| /****************************************************************************/ | |
| /* | |
| * QEMU bFLT binary loader. Based on linux/fs/binfmt_flat.c | |
| * | |
| * This program is free software; you can redistribute it and/or modify | |
| * it under the terms of the GNU General Public License as published by | |
| * the Free Software Foundation; either version 2 of the License, or | |
| * (at your option) any later version. | |
| * | |
| * This program is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| * GNU General Public License for more details. | |
| * | |
| * You should have received a copy of the GNU General Public License | |
| * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
| * | |
| * Copyright (C) 2006 CodeSourcery. | |
| * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> | |
| * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> | |
| * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> | |
| * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> | |
| * based heavily on: | |
| * | |
| * linux/fs/binfmt_aout.c: | |
| * Copyright (C) 1991, 1992, 1996 Linus Torvalds | |
| * linux/fs/binfmt_flat.c for 2.0 kernel | |
| * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> | |
| * JAN/99 -- coded full program relocation (gerg@snapgear.com) | |
| */ | |
| /****************************************************************************/ | |
| #include "qemu/osdep.h" | |
| #include "qemu.h" | |
| #include "exec/page-protection.h" | |
| #include "user-internals.h" | |
| #include "loader.h" | |
| #include "user-mmap.h" | |
| #include "flat.h" | |
| #include "target_flat.h" | |
| //#define DEBUG | |
| #ifdef DEBUG | |
| #define DBG_FLT(...) printf(__VA_ARGS__) | |
| #else | |
| #define DBG_FLT(...) | |
| #endif | |
| #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ | |
| #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ | |
| struct lib_info { | |
| abi_ulong start_code; /* Start of text segment */ | |
| abi_ulong start_data; /* Start of data segment */ | |
| abi_ulong end_data; /* Start of bss section */ | |
| abi_ulong start_brk; /* End of data segment */ | |
| abi_ulong text_len; /* Length of text segment */ | |
| abi_ulong entry; /* Start address for this module */ | |
| abi_ulong build_date; /* When this one was compiled */ | |
| short loaded; /* Has this library been loaded? */ | |
| }; | |
| struct linux_binprm; | |
| /****************************************************************************/ | |
| /* | |
| * create_flat_tables() parses the env- and arg-strings in new user | |
| * memory and creates the pointer tables from them, and puts their | |
| * addresses on the "stack", returning the new stack pointer value. | |
| */ | |
| /* Push a block of strings onto the guest stack. */ | |
| static abi_ulong copy_strings(abi_ulong p, int n, char **s) | |
| { | |
| int len; | |
| while (n-- > 0) { | |
| len = strlen(s[n]) + 1; | |
| p -= len; | |
| memcpy_to_target(p, s[n], len); | |
| } | |
| return p; | |
| } | |
| static int target_pread(int fd, abi_ulong ptr, abi_ulong len, | |
| abi_ulong offset) | |
| { | |
| void *buf; | |
| int ret; | |
| buf = lock_user(VERIFY_WRITE, ptr, len, 0); | |
| if (!buf) { | |
| return -EFAULT; | |
| } | |
| ret = pread(fd, buf, len, offset); | |
| if (ret < 0) { | |
| ret = -errno; | |
| } | |
| unlock_user(buf, ptr, len); | |
| return ret; | |
| } | |
| /****************************************************************************/ | |
| static abi_ulong | |
| calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp) | |
| { | |
| abi_ulong addr; | |
| int id; | |
| abi_ulong start_brk; | |
| abi_ulong start_data; | |
| abi_ulong text_len; | |
| abi_ulong start_code; | |
| id = 0; | |
| start_brk = p[id].start_brk; | |
| start_data = p[id].start_data; | |
| start_code = p[id].start_code; | |
| text_len = p[id].text_len; | |
| if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { | |
| fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x " | |
| "(0 - 0x%x/0x%x)\n", | |
| (int) r,(int)(start_brk-start_code),(int)text_len); | |
| goto failed; | |
| } | |
| if (r < text_len) /* In text segment */ | |
| addr = r + start_code; | |
| else /* In data segment */ | |
| addr = r - text_len + start_data; | |
| /* Range checked already above so doing the range tests is redundant...*/ | |
| return(addr); | |
| failed: | |
| abort(); | |
| return RELOC_FAILED; | |
| } | |
| /****************************************************************************/ | |
| /* ??? This does not handle endianness correctly. */ | |
| static void old_reloc(struct lib_info *libinfo, uint32_t rl) | |
| { | |
| #ifdef DEBUG | |
| const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; | |
| #endif | |
| uint32_t *ptr; | |
| uint32_t offset; | |
| int reloc_type; | |
| offset = rl & 0x3fffffff; | |
| reloc_type = rl >> 30; | |
| /* ??? How to handle this? */ | |
| #if defined(CONFIG_COLDFIRE) | |
| ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset); | |
| #else | |
| ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset); | |
| #endif | |
| #ifdef DEBUG | |
| fprintf(stderr, "Relocation of variable at DATASEG+%x " | |
| "(address %p, currently %x) into segment %s\n", | |
| offset, ptr, (int)*ptr, segment[reloc_type]); | |
| #endif | |
| switch (reloc_type) { | |
| case OLD_FLAT_RELOC_TYPE_TEXT: | |
| *ptr += libinfo->start_code; | |
| break; | |
| case OLD_FLAT_RELOC_TYPE_DATA: | |
| *ptr += libinfo->start_data; | |
| break; | |
| case OLD_FLAT_RELOC_TYPE_BSS: | |
| *ptr += libinfo->end_data; | |
| break; | |
| default: | |
| fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n", | |
| reloc_type); | |
| break; | |
| } | |
| DBG_FLT("Relocation became %x\n", (int)*ptr); | |
| } | |
| /****************************************************************************/ | |
| static int load_flat_file(struct linux_binprm * bprm, | |
| struct lib_info *libinfo, int id, abi_ulong *extra_stack) | |
| { | |
| struct flat_hdr * hdr; | |
| abi_ulong textpos = 0, datapos = 0; | |
| abi_long result; | |
| abi_ulong realdatastart = 0; | |
| abi_ulong text_len, data_len, bss_len, stack_len, flags; | |
| abi_ulong extra; | |
| abi_ulong reloc = 0, rp; | |
| int i, rev, relocs = 0; | |
| abi_ulong fpos; | |
| abi_ulong start_code; | |
| abi_ulong indx_len; | |
| hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ | |
| text_len = ntohl(hdr->data_start); | |
| data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); | |
| bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); | |
| stack_len = ntohl(hdr->stack_size); | |
| if (extra_stack) { | |
| stack_len += *extra_stack; | |
| *extra_stack = stack_len; | |
| } | |
| relocs = ntohl(hdr->reloc_count); | |
| flags = ntohl(hdr->flags); | |
| rev = ntohl(hdr->rev); | |
| DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename); | |
| if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { | |
| fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n", | |
| rev, (int) FLAT_VERSION); | |
| return -ENOEXEC; | |
| } | |
| /* Don't allow old format executables to use shared libraries */ | |
| if (rev == OLD_FLAT_VERSION && id != 0) { | |
| fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n"); | |
| return -ENOEXEC; | |
| } | |
| /* | |
| * fix up the flags for the older format, there were all kinds | |
| * of endian hacks, this only works for the simple cases | |
| */ | |
| if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) | |
| flags = FLAT_FLAG_RAM; | |
| if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { | |
| fprintf(stderr, "ZFLAT executables are not supported\n"); | |
| return -ENOEXEC; | |
| } | |
| /* | |
| * calculate the extra space we need to map in | |
| */ | |
| extra = relocs * sizeof(abi_ulong); | |
| if (extra < bss_len + stack_len) | |
| extra = bss_len + stack_len; | |
| /* Add space for library base pointers. Make sure this does not | |
| misalign the doesn't misalign the data segment. */ | |
| indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong); | |
| indx_len = (indx_len + 15) & ~(abi_ulong)15; | |
| /* | |
| * Allocate the address space. | |
| */ | |
| probe_guest_base(bprm->filename, 0, | |
| text_len + data_len + extra + indx_len - 1); | |
| /* | |
| * there are a couple of cases here, the separate code/data | |
| * case, and then the fully copied to RAM case which lumps | |
| * it all together. | |
| */ | |
| if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { | |
| /* | |
| * this should give us a ROM ptr, but if it doesn't we don't | |
| * really care | |
| */ | |
| DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); | |
| textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC, | |
| MAP_PRIVATE, bprm->src.fd, 0); | |
| if (textpos == -1) { | |
| fprintf(stderr, "Unable to mmap process text\n"); | |
| return -1; | |
| } | |
| realdatastart = target_mmap(0, data_len + extra + indx_len, | |
| PROT_READ|PROT_WRITE|PROT_EXEC, | |
| MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | |
| if (realdatastart == -1) { | |
| fprintf(stderr, "Unable to allocate RAM for process data\n"); | |
| return realdatastart; | |
| } | |
| datapos = realdatastart + indx_len; | |
| DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", | |
| (int)(data_len + bss_len + stack_len), (int)datapos); | |
| fpos = ntohl(hdr->data_start); | |
| result = target_pread(bprm->src.fd, datapos, | |
| data_len + (relocs * sizeof(abi_ulong)), | |
| fpos); | |
| if (result < 0) { | |
| fprintf(stderr, "Unable to read data+bss\n"); | |
| return result; | |
| } | |
| reloc = datapos + (ntohl(hdr->reloc_start) - text_len); | |
| } else { | |
| textpos = target_mmap(0, text_len + data_len + extra + indx_len, | |
| PROT_READ | PROT_EXEC | PROT_WRITE, | |
| MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | |
| if (textpos == -1 ) { | |
| fprintf(stderr, "Unable to allocate RAM for process text/data\n"); | |
| return -1; | |
| } | |
| realdatastart = textpos + ntohl(hdr->data_start); | |
| datapos = realdatastart + indx_len; | |
| reloc = (textpos + ntohl(hdr->reloc_start) + indx_len); | |
| result = target_pread(bprm->src.fd, textpos, | |
| text_len, 0); | |
| if (result >= 0) { | |
| result = target_pread(bprm->src.fd, datapos, | |
| data_len + (relocs * sizeof(abi_ulong)), | |
| ntohl(hdr->data_start)); | |
| } | |
| if (result < 0) { | |
| fprintf(stderr, "Unable to read code+data+bss\n"); | |
| return result; | |
| } | |
| } | |
| DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n", | |
| (int)textpos, 0x00ffffff&ntohl(hdr->entry), | |
| ntohl(hdr->data_start)); | |
| /* The main program needs a little extra setup in the task structure */ | |
| start_code = textpos + sizeof (struct flat_hdr); | |
| DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", | |
| id ? "Lib" : "Load", bprm->filename, | |
| (int) start_code, (int) (textpos + text_len), | |
| (int) datapos, | |
| (int) (datapos + data_len), | |
| (int) (datapos + data_len), | |
| (int) (((datapos + data_len + bss_len) + 3) & ~3)); | |
| text_len -= sizeof(struct flat_hdr); /* the real code len */ | |
| /* Store the current module values into the global library structure */ | |
| libinfo[id].start_code = start_code; | |
| libinfo[id].start_data = datapos; | |
| libinfo[id].end_data = datapos + data_len; | |
| libinfo[id].start_brk = datapos + data_len + bss_len; | |
| libinfo[id].text_len = text_len; | |
| libinfo[id].loaded = 1; | |
| libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; | |
| libinfo[id].build_date = ntohl(hdr->build_date); | |
| /* | |
| * We just load the allocations into some temporary memory to | |
| * help simplify all this mumbo jumbo | |
| * | |
| * We've got two different sections of relocation entries. | |
| * The first is the GOT which resides at the beginning of the data segment | |
| * and is terminated with a -1. This one can be relocated in place. | |
| * The second is the extra relocation entries tacked after the image's | |
| * data segment. These require a little more processing as the entry is | |
| * really an offset into the image which contains an offset into the | |
| * image. | |
| */ | |
| if (flags & FLAT_FLAG_GOTPIC) { | |
| rp = datapos; | |
| while (1) { | |
| abi_ulong addr; | |
| if (get_user_ual(addr, rp)) | |
| return -EFAULT; | |
| if (addr == -1) | |
| break; | |
| if (addr) { | |
| addr = calc_reloc(addr, libinfo, id, 0); | |
| if (addr == RELOC_FAILED) | |
| return -ENOEXEC; | |
| if (put_user_ual(addr, rp)) | |
| return -EFAULT; | |
| } | |
| rp += sizeof(abi_ulong); | |
| } | |
| } | |
| /* | |
| * Now run through the relocation entries. | |
| * We've got to be careful here as C++ produces relocatable zero | |
| * entries in the constructor and destructor tables which are then | |
| * tested for being not zero (which will always occur unless we're | |
| * based from address zero). This causes an endless loop as __start | |
| * is at zero. The solution used is to not relocate zero addresses. | |
| * This has the negative side effect of not allowing a global data | |
| * reference to be statically initialised to _stext (I've moved | |
| * __start to address 4 so that is okay). | |
| */ | |
| if (rev > OLD_FLAT_VERSION) { | |
| abi_ulong persistent = 0; | |
| for (i = 0; i < relocs; i++) { | |
| abi_ulong addr, relval; | |
| /* Get the address of the pointer to be | |
| relocated (of course, the address has to be | |
| relocated first). */ | |
| if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) | |
| return -EFAULT; | |
| relval = ntohl(relval); | |
| if (flat_set_persistent(relval, &persistent)) | |
| continue; | |
| addr = flat_get_relocate_addr(relval); | |
| rp = calc_reloc(addr, libinfo, id, 1); | |
| if (rp == RELOC_FAILED) | |
| return -ENOEXEC; | |
| /* Get the pointer's value. */ | |
| if (get_user_ual(addr, rp)) | |
| return -EFAULT; | |
| addr = flat_get_addr_from_rp(addr, relval, flags, &persistent); | |
| if (addr != 0) { | |
| /* | |
| * Do the relocation. PIC relocs in the data section are | |
| * already in target order | |
| */ | |
| if ((flags & FLAT_FLAG_GOTPIC) == 0) | |
| addr = ntohl(addr); | |
| addr = calc_reloc(addr, libinfo, id, 0); | |
| if (addr == RELOC_FAILED) | |
| return -ENOEXEC; | |
| /* Write back the relocated pointer. */ | |
| if (flat_put_addr_at_rp(rp, addr, relval)) | |
| return -EFAULT; | |
| } | |
| } | |
| } else { | |
| for (i = 0; i < relocs; i++) { | |
| abi_ulong relval; | |
| if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) | |
| return -EFAULT; | |
| old_reloc(&libinfo[0], relval); | |
| } | |
| } | |
| /* zero the BSS. */ | |
| memset(g2h_untagged(datapos + data_len), 0, bss_len); | |
| return 0; | |
| } | |
| /****************************************************************************/ | |
| int load_flt_binary(struct linux_binprm *bprm, struct image_info *info) | |
| { | |
| struct lib_info libinfo[MAX_SHARED_LIBS]; | |
| abi_ulong p; | |
| abi_ulong stack_len; | |
| abi_ulong start_addr; | |
| abi_ulong sp; | |
| int res; | |
| int i, j; | |
| memset(libinfo, 0, sizeof(libinfo)); | |
| /* | |
| * We have to add the size of our arguments to our stack size | |
| * otherwise it's too easy for users to create stack overflows | |
| * by passing in a huge argument list. And yes, we have to be | |
| * pedantic and include space for the argv/envp array as it may have | |
| * a lot of entries. | |
| */ | |
| stack_len = 0; | |
| for (i = 0; i < bprm->argc; ++i) { | |
| /* the argv strings */ | |
| stack_len += strlen(bprm->argv[i]); | |
| } | |
| for (i = 0; i < bprm->envc; ++i) { | |
| /* the envp strings */ | |
| stack_len += strlen(bprm->envp[i]); | |
| } | |
| stack_len += (bprm->argc + 1) * 4; /* the argv array */ | |
| stack_len += (bprm->envc + 1) * 4; /* the envp array */ | |
| mmap_lock(); | |
| res = load_flat_file(bprm, libinfo, 0, &stack_len); | |
| mmap_unlock(); | |
| if (is_error(res)) { | |
| return res; | |
| } | |
| /* Update data segment pointers for all libraries */ | |
| for (i=0; i<MAX_SHARED_LIBS; i++) { | |
| if (libinfo[i].loaded) { | |
| abi_ulong seg; | |
| seg = libinfo[i].start_data; | |
| for (j=0; j<MAX_SHARED_LIBS; j++) { | |
| seg -= 4; | |
| /* FIXME - handle put_user() failures */ | |
| if (put_user_ual(libinfo[j].loaded | |
| ? libinfo[j].start_data | |
| : UNLOADED_LIB, | |
| seg)) | |
| return -EFAULT; | |
| } | |
| } | |
| } | |
| p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4; | |
| DBG_FLT("p=%x\n", (int)p); | |
| /* Copy argv/envp. */ | |
| p = copy_strings(p, bprm->envc, bprm->envp); | |
| p = copy_strings(p, bprm->argc, bprm->argv); | |
| /* Align stack. */ | |
| sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1); | |
| /* Enforce final stack alignment of 16 bytes. This is sufficient | |
| for all current targets, and excess alignment is harmless. */ | |
| stack_len = bprm->envc + bprm->argc + 2; | |
| stack_len += flat_argvp_envp_on_stack() ? 2 : 0; /* argv, argp */ | |
| stack_len += 1; /* argc */ | |
| stack_len *= sizeof(abi_ulong); | |
| sp -= (sp - stack_len) & 15; | |
| sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, | |
| flat_argvp_envp_on_stack()); | |
| /* Fake some return addresses to ensure the call chain will | |
| * initialise library in order for us. We are required to call | |
| * lib 1 first, then 2, ... and finally the main program (id 0). | |
| */ | |
| start_addr = libinfo[0].entry; | |
| /* Stash our initial stack pointer into the mm structure */ | |
| info->start_code = libinfo[0].start_code; | |
| info->end_code = libinfo[0].start_code + libinfo[0].text_len; | |
| info->start_data = libinfo[0].start_data; | |
| info->end_data = libinfo[0].end_data; | |
| info->brk = libinfo[0].start_brk; | |
| info->start_stack = sp; | |
| info->stack_limit = libinfo[0].start_brk; | |
| info->entry = start_addr; | |
| info->code_offset = info->start_code; | |
| info->data_offset = info->start_data - libinfo[0].text_len; | |
| DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n", | |
| (int)info->entry, (int)info->start_stack); | |
| return 0; | |
| } |