[PATCH] metag/kernel/stacktrace.c: Use current_stack_pointer instead of current_sp

[gang . chen . 5i5j]

From: Chen Gang 

Since we have defined current_stack_pointer, current_sp is redudancy, so
remove it.

Signed-off-by: Chen Gang 
---
 arch/metag/kernel/stacktrace.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/metag/kernel/stacktrace.c b/arch/metag/kernel/stacktrace.c
index 5510361..5db1176 100644
--- a/arch/metag/kernel/stacktrace.c
+++ b/arch/metag/kernel/stacktrace.c
@@ -165,11 +165,9 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct 
stack_trace *trace)
frame.pc = thread_saved_pc(tsk);
 #endif
} else {
-   register unsigned long current_sp asm ("A0StP");
-
data.no_sched_functions = 0;
frame.fp = (unsigned long)__builtin_frame_address(0);
-   frame.sp = current_sp;
+   frame.sp = current_stack_pointer;
frame.lr = (unsigned long)__builtin_return_address(0);
frame.pc = (unsigned long)save_stack_trace_tsk;
}
-- 
1.9.3
--
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[PATCH] metag/kernel/stacktrace.c: Use current_stack_pointer instead of current_sp

[gang . chen . 5i5j]

From: Chen Gang 

Since we have defined current_stack_pointer, current_sp is redudancy, so
remove it.

Signed-off-by: Chen Gang 
---
 arch/metag/kernel/stacktrace.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/metag/kernel/stacktrace.c b/arch/metag/kernel/stacktrace.c
index 5510361..5db1176 100644
--- a/arch/metag/kernel/stacktrace.c
+++ b/arch/metag/kernel/stacktrace.c
@@ -165,11 +165,9 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct 
stack_trace *trace)
frame.pc = thread_saved_pc(tsk);
 #endif
} else {
-   register unsigned long current_sp asm ("A0StP");
-
data.no_sched_functions = 0;
frame.fp = (unsigned long)__builtin_frame_address(0);
-   frame.sp = current_sp;
+   frame.sp = current_stack_pointer;
frame.lr = (unsigned long)__builtin_return_address(0);
frame.pc = (unsigned long)save_stack_trace_tsk;
}
-- 
1.9.3
--
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[PATCH] mm/mmap.c: Remove redundent 'get_area' function pointer in get_unmapped_area()

[gang . chen . 5i5j]

From: Chen Gang 

Call the function pointer directly, then let code a bit simpler.

Signed-off-by: Chen Gang 
---
 mm/mmap.c | 12 ++--
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 4db7cf0..39fd727 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2012,10 +2012,8 @@ unsigned long
 get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
 {
-   unsigned long (*get_area)(struct file *, unsigned long,
- unsigned long, unsigned long, unsigned long);
-
unsigned long error = arch_mmap_check(addr, len, flags);
+
if (error)
return error;
 
@@ -2023,10 +2021,12 @@ get_unmapped_area(struct file *file, unsigned long 
addr, unsigned long len,
if (len > TASK_SIZE)
return -ENOMEM;
 
-   get_area = current->mm->get_unmapped_area;
if (file && file->f_op->get_unmapped_area)
-   get_area = file->f_op->get_unmapped_area;
-   addr = get_area(file, addr, len, pgoff, flags);
+   addr = file->f_op->get_unmapped_area(file, addr, len,
+   pgoff, flags);
+   else
+   addr = current->mm->get_unmapped_area(file, addr, len,
+   pgoff, flags);
if (IS_ERR_VALUE(addr))
return addr;
 
-- 
1.9.3
--
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[PATCH] mm/mmap.c: Remove useless statement "vma = NULL" in find_vma()

[gang . chen . 5i5j]

From: Chen Gang 

Before the main looping, vma is already is NULL, so need not set it to
NULL, again.

Signed-off-by: Chen Gang 
---
 mm/mmap.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index df6d5f0..4db7cf0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2054,7 +2054,6 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, 
unsigned long addr)
return vma;
 
rb_node = mm->mm_rb.rb_node;
-   vma = NULL;
 
while (rb_node) {
struct vm_area_struct *tmp;
-- 
1.9.3
--
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Re: [PATCH] mm/mmap.c: Only call vma_unlock_anon_vm() when failure occurs in expand_upwards() and expand_downwards()

[gang . chen . 5i5j]

At present, I can use git client via 21cn mail address. Hope it can be
accepted by our mailing list.

Thanks.

On 9/1/15 21:49, Chen Gang wrote:
> 
> Sorry for the incorrect format of the patch. So I put the patch into the
> attachment which generated by "git format-patch -M HEAD^". Please help
> check, thanks.
> 
> Next, I shall try to find another mail address which can be accepted by
> both China and our mailing list.
> 
> Thanks.
> 
> On 9/1/15 04:54, Chen Gang wrote:
>> When failure occurs, we need not call khugepaged_enter_vma_merge() or
>> validate_mm().
>>
>> Also simplify do_munmap(): declare 'error' 1 time instead of 2 times in
>> sub-blocks.
>>
>> Signed-off-by: Chen Gang 
>> ---
>> mm/mmap.c | 116 
>> +++---
>> 1 file changed, 58 insertions(+), 58 deletions(-)
>>
>> diff --git a/mm/mmap.c b/mm/mmap.c
>> index df6d5f0..d32199a 100644
>> --- a/mm/mmap.c
>> +++ b/mm/mmap.c
>> @@ -2182,10 +2182,9 @@ int expand_upwards(struct vm_area_struct *vma, 
>> unsigned long address)
>> if (address < PAGE_ALIGN(address+4))
>> address = PAGE_ALIGN(address+4);
>> else {
>> - vma_unlock_anon_vma(vma);
>> - return -ENOMEM;
>> + error = -ENOMEM;
>> + goto err;
>> }
>> - error = 0;
>>
>> /* Somebody else might have raced and expanded it already */
>> if (address> vma->vm_end) {
>> @@ -2194,38 +2193,39 @@ int expand_upwards(struct vm_area_struct *vma, 
>> unsigned long address)
>> size = address - vma->vm_start;
>> grow = (address - vma->vm_end)>> PAGE_SHIFT;
>>
>> - error = -ENOMEM;
>> - if (vma->vm_pgoff + (size>> PAGE_SHIFT)>= vma->vm_pgoff) {
>> - error = acct_stack_growth(vma, size, grow);
>> - if (!error) {
>> - /*
>> - * vma_gap_update() doesn't support concurrent
>> - * updates, but we only hold a shared mmap_sem
>> - * lock here, so we need to protect against
>> - * concurrent vma expansions.
>> - * vma_lock_anon_vma() doesn't help here, as
>> - * we don't guarantee that all growable vmas
>> - * in a mm share the same root anon vma.
>> - * So, we reuse mm->page_table_lock to guard
>> - * against concurrent vma expansions.
>> - */
>> - spin_lock(>vm_mm->page_table_lock);
>> - anon_vma_interval_tree_pre_update_vma(vma);
>> - vma->vm_end = address;
>> - anon_vma_interval_tree_post_update_vma(vma);
>> - if (vma->vm_next)
>> - vma_gap_update(vma->vm_next);
>> - else
>> - vma->vm_mm->highest_vm_end = address;
>> - spin_unlock(>vm_mm->page_table_lock);
>> -
>> - perf_event_mmap(vma);
>> - }
>> + if (vma->vm_pgoff + (size>> PAGE_SHIFT) < vma->vm_pgoff) {
>> + error = -ENOMEM;
>> + goto err;
>> }
>> + error = acct_stack_growth(vma, size, grow);
>> + if (error)
>> + goto err;
>> + /*
>> + * vma_gap_update() doesn't support concurrent updates, but we
>> + * only hold a shared mmap_sem lock here, so we need to protect
>> + * against concurrent vma expansions. vma_lock_anon_vma()
>> + * doesn't help here, as we don't guarantee that all growable
>> + * vmas in a mm share the same root anon vma. So, we reuse mm->
>> + * page_table_lock to guard against concurrent vma expansions.
>> + */
>> + spin_lock(>vm_mm->page_table_lock);
>> + anon_vma_interval_tree_pre_update_vma(vma);
>> + vma->vm_end = address;
>> + anon_vma_interval_tree_post_update_vma(vma);
>> + if (vma->vm_next)
>> + vma_gap_update(vma->vm_next);
>> + else
>> + vma->vm_mm->highest_vm_end = address;
>> + spin_unlock(>vm_mm->page_table_lock);
>> +
>> + perf_event_mmap(vma);
>> }
>> vma_unlock_anon_vma(vma);
>> khugepaged_enter_vma_merge(vma, vma->vm_flags);
>> validate_mm(vma->vm_mm);
>> + return 0;
>> +err:
>> + vma_unlock_anon_vma(vma);
>> return error;
>> }
>> #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
>> @@ -2265,36 +2265,37 @@ int expand_downwards(struct vm_area_struct *vma,
>> size = vma->vm_end - address;
>> grow = (vma->vm_start - address)>> PAGE_SHIFT;
>>
>> - error = -ENOMEM;
>> - if (grow <= vma->vm_pgoff) {
>> - error = acct_stack_growth(vma, size, grow);
>> - if (!error) {
>> - /*
>> - * vma_gap_update() doesn't support concurrent
>> - * updates, but we only hold a shared mmap_sem
>> - * lock here, so we need to protect against
>> - * concurrent vma expansions.
>> - * vma_lock_anon_vma() doesn't help here, as
>> - * we don't guarantee that all growable vmas
>> - * in a mm share the same root anon vma.
>> - * So, we reuse mm->page_table_lock to guard
>> - * against concurrent vma expansions.
>> - */
>> - spin_lock(>vm_mm->page_table_lock);
>> - anon_vma_interval_tree_pre_update_vma(vma);
>> - vma->vm_start = address;
>> - vma->vm_pgoff -= grow;
>> - anon_vma_interval_tree_post_update_vma(vma);
>> - vma_gap_update(vma);
>> - spin_unlock(>vm_mm->page_table_lock);
>> -
>> - perf_event_mmap(vma);
>> - }
>> + if (grow> vma->vm_pgoff) {
>> + error = -ENOMEM;
>> + goto err;
>> }
>> + error = acct_stack_growth(vma, size, grow);
>> + if (error)
>> + goto err;
>> + /*
>> + * vma_gap_update() doesn't support concurrent updates, but we
>> + * only hold a shared mmap_sem lock here, so we need to 

[PATCH] mm/mmap.c: Remove redundent 'get_area' function pointer in get_unmapped_area()

[gang . chen . 5i5j]

From: Chen Gang 

Call the function pointer directly, then let code a bit simpler.

Signed-off-by: Chen Gang 
---
 mm/mmap.c | 12 ++--
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 4db7cf0..39fd727 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2012,10 +2012,8 @@ unsigned long
 get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
 {
-   unsigned long (*get_area)(struct file *, unsigned long,
- unsigned long, unsigned long, unsigned long);
-
unsigned long error = arch_mmap_check(addr, len, flags);
+
if (error)
return error;
 
@@ -2023,10 +2021,12 @@ get_unmapped_area(struct file *file, unsigned long 
addr, unsigned long len,
if (len > TASK_SIZE)
return -ENOMEM;
 
-   get_area = current->mm->get_unmapped_area;
if (file && file->f_op->get_unmapped_area)
-   get_area = file->f_op->get_unmapped_area;
-   addr = get_area(file, addr, len, pgoff, flags);
+   addr = file->f_op->get_unmapped_area(file, addr, len,
+   pgoff, flags);
+   else
+   addr = current->mm->get_unmapped_area(file, addr, len,
+   pgoff, flags);
if (IS_ERR_VALUE(addr))
return addr;
 
-- 
1.9.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[PATCH] mm/mmap.c: Remove useless statement "vma = NULL" in find_vma()

[gang . chen . 5i5j]

From: Chen Gang 

Before the main looping, vma is already is NULL, so need not set it to
NULL, again.

Signed-off-by: Chen Gang 
---
 mm/mmap.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index df6d5f0..4db7cf0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2054,7 +2054,6 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, 
unsigned long addr)
return vma;
 
rb_node = mm->mm_rb.rb_node;
-   vma = NULL;
 
while (rb_node) {
struct vm_area_struct *tmp;
-- 
1.9.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH] mm/mmap.c: Only call vma_unlock_anon_vm() when failure occurs in expand_upwards() and expand_downwards()

[gang . chen . 5i5j]

At present, I can use git client via 21cn mail address. Hope it can be
accepted by our mailing list.

Thanks.

On 9/1/15 21:49, Chen Gang wrote:
> 
> Sorry for the incorrect format of the patch. So I put the patch into the
> attachment which generated by "git format-patch -M HEAD^". Please help
> check, thanks.
> 
> Next, I shall try to find another mail address which can be accepted by
> both China and our mailing list.
> 
> Thanks.
> 
> On 9/1/15 04:54, Chen Gang wrote:
>> When failure occurs, we need not call khugepaged_enter_vma_merge() or
>> validate_mm().
>>
>> Also simplify do_munmap(): declare 'error' 1 time instead of 2 times in
>> sub-blocks.
>>
>> Signed-off-by: Chen Gang 
>> ---
>> mm/mmap.c | 116 
>> +++---
>> 1 file changed, 58 insertions(+), 58 deletions(-)
>>
>> diff --git a/mm/mmap.c b/mm/mmap.c
>> index df6d5f0..d32199a 100644
>> --- a/mm/mmap.c
>> +++ b/mm/mmap.c
>> @@ -2182,10 +2182,9 @@ int expand_upwards(struct vm_area_struct *vma, 
>> unsigned long address)
>> if (address < PAGE_ALIGN(address+4))
>> address = PAGE_ALIGN(address+4);
>> else {
>> - vma_unlock_anon_vma(vma);
>> - return -ENOMEM;
>> + error = -ENOMEM;
>> + goto err;
>> }
>> - error = 0;
>>
>> /* Somebody else might have raced and expanded it already */
>> if (address> vma->vm_end) {
>> @@ -2194,38 +2193,39 @@ int expand_upwards(struct vm_area_struct *vma, 
>> unsigned long address)
>> size = address - vma->vm_start;
>> grow = (address - vma->vm_end)>> PAGE_SHIFT;
>>
>> - error = -ENOMEM;
>> - if (vma->vm_pgoff + (size>> PAGE_SHIFT)>= vma->vm_pgoff) {
>> - error = acct_stack_growth(vma, size, grow);
>> - if (!error) {
>> - /*
>> - * vma_gap_update() doesn't support concurrent
>> - * updates, but we only hold a shared mmap_sem
>> - * lock here, so we need to protect against
>> - * concurrent vma expansions.
>> - * vma_lock_anon_vma() doesn't help here, as
>> - * we don't guarantee that all growable vmas
>> - * in a mm share the same root anon vma.
>> - * So, we reuse mm->page_table_lock to guard
>> - * against concurrent vma expansions.
>> - */
>> - spin_lock(>vm_mm->page_table_lock);
>> - anon_vma_interval_tree_pre_update_vma(vma);
>> - vma->vm_end = address;
>> - anon_vma_interval_tree_post_update_vma(vma);
>> - if (vma->vm_next)
>> - vma_gap_update(vma->vm_next);
>> - else
>> - vma->vm_mm->highest_vm_end = address;
>> - spin_unlock(>vm_mm->page_table_lock);
>> -
>> - perf_event_mmap(vma);
>> - }
>> + if (vma->vm_pgoff + (size>> PAGE_SHIFT) < vma->vm_pgoff) {
>> + error = -ENOMEM;
>> + goto err;
>> }
>> + error = acct_stack_growth(vma, size, grow);
>> + if (error)
>> + goto err;
>> + /*
>> + * vma_gap_update() doesn't support concurrent updates, but we
>> + * only hold a shared mmap_sem lock here, so we need to protect
>> + * against concurrent vma expansions. vma_lock_anon_vma()
>> + * doesn't help here, as we don't guarantee that all growable
>> + * vmas in a mm share the same root anon vma. So, we reuse mm->
>> + * page_table_lock to guard against concurrent vma expansions.
>> + */
>> + spin_lock(>vm_mm->page_table_lock);
>> + anon_vma_interval_tree_pre_update_vma(vma);
>> + vma->vm_end = address;
>> + anon_vma_interval_tree_post_update_vma(vma);
>> + if (vma->vm_next)
>> + vma_gap_update(vma->vm_next);
>> + else
>> + vma->vm_mm->highest_vm_end = address;
>> + spin_unlock(>vm_mm->page_table_lock);
>> +
>> + perf_event_mmap(vma);
>> }
>> vma_unlock_anon_vma(vma);
>> khugepaged_enter_vma_merge(vma, vma->vm_flags);
>> validate_mm(vma->vm_mm);
>> + return 0;
>> +err:
>> + vma_unlock_anon_vma(vma);
>> return error;
>> }
>> #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
>> @@ -2265,36 +2265,37 @@ int expand_downwards(struct vm_area_struct *vma,
>> size = vma->vm_end - address;
>> grow = (vma->vm_start - address)>> PAGE_SHIFT;
>>
>> - error = -ENOMEM;
>> - if (grow <= vma->vm_pgoff) {
>> - error = acct_stack_growth(vma, size, grow);
>> - if (!error) {
>> - /*
>> - * vma_gap_update() doesn't support concurrent
>> - * updates, but we only hold a shared mmap_sem
>> - * lock here, so we need to protect against
>> - * concurrent vma expansions.
>> - * vma_lock_anon_vma() doesn't help here, as
>> - * we don't guarantee that all growable vmas
>> - * in a mm share the same root anon vma.
>> - * So, we reuse mm->page_table_lock to guard
>> - * against concurrent vma expansions.
>> - */
>> - spin_lock(>vm_mm->page_table_lock);
>> - anon_vma_interval_tree_pre_update_vma(vma);
>> - vma->vm_start = address;
>> - vma->vm_pgoff -= grow;
>> - anon_vma_interval_tree_post_update_vma(vma);
>> - vma_gap_update(vma);
>> - spin_unlock(>vm_mm->page_table_lock);
>> -
>> - perf_event_mmap(vma);
>> - }
>> + if (grow> vma->vm_pgoff) {
>> + error = -ENOMEM;
>> + goto err;
>> }
>> + error = acct_stack_growth(vma, size, grow);
>> + if (error)
>> + goto err;
>> + /*
>> + * vma_gap_update() doesn't support concurrent updates, but we
>> + * only hold a shared mmap_sem lock