diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index a76a26a1db8a6fe855b0eeea32dee251296c0c8a..b7413cb46dcb1f1a331068861e766a6c03a5da40 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -290,7 +290,7 @@ Table 1-4: Contents of the stat files (as of 2.6.30-rc7)
rsslim current limit in bytes on the rss
start_code address above which program text can run
end_code address below which program text can run
- start_stack address of the start of the stack
+ start_stack address of the start of the main process stack
esp current value of ESP
eip current value of EIP
pending bitmap of pending signals
@@ -325,7 +325,7 @@ address perms offset dev inode pathname
a7cb1000-a7cb2000 ---p 00000000 00:00 0
a7cb2000-a7eb2000 rw-p 00000000 00:00 0
a7eb2000-a7eb3000 ---p 00000000 00:00 0
-a7eb3000-a7ed5000 rw-p 00000000 00:00 0
+a7eb3000-a7ed5000 rw-p 00000000 00:00 0 [stack:1001]
a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6
a8008000-a800a000 r--p 00133000 03:00 4222 /lib/libc.so.6
a800a000-a800b000 rw-p 00135000 03:00 4222 /lib/libc.so.6
@@ -357,11 +357,39 @@ is not associated with a file:
[heap] = the heap of the program
[stack] = the stack of the main process
+ [stack:1001] = the stack of the thread with tid 1001
[vdso] = the "virtual dynamic shared object",
the kernel system call handler
or if empty, the mapping is anonymous.
+The /proc/PID/task/TID/maps is a view of the virtual memory from the viewpoint
+of the individual tasks of a process. In this file you will see a mapping marked
+as [stack] if that task sees it as a stack. This is a key difference from the
+content of /proc/PID/maps, where you will see all mappings that are being used
+as stack by all of those tasks. Hence, for the example above, the task-level
+map, i.e. /proc/PID/task/TID/maps for thread 1001 will look like this:
+
+08048000-08049000 r-xp 00000000 03:00 8312 /opt/test
+08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test
+0804a000-0806b000 rw-p 00000000 00:00 0 [heap]
+a7cb1000-a7cb2000 ---p 00000000 00:00 0
+a7cb2000-a7eb2000 rw-p 00000000 00:00 0
+a7eb2000-a7eb3000 ---p 00000000 00:00 0
+a7eb3000-a7ed5000 rw-p 00000000 00:00 0 [stack]
+a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6
+a8008000-a800a000 r--p 00133000 03:00 4222 /lib/libc.so.6
+a800a000-a800b000 rw-p 00135000 03:00 4222 /lib/libc.so.6
+a800b000-a800e000 rw-p 00000000 00:00 0
+a800e000-a8022000 r-xp 00000000 03:00 14462 /lib/libpthread.so.0
+a8022000-a8023000 r--p 00013000 03:00 14462 /lib/libpthread.so.0
+a8023000-a8024000 rw-p 00014000 03:00 14462 /lib/libpthread.so.0
+a8024000-a8027000 rw-p 00000000 00:00 0
+a8027000-a8043000 r-xp 00000000 03:00 8317 /lib/ld-linux.so.2
+a8043000-a8044000 r--p 0001b000 03:00 8317 /lib/ld-linux.so.2
+a8044000-a8045000 rw-p 0001c000 03:00 8317 /lib/ld-linux.so.2
+aff35000-aff4a000 rw-p 00000000 00:00 0
+ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
The /proc/PID/smaps is an extension based on maps, showing the memory
consumption for each of the process's mappings. For each of mappings there
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 965d4bde3a3b41816e1f08627ccd500bc6cc1544..3b42c1418f3118871d93275848f633217419129f 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2989,9 +2989,9 @@ static const struct pid_entry tgid_base_stuff[] = {
INF("cmdline", S_IRUGO, proc_pid_cmdline),
ONE("stat", S_IRUGO, proc_tgid_stat),
ONE("statm", S_IRUGO, proc_pid_statm),
- REG("maps", S_IRUGO, proc_maps_operations),
+ REG("maps", S_IRUGO, proc_pid_maps_operations),
#ifdef CONFIG_NUMA
- REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
+ REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
#endif
REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
LNK("cwd", proc_cwd_link),
@@ -3002,7 +3002,7 @@ static const struct pid_entry tgid_base_stuff[] = {
REG("mountstats", S_IRUSR, proc_mountstats_operations),
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
- REG("smaps", S_IRUGO, proc_smaps_operations),
+ REG("smaps", S_IRUGO, proc_pid_smaps_operations),
REG("pagemap", S_IRUGO, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
@@ -3348,9 +3348,9 @@ static const struct pid_entry tid_base_stuff[] = {
INF("cmdline", S_IRUGO, proc_pid_cmdline),
ONE("stat", S_IRUGO, proc_tid_stat),
ONE("statm", S_IRUGO, proc_pid_statm),
- REG("maps", S_IRUGO, proc_maps_operations),
+ REG("maps", S_IRUGO, proc_tid_maps_operations),
#ifdef CONFIG_NUMA
- REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
+ REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations),
#endif
REG("mem", S_IRUSR|S_IWUSR, proc_mem_operations),
LNK("cwd", proc_cwd_link),
@@ -3360,7 +3360,7 @@ static const struct pid_entry tid_base_stuff[] = {
REG("mountinfo", S_IRUGO, proc_mountinfo_operations),
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
- REG("smaps", S_IRUGO, proc_smaps_operations),
+ REG("smaps", S_IRUGO, proc_tid_smaps_operations),
REG("pagemap", S_IRUGO, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 292577531ad13e665bfd94ff63dbfd5a206a5472..c44efe19798fde8f11741448bbbfad548a0c151f 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -53,9 +53,12 @@ extern int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task);
extern loff_t mem_lseek(struct file *file, loff_t offset, int orig);
-extern const struct file_operations proc_maps_operations;
-extern const struct file_operations proc_numa_maps_operations;
-extern const struct file_operations proc_smaps_operations;
+extern const struct file_operations proc_pid_maps_operations;
+extern const struct file_operations proc_tid_maps_operations;
+extern const struct file_operations proc_pid_numa_maps_operations;
+extern const struct file_operations proc_tid_numa_maps_operations;
+extern const struct file_operations proc_pid_smaps_operations;
+extern const struct file_operations proc_tid_smaps_operations;
extern const struct file_operations proc_clear_refs_operations;
extern const struct file_operations proc_pagemap_operations;
extern const struct file_operations proc_net_operations;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index c7e3a163295cb8169163cdaa2468d5d8f54a4a6a..9694cc2835115f18c5c6f9719d8ab9a332631901 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -209,16 +209,20 @@ static int do_maps_open(struct inode *inode, struct file *file,
return ret;
}
-static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
+static void
+show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid)
{
struct mm_struct *mm = vma->vm_mm;
struct file *file = vma->vm_file;
+ struct proc_maps_private *priv = m->private;
+ struct task_struct *task = priv->task;
vm_flags_t flags = vma->vm_flags;
unsigned long ino = 0;
unsigned long long pgoff = 0;
unsigned long start, end;
dev_t dev = 0;
int len;
+ const char *name = NULL;
if (file) {
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
@@ -252,36 +256,57 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
if (file) {
pad_len_spaces(m, len);
seq_path(m, &file->f_path, "\n");
- } else {
- const char *name = arch_vma_name(vma);
- if (!name) {
- if (mm) {
- if (vma->vm_start <= mm->brk &&
- vma->vm_end >= mm->start_brk) {
- name = "[heap]";
- } else if (vma->vm_start <= mm->start_stack &&
- vma->vm_end >= mm->start_stack) {
- name = "[stack]";
- }
+ goto done;
+ }
+
+ name = arch_vma_name(vma);
+ if (!name) {
+ pid_t tid;
+
+ if (!mm) {
+ name = "[vdso]";
+ goto done;
+ }
+
+ if (vma->vm_start <= mm->brk &&
+ vma->vm_end >= mm->start_brk) {
+ name = "[heap]";
+ goto done;
+ }
+
+ tid = vm_is_stack(task, vma, is_pid);
+
+ if (tid != 0) {
+ /*
+ * Thread stack in /proc/PID/task/TID/maps or
+ * the main process stack.
+ */
+ if (!is_pid || (vma->vm_start <= mm->start_stack &&
+ vma->vm_end >= mm->start_stack)) {
+ name = "[stack]";
} else {
- name = "[vdso]";
+ /* Thread stack in /proc/PID/maps */
+ pad_len_spaces(m, len);
+ seq_printf(m, "[stack:%d]", tid);
}
}
- if (name) {
- pad_len_spaces(m, len);
- seq_puts(m, name);
- }
+ }
+
+done:
+ if (name) {
+ pad_len_spaces(m, len);
+ seq_puts(m, name);
}
seq_putc(m, '\n');
}
-static int show_map(struct seq_file *m, void *v)
+static int show_map(struct seq_file *m, void *v, int is_pid)
{
struct vm_area_struct *vma = v;
struct proc_maps_private *priv = m->private;
struct task_struct *task = priv->task;
- show_map_vma(m, vma);
+ show_map_vma(m, vma, is_pid);
if (m->count < m->size) /* vma is copied successfully */
m->version = (vma != get_gate_vma(task->mm))
@@ -289,20 +314,49 @@ static int show_map(struct seq_file *m, void *v)
return 0;
}
+static int show_pid_map(struct seq_file *m, void *v)
+{
+ return show_map(m, v, 1);
+}
+
+static int show_tid_map(struct seq_file *m, void *v)
+{
+ return show_map(m, v, 0);
+}
+
static const struct seq_operations proc_pid_maps_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
- .show = show_map
+ .show = show_pid_map
+};
+
+static const struct seq_operations proc_tid_maps_op = {
+ .start = m_start,
+ .next = m_next,
+ .stop = m_stop,
+ .show = show_tid_map
};
-static int maps_open(struct inode *inode, struct file *file)
+static int pid_maps_open(struct inode *inode, struct file *file)
{
return do_maps_open(inode, file, &proc_pid_maps_op);
}
-const struct file_operations proc_maps_operations = {
- .open = maps_open,
+static int tid_maps_open(struct inode *inode, struct file *file)
+{
+ return do_maps_open(inode, file, &proc_tid_maps_op);
+}
+
+const struct file_operations proc_pid_maps_operations = {
+ .open = pid_maps_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+const struct file_operations proc_tid_maps_operations = {
+ .open = tid_maps_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
@@ -416,7 +470,7 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
return 0;
}
-static int show_smap(struct seq_file *m, void *v)
+static int show_smap(struct seq_file *m, void *v, int is_pid)
{
struct proc_maps_private *priv = m->private;
struct task_struct *task = priv->task;
@@ -434,7 +488,7 @@ static int show_smap(struct seq_file *m, void *v)
if (vma->vm_mm && !is_vm_hugetlb_page(vma))
walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);
- show_map_vma(m, vma);
+ show_map_vma(m, vma, is_pid);
seq_printf(m,
"Size: %8lu kB\n"
@@ -473,20 +527,49 @@ static int show_smap(struct seq_file *m, void *v)
return 0;
}
+static int show_pid_smap(struct seq_file *m, void *v)
+{
+ return show_smap(m, v, 1);
+}
+
+static int show_tid_smap(struct seq_file *m, void *v)
+{
+ return show_smap(m, v, 0);
+}
+
static const struct seq_operations proc_pid_smaps_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
- .show = show_smap
+ .show = show_pid_smap
+};
+
+static const struct seq_operations proc_tid_smaps_op = {
+ .start = m_start,
+ .next = m_next,
+ .stop = m_stop,
+ .show = show_tid_smap
};
-static int smaps_open(struct inode *inode, struct file *file)
+static int pid_smaps_open(struct inode *inode, struct file *file)
{
return do_maps_open(inode, file, &proc_pid_smaps_op);
}
-const struct file_operations proc_smaps_operations = {
- .open = smaps_open,
+static int tid_smaps_open(struct inode *inode, struct file *file)
+{
+ return do_maps_open(inode, file, &proc_tid_smaps_op);
+}
+
+const struct file_operations proc_pid_smaps_operations = {
+ .open = pid_smaps_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+const struct file_operations proc_tid_smaps_operations = {
+ .open = tid_smaps_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
@@ -1039,7 +1122,7 @@ static int gather_hugetbl_stats(pte_t *pte, unsigned long hmask,
/*
* Display pages allocated per node and memory policy via /proc.
*/
-static int show_numa_map(struct seq_file *m, void *v)
+static int show_numa_map(struct seq_file *m, void *v, int is_pid)
{
struct numa_maps_private *numa_priv = m->private;
struct proc_maps_private *proc_priv = &numa_priv->proc_maps;
@@ -1076,9 +1159,19 @@ static int show_numa_map(struct seq_file *m, void *v)
seq_path(m, &file->f_path, "\n\t= ");
} else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
seq_printf(m, " heap");
- } else if (vma->vm_start <= mm->start_stack &&
- vma->vm_end >= mm->start_stack) {
- seq_printf(m, " stack");
+ } else {
+ pid_t tid = vm_is_stack(proc_priv->task, vma, is_pid);
+ if (tid != 0) {
+ /*
+ * Thread stack in /proc/PID/task/TID/maps or
+ * the main process stack.
+ */
+ if (!is_pid || (vma->vm_start <= mm->start_stack &&
+ vma->vm_end >= mm->start_stack))
+ seq_printf(m, " stack");
+ else
+ seq_printf(m, " stack:%d", tid);
+ }
}
if (is_vm_hugetlb_page(vma))
@@ -1121,21 +1214,39 @@ static int show_numa_map(struct seq_file *m, void *v)
return 0;
}
+static int show_pid_numa_map(struct seq_file *m, void *v)
+{
+ return show_numa_map(m, v, 1);
+}
+
+static int show_tid_numa_map(struct seq_file *m, void *v)
+{
+ return show_numa_map(m, v, 0);
+}
+
static const struct seq_operations proc_pid_numa_maps_op = {
- .start = m_start,
- .next = m_next,
- .stop = m_stop,
- .show = show_numa_map,
+ .start = m_start,
+ .next = m_next,
+ .stop = m_stop,
+ .show = show_pid_numa_map,
};
-static int numa_maps_open(struct inode *inode, struct file *file)
+static const struct seq_operations proc_tid_numa_maps_op = {
+ .start = m_start,
+ .next = m_next,
+ .stop = m_stop,
+ .show = show_tid_numa_map,
+};
+
+static int numa_maps_open(struct inode *inode, struct file *file,
+ const struct seq_operations *ops)
{
struct numa_maps_private *priv;
int ret = -ENOMEM;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (priv) {
priv->proc_maps.pid = proc_pid(inode);
- ret = seq_open(file, &proc_pid_numa_maps_op);
+ ret = seq_open(file, ops);
if (!ret) {
struct seq_file *m = file->private_data;
m->private = priv;
@@ -1146,8 +1257,25 @@ static int numa_maps_open(struct inode *inode, struct file *file)
return ret;
}
-const struct file_operations proc_numa_maps_operations = {
- .open = numa_maps_open,
+static int pid_numa_maps_open(struct inode *inode, struct file *file)
+{
+ return numa_maps_open(inode, file, &proc_pid_numa_maps_op);
+}
+
+static int tid_numa_maps_open(struct inode *inode, struct file *file)
+{
+ return numa_maps_open(inode, file, &proc_tid_numa_maps_op);
+}
+
+const struct file_operations proc_pid_numa_maps_operations = {
+ .open = pid_numa_maps_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+const struct file_operations proc_tid_numa_maps_operations = {
+ .open = tid_numa_maps_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 980de547c0709b758307dce07a6e81ea9a9c59bd..74fe164d1b233924f6a4d3e8ddd24624660dd63a 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -134,9 +134,11 @@ static void pad_len_spaces(struct seq_file *m, int len)
/*
* display a single VMA to a sequenced file
*/
-static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
+static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
+ int is_pid)
{
struct mm_struct *mm = vma->vm_mm;
+ struct proc_maps_private *priv = m->private;
unsigned long ino = 0;
struct file *file;
dev_t dev = 0;
@@ -168,10 +170,19 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
pad_len_spaces(m, len);
seq_path(m, &file->f_path, "");
} else if (mm) {
- if (vma->vm_start <= mm->start_stack &&
- vma->vm_end >= mm->start_stack) {
+ pid_t tid = vm_is_stack(priv->task, vma, is_pid);
+
+ if (tid != 0) {
pad_len_spaces(m, len);
- seq_puts(m, "[stack]");
+ /*
+ * Thread stack in /proc/PID/task/TID/maps or
+ * the main process stack.
+ */
+ if (!is_pid || (vma->vm_start <= mm->start_stack &&
+ vma->vm_end >= mm->start_stack))
+ seq_printf(m, "[stack]");
+ else
+ seq_printf(m, "[stack:%d]", tid);
}
}
@@ -182,11 +193,22 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
/*
* display mapping lines for a particular process's /proc/pid/maps
*/
-static int show_map(struct seq_file *m, void *_p)
+static int show_map(struct seq_file *m, void *_p, int is_pid)
{
struct rb_node *p = _p;
- return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
+ return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb),
+ is_pid);
+}
+
+static int show_pid_map(struct seq_file *m, void *_p)
+{
+ return show_map(m, _p, 1);
+}
+
+static int show_tid_map(struct seq_file *m, void *_p)
+{
+ return show_map(m, _p, 0);
}
static void *m_start(struct seq_file *m, loff_t *pos)
@@ -240,10 +262,18 @@ static const struct seq_operations proc_pid_maps_ops = {
.start = m_start,
.next = m_next,
.stop = m_stop,
- .show = show_map
+ .show = show_pid_map
+};
+
+static const struct seq_operations proc_tid_maps_ops = {
+ .start = m_start,
+ .next = m_next,
+ .stop = m_stop,
+ .show = show_tid_map
};
-static int maps_open(struct inode *inode, struct file *file)
+static int maps_open(struct inode *inode, struct file *file,
+ const struct seq_operations *ops)
{
struct proc_maps_private *priv;
int ret = -ENOMEM;
@@ -251,7 +281,7 @@ static int maps_open(struct inode *inode, struct file *file)
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (priv) {
priv->pid = proc_pid(inode);
- ret = seq_open(file, &proc_pid_maps_ops);
+ ret = seq_open(file, ops);
if (!ret) {
struct seq_file *m = file->private_data;
m->private = priv;
@@ -262,8 +292,25 @@ static int maps_open(struct inode *inode, struct file *file)
return ret;
}
-const struct file_operations proc_maps_operations = {
- .open = maps_open,
+static int pid_maps_open(struct inode *inode, struct file *file)
+{
+ return maps_open(inode, file, &proc_pid_maps_ops);
+}
+
+static int tid_maps_open(struct inode *inode, struct file *file)
+{
+ return maps_open(inode, file, &proc_tid_maps_ops);
+}
+
+const struct file_operations proc_pid_maps_operations = {
+ .open = pid_maps_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+const struct file_operations proc_tid_maps_operations = {
+ .open = tid_maps_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 378bccebc26c2108177765f1a6e701bd185020dc..df17ff23d50e995b3e9ddc84888720a8f1ec017f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1040,6 +1040,9 @@ static inline int stack_guard_page_end(struct vm_area_struct *vma,
!vma_growsup(vma->vm_next, addr);
}
+extern pid_t
+vm_is_stack(struct task_struct *task, struct vm_area_struct *vma, int in_group);
+
extern unsigned long move_page_tables(struct vm_area_struct *vma,
unsigned long old_addr, struct vm_area_struct *new_vma,
unsigned long new_addr, unsigned long len);
diff --git a/mm/util.c b/mm/util.c
index 136ac4f322b8248a5bea3c11d93c69c001b7bda8..ae962b31de888a55990769aae948bac3ef0db338 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -239,6 +239,47 @@ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
next->vm_prev = vma;
}
+/* Check if the vma is being used as a stack by this task */
+static int vm_is_stack_for_task(struct task_struct *t,
+ struct vm_area_struct *vma)
+{
+ return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t));
+}
+
+/*
+ * Check if the vma is being used as a stack.
+ * If is_group is non-zero, check in the entire thread group or else
+ * just check in the current task. Returns the pid of the task that
+ * the vma is stack for.
+ */
+pid_t vm_is_stack(struct task_struct *task,
+ struct vm_area_struct *vma, int in_group)
+{
+ pid_t ret = 0;
+
+ if (vm_is_stack_for_task(task, vma))
+ return task->pid;
+
+ if (in_group) {
+ struct task_struct *t;
+ rcu_read_lock();
+ if (!pid_alive(task))
+ goto done;
+
+ t = task;
+ do {
+ if (vm_is_stack_for_task(t, vma)) {
+ ret = t->pid;
+ goto done;
+ }
+ } while_each_thread(task, t);
+done:
+ rcu_read_unlock();
+ }
+
+ return ret;
+}
+
#if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT)
void arch_pick_mmap_layout(struct mm_struct *mm)
{