[PATCH 3/5] mm: arch: make get_gate_vma take an mm_struct instead of a task_struct

Stephen Wilson
2011-03-09T00:31:59Z

Morally, the presence of a gate vma is more an attribute of a particular mm than
a particular task. Moreover, dropping the dependency on task_struct will help
make both existing and future operations on mm's more flexible and convenient.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
---
arch/powerpc/kernel/vdso.c | 2 +-
arch/s390/kernel/vdso.c | 2 +-
arch/sh/kernel/vsyscall/vsyscall.c | 2 +-
arch/x86/mm/init_64.c | 6 +++---
arch/x86/vdso/vdso32-setup.c | 11 ++++++-----
fs/binfmt_elf.c | 2 +-
fs/proc/task_mmu.c | 8 +++++---
include/linux/mm.h | 2 +-
mm/memory.c | 4 ++--
mm/mlock.c | 4 ++--
10 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index fd87287..6169f17 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -830,7 +830,7 @@ int in_gate_area(struct task_struct *task, unsigned long addr)
return 0;
}

-struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
return NULL;
}
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index f438d74..d19f305 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -347,7 +347,7 @@ int in_gate_area(struct task_struct *task, unsigned long addr)
return 0;
}

-struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
return NULL;
}
diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
index 242117c..3f9b6f4 100644
--- a/arch/sh/kernel/vsyscall/vsyscall.c
+++ b/arch/sh/kernel/vsyscall/vsyscall.c
@@ -94,7 +94,7 @@ const char *arch_vma_name(struct vm_area_struct *vma)
return NULL;
}

-struct vm_area_struct *get_gate_vma(struct task_struct *task)
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
return NULL;
}
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 71a5929..2c1799f 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -870,10 +870,10 @@ static struct vm_area_struct gate_vma = {
.vm_flags = VM_READ | VM_EXEC
};

-struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
#ifdef CONFIG_IA32_EMULATION
- if (test_tsk_thread_flag(tsk, TIF_IA32))
+ if (!mm || mm->context.compat)
return NULL;
#endif
return &gate_vma;
@@ -881,7 +881,7 @@ struct vm_area_struct *get_gate_vma(struct task_struct *tsk)

int in_gate_area(struct task_struct *task, unsigned long addr)
{
- struct vm_area_struct *vma = get_gate_vma(task);
+ struct vm_area_struct *vma = get_gate_vma(task->mm);

if (!vma)
return 0;
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 36df991..1f651f6 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -417,11 +417,12 @@ const char *arch_vma_name(struct vm_area_struct *vma)
return NULL;
}

-struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
- struct mm_struct *mm = tsk->mm;
-
- /* Check to see if this task was created in compat vdso mode */
+ /*
+ * Check to see if the corresponding task was created in compat vdso
+ * mode.
+ */
if (mm && mm->context.vdso == (void *)VDSO_HIGH_BASE)
return &gate_vma;
return NULL;
@@ -429,7 +430,7 @@ struct vm_area_struct *get_gate_vma(struct task_struct *tsk)

int in_gate_area(struct task_struct *task, unsigned long addr)
{
- const struct vm_area_struct *vma = get_gate_vma(task);
+ const struct vm_area_struct *vma = get_gate_vma(task->mm);

return vma && addr >= vma->vm_start && addr < vma->vm_end;
}
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index d5b640b..bbabdcc 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1906,7 +1906,7 @@ static int elf_core_dump(struct coredump_params *cprm)
segs = current->mm->map_count;
segs += elf_core_extra_phdrs();

- gate_vma = get_gate_vma(current);
+ gate_vma = get_gate_vma(current->mm);
if (gate_vma != NULL)
segs++;

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 60b9148..bb548d4 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -126,7 +126,7 @@ static void *m_start(struct seq_file *m, loff_t *pos)
return NULL;
down_read(&mm->mmap_sem);

- tail_vma = get_gate_vma(priv->task);
+ tail_vma = get_gate_vma(priv->task->mm);
priv->tail_vma = tail_vma;

/* Start with last addr hint */
@@ -277,7 +277,8 @@ static int show_map(struct seq_file *m, void *v)
show_map_vma(m, vma);

if (m->count < m->size) /* vma is copied successfully */
- m->version = (vma != get_gate_vma(task))? vma->vm_start: 0;
+ m->version = (vma != get_gate_vma(task->mm))
+ ? vma->vm_start : 0;
return 0;
}

@@ -436,7 +437,8 @@ static int show_smap(struct seq_file *m, void *v)
(unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);

if (m->count < m->size) /* vma is copied successfully */
- m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0;
+ m->version = (vma != get_gate_vma(task->mm))
+ ? vma->vm_start : 0;
return 0;
}

diff --git a/include/linux/mm.h b/include/linux/mm.h
index f6385fc..b571921 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1568,7 +1568,7 @@ static inline bool kernel_page_present(struct page *page) { return true; }
#endif /* CONFIG_HIBERNATION */
#endif

-extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
+extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
#ifdef __HAVE_ARCH_GATE_AREA
int in_gate_area_no_task(unsigned long addr);
int in_gate_area(struct task_struct *task, unsigned long addr);
diff --git a/mm/memory.c b/mm/memory.c
index 5823698..aec7cbd 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1439,7 +1439,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
vma = find_extend_vma(mm, start);
if (!vma && in_gate_area(tsk, start)) {
unsigned long pg = start & PAGE_MASK;
- struct vm_area_struct *gate_vma = get_gate_vma(tsk);
+ struct vm_area_struct *gate_vma = get_gate_vma(tsk->mm);
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
@@ -3439,7 +3439,7 @@ static int __init gate_vma_init(void)
__initcall(gate_vma_init);
#endif

-struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
#ifdef AT_SYSINFO_EHDR
return &gate_vma;
diff --git a/mm/mlock.c b/mm/mlock.c
index c3924c7f..2689a08c 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -237,7 +237,7 @@ long mlock_vma_pages_range(struct vm_area_struct *vma,

if (!((vma->vm_flags & (VM_DONTEXPAND | VM_RESERVED)) ||
is_vm_hugetlb_page(vma) ||
- vma == get_gate_vma(current))) {
+ vma == get_gate_vma(current->mm))) {

__mlock_vma_pages_range(vma, start, end, NULL);

@@ -332,7 +332,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
int lock = newflags & VM_LOCKED;

if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
- is_vm_hugetlb_page(vma) || vma == get_gate_vma(current))
+ is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm))
goto out; /* don't set VM_LOCKED, don't count */

pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
--
1.7.3.5