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-rw-r--r--fs/binfmt_flat.c3
-rw-r--r--fs/exec.c2
-rw-r--r--fs/proc/base.c75
-rw-r--r--fs/proc/internal.h1
-rw-r--r--fs/proc/task_mmu.c34
-rw-r--r--fs/proc/task_nommu.c34
-rw-r--r--include/linux/mm.h13
-rw-r--r--include/linux/mm_types.h6
-rw-r--r--include/linux/proc_fs.h20
-rw-r--r--kernel/fork.c3
-rw-r--r--mm/mmap.c24
-rw-r--r--mm/nommu.c23
12 files changed, 157 insertions, 81 deletions
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index c12cc362fd3..3b40d45a3a1 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(&current->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(&current->mm->mmap_sem);
if (!textpos || textpos >= (unsigned long) -4096) {
if (!textpos)
diff --git a/fs/exec.c b/fs/exec.c
index 711bc45d789..a13883903ee 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -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 c5e412a00b1..b48ddb11994 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 bc72f5c8c47..45abb980398 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 7415eeb7cc3..e2b8e769f51 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 8011528518b..4b733f10845 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 fef602d8272..c31a9cd2a30 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 bc97bd54f60..eb7c16cc955 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 9b6c935f69c..65f2299b772 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 de5c16c6b6e..068ffe00752 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;
diff --git a/mm/mmap.c b/mm/mmap.c
index 677d184b0d4..fac66337da2 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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);
diff --git a/mm/nommu.c b/mm/nommu.c
index 1d32fe89d57..ef8c62cec69 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -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);
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-03 06:11:11 +0000