diff options
| -rw-r--r-- | fs/binfmt_flat.c | 3 | ||||
| -rw-r--r-- | fs/exec.c | 2 | ||||
| -rw-r--r-- | fs/proc/base.c | 75 | ||||
| -rw-r--r-- | fs/proc/internal.h | 1 | ||||
| -rw-r--r-- | fs/proc/task_mmu.c | 34 | ||||
| -rw-r--r-- | fs/proc/task_nommu.c | 34 | ||||
| -rw-r--r-- | include/linux/mm.h | 13 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 6 | ||||
| -rw-r--r-- | include/linux/proc_fs.h | 20 | ||||
| -rw-r--r-- | kernel/fork.c | 3 | ||||
| -rw-r--r-- | mm/mmap.c | 24 | ||||
| -rw-r--r-- | mm/nommu.c | 23 |
12 files changed, 157 insertions, 81 deletions
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index c12cc36..3b40d45 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -531,7 +531,8 @@ static int load_flat_file(struct linux_binprm * bprm, DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); down_write(¤t->mm->mmap_sem); - textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0); + textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, + MAP_PRIVATE|MAP_EXECUTABLE, 0); up_write(¤t->mm->mmap_sem); if (!textpos || textpos >= (unsigned long) -4096) { if (!textpos) @@ -964,6 +964,8 @@ int flush_old_exec(struct linux_binprm * bprm) if (retval) goto out; + set_mm_exe_file(bprm->mm, bprm->file); + /* * Release all of the old mmap stuff */ diff --git a/fs/proc/base.c b/fs/proc/base.c index c5e412a..b48ddb1 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1181,6 +1181,81 @@ static const struct file_operations proc_pid_sched_operations = { #endif +/* + * We added or removed a vma mapping the executable. The vmas are only mapped + * during exec and are not mapped with the mmap system call. + * Callers must hold down_write() on the mm's mmap_sem for these + */ +void added_exe_file_vma(struct mm_struct *mm) +{ + mm->num_exe_file_vmas++; +} + +void removed_exe_file_vma(struct mm_struct *mm) +{ + mm->num_exe_file_vmas--; + if ((mm->num_exe_file_vmas == 0) && mm->exe_file){ + fput(mm->exe_file); + mm->exe_file = NULL; + } + +} + +void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) +{ + if (new_exe_file) + get_file(new_exe_file); + if (mm->exe_file) + fput(mm->exe_file); + mm->exe_file = new_exe_file; + mm->num_exe_file_vmas = 0; +} + +struct file *get_mm_exe_file(struct mm_struct *mm) +{ + struct file *exe_file; + + /* We need mmap_sem to protect against races with removal of + * VM_EXECUTABLE vmas */ + down_read(&mm->mmap_sem); + exe_file = mm->exe_file; + if (exe_file) + get_file(exe_file); + up_read(&mm->mmap_sem); + return exe_file; +} + +void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm) +{ + /* It's safe to write the exe_file pointer without exe_file_lock because + * this is called during fork when the task is not yet in /proc */ + newmm->exe_file = get_mm_exe_file(oldmm); +} + +static int proc_exe_link(struct inode *inode, struct path *exe_path) +{ + struct task_struct *task; + struct mm_struct *mm; + struct file *exe_file; + + task = get_proc_task(inode); + if (!task) + return -ENOENT; + mm = get_task_mm(task); + put_task_struct(task); + if (!mm) + return -ENOENT; + exe_file = get_mm_exe_file(mm); + mmput(mm); + if (exe_file) { + *exe_path = exe_file->f_path; + path_get(&exe_file->f_path); + fput(exe_file); + return 0; + } else + return -ENOENT; +} + static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) { struct inode *inode = dentry->d_inode; diff --git a/fs/proc/internal.h b/fs/proc/internal.h index bc72f5c..45abb98 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -48,7 +48,6 @@ extern int maps_protect; extern void create_seq_entry(char *name, mode_t mode, const struct file_operations *f); -extern int proc_exe_link(struct inode *, struct path *); extern int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task); extern int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns, diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 7415eeb..e2b8e76 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -75,40 +75,6 @@ int task_statm(struct mm_struct *mm, int *shared, int *text, return mm->total_vm; } -int proc_exe_link(struct inode *inode, struct path *path) -{ - struct vm_area_struct * vma; - int result = -ENOENT; - struct task_struct *task = get_proc_task(inode); - struct mm_struct * mm = NULL; - - if (task) { - mm = get_task_mm(task); - put_task_struct(task); - } - if (!mm) - goto out; - down_read(&mm->mmap_sem); - - vma = mm->mmap; - while (vma) { - if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) - break; - vma = vma->vm_next; - } - - if (vma) { - *path = vma->vm_file->f_path; - path_get(&vma->vm_file->f_path); - result = 0; - } - - up_read(&mm->mmap_sem); - mmput(mm); -out: - return result; -} - static void pad_len_spaces(struct seq_file *m, int len) { len = 25 + sizeof(void*) * 6 - len; diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 8011528..4b733f1 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -103,40 +103,6 @@ int task_statm(struct mm_struct *mm, int *shared, int *text, return size; } -int proc_exe_link(struct inode *inode, struct path *path) -{ - struct vm_list_struct *vml; - struct vm_area_struct *vma; - struct task_struct *task = get_proc_task(inode); - struct mm_struct *mm = get_task_mm(task); - int result = -ENOENT; - - if (!mm) - goto out; - down_read(&mm->mmap_sem); - - vml = mm->context.vmlist; - vma = NULL; - while (vml) { - if ((vml->vma->vm_flags & VM_EXECUTABLE) && vml->vma->vm_file) { - vma = vml->vma; - break; - } - vml = vml->next; - } - - if (vma) { - *path = vma->vm_file->f_path; - path_get(&vma->vm_file->f_path); - result = 0; - } - - up_read(&mm->mmap_sem); - mmput(mm); -out: - return result; -} - /* * display mapping lines for a particular process's /proc/pid/maps */ diff --git a/include/linux/mm.h b/include/linux/mm.h index fef602d..c31a9cd 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1066,6 +1066,19 @@ extern void unlink_file_vma(struct vm_area_struct *); extern struct vm_area_struct *copy_vma(struct vm_area_struct **, unsigned long addr, unsigned long len, pgoff_t pgoff); extern void exit_mmap(struct mm_struct *); + +#ifdef CONFIG_PROC_FS +/* From fs/proc/base.c. callers must _not_ hold the mm's exe_file_lock */ +extern void added_exe_file_vma(struct mm_struct *mm); +extern void removed_exe_file_vma(struct mm_struct *mm); +#else +static inline void added_exe_file_vma(struct mm_struct *mm) +{} + +static inline void removed_exe_file_vma(struct mm_struct *mm) +{} +#endif /* CONFIG_PROC_FS */ + extern int may_expand_vm(struct mm_struct *mm, unsigned long npages); extern int install_special_mapping(struct mm_struct *mm, unsigned long addr, unsigned long len, diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index bc97bd5..eb7c16c 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -229,6 +229,12 @@ struct mm_struct { struct task_struct *owner; /* The thread group leader that */ /* owns the mm_struct. */ #endif + +#ifdef CONFIG_PROC_FS + /* store ref to file /proc/<pid>/exe symlink points to */ + struct file *exe_file; + unsigned long num_exe_file_vmas; +#endif }; #endif /* _LINUX_MM_TYPES_H */ diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 9b6c935..65f2299 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -9,7 +9,6 @@ struct net; struct completion; - /* * The proc filesystem constants/structures */ @@ -206,6 +205,12 @@ extern void proc_net_remove(struct net *net, const char *name); extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name, struct proc_dir_entry *parent); +/* While the {get|set|dup}_mm_exe_file functions are for mm_structs, they are + * only needed to implement /proc/<pid>|self/exe so we define them here. */ +extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file); +extern struct file *get_mm_exe_file(struct mm_struct *mm); +extern void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm); + #else #define proc_root_driver NULL @@ -255,6 +260,19 @@ static inline void pid_ns_release_proc(struct pid_namespace *ns) { } +static inline void set_mm_exe_file(struct mm_struct *mm, + struct file *new_exe_file) +{} + +static inline struct file *get_mm_exe_file(struct mm_struct *mm) +{ + return NULL; +} + +static inline void dup_mm_exe_file(struct mm_struct *oldmm, + struct mm_struct *newmm) +{} + #endif /* CONFIG_PROC_FS */ #if !defined(CONFIG_PROC_KCORE) diff --git a/kernel/fork.c b/kernel/fork.c index de5c16c..068ffe0 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -431,6 +431,7 @@ void mmput(struct mm_struct *mm) if (atomic_dec_and_test(&mm->mm_users)) { exit_aio(mm); exit_mmap(mm); + set_mm_exe_file(mm, NULL); if (!list_empty(&mm->mmlist)) { spin_lock(&mmlist_lock); list_del(&mm->mmlist); @@ -543,6 +544,8 @@ struct mm_struct *dup_mm(struct task_struct *tsk) if (init_new_context(tsk, mm)) goto fail_nocontext; + dup_mm_exe_file(oldmm, mm); + err = dup_mmap(mm, oldmm); if (err) goto free_pt; @@ -230,8 +230,11 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma) might_sleep(); if (vma->vm_ops && vma->vm_ops->close) vma->vm_ops->close(vma); - if (vma->vm_file) + if (vma->vm_file) { fput(vma->vm_file); + if (vma->vm_flags & VM_EXECUTABLE) + removed_exe_file_vma(vma->vm_mm); + } mpol_put(vma_policy(vma)); kmem_cache_free(vm_area_cachep, vma); return next; @@ -623,8 +626,11 @@ again: remove_next = 1 + (end > next->vm_end); spin_unlock(&mapping->i_mmap_lock); if (remove_next) { - if (file) + if (file) { fput(file); + if (next->vm_flags & VM_EXECUTABLE) + removed_exe_file_vma(mm); + } mm->map_count--; mpol_put(vma_policy(next)); kmem_cache_free(vm_area_cachep, next); @@ -1154,6 +1160,8 @@ munmap_back: error = file->f_op->mmap(file, vma); if (error) goto unmap_and_free_vma; + if (vm_flags & VM_EXECUTABLE) + added_exe_file_vma(mm); } else if (vm_flags & VM_SHARED) { error = shmem_zero_setup(vma); if (error) @@ -1185,6 +1193,8 @@ munmap_back: mpol_put(vma_policy(vma)); kmem_cache_free(vm_area_cachep, vma); fput(file); + if (vm_flags & VM_EXECUTABLE) + removed_exe_file_vma(mm); } else { vma_link(mm, vma, prev, rb_link, rb_parent); file = vma->vm_file; @@ -1817,8 +1827,11 @@ int split_vma(struct mm_struct * mm, struct vm_area_struct * vma, } vma_set_policy(new, pol); - if (new->vm_file) + if (new->vm_file) { get_file(new->vm_file); + if (vma->vm_flags & VM_EXECUTABLE) + added_exe_file_vma(mm); + } if (new->vm_ops && new->vm_ops->open) new->vm_ops->open(new); @@ -2135,8 +2148,11 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, new_vma->vm_start = addr; new_vma->vm_end = addr + len; new_vma->vm_pgoff = pgoff; - if (new_vma->vm_file) + if (new_vma->vm_file) { get_file(new_vma->vm_file); + if (vma->vm_flags & VM_EXECUTABLE) + added_exe_file_vma(mm); + } if (new_vma->vm_ops && new_vma->vm_ops->open) new_vma->vm_ops->open(new_vma); vma_link(mm, new_vma, prev, rb_link, rb_parent); @@ -966,8 +966,13 @@ unsigned long do_mmap_pgoff(struct file *file, INIT_LIST_HEAD(&vma->anon_vma_node); atomic_set(&vma->vm_usage, 1); - if (file) + if (file) { get_file(file); + if (vm_flags & VM_EXECUTABLE) { + added_exe_file_vma(current->mm); + vma->vm_mm = current->mm; + } + } vma->vm_file = file; vma->vm_flags = vm_flags; vma->vm_start = addr; @@ -1022,8 +1027,11 @@ unsigned long do_mmap_pgoff(struct file *file, up_write(&nommu_vma_sem); kfree(vml); if (vma) { - if (vma->vm_file) + if (vma->vm_file) { fput(vma->vm_file); + if (vma->vm_flags & VM_EXECUTABLE) + removed_exe_file_vma(vma->vm_mm); + } kfree(vma); } return ret; @@ -1053,7 +1061,7 @@ EXPORT_SYMBOL(do_mmap_pgoff); /* * handle mapping disposal for uClinux */ -static void put_vma(struct vm_area_struct *vma) +static void put_vma(struct mm_struct *mm, struct vm_area_struct *vma) { if (vma) { down_write(&nommu_vma_sem); @@ -1075,8 +1083,11 @@ static void put_vma(struct vm_area_struct *vma) realalloc -= kobjsize(vma); askedalloc -= sizeof(*vma); - if (vma->vm_file) + if (vma->vm_file) { fput(vma->vm_file); + if (vma->vm_flags & VM_EXECUTABLE) + removed_exe_file_vma(mm); + } kfree(vma); } @@ -1113,7 +1124,7 @@ int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len) found: vml = *parent; - put_vma(vml->vma); + put_vma(mm, vml->vma); *parent = vml->next; realalloc -= kobjsize(vml); @@ -1158,7 +1169,7 @@ void exit_mmap(struct mm_struct * mm) while ((tmp = mm->context.vmlist)) { mm->context.vmlist = tmp->next; - put_vma(tmp->vma); + put_vma(mm, tmp->vma); realalloc -= kobjsize(tmp); askedalloc -= sizeof(*tmp); |