ranch Road, Ukiah, CA 95482. */ |
| |
| #include "libdwflP.h" |
| #include <fcntl.h> |
| #include <unistd.h> |
| |
| |
| Dwfl_Module * |
| dwfl_report_elf (Dwfl *dwfl, const char *name, |
| const char *file_name, int fd, GElf_Addr base) |
| { |
| bool closefd = false; |
| |
| if (fd < 0) |
| { |
| fd = open64 (file_name, O_RDONLY); |
| if (fd < 0) |
| { |
| __libdwfl_seterrno (DWFL_E_ERRNO); |
| return NULL; |
| } |
| closefd = true; |
| } |
| |
| Elf *elf = elf_begin (fd, ELF_C_READ_MMAP_PRIVATE, NULL); |
| |
| GElf_Ehdr ehdr_mem, *ehdr = gelf_getehdr (elf, &ehdr_mem); |
| if (ehdr == NULL) |
| { |
| elf_error: |
| __libdwfl_seterrno (DWFL_E_LIBELF); |
| if (closefd) |
| close (fd); |
| return NULL; |
| } |
| |
| GElf_Addr start = 0, end = 0, bias = 0; |
| switch (ehdr->e_type) |
| { |
| case ET_REL: |
| /* For a relocatable object, we do an arbitrary section layout. |
| By updating the section header in place, we leave the layout |
| information to be found by relocation. */ |
| |
| start = end = base; |
| |
| Elf_Scn *scn = NULL; |
| while ((scn = elf_nextscn (elf, scn)) != NULL) |
| { |
| GElf_Shdr shdr_mem; |
| GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| if (shdr == NULL) |
| goto elf_error; |
| |
| if (shdr->sh_flags & SHF_ALLOC) |
| { |
| const GElf_Xword align = shdr->sh_addralign ?: 1; |
| shdr->sh_addr = (end + align - 1) & -align; |
| if (end == base) |
| /* This is the first section assigned a location. |
| Use its aligned address as the module's base. */ |
| start = shdr->sh_addr; |
| end = shdr->sh_addr + shdr->sh_size; |
| if (! gelf_update_shdr (scn, shdr)) |
| goto elf_error; |
| } |
| } |
| |
| if (end == start) |
| { |
| __libdwfl_seterrno (DWFL_E_BADELF); |
| if (closefd) |
| close (fd); |
| return NULL; |
| } |
| break; |
| |
| /* Everything else has to have program headers. */ |
| |
| case ET_EXEC: |
| case ET_CORE: |
| /* An assigned base address is meaningless for these. */ |
| base = 0; |
| |
| case ET_DYN: |
| default: |
| for (uint_fast16_t i = 0; i < ehdr->e_phnum; ++i) |
| { |
| GElf_Phdr phdr_mem, *ph = gelf_getphdr (elf, i, &phdr_mem); |
| if (ph == NULL) |
| goto elf_error; |
| if (ph->p_type == PT_LOAD) |
| { |
| if ((base & (ph->p_align - 1)) != 0) |
| base = (base + ph->p_align - 1) & -ph->p_align; |
| start = base + (ph->p_vaddr & -ph->p_align); |
| break; |
| } |
| } |
| bias = base; |
| |
| for (uint_fast16_t i = ehdr->e_phnum; i-- > 0;) |
| { |
| GElf_Phdr phdr_mem, *ph = gelf_getphdr (elf, i, &phdr_mem); |
| if (ph == NULL) |
| goto elf_error; |
| if (ph->p_type == PT_LOAD) |
| { |
| end = base + (ph->p_vaddr + ph->p_memsz); |
| break; |
| } |
| } |
| |
| if (end == 0) |
| { |
| __libdwfl_seterrno (DWFL_E_NO_PHDR); |
| if (closefd) |
| close (fd); |
| return NULL; |
| } |
| break; |
| } |
| |
| Dwfl_Module *m = INTUSE(dwfl_report_module) (dwfl, name, start, end); |
| if (m != NULL) |
| { |
| if (m->main.name == NULL) |
| { |
| m->main.name = strdup (file_name); |
| m->main.fd = fd; |
| } |
| else if ((fd >= 0 && m->main.fd != fd) |
| || strcmp (m->main.name, file_name)) |
| { |
| elf_end (elf); |
| overlap: |
| if (closefd) |
| close (fd); |
| m->gc = true; |
| __libdwfl_seterrno (DWFL_E_OVERLAP); |
| m = NULL; |
| } |
| |
| /* Preinstall the open ELF handle for the module. */ |
| if (m->main.elf == NULL) |
| { |
| m->main.elf = elf; |
| m->main.bias = bias; |
| m->e_type = ehdr->e_type; |
| } |
| else |
| { |
| elf_end (elf); |
| if (m->main.bias != base) |
| goto overlap; |
| } |
| } |
| return m; |
| } |
| INTDEF (dwfl_report_elf) |