X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fbinfmt_elf_fdpic.c;h=2c5f9a0e5d72bb0357c45d5524186c14b3284bca;hb=3374cd1abd478f767aaedf2c21d109596ff0fe72;hp=20fbeced472b82c8653e963bc8fe2bb2455c0023;hpb=3b34fc5880a2dcc7e5ed9837ef8d6bae051ab266;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 20fbece..2c5f9a0 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include @@ -75,14 +76,14 @@ static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, struct file *, struct mm_struct *); -#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) -static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit); +#ifdef CONFIG_ELF_CORE +static int elf_fdpic_core_dump(struct coredump_params *cprm); #endif static struct linux_binfmt elf_fdpic_format = { .module = THIS_MODULE, .load_binary = load_elf_fdpic_binary, -#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) +#ifdef CONFIG_ELF_CORE .core_dump = elf_fdpic_core_dump, #endif .min_coredump = ELF_EXEC_PAGESIZE, @@ -171,6 +172,9 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, #ifdef ELF_FDPIC_PLAT_INIT unsigned long dynaddr; #endif +#ifndef CONFIG_MMU + unsigned long stack_prot; +#endif struct file *interpreter = NULL; /* to shut gcc up */ char *interpreter_name = NULL; int executable_stack; @@ -283,20 +287,23 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, } stack_size = exec_params.stack_size; - if (stack_size < interp_params.stack_size) - stack_size = interp_params.stack_size; - if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) executable_stack = EXSTACK_ENABLE_X; else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) executable_stack = EXSTACK_DISABLE_X; - else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) - executable_stack = EXSTACK_ENABLE_X; - else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) - executable_stack = EXSTACK_DISABLE_X; else executable_stack = EXSTACK_DEFAULT; + if (stack_size == 0) { + stack_size = interp_params.stack_size; + if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) + executable_stack = EXSTACK_ENABLE_X; + else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) + executable_stack = EXSTACK_DISABLE_X; + else + executable_stack = EXSTACK_DEFAULT; + } + retval = -ENOEXEC; if (stack_size == 0) goto error; @@ -313,6 +320,11 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, * defunct, deceased, etc. after this point we have to exit via * error_kill */ set_personality(PER_LINUX_FDPIC); + if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) + current->personality |= READ_IMPLIES_EXEC; + + setup_new_exec(bprm); + set_binfmt(&elf_fdpic_format); current->mm->start_code = 0; @@ -374,10 +386,15 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, if (stack_size < PAGE_SIZE * 2) stack_size = PAGE_SIZE * 2; + stack_prot = PROT_READ | PROT_WRITE; + if (executable_stack == EXSTACK_ENABLE_X || + (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) + stack_prot |= PROT_EXEC; + down_write(¤t->mm->mmap_sem); - current->mm->start_brk = do_mmap(NULL, 0, stack_size, - PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN, + current->mm->start_brk = do_mmap(NULL, 0, stack_size, stack_prot, + MAP_PRIVATE | MAP_ANONYMOUS | + MAP_UNINITIALIZED | MAP_GROWSDOWN, 0); if (IS_ERR_VALUE(current->mm->start_brk)) { @@ -988,15 +1005,8 @@ static int elf_fdpic_map_file_constdisp_on_uclinux( } } else if (!mm->start_data) { mm->start_data = seg->addr; -#ifndef CONFIG_MMU mm->end_data = seg->addr + phdr->p_memsz; -#endif } - -#ifdef CONFIG_MMU - if (seg->addr + phdr->p_memsz > mm->end_data) - mm->end_data = seg->addr + phdr->p_memsz; -#endif } seg++; @@ -1197,27 +1207,7 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, * * Modelled on fs/binfmt_elf.c core dumper */ -#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) - -/* - * These are the only things you should do on a core-file: use only these - * functions to write out all the necessary info. - */ -static int dump_write(struct file *file, const void *addr, int nr) -{ - return file->f_op->write(file, addr, nr, &file->f_pos) == nr; -} - -static int dump_seek(struct file *file, loff_t off) -{ - if (file->f_op->llseek) { - if (file->f_op->llseek(file, off, SEEK_SET) != off) - return 0; - } else { - file->f_pos = off; - } - return 1; -} +#ifdef CONFIG_ELF_CORE /* * Decide whether a segment is worth dumping; default is yes to be @@ -1297,37 +1287,35 @@ static int notesize(struct memelfnote *en) /* #define DEBUG */ -#define DUMP_WRITE(addr, nr) \ - do { if (!dump_write(file, (addr), (nr))) return 0; } while(0) -#define DUMP_SEEK(off) \ - do { if (!dump_seek(file, (off))) return 0; } while(0) +#define DUMP_WRITE(addr, nr, foffset) \ + do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) -static int writenote(struct memelfnote *men, struct file *file) +static int alignfile(struct file *file, loff_t *foffset) { - struct elf_note en; + static const char buf[4] = { 0, }; + DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); + return 1; +} +static int writenote(struct memelfnote *men, struct file *file, + loff_t *foffset) +{ + struct elf_note en; en.n_namesz = strlen(men->name) + 1; en.n_descsz = men->datasz; en.n_type = men->type; - DUMP_WRITE(&en, sizeof(en)); - DUMP_WRITE(men->name, en.n_namesz); - /* XXX - cast from long long to long to avoid need for libgcc.a */ - DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ - DUMP_WRITE(men->data, men->datasz); - DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ + DUMP_WRITE(&en, sizeof(en), foffset); + DUMP_WRITE(men->name, en.n_namesz, foffset); + if (!alignfile(file, foffset)) + return 0; + DUMP_WRITE(men->data, men->datasz, foffset); + if (!alignfile(file, foffset)) + return 0; return 1; } #undef DUMP_WRITE -#undef DUMP_SEEK - -#define DUMP_WRITE(addr, nr) \ - if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ - goto end_coredump; -#define DUMP_SEEK(off) \ - if (!dump_seek(file, (off))) \ - goto end_coredump; static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) { @@ -1379,7 +1367,7 @@ static inline void fill_note(struct memelfnote *note, const char *name, int type /* * fill up all the fields in prstatus from the given task struct, except - * registers which need to be filled up seperately. + * registers which need to be filled up separately. */ static void fill_prstatus(struct elf_prstatus *prstatus, struct task_struct *p, long signr) @@ -1510,6 +1498,22 @@ static int elf_dump_thread_status(long signr, struct elf_thread_status *t) return sz; } +static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, + elf_addr_t e_shoff, int segs) +{ + elf->e_shoff = e_shoff; + elf->e_shentsize = sizeof(*shdr4extnum); + elf->e_shnum = 1; + elf->e_shstrndx = SHN_UNDEF; + + memset(shdr4extnum, 0, sizeof(*shdr4extnum)); + + shdr4extnum->sh_type = SHT_NULL; + shdr4extnum->sh_size = elf->e_shnum; + shdr4extnum->sh_link = elf->e_shstrndx; + shdr4extnum->sh_info = segs; +} + /* * dump the segments for an MMU process */ @@ -1518,6 +1522,7 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size, unsigned long *limit, unsigned long mm_flags) { struct vm_area_struct *vma; + int err = 0; for (vma = current->mm->mmap; vma; vma = vma->vm_next) { unsigned long addr; @@ -1525,43 +1530,26 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size, if (!maydump(vma, mm_flags)) continue; - for (addr = vma->vm_start; - addr < vma->vm_end; - addr += PAGE_SIZE - ) { - struct vm_area_struct *vma; - struct page *page; - - if (get_user_pages(current, current->mm, addr, 1, 0, 1, - &page, &vma) <= 0) { - DUMP_SEEK(file->f_pos + PAGE_SIZE); - } - else if (page == ZERO_PAGE(0)) { - page_cache_release(page); - DUMP_SEEK(file->f_pos + PAGE_SIZE); - } - else { - void *kaddr; - - flush_cache_page(vma, addr, page_to_pfn(page)); - kaddr = kmap(page); - if ((*size += PAGE_SIZE) > *limit || - !dump_write(file, kaddr, PAGE_SIZE) - ) { - kunmap(page); - page_cache_release(page); - return -EIO; - } + for (addr = vma->vm_start; addr < vma->vm_end; + addr += PAGE_SIZE) { + struct page *page = get_dump_page(addr); + if (page) { + void *kaddr = kmap(page); + *size += PAGE_SIZE; + if (*size > *limit) + err = -EFBIG; + else if (!dump_write(file, kaddr, PAGE_SIZE)) + err = -EIO; kunmap(page); page_cache_release(page); - } + } else if (!dump_seek(file, PAGE_SIZE)) + err = -EFBIG; + if (err) + goto out; } } - - return 0; - -end_coredump: - return -EFBIG; +out: + return err; } #endif @@ -1590,6 +1578,17 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size, } #endif +static size_t elf_core_vma_data_size(unsigned long mm_flags) +{ + struct vm_area_struct *vma; + size_t size = 0; + + for (vma = current->mm->mmap; vma; vma = vma->vm_next) + if (maydump(vma, mm_flags)) + size += vma->vm_end - vma->vm_start; + return size; +} + /* * Actual dumper * @@ -1597,8 +1596,7 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size, * and then they are actually written out. If we run out of core limit * we just truncate. */ -static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, - struct file *file, unsigned long limit) +static int elf_fdpic_core_dump(struct coredump_params *cprm) { #define NUM_NOTES 6 int has_dumped = 0; @@ -1608,7 +1606,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, int i; struct vm_area_struct *vma; struct elfhdr *elf = NULL; - loff_t offset = 0, dataoff; + loff_t offset = 0, dataoff, foffset; int numnote; struct memelfnote *notes = NULL; struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ @@ -1621,7 +1619,10 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, #endif int thread_status_size = 0; elf_addr_t *auxv; - unsigned long mm_flags; + struct elf_phdr *phdr4note = NULL; + struct elf_shdr *shdr4extnum = NULL; + Elf_Half e_phnum; + elf_addr_t e_shoff; /* * We no longer stop all VM operations. @@ -1657,7 +1658,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, goto cleanup; #endif - if (signr) { + if (cprm->signr) { struct core_thread *ct; struct elf_thread_status *tmp; @@ -1676,22 +1677,28 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, int sz; tmp = list_entry(t, struct elf_thread_status, list); - sz = elf_dump_thread_status(signr, tmp); + sz = elf_dump_thread_status(cprm->signr, tmp); thread_status_size += sz; } } /* now collect the dump for the current */ - fill_prstatus(prstatus, current, signr); - elf_core_copy_regs(&prstatus->pr_reg, regs); + fill_prstatus(prstatus, current, cprm->signr); + elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); segs = current->mm->map_count; -#ifdef ELF_CORE_EXTRA_PHDRS - segs += ELF_CORE_EXTRA_PHDRS; -#endif + segs += elf_core_extra_phdrs(); + + /* for notes section */ + segs++; + + /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid + * this, kernel supports extended numbering. Have a look at + * include/linux/elf.h for further information. */ + e_phnum = segs > PN_XNUM ? PN_XNUM : segs; /* Set up header */ - fill_elf_fdpic_header(elf, segs + 1); /* including notes section */ + fill_elf_fdpic_header(elf, e_phnum); has_dumped = 1; current->flags |= PF_DUMPCORE; @@ -1718,7 +1725,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, /* Try to dump the FPU. */ if ((prstatus->pr_fpvalid = - elf_core_copy_task_fpregs(current, regs, fpu))) + elf_core_copy_task_fpregs(current, cprm->regs, fpu))) fill_note(notes + numnote++, "CORE", NT_PRFPREG, sizeof(*fpu), fpu); #ifdef ELF_CORE_COPY_XFPREGS @@ -1730,13 +1737,12 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, fs = get_fs(); set_fs(KERNEL_DS); - DUMP_WRITE(elf, sizeof(*elf)); offset += sizeof(*elf); /* Elf header */ - offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */ + offset += segs * sizeof(struct elf_phdr); /* Program headers */ + foffset = offset; /* Write notes phdr entry */ { - struct elf_phdr phdr; int sz = 0; for (i = 0; i < numnote; i++) @@ -1744,20 +1750,38 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, sz += thread_status_size; - fill_elf_note_phdr(&phdr, sz, offset); + phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); + if (!phdr4note) + goto end_coredump; + + fill_elf_note_phdr(phdr4note, sz, offset); offset += sz; - DUMP_WRITE(&phdr, sizeof(phdr)); } /* Page-align dumped data */ dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); - /* - * We must use the same mm->flags while dumping core to avoid - * inconsistency between the program headers and bodies, otherwise an - * unusable core file can be generated. - */ - mm_flags = current->mm->flags; + offset += elf_core_vma_data_size(cprm->mm_flags); + offset += elf_core_extra_data_size(); + e_shoff = offset; + + if (e_phnum == PN_XNUM) { + shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); + if (!shdr4extnum) + goto end_coredump; + fill_extnum_info(elf, shdr4extnum, e_shoff, segs); + } + + offset = dataoff; + + size += sizeof(*elf); + if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) + goto end_coredump; + + size += sizeof(*phdr4note); + if (size > cprm->limit + || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) + goto end_coredump; /* write program headers for segments dump */ for (vma = current->mm->mmap; vma; vma = vma->vm_next) { @@ -1770,7 +1794,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, phdr.p_offset = offset; phdr.p_vaddr = vma->vm_start; phdr.p_paddr = 0; - phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0; + phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; phdr.p_memsz = sz; offset += phdr.p_filesz; phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; @@ -1780,16 +1804,18 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, phdr.p_flags |= PF_X; phdr.p_align = ELF_EXEC_PAGESIZE; - DUMP_WRITE(&phdr, sizeof(phdr)); + size += sizeof(phdr); + if (size > cprm->limit + || !dump_write(cprm->file, &phdr, sizeof(phdr))) + goto end_coredump; } -#ifdef ELF_CORE_WRITE_EXTRA_PHDRS - ELF_CORE_WRITE_EXTRA_PHDRS; -#endif + if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) + goto end_coredump; /* write out the notes section */ for (i = 0; i < numnote; i++) - if (!writenote(notes + i, file)) + if (!writenote(notes + i, cprm->file, &foffset)) goto end_coredump; /* write out the thread status notes section */ @@ -1798,24 +1824,33 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, list_entry(t, struct elf_thread_status, list); for (i = 0; i < tmp->num_notes; i++) - if (!writenote(&tmp->notes[i], file)) + if (!writenote(&tmp->notes[i], cprm->file, &foffset)) goto end_coredump; } - DUMP_SEEK(dataoff); + if (!dump_seek(cprm->file, dataoff - foffset)) + goto end_coredump; - if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0) + if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit, + cprm->mm_flags) < 0) goto end_coredump; -#ifdef ELF_CORE_WRITE_EXTRA_DATA - ELF_CORE_WRITE_EXTRA_DATA; -#endif + if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) + goto end_coredump; - if (file->f_pos != offset) { + if (e_phnum == PN_XNUM) { + size += sizeof(*shdr4extnum); + if (size > cprm->limit + || !dump_write(cprm->file, shdr4extnum, + sizeof(*shdr4extnum))) + goto end_coredump; + } + + if (cprm->file->f_pos != offset) { /* Sanity check */ printk(KERN_WARNING "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", - file->f_pos, offset); + cprm->file->f_pos, offset); } end_coredump: @@ -1827,7 +1862,7 @@ cleanup: list_del(tmp); kfree(list_entry(tmp, struct elf_thread_status, list)); } - + kfree(phdr4note); kfree(elf); kfree(prstatus); kfree(psinfo); @@ -1840,4 +1875,4 @@ cleanup: #undef NUM_NOTES } -#endif /* USE_ELF_CORE_DUMP */ +#endif /* CONFIG_ELF_CORE */