diff options
| -rw-r--r-- | fs/binfmt_elf_fdpic.c | 52 |
1 files changed, 35 insertions, 17 deletions
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 1a6c8e2eb1c5..2f5d8dbe676d 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1181,8 +1181,10 @@ static int dump_seek(struct file *file, loff_t off) * * I think we should skip something. But I am not sure how. H.J. */ -static int maydump(struct vm_area_struct *vma) +static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) { + int dump_ok; + /* Do not dump I/O mapped devices or special mappings */ if (vma->vm_flags & (VM_IO | VM_RESERVED)) { kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); @@ -1197,27 +1199,35 @@ static int maydump(struct vm_area_struct *vma) return 0; } - /* Dump shared memory only if mapped from an anonymous file. */ + /* By default, dump shared memory if mapped from an anonymous file. */ if (vma->vm_flags & VM_SHARED) { if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { - kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags); - return 1; + dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); + kdcore("%08lx: %08lx: %s (share)", vma->vm_start, + vma->vm_flags, dump_ok ? "yes" : "no"); + return dump_ok; } - kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags); - return 0; + dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); + kdcore("%08lx: %08lx: %s (share)", vma->vm_start, + vma->vm_flags, dump_ok ? "yes" : "no"); + return dump_ok; } #ifdef CONFIG_MMU - /* If it hasn't been written to, don't write it out */ + /* By default, if it hasn't been written to, don't write it out */ if (!vma->anon_vma) { - kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags); - return 0; + dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); + kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, + vma->vm_flags, dump_ok ? "yes" : "no"); + return dump_ok; } #endif - kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags); - return 1; + dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); + kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, + dump_ok ? "yes" : "no"); + return dump_ok; } /* An ELF note in memory */ @@ -1457,14 +1467,14 @@ static int elf_dump_thread_status(long signr, struct elf_thread_status *t) */ #ifdef CONFIG_MMU static int elf_fdpic_dump_segments(struct file *file, size_t *size, - unsigned long *limit) + unsigned long *limit, unsigned long mm_flags) { struct vm_area_struct *vma; for (vma = current->mm->mmap; vma; vma = vma->vm_next) { unsigned long addr; - if (!maydump(vma)) + if (!maydump(vma, mm_flags)) continue; for (addr = vma->vm_start; @@ -1512,14 +1522,14 @@ end_coredump: */ #ifndef CONFIG_MMU static int elf_fdpic_dump_segments(struct file *file, size_t *size, - unsigned long *limit) + unsigned long *limit, unsigned long mm_flags) { struct vm_list_struct *vml; for (vml = current->mm->context.vmlist; vml; vml = vml->next) { struct vm_area_struct *vma = vml->vma; - if (!maydump(vma)) + if (!maydump(vma, mm_flags)) continue; if ((*size += PAGE_SIZE) > *limit) @@ -1570,6 +1580,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, struct vm_list_struct *vml; #endif elf_addr_t *auxv; + unsigned long mm_flags; /* * We no longer stop all VM operations. @@ -1707,6 +1718,13 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, /* 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; + /* write program headers for segments dump */ for ( #ifdef CONFIG_MMU @@ -1728,7 +1746,7 @@ 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) ? sz : 0; + phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0; phdr.p_memsz = sz; offset += phdr.p_filesz; phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; @@ -1762,7 +1780,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, DUMP_SEEK(dataoff); - if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0) + if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0) goto end_coredump; #ifdef ELF_CORE_WRITE_EXTRA_DATA |