2023-07-19 08:01:03

by Kefeng Wang

[permalink] [raw]
Subject: [PATCH v2 0/4] mm: convert to vma_is_initial_heap/stack()

Add vma_is_initial_stack() and vma_is_initial_heap() helper and use
them to simplify code.

v2:
- address comments per David Hildenbrand and Christian Göttsche
- fix selinux build

Kefeng Wang (4):
mm: factor out VMA stack and heap checks
drm/amdkfd: use vma_is_initial_stack() and vma_is_initial_heap()
selinux: use vma_is_initial_stack() and vma_is_initial_heap()
perf/core: use vma_is_initial_stack() and vma_is_initial_heap()

drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 5 +----
fs/proc/task_mmu.c | 24 ++++--------------------
fs/proc/task_nommu.c | 15 +--------------
include/linux/mm.h | 21 +++++++++++++++++++++
kernel/events/core.c | 22 +++++++---------------
security/selinux/hooks.c | 7 ++-----
6 files changed, 36 insertions(+), 58 deletions(-)

--
2.27.0



2023-07-19 08:02:26

by Kefeng Wang

[permalink] [raw]
Subject: [PATCH v2 4/4] perf/core: use vma_is_initial_stack() and vma_is_initial_heap()

Use the helpers to simplify code, also kill unneeded goto cpy_name.

Cc: Peter Zijlstra <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Kefeng Wang <[email protected]>
---
kernel/events/core.c | 22 +++++++---------------
1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 78ae7b6f90fd..d59f6327472f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8685,22 +8685,14 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
}

name = (char *)arch_vma_name(vma);
- if (name)
- goto cpy_name;
-
- if (vma->vm_start <= vma->vm_mm->start_brk &&
- vma->vm_end >= vma->vm_mm->brk) {
- name = "[heap]";
- goto cpy_name;
+ if (!name) {
+ if (vma_is_initial_heap(vma))
+ name = "[heap]";
+ else if (vma_is_initial_stack(vma))
+ name = "[stack]";
+ else
+ name = "//anon";
}
- if (vma->vm_start <= vma->vm_mm->start_stack &&
- vma->vm_end >= vma->vm_mm->start_stack) {
- name = "[stack]";
- goto cpy_name;
- }
-
- name = "//anon";
- goto cpy_name;
}

cpy_name:
--
2.27.0


2023-07-19 08:18:39

by Kefeng Wang

[permalink] [raw]
Subject: [PATCH v2 1/4] mm: factor out VMA stack and heap checks

Factor out VMA stack and heap checks and name them
vma_is_initial_stack() and vma_is_initial_heap() for
general use.

Cc: Christian Göttsche <[email protected]>
Cc: David Hildenbrand <[email protected]>
Signed-off-by: Kefeng Wang <[email protected]>
---
fs/proc/task_mmu.c | 24 ++++--------------------
fs/proc/task_nommu.c | 15 +--------------
include/linux/mm.h | 21 +++++++++++++++++++++
3 files changed, 26 insertions(+), 34 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 507cd4e59d07..bf25178ae66a 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -236,21 +236,6 @@ static int do_maps_open(struct inode *inode, struct file *file,
sizeof(struct proc_maps_private));
}

-/*
- * Indicate if the VMA is a stack for the given task; for
- * /proc/PID/maps that is the stack of the main task.
- */
-static int is_stack(struct vm_area_struct *vma)
-{
- /*
- * We make no effort to guess what a given thread considers to be
- * its "stack". It's not even well-defined for programs written
- * languages like Go.
- */
- return vma->vm_start <= vma->vm_mm->start_stack &&
- vma->vm_end >= vma->vm_mm->start_stack;
-}
-
static void show_vma_header_prefix(struct seq_file *m,
unsigned long start, unsigned long end,
vm_flags_t flags, unsigned long long pgoff,
@@ -327,13 +312,12 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma)
goto done;
}

- if (vma->vm_start <= mm->brk &&
- vma->vm_end >= mm->start_brk) {
+ if (vma_is_initial_heap(vma)) {
name = "[heap]";
goto done;
}

- if (is_stack(vma)) {
+ if (vma_is_initial_stack(vma)) {
name = "[stack]";
goto done;
}
@@ -1971,9 +1955,9 @@ static int show_numa_map(struct seq_file *m, void *v)
if (file) {
seq_puts(m, " file=");
seq_file_path(m, file, "\n\t= ");
- } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
+ } else if (vma_is_initial_heap(vma)) {
seq_puts(m, " heap");
- } else if (is_stack(vma)) {
+ } else if (vma_is_initial_stack(vma)) {
seq_puts(m, " stack");
}

diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index 2c8b62265981..a8ac0dd8041e 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -121,19 +121,6 @@ unsigned long task_statm(struct mm_struct *mm,
return size;
}

-static int is_stack(struct vm_area_struct *vma)
-{
- struct mm_struct *mm = vma->vm_mm;
-
- /*
- * We make no effort to guess what a given thread considers to be
- * its "stack". It's not even well-defined for programs written
- * languages like Go.
- */
- return vma->vm_start <= mm->start_stack &&
- vma->vm_end >= mm->start_stack;
-}
-
/*
* display a single VMA to a sequenced file
*/
@@ -171,7 +158,7 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
if (file) {
seq_pad(m, ' ');
seq_file_path(m, file, "");
- } else if (mm && is_stack(vma)) {
+ } else if (mm && vma_is_initial_stack(vma)) {
seq_pad(m, ' ');
seq_puts(m, "[stack]");
}
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2dd73e4f3d8e..51f8c573db74 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -822,6 +822,27 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma)
return !vma->vm_ops;
}

+static inline bool vma_is_initial_heap(const struct vm_area_struct *vma)
+{
+ return vma->vm_start <= vma->vm_mm->brk &&
+ vma->vm_end >= vma->vm_mm->start_brk;
+}
+
+/*
+ * Indicate if the VMA is a stack for the given task; for
+ * /proc/PID/maps that is the stack of the main task.
+ */
+static inline bool vma_is_initial_stack(const struct vm_area_struct *vma)
+{
+ /*
+ * We make no effort to guess what a given thread considers to be
+ * its "stack". It's not even well-defined for programs written
+ * languages like Go.
+ */
+ return vma->vm_start <= vma->vm_mm->start_stack &&
+ vma->vm_end >= vma->vm_mm->start_stack;
+}
+
static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
{
int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
--
2.27.0


2023-07-19 08:27:44

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH v2 1/4] mm: factor out VMA stack and heap checks

On 19.07.23 09:51, Kefeng Wang wrote:
> Factor out VMA stack and heap checks and name them
> vma_is_initial_stack() and vma_is_initial_heap() for
> general use.
>
> Cc: Christian Göttsche <[email protected]>
> Cc: David Hildenbrand <[email protected]>
> Signed-off-by: Kefeng Wang <[email protected]>
> ---


[...]

> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 2dd73e4f3d8e..51f8c573db74 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -822,6 +822,27 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma)
> return !vma->vm_ops;
> }
>

Worth adding a similar comment like for vma_is_initial_stack() ?

> +static inline bool vma_is_initial_heap(const struct vm_area_struct *vma)
> +{
> + return vma->vm_start <= vma->vm_mm->brk &&
> + vma->vm_end >= vma->vm_mm->start_brk;
> +}
> +
> +/*
> + * Indicate if the VMA is a stack for the given task; for
> + * /proc/PID/maps that is the stack of the main task.
> + */
> +static inline bool vma_is_initial_stack(const struct vm_area_struct *vma)
> +{
> + /*
> + * We make no effort to guess what a given thread considers to be
> + * its "stack". It's not even well-defined for programs written
> + * languages like Go.
> + */
> + return vma->vm_start <= vma->vm_mm->start_stack &&
> + vma->vm_end >= vma->vm_mm->start_stack;
> +}
> +
> static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
> {
> int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);

Reviewed-by: David Hildenbrand <[email protected]>

--
Cheers,

David / dhildenb


2023-07-19 08:58:09

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH v2 4/4] perf/core: use vma_is_initial_stack() and vma_is_initial_heap()

On 19.07.23 09:51, Kefeng Wang wrote:
> Use the helpers to simplify code, also kill unneeded goto cpy_name.
>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Arnaldo Carvalho de Melo <[email protected]>
> Signed-off-by: Kefeng Wang <[email protected]>
> ---
> kernel/events/core.c | 22 +++++++---------------
> 1 file changed, 7 insertions(+), 15 deletions(-)
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 78ae7b6f90fd..d59f6327472f 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -8685,22 +8685,14 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
> }
>
> name = (char *)arch_vma_name(vma);
> - if (name)
> - goto cpy_name;
> -
> - if (vma->vm_start <= vma->vm_mm->start_brk &&
> - vma->vm_end >= vma->vm_mm->brk) {
> - name = "[heap]";
> - goto cpy_name;
> + if (!name) {
> + if (vma_is_initial_heap(vma))
> + name = "[heap]";
> + else if (vma_is_initial_stack(vma))
> + name = "[stack]";
> + else
> + name = "//anon";
> }
> - if (vma->vm_start <= vma->vm_mm->start_stack &&
> - vma->vm_end >= vma->vm_mm->start_stack) {
> - name = "[stack]";
> - goto cpy_name;
> - }
> -
> - name = "//anon";
> - goto cpy_name;

If you're removing that goto, maybe also worth removing the goto at the
end of the previous if branch.

Reviewed-by: David Hildenbrand <[email protected]>


--
Cheers,

David / dhildenb


2023-07-19 10:04:10

by Peter Zijlstra

[permalink] [raw]
Subject: Re: [PATCH v2 4/4] perf/core: use vma_is_initial_stack() and vma_is_initial_heap()

On Wed, Jul 19, 2023 at 03:51:14PM +0800, Kefeng Wang wrote:
> Use the helpers to simplify code, also kill unneeded goto cpy_name.

Grrr.. why am I only getting 4/4 ?

I'm going to write a bot that auto NAKs all partial series :/

2023-07-19 10:38:54

by Kefeng Wang

[permalink] [raw]
Subject: Re: [PATCH v2 4/4] perf/core: use vma_is_initial_stack() and vma_is_initial_heap()



On 2023/7/19 17:29, Peter Zijlstra wrote:
> On Wed, Jul 19, 2023 at 03:51:14PM +0800, Kefeng Wang wrote:
>> Use the helpers to simplify code, also kill unneeded goto cpy_name.
>
> Grrr.. why am I only getting 4/4 ?
>
> I'm going to write a bot that auto NAKs all partial series :/
Sorry, I should add all to cc list, here is all patches linke[1]

[1]
https://lore.kernel.org/linux-mm/[email protected]/


Thanks.
>