/*
 * Copyright 2022, Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Trung Nguyen, trungnt282910@gmail.com
 */


#include <kernel/image.h>
#include <link.h>
#include <stddef.h>


#if B_HAIKU_32_BIT
        typedef Elf32_Ehdr Elf_Ehdr;
#elif B_HAIKU_64_BIT
        typedef Elf64_Ehdr Elf_Ehdr;
#endif


// While get_next_image_info does not return the address of
// the ELF header, it does return the first page of the image's
// text segment (defined by runtime_loader as the first loaded page
// with read-only protection). For most images produced by
// normal compilers, including Haiku ELF files, the file header
// is always loaded at the beginning of the text segment.
//
// We can therefore take advantage of this fact and populate
// struct dl_phdr_info.
int
dl_iterate_phdr(int (*callback)(struct dl_phdr_info* info, size_t size, void* data), void* data)
{
        image_info info;
        int32 cookie = 0;
        int status;

        struct dl_phdr_info phdr_info;

        while (get_next_image_info(0, &cookie, &info) == B_OK) {
                const Elf_Ehdr* header = (const Elf_Ehdr*)info.text;

                // Check for the special commpage info (which is not an ELF image),
                // and also guard against any maliciously crafted file which
                // does not load its header in memory.
                if (!IS_ELF(*header))
                        continue;

                phdr_info.dlpi_addr = (Elf_Addr)info.text;
                phdr_info.dlpi_name = info.name;
                phdr_info.dlpi_phnum = header->e_phnum;
                phdr_info.dlpi_phdr = (const Elf_Phdr*)((const char*)info.text + header->e_phoff);

                status = callback(&phdr_info, sizeof(phdr_info), data);

                if (status != 0)
                        return status;
        }

        return 0;
}