bsd-user: Refactor load_elf_sections and is_target_elf_binary
Factor out load_elf_sections and is_target_elf_binary out of load_elf_interp. Signed-off-by: Mikaël Urankar <mikael.urankar@gmail.com> Signed-off-by: Stacey Son <sson@FreeBSD.org> Signed-off-by: Warner Losh <imp@bsdimp.com> Reviewed-by: Kyle Evans <kevans@FreeBSD.org>
This commit is contained in:
Warner Losh
Warner Losh
parent
0456a1772b
commit
c09f12feba
@ -36,6 +36,8 @@ abi_ulong target_stksiz;
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abi_ulong target_stkbas;
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static int elf_core_dump(int signr, CPUArchState *env);
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static int load_elf_sections(const struct elfhdr *hdr, struct elf_phdr *phdr,
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int fd, abi_ulong rbase, abi_ulong *baddrp);
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static inline void memcpy_fromfs(void *to, const void *from, unsigned long n)
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{
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@ -271,16 +273,10 @@ static abi_ulong load_elf_interp(struct elfhdr *interp_elf_ex,
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abi_ulong *interp_load_addr)
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{
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struct elf_phdr *elf_phdata = NULL;
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struct elf_phdr *eppnt;
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abi_ulong load_addr = 0;
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int load_addr_set = 0;
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abi_ulong rbase;
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int retval;
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abi_ulong last_bss, elf_bss;
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abi_ulong error;
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int i;
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abi_ulong baddr, error;
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elf_bss = 0;
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last_bss = 0;
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error = 0;
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bswap_ehdr(interp_elf_ex);
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@ -325,93 +321,33 @@ static abi_ulong load_elf_interp(struct elfhdr *interp_elf_ex,
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}
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bswap_phdr(elf_phdata, interp_elf_ex->e_phnum);
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rbase = 0;
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if (interp_elf_ex->e_type == ET_DYN) {
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/*
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* In order to avoid hardcoding the interpreter load
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* address in qemu, we allocate a big enough memory zone.
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*/
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error = target_mmap(0, INTERP_MAP_SIZE, PROT_NONE,
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rbase = target_mmap(0, INTERP_MAP_SIZE, PROT_NONE,
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MAP_PRIVATE | MAP_ANON, -1, 0);
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if (error == -1) {
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if (rbase == -1) {
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perror("mmap");
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exit(-1);
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}
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load_addr = error;
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load_addr_set = 1;
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}
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eppnt = elf_phdata;
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for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++)
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if (eppnt->p_type == PT_LOAD) {
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int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
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int elf_prot = 0;
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abi_ulong vaddr = 0;
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abi_ulong k;
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if (eppnt->p_flags & PF_R) elf_prot = PROT_READ;
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if (eppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
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if (eppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
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if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) {
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elf_type |= MAP_FIXED;
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vaddr = eppnt->p_vaddr;
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}
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error = target_mmap(load_addr + TARGET_ELF_PAGESTART(vaddr),
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eppnt->p_filesz + TARGET_ELF_PAGEOFFSET(eppnt->p_vaddr),
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elf_prot,
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elf_type,
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interpreter_fd,
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eppnt->p_offset - TARGET_ELF_PAGEOFFSET(eppnt->p_vaddr));
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if (error == -1) {
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/* Real error */
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close(interpreter_fd);
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free(elf_phdata);
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return ~((abi_ulong)0UL);
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}
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if (!load_addr_set && interp_elf_ex->e_type == ET_DYN) {
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load_addr = error;
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load_addr_set = 1;
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}
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/*
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* Find the end of the file mapping for this phdr, and keep
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* track of the largest address we see for this.
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*/
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k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
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if (k > elf_bss) elf_bss = k;
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/*
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* Do the same thing for the memory mapping - between
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* elf_bss and last_bss is the bss section.
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*/
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k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
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if (k > last_bss) last_bss = k;
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}
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error = load_elf_sections(interp_elf_ex, elf_phdata, interpreter_fd, rbase,
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&baddr);
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if (error != 0) {
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perror("load_elf_sections");
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exit(-1);
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}
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/* Now use mmap to map the library into memory. */
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close(interpreter_fd);
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/*
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* Now fill out the bss section. First pad the last page up
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* to the page boundary, and then perform a mmap to make sure
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* that there are zeromapped pages up to and including the last
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* bss page.
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*/
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padzero(elf_bss, last_bss);
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elf_bss = TARGET_ELF_PAGESTART(elf_bss + qemu_host_page_size - 1); /* What we have mapped so far */
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/* Map the last of the bss segment */
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if (last_bss > elf_bss) {
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target_mmap(elf_bss, last_bss - elf_bss,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, 0);
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}
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free(elf_phdata);
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*interp_load_addr = load_addr;
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return ((abi_ulong) interp_elf_ex->e_entry) + load_addr;
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*interp_load_addr = baddr;
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return ((abi_ulong) interp_elf_ex->e_entry) + rbase;
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}
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static int symfind(const void *s0, const void *s1)
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@ -521,6 +457,10 @@ found:
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}
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continue;
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}
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#if defined(TARGET_ARM) || defined(TARGET_MIPS)
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/* The bottom address bit marks a Thumb or MIPS16 symbol. */
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syms[i].st_value &= ~(target_ulong)1;
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#endif
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i++;
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}
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@ -560,26 +500,119 @@ found:
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syminfos = s;
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}
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/* Check the elf header and see if this a target elf binary. */
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int is_target_elf_binary(int fd)
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{
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uint8_t buf[128];
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struct elfhdr elf_ex;
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if (lseek(fd, 0L, SEEK_SET) < 0) {
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return 0;
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}
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if (read(fd, buf, sizeof(buf)) < 0) {
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return 0;
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}
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elf_ex = *((struct elfhdr *)buf);
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bswap_ehdr(&elf_ex);
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if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) ||
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(!elf_check_arch(elf_ex.e_machine))) {
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return 0;
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} else {
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return 1;
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}
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}
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static int
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load_elf_sections(const struct elfhdr *hdr, struct elf_phdr *phdr, int fd,
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abi_ulong rbase, abi_ulong *baddrp)
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{
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struct elf_phdr *elf_ppnt;
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abi_ulong baddr;
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int i;
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bool first;
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/*
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* Now we do a little grungy work by mmaping the ELF image into
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* the correct location in memory. At this point, we assume that
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* the image should be loaded at fixed address, not at a variable
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* address.
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*/
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first = true;
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for (i = 0, elf_ppnt = phdr; i < hdr->e_phnum; i++, elf_ppnt++) {
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int elf_prot = 0;
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abi_ulong error;
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/* XXX Skip memsz == 0. */
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if (elf_ppnt->p_type != PT_LOAD) {
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continue;
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}
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if (elf_ppnt->p_flags & PF_R) {
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elf_prot |= PROT_READ;
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}
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if (elf_ppnt->p_flags & PF_W) {
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elf_prot |= PROT_WRITE;
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}
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if (elf_ppnt->p_flags & PF_X) {
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elf_prot |= PROT_EXEC;
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}
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error = target_mmap(TARGET_ELF_PAGESTART(rbase + elf_ppnt->p_vaddr),
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(elf_ppnt->p_filesz +
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TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)),
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elf_prot,
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(MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE),
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fd,
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(elf_ppnt->p_offset -
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TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)));
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if (error == -1) {
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perror("mmap");
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exit(-1);
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} else if (elf_ppnt->p_memsz != elf_ppnt->p_filesz) {
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abi_ulong start_bss, end_bss;
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start_bss = rbase + elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
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end_bss = rbase + elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
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/*
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* Calling set_brk effectively mmaps the pages that we need for the
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* bss and break sections.
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*/
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set_brk(start_bss, end_bss);
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padzero(start_bss, end_bss);
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}
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if (first) {
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baddr = TARGET_ELF_PAGESTART(rbase + elf_ppnt->p_vaddr);
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first = false;
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}
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}
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if (baddrp != NULL) {
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*baddrp = baddr;
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}
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return 0;
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}
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int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
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struct image_info *info)
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{
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struct elfhdr elf_ex;
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struct elfhdr interp_elf_ex;
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int interpreter_fd = -1; /* avoid warning */
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abi_ulong load_addr, load_bias;
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int load_addr_set = 0;
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abi_ulong load_addr;
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int i;
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struct elf_phdr * elf_ppnt;
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struct elf_phdr *elf_ppnt;
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struct elf_phdr *elf_phdata;
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abi_ulong elf_bss, k, elf_brk;
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int retval;
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char * elf_interpreter;
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abi_ulong elf_entry, interp_load_addr = 0;
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abi_ulong start_code, end_code, start_data, end_data;
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abi_ulong elf_brk;
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int error, retval;
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char *elf_interpreter;
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abi_ulong baddr, elf_entry, et_dyn_addr, interp_load_addr = 0;
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abi_ulong reloc_func_desc = 0;
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load_addr = 0;
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load_bias = 0;
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elf_ex = *((struct elfhdr *) bprm->buf); /* exec-header */
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bswap_ehdr(&elf_ex);
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@ -618,16 +651,10 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
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bswap_phdr(elf_phdata, elf_ex.e_phnum);
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elf_ppnt = elf_phdata;
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elf_bss = 0;
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elf_brk = 0;
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elf_interpreter = NULL;
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start_code = ~((abi_ulong)0UL);
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end_code = 0;
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start_data = 0;
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end_data = 0;
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for (i = 0; i < elf_ex.e_phnum; i++) {
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if (elf_ppnt->p_type == PT_INTERP) {
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if (elf_interpreter != NULL) {
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@ -714,94 +741,45 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
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info->mmap = 0;
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elf_entry = (abi_ulong) elf_ex.e_entry;
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/* Do this so that we can load the interpreter, if need be. We will
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change some of these later */
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/* XXX Join this with PT_INTERP search? */
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baddr = 0;
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for (i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; i++, elf_ppnt++) {
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if (elf_ppnt->p_type != PT_LOAD) {
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continue;
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}
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baddr = elf_ppnt->p_vaddr;
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break;
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}
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et_dyn_addr = 0;
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if (elf_ex.e_type == ET_DYN && baddr == 0) {
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et_dyn_addr = ELF_ET_DYN_LOAD_ADDR;
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}
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/*
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* Do this so that we can load the interpreter, if need be. We will
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* change some of these later
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*/
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info->rss = 0;
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setup_arg_pages(bprm, info, &bprm->p, &bprm->stringp);
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info->start_stack = bprm->p;
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/* Now we do a little grungy work by mmaping the ELF image into
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* the correct location in memory. At this point, we assume that
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* the image should be loaded at fixed address, not at a variable
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* address.
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*/
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info->elf_flags = elf_ex.e_flags;
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error = load_elf_sections(&elf_ex, elf_phdata, bprm->fd, et_dyn_addr,
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&load_addr);
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for (i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; i++, elf_ppnt++) {
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int elf_prot = 0;
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int elf_flags = 0;
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abi_ulong error;
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if (elf_ppnt->p_type != PT_LOAD)
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if (elf_ppnt->p_type != PT_LOAD) {
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continue;
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if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ;
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if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
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if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
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elf_flags = MAP_PRIVATE | MAP_DENYWRITE;
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if (elf_ex.e_type == ET_EXEC || load_addr_set) {
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elf_flags |= MAP_FIXED;
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} else if (elf_ex.e_type == ET_DYN) {
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/* Try and get dynamic programs out of the way of the default mmap
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base, as well as whatever program they might try to exec. This
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is because the brk will follow the loader, and is not movable. */
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/* NOTE: for qemu, we do a big mmap to get enough space
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without hardcoding any address */
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error = target_mmap(0, ET_DYN_MAP_SIZE,
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PROT_NONE, MAP_PRIVATE | MAP_ANON,
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-1, 0);
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if (error == -1) {
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perror("mmap");
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exit(-1);
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}
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load_bias = TARGET_ELF_PAGESTART(error - elf_ppnt->p_vaddr);
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}
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error = target_mmap(TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr),
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(elf_ppnt->p_filesz +
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TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)),
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elf_prot,
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(MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE),
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bprm->fd,
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(elf_ppnt->p_offset -
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TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)));
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if (error == -1) {
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perror("mmap");
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exit(-1);
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}
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if (!load_addr_set) {
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load_addr_set = 1;
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load_addr = elf_ppnt->p_vaddr - elf_ppnt->p_offset;
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if (elf_ex.e_type == ET_DYN) {
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load_bias += error -
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TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr);
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load_addr += load_bias;
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reloc_func_desc = load_bias;
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}
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}
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k = elf_ppnt->p_vaddr;
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if (k < start_code)
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start_code = k;
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if (start_data < k)
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start_data = k;
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k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
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if (k > elf_bss)
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elf_bss = k;
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if ((elf_ppnt->p_flags & PF_X) && end_code < k)
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end_code = k;
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if (end_data < k)
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end_data = k;
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k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
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if (k > elf_brk) elf_brk = k;
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if (elf_ppnt->p_memsz > elf_ppnt->p_filesz)
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elf_brk = MAX(elf_brk, et_dyn_addr + elf_ppnt->p_vaddr +
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elf_ppnt->p_memsz);
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}
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if (error != 0) {
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perror("load_elf_sections");
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exit(-1);
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}
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elf_entry += load_bias;
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elf_bss += load_bias;
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elf_brk += load_bias;
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start_code += load_bias;
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end_code += load_bias;
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start_data += load_bias;
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end_data += load_bias;
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if (elf_interpreter) {
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elf_entry = load_elf_interp(&interp_elf_ex, interpreter_fd,
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@ -817,6 +795,9 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
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exit(-1);
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return 0;
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}
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} else {
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interp_load_addr = et_dyn_addr;
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elf_entry += interp_load_addr;
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}
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free(elf_phdata);
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@ -829,20 +810,11 @@ int load_elf_binary(struct bsd_binprm *bprm, struct target_pt_regs *regs,
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bprm->p = target_create_elf_tables(bprm->p, bprm->argc, bprm->envc,
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bprm->stringp, &elf_ex, load_addr,
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load_bias, interp_load_addr, info);
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et_dyn_addr, interp_load_addr, info);
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info->load_addr = reloc_func_desc;
|
||||
info->start_brk = info->brk = elf_brk;
|
||||
info->end_code = end_code;
|
||||
info->start_code = start_code;
|
||||
info->start_data = start_data;
|
||||
info->end_data = end_data;
|
||||
info->start_stack = bprm->p;
|
||||
|
||||
/* Calling set_brk effectively mmaps the pages that we need for the bss and break
|
||||
sections */
|
||||
set_brk(elf_bss, elf_brk);
|
||||
|
||||
padzero(elf_bss, elf_brk);
|
||||
info->load_bias = 0;
|
||||
|
||||
info->entry = elf_entry;
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user