mm: extract exe_file handling from procfs

Setup and cleanup of mm_struct->exe_file is currently done in fs/proc/.
This was because exe_file was needed only for /proc/<pid>/exe.  Since we
will need the exe_file functionality also for core dumps (so core name can
contain full binary path), built this functionality always into the
kernel.

To achieve that move that out of proc FS to the kernel/ where in fact it
should belong.  By doing that we can make dup_mm_exe_file static.  Also we
can drop linux/proc_fs.h inclusion in fs/exec.c and kernel/fork.c.

Signed-off-by: Jiri Slaby <[email protected]>
Cc: Alexander Viro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/fs/exec.c b/fs/exec.c
index 936f5776655c906c25a40400ace80bc33b643c87..88a16c5722824a8b579043514b877855481dd9d9 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -42,7 +42,6 @@
 #include <linux/pid_namespace.h>
 #include <linux/module.h>
 #include <linux/namei.h>
-#include <linux/proc_fs.h>
 #include <linux/mount.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index dc8bca72b002d9b01036bb7e659495eb972af322..c2ac2fb123c8d8b0b266522eb7055c074ce526b1 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1576,57 +1576,6 @@ static const struct file_operations proc_pid_set_comm_operations = {
        .release        = single_release,
 };
 
-/*
- * 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;

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fb8e814f78dcba276b46724d8b4a0763663b87c1..9670f71d7be961bbe56e9c1701f475bc4be7981c 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1408,17 +1408,11 @@ extern void exit_mmap(struct mm_struct *);
 extern int mm_take_all_locks(struct mm_struct *mm);
 extern void mm_drop_all_locks(struct mm_struct *mm);
 
-#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 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 int may_expand_vm(struct mm_struct *mm, unsigned long npages);
 extern int install_special_mapping(struct mm_struct *mm,

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 6fe96c19f85e82bbfc29fce8a69e87013dc26fce..2a78aae78c690b7897a6fbe835201a023a579a3c 100644 (file)
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -302,11 +302,9 @@ struct mm_struct {
        struct task_struct __rcu *owner;
 #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
 #ifdef CONFIG_MMU_NOTIFIER
        struct mmu_notifier_mm *mmu_notifier_mm;
 #endif

diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 648c9c58add7ccafd511d1864cd78f1c5b80df79..e7576cf9e32d7bf8cdc1bb50230a42fb80d184ad 100644 (file)
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -173,12 +173,6 @@ 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);
-
 extern struct file *proc_ns_fget(int fd);
 
 #else
@@ -230,19 +224,6 @@ 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)
-{}
-
 static inline struct file *proc_ns_fget(int fd)
 {
        return ERR_PTR(-EINVAL);

diff --git a/kernel/fork.c b/kernel/fork.c
index 1f84099ecce60b0ea8979d795aa3b05c127d460a..ca406d916713696c66e2a47b60cfd5d7a615f711 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -59,7 +59,6 @@
 #include <linux/taskstats_kern.h>
 #include <linux/random.h>
 #include <linux/tty.h>
-#include <linux/proc_fs.h>
 #include <linux/blkdev.h>
 #include <linux/fs_struct.h>
 #include <linux/magic.h>
@@ -597,6 +596,57 @@ void mmput(struct mm_struct *mm)
 }
 EXPORT_SYMBOL_GPL(mmput);
 
+/*
+ * 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;
+}
+
+static 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);
+}
+
 /**
  * get_task_mm - acquire a reference to the task's mm
  *