The patch titled
mm: remove struct mm_struct::exe_file et al
has been added to the -mm tree. Its filename is
mm-remove-struct-mm_struct-exe_file-et-al.patch
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out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm: remove struct mm_struct::exe_file et al
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Commit 925d1c401fa6cfd0df5d2e37da8981494ccdec07 ("procfs task exe
symlink"). introduced struct mm_struct::exe_file and struct
mm_struct::num_exe_file_vmas.
The rationale is weak: unifying MMU and no-MMU version of /proc/*/exe
code. For this a) struct mm_struct becomes bigger, b) mmap/munmap/exit
become slower, c) patch adds more code than removes in fact.
->exe_file maybe well defined, but doesn't make sense always. After
original executable is unmapped, /proc/*/exe will still report it and,
more importantly, pin corresponding struct file.
->num_exe_file_vmas is even worse -- it just counts number of executable
file-backed VMAs even if those VMAs aren't related to ->exe_file.
After commit 8feae13110d60cc6287afabc2887366b0eb226c2 aka "NOMMU: Make
VMAs per MM as for MMU-mode linux" no-MMU kernels also maintain list of
VMAs in ->mmap, so we can switch back for MMU version of /proc/*/exe.
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Matt Helsley <matthltc@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_flat.c | 3 -
fs/exec.c | 2
fs/proc/base.c | 105 ++++++++++---------------------------
include/linux/mm.h | 12 ----
include/linux/mm_types.h | 6 --
include/linux/proc_fs.h | 20 -------
kernel/fork.c | 3 -
mm/mmap.c | 22 +------
mm/nommu.c | 16 -----
9 files changed, 37 insertions(+), 152 deletions(-)
diff -puN fs/binfmt_flat.c~mm-remove-struct-mm_struct-exe_file-et-al fs/binfmt_flat.c
--- a/fs/binfmt_flat.c~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/fs/binfmt_flat.c
@@ -531,8 +531,7 @@ static int load_flat_file(struct linux_b
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|MAP_EXECUTABLE, 0);
+ textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0);
up_write(¤t->mm->mmap_sem);
if (!textpos || textpos >= (unsigned long) -4096) {
if (!textpos)
diff -puN fs/exec.c~mm-remove-struct-mm_struct-exe_file-et-al fs/exec.c
--- a/fs/exec.c~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/fs/exec.c
@@ -965,8 +965,6 @@ int flush_old_exec(struct linux_binprm *
if (retval)
goto out;
- set_mm_exe_file(bprm->mm, bprm->file);
-
/*
* Release all of the old mmap stuff
*/
diff -puN fs/proc/base.c~mm-remove-struct-mm_struct-exe_file-et-al fs/proc/base.c
--- a/fs/proc/base.c~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/fs/proc/base.c
@@ -202,6 +202,36 @@ static int proc_root_link(struct inode *
return result;
}
+static int proc_exe_link(struct inode *inode, struct path *path)
+{
+ struct task_struct *tsk;
+ struct mm_struct *mm;
+ struct vm_area_struct *vma;
+
+ tsk = get_proc_task(inode);
+ if (!tsk)
+ return -ENOENT;
+ mm = get_task_mm(tsk);
+ put_task_struct(tsk);
+ if (!mm)
+ return -ENOENT;
+
+ down_read(&mm->mmap_sem);
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
+ *path = vma->vm_file->f_path;
+ path_get(&vma->vm_file->f_path);
+
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ return 0;
+ }
+ }
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ return -ENOENT;
+}
+
/*
* Return zero if current may access user memory in @task, -error if not.
*/
@@ -1249,81 +1279,6 @@ static const struct file_operations proc
#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 -puN include/linux/mm.h~mm-remove-struct-mm_struct-exe_file-et-al include/linux/mm.h
--- a/include/linux/mm.h~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/include/linux/mm.h
@@ -1123,18 +1123,6 @@ 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 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 -puN include/linux/mm_types.h~mm-remove-struct-mm_struct-exe_file-et-al include/linux/mm_types.h
--- a/include/linux/mm_types.h~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/include/linux/mm_types.h
@@ -269,12 +269,6 @@ struct mm_struct {
*/
struct task_struct *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 -puN include/linux/proc_fs.h~mm-remove-struct-mm_struct-exe_file-et-al include/linux/proc_fs.h
--- a/include/linux/proc_fs.h~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/include/linux/proc_fs.h
@@ -189,12 +189,6 @@ extern void proc_net_remove(struct net *
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_net_fops_create(net, name, mode, fops) ({ (void)(mode), NULL; })
@@ -245,20 +239,6 @@ static inline int pid_ns_prepare_proc(st
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 -puN kernel/fork.c~mm-remove-struct-mm_struct-exe_file-et-al kernel/fork.c
--- a/kernel/fork.c~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/kernel/fork.c
@@ -487,7 +487,6 @@ 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);
@@ -610,8 +609,6 @@ struct mm_struct *dup_mm(struct task_str
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 -puN mm/mmap.c~mm-remove-struct-mm_struct-exe_file-et-al mm/mmap.c
--- a/mm/mmap.c~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/mm/mmap.c
@@ -236,11 +236,8 @@ static struct vm_area_struct *remove_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;
@@ -637,11 +634,8 @@ again: remove_next = 1 + (end > next->
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);
@@ -1196,8 +1190,6 @@ 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)
@@ -1853,11 +1845,8 @@ int split_vma(struct mm_struct * mm, str
}
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);
@@ -2204,11 +2193,8 @@ struct vm_area_struct *copy_vma(struct v
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 -puN mm/nommu.c~mm-remove-struct-mm_struct-exe_file-et-al mm/nommu.c
--- a/mm/nommu.c~mm-remove-struct-mm_struct-exe_file-et-al
+++ a/mm/nommu.c
@@ -719,11 +719,8 @@ static void delete_vma(struct mm_struct
kenter("%p", vma);
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(mm);
- }
put_nommu_region(vma->vm_region);
kmem_cache_free(vm_area_cachep, vma);
}
@@ -1216,10 +1213,6 @@ unsigned long do_mmap_pgoff(struct file
get_file(file);
vma->vm_file = file;
get_file(file);
- if (vm_flags & VM_EXECUTABLE) {
- added_exe_file_vma(current->mm);
- vma->vm_mm = current->mm;
- }
}
down_write(&nommu_region_sem);
@@ -1357,11 +1350,8 @@ share:
error_put_region:
__put_nommu_region(region);
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);
- }
kmem_cache_free(vm_area_cachep, vma);
}
kleave(" = %d [pr]", ret);
@@ -1373,8 +1363,6 @@ error:
fput(region->vm_file);
kmem_cache_free(vm_region_jar, region);
fput(vma->vm_file);
- if (vma->vm_flags & VM_EXECUTABLE)
- removed_exe_file_vma(vma->vm_mm);
kmem_cache_free(vm_area_cachep, vma);
kleave(" = %d", ret);
return ret;
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
origin.patch
linux-next.patch
sysctl-dont-take-the-use-count-of-multiple-heads-at-a-time.patch
sysctl-lockdep-support-for-sysctl-reference-counting.patch
proc-tty-add-struct-tty_operations-proc_fops.patch
proc-tty-switch-cyclades-to-proc_fops.patch
proc-tty-switch-ip2-to-proc_fops.patch
proc-tty-switch-istallion-to-proc_fops.patch
proc-tty-switch-synclink_cs-to-proc_fops.patch
proc-tty-switch-stallion-to-proc_fops.patch
proc-tty-switch-synclink-to-proc_fops.patch
proc-tty-switch-synclink_gt-to-proc_fops.patch
proc-tty-switch-synclinkmp-to-proc_fops.patch
proc-tty-switch-sdio_uart-to-proc_fops.patch
proc-tty-switch-serial_core-to-proc_fops.patch
proc-tty-switch-usb-serial-to-proc_fops.patch
proc-tty-switch-ircomm-to-proc_fops.patch
proc-tty-switch-amiserial-to-proc_fops.patch
proc-tty-switch-ia64-simserial-to-proc_fops.patch
proc-tty-switch-xtensa-iss-console-to-proc_fops.patch
proc-tty-remove-struct-tty_operations-read_proc.patch
memdup_user-introduce.patch
memdup_user-introduce-fix.patch
mm-fix-proc_dointvec_userhz_jiffies-breakage.patch
mm-fix-proc_dointvec_userhz_jiffies-breakage-checkpatch-fixes.patch
mm-remove-struct-mm_struct-exe_file-et-al.patch
simplify-copy_thread.patch
simplify-copy_thread-checkpatch-fixes.patch
softirq-introduce-statistics-for-softirq.patch
proc-export-statistics-for-softirq-to-proc.patch
proc-export-statistics-for-softirq-to-proc-fix.patch
proc-update-document-for-proc-softirqs-and-proc-stat.patch
proc_sysctl-use-config_proc_sysctl-around-ipc-and-utsname-proc_handlers.patch
sysctl-fix-suid_dumpable-and-lease-break-time-sysctls.patch
namespaces-move-proc_net_get_sb-to-a-generic-fs-superc-helper.patch
namespaces-move-proc_net_get_sb-to-a-generic-fs-superc-helper-fix.patch
namespaces-mqueue-ns-move-mqueue_mnt-into-struct-ipc_namespace.patch
namespaces-ipc-namespaces-implement-support-for-posix-msqueues.patch
namespaces-ipc-namespaces-implement-support-for-posix-msqueues-initialize-init_ipc_nscount-to-1.patch
namespaces-mqueue-namespace-adapt-sysctl.patch
namespaces-mqueue-namespace-adapt-sysctl-update.patch
namespaces-mqueue-namespace-adapt-sysctl-update-fix.patch
--
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