X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fbinfmt_elf.c;h=535e763ab1a61e56ef5d25d725dc4f39eb899a49;hb=0dbb5671921b6dad2396090ef81a3efee1ae7da1;hp=fd5b2ea5d2993bbafa4b370fee3aba3f172577c0;hpb=221af7f87b97431e3ee21ce4b0e77d5411cf1549;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index fd5b2ea..535e763 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -1085,36 +1086,6 @@ out: * Modelled on fs/exec.c:aout_core_dump() * Jeremy Fitzhardinge */ -/* - * 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 && file->f_op->llseek != no_llseek) { - if (file->f_op->llseek(file, off, SEEK_CUR) < 0) - return 0; - } else { - char *buf = (char *)get_zeroed_page(GFP_KERNEL); - if (!buf) - return 0; - while (off > 0) { - unsigned long n = off; - if (n > PAGE_SIZE) - n = PAGE_SIZE; - if (!dump_write(file, buf, n)) - return 0; - off -= n; - } - free_page((unsigned long)buf); - } - return 1; -} /* * Decide what to dump of a segment, part, all or none. @@ -1249,11 +1220,6 @@ static int writenote(struct memelfnote *men, struct file *file, } #undef DUMP_WRITE -#define DUMP_WRITE(addr, nr) \ - if ((size += (nr)) > cprm->limit || \ - !dump_write(cprm->file, (addr), (nr))) \ - goto end_coredump; - static void fill_elf_header(struct elfhdr *elf, int segs, u16 machine, u32 flags, u8 osabi) { @@ -1872,6 +1838,34 @@ static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, return gate_vma; } +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; +} + +static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, + unsigned long mm_flags) +{ + struct vm_area_struct *vma; + size_t size = 0; + + for (vma = first_vma(current, gate_vma); vma != NULL; + vma = next_vma(vma, gate_vma)) + size += vma_dump_size(vma, mm_flags); + return size; +} + /* * Actual dumper * @@ -1888,8 +1882,11 @@ static int elf_core_dump(struct coredump_params *cprm) struct vm_area_struct *vma, *gate_vma; struct elfhdr *elf = NULL; loff_t offset = 0, dataoff, foffset; - unsigned long mm_flags; struct elf_note_info info; + 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. @@ -1912,20 +1909,25 @@ static int elf_core_dump(struct coredump_params *cprm) * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. */ segs = current->mm->map_count; -#ifdef ELF_CORE_EXTRA_PHDRS - segs += ELF_CORE_EXTRA_PHDRS; -#endif + segs += elf_core_extra_phdrs(); gate_vma = get_gate_vma(current); if (gate_vma != NULL) segs++; + /* 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; + /* * Collect all the non-memory information about the process for the * notes. This also sets up the file header. */ - if (!fill_note_info(elf, segs + 1, /* including notes section */ - &info, cprm->signr, cprm->regs)) + if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs)) goto cleanup; has_dumped = 1; @@ -1934,31 +1936,47 @@ static int elf_core_dump(struct coredump_params *cprm) 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; size_t sz = get_note_info_size(&info); sz += elf_coredump_extra_notes_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)); } 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(gate_vma, 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 = first_vma(current, gate_vma); vma != NULL; @@ -1969,7 +1987,7 @@ static int elf_core_dump(struct coredump_params *cprm) phdr.p_offset = offset; phdr.p_vaddr = vma->vm_start; phdr.p_paddr = 0; - phdr.p_filesz = vma_dump_size(vma, mm_flags); + phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags); phdr.p_memsz = vma->vm_end - vma->vm_start; offset += phdr.p_filesz; phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; @@ -1979,12 +1997,14 @@ static int elf_core_dump(struct coredump_params *cprm) 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 */ if (!write_note_info(&info, cprm->file, &foffset)) @@ -2002,7 +2022,7 @@ static int elf_core_dump(struct coredump_params *cprm) unsigned long addr; unsigned long end; - end = vma->vm_start + vma_dump_size(vma, mm_flags); + end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags); for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { struct page *page; @@ -2023,15 +2043,24 @@ static int elf_core_dump(struct coredump_params *cprm) } } -#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 (e_phnum == PN_XNUM) { + size += sizeof(*shdr4extnum); + if (size > cprm->limit + || !dump_write(cprm->file, shdr4extnum, + sizeof(*shdr4extnum))) + goto end_coredump; + } end_coredump: set_fs(fs); cleanup: free_note_info(&info); + kfree(shdr4extnum); + kfree(phdr4note); kfree(elf); out: return has_dumped;