Apple Silicon kernels

assym.c

#include <fcntl.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <mach-o/loader.h>
#include <mach-o/nlist.h>

int main(int argc, const char **argv)
{
    if(argc != 2)
    {
        fprintf(stderr, "Usage: %s file\n", argv[0]);
        return -1;
    }
    int fd = open(argv[1], O_RDONLY);
    if(fd < 0) perror("open");
    struct stat s;
    int r = fstat(fd, &s);
    if(r != 0) perror("fstat");
    void *file = mmap(NULL, s.st_size, PROT_READ, MAP_FILE | MAP_PRIVATE, fd, 0);
    if(file == MAP_FAILED) perror("mmap");
    struct mach_header_64 *mh = file;
    if(mh->filetype != 0xc)
    {
        fprintf(stderr, "Not an Apple Silicon kernel\n");
        return -1;
    }
    for(struct load_command *lc = (struct load_command*)(mh + 1), *max = (struct load_command*)((uintptr_t)lc + mh->sizeofcmds); lc < max; lc = (struct load_command*)((uintptr_t)lc + lc->cmdsize))
    {
        if(lc->cmd == 0x80000035)
        {
            struct
            {
                uint32_t cmd;
                uint32_t cmdsize;
                uint64_t addr;
                uint64_t off;
                uint32_t name;
            } *ent = (void*)lc;
            const char *name = (const char*)((uintptr_t)ent + ent->name);
            printf("\e[1;96m%s\e[0m\n", name);
            struct mach_header_64 *hdr = (struct mach_header_64*)((uintptr_t)file + ent->off);
            for(struct load_command *cmd = (struct load_command*)(hdr + 1), *end = (struct load_command*)((uintptr_t)cmd + hdr->sizeofcmds); cmd < end; cmd = (struct load_command*)((uintptr_t)cmd + cmd->cmdsize))
            {
                if(cmd->cmd == LC_SYMTAB)
                {
                    struct symtab_command *stab = (struct symtab_command*)cmd;
                    struct nlist_64 *symtab = (struct nlist_64*)((uintptr_t)file + stab->symoff);
                    const char *strtab = (const char*)((uintptr_t)file + stab->stroff);
                    for(uint32_t i = 0; i < stab->nsyms; ++i)
                    {
                        if((symtab[i].n_type & 0xe) == 0xe)
                        {
                            printf("0x%016llx %s\n", symtab[i].n_value, &strtab[symtab[i].n_un.n_strx]);
                        }
                    }
                }
            }
        }
    }
    return 0;
}