* + fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch added to mm-nonmm-unstable branch
@ 2025-05-10 0:45 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2025-05-10 0:45 UTC (permalink / raw)
To: mm-commits, linus.walleij, pasha.tatashin, akpm
The patch titled
Subject: fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
has been added to the -mm mm-nonmm-unstable branch. Its filename is
fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Pasha Tatashin <pasha.tatashin@soleen.com>
Subject: fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
Date: Fri, 09 May 2025 08:29:27 +0200
There are two data types: "struct vm_struct" and "struct vm_stack" that
have the same local variable names: vm_stack, or vm, or s, which makes the
code confusing to read.
Change the code so the naming is consistent:
struct vm_struct is always called vm_area
struct vm_stack is always called vm_stack
One change altering vfree(vm_stack) to vfree(vm_area->addr) may look like
a semantic change but it is not: vm_area->addr points to the vm_stack.
This was done to improve readability.
[linus.walleij@linaro.org: rebased and added new users of the variable names, address review comments]
Link: https://lore.kernel.org/20240311164638.2015063-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20250509-fork-fixes-v3-2-e6c69dd356f2@linaro.org
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
kernel/fork.c | 60 +++++++++++++++++++++++-------------------------
1 file changed, 29 insertions(+), 31 deletions(-)
--- a/kernel/fork.c~fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code
+++ a/kernel/fork.c
@@ -201,14 +201,14 @@ struct vm_stack {
struct vm_struct *stack_vm_area;
};
-static bool try_release_thread_stack_to_cache(struct vm_struct *vm)
+static bool try_release_thread_stack_to_cache(struct vm_struct *vm_area)
{
unsigned int i;
for (i = 0; i < NR_CACHED_STACKS; i++) {
struct vm_struct *tmp = NULL;
- if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm))
+ if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm_area))
return true;
}
return false;
@@ -217,11 +217,12 @@ static bool try_release_thread_stack_to_
static void thread_stack_free_rcu(struct rcu_head *rh)
{
struct vm_stack *vm_stack = container_of(rh, struct vm_stack, rcu);
+ struct vm_struct *vm_area = vm_stack->stack_vm_area;
if (try_release_thread_stack_to_cache(vm_stack->stack_vm_area))
return;
- vfree(vm_stack);
+ vfree(vm_area->addr);
}
static void thread_stack_delayed_free(struct task_struct *tsk)
@@ -234,32 +235,32 @@ static void thread_stack_delayed_free(st
static int free_vm_stack_cache(unsigned int cpu)
{
- struct vm_struct **cached_vm_stacks = per_cpu_ptr(cached_stacks, cpu);
+ struct vm_struct **cached_vm_stack_areas = per_cpu_ptr(cached_stacks, cpu);
int i;
for (i = 0; i < NR_CACHED_STACKS; i++) {
- struct vm_struct *vm_stack = cached_vm_stacks[i];
+ struct vm_struct *vm_area = cached_vm_stack_areas[i];
- if (!vm_stack)
+ if (!vm_area)
continue;
- vfree(vm_stack->addr);
- cached_vm_stacks[i] = NULL;
+ vfree(vm_area->addr);
+ cached_vm_stack_areas[i] = NULL;
}
return 0;
}
-static int memcg_charge_kernel_stack(struct vm_struct *vm)
+static int memcg_charge_kernel_stack(struct vm_struct *vm_area)
{
int i;
int ret;
int nr_charged = 0;
- BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE);
+ BUG_ON(vm_area->nr_pages != THREAD_SIZE / PAGE_SIZE);
for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
- ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL, 0);
+ ret = memcg_kmem_charge_page(vm_area->pages[i], GFP_KERNEL, 0);
if (ret)
goto err;
nr_charged++;
@@ -267,38 +268,35 @@ static int memcg_charge_kernel_stack(str
return 0;
err:
for (i = 0; i < nr_charged; i++)
- memcg_kmem_uncharge_page(vm->pages[i], 0);
+ memcg_kmem_uncharge_page(vm_area->pages[i], 0);
return ret;
}
static int alloc_thread_stack_node(struct task_struct *tsk, int node)
{
- struct vm_struct *vm;
+ struct vm_struct *vm_area;
void *stack;
int i;
for (i = 0; i < NR_CACHED_STACKS; i++) {
- struct vm_struct *s;
-
- s = this_cpu_xchg(cached_stacks[i], NULL);
-
- if (!s)
+ vm_area = this_cpu_xchg(cached_stacks[i], NULL);
+ if (!vm_area)
continue;
/* Reset stack metadata. */
- kasan_unpoison_range(s->addr, THREAD_SIZE);
+ kasan_unpoison_range(vm_area->addr, THREAD_SIZE);
- stack = kasan_reset_tag(s->addr);
+ stack = kasan_reset_tag(vm_area->addr);
/* Clear stale pointers from reused stack. */
memset(stack, 0, THREAD_SIZE);
- if (memcg_charge_kernel_stack(s)) {
- vfree(s->addr);
+ if (memcg_charge_kernel_stack(vm_area)) {
+ vfree(vm_area->addr);
return -ENOMEM;
}
- tsk->stack_vm_area = s;
+ tsk->stack_vm_area = vm_area;
tsk->stack = stack;
return 0;
}
@@ -314,8 +312,8 @@ static int alloc_thread_stack_node(struc
if (!stack)
return -ENOMEM;
- vm = find_vm_area(stack);
- if (memcg_charge_kernel_stack(vm)) {
+ vm_area = find_vm_area(stack);
+ if (memcg_charge_kernel_stack(vm_area)) {
vfree(stack);
return -ENOMEM;
}
@@ -324,7 +322,7 @@ static int alloc_thread_stack_node(struc
* free_thread_stack() can be called in interrupt context,
* so cache the vm_struct.
*/
- tsk->stack_vm_area = vm;
+ tsk->stack_vm_area = vm_area;
stack = kasan_reset_tag(stack);
tsk->stack = stack;
return 0;
@@ -437,11 +435,11 @@ static struct kmem_cache *mm_cachep;
static void account_kernel_stack(struct task_struct *tsk, int account)
{
if (IS_ENABLED(CONFIG_VMAP_STACK)) {
- struct vm_struct *vm = task_stack_vm_area(tsk);
+ struct vm_struct *vm_area = task_stack_vm_area(tsk);
int i;
for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++)
- mod_lruvec_page_state(vm->pages[i], NR_KERNEL_STACK_KB,
+ mod_lruvec_page_state(vm_area->pages[i], NR_KERNEL_STACK_KB,
account * (PAGE_SIZE / 1024));
} else {
void *stack = task_stack_page(tsk);
@@ -457,12 +455,12 @@ void exit_task_stack_account(struct task
account_kernel_stack(tsk, -1);
if (IS_ENABLED(CONFIG_VMAP_STACK)) {
- struct vm_struct *vm;
+ struct vm_struct *vm_area;
int i;
- vm = task_stack_vm_area(tsk);
+ vm_area = task_stack_vm_area(tsk);
for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++)
- memcg_kmem_uncharge_page(vm->pages[i], 0);
+ memcg_kmem_uncharge_page(vm_area->pages[i], 0);
}
}
_
Patches currently in -mm which might be from pasha.tatashin@soleen.com are
task_stackh-remove-obsolete-__have_arch_kstack_end-check.patch
fork-clean-up-ifdef-logic-around-stack-allocation.patch
fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch
fork-check-charging-success-before-zeroing-stack.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* + fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch added to mm-nonmm-unstable branch
@ 2025-06-09 19:35 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2025-06-09 19:35 UTC (permalink / raw)
To: mm-commits, rppt, mjguzik, linus.walleij, pasha.tatashin, akpm
The patch titled
Subject: fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
has been added to the -mm mm-nonmm-unstable branch. Its filename is
fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Pasha Tatashin <pasha.tatashin@soleen.com>
Subject: fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
Date: Fri, 09 May 2025 08:29:27 +0200
There are two data types: "struct vm_struct" and "struct vm_stack" that
have the same local variable names: vm_stack, or vm, or s, which makes the
code confusing to read.
Change the code so the naming is consistent:
struct vm_struct is always called vm_area
struct vm_stack is always called vm_stack
One change altering vfree(vm_stack) to vfree(vm_area->addr) may look like
a semantic change but it is not: vm_area->addr points to the vm_stack.
This was done to improve readability.
[linus.walleij@linaro.org: rebased and added new users of the variable names, address review comments]
Link: https://lore.kernel.org/20240311164638.2015063-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20250509-fork-fixes-v3-2-e6c69dd356f2@linaro.org
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
kernel/fork.c | 60 +++++++++++++++++++++++-------------------------
1 file changed, 29 insertions(+), 31 deletions(-)
--- a/kernel/fork.c~fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code
+++ a/kernel/fork.c
@@ -207,14 +207,14 @@ struct vm_stack {
struct vm_struct *stack_vm_area;
};
-static bool try_release_thread_stack_to_cache(struct vm_struct *vm)
+static bool try_release_thread_stack_to_cache(struct vm_struct *vm_area)
{
unsigned int i;
for (i = 0; i < NR_CACHED_STACKS; i++) {
struct vm_struct *tmp = NULL;
- if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm))
+ if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm_area))
return true;
}
return false;
@@ -223,11 +223,12 @@ static bool try_release_thread_stack_to_
static void thread_stack_free_rcu(struct rcu_head *rh)
{
struct vm_stack *vm_stack = container_of(rh, struct vm_stack, rcu);
+ struct vm_struct *vm_area = vm_stack->stack_vm_area;
if (try_release_thread_stack_to_cache(vm_stack->stack_vm_area))
return;
- vfree(vm_stack);
+ vfree(vm_area->addr);
}
static void thread_stack_delayed_free(struct task_struct *tsk)
@@ -240,32 +241,32 @@ static void thread_stack_delayed_free(st
static int free_vm_stack_cache(unsigned int cpu)
{
- struct vm_struct **cached_vm_stacks = per_cpu_ptr(cached_stacks, cpu);
+ struct vm_struct **cached_vm_stack_areas = per_cpu_ptr(cached_stacks, cpu);
int i;
for (i = 0; i < NR_CACHED_STACKS; i++) {
- struct vm_struct *vm_stack = cached_vm_stacks[i];
+ struct vm_struct *vm_area = cached_vm_stack_areas[i];
- if (!vm_stack)
+ if (!vm_area)
continue;
- vfree(vm_stack->addr);
- cached_vm_stacks[i] = NULL;
+ vfree(vm_area->addr);
+ cached_vm_stack_areas[i] = NULL;
}
return 0;
}
-static int memcg_charge_kernel_stack(struct vm_struct *vm)
+static int memcg_charge_kernel_stack(struct vm_struct *vm_area)
{
int i;
int ret;
int nr_charged = 0;
- BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE);
+ BUG_ON(vm_area->nr_pages != THREAD_SIZE / PAGE_SIZE);
for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
- ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL, 0);
+ ret = memcg_kmem_charge_page(vm_area->pages[i], GFP_KERNEL, 0);
if (ret)
goto err;
nr_charged++;
@@ -273,38 +274,35 @@ static int memcg_charge_kernel_stack(str
return 0;
err:
for (i = 0; i < nr_charged; i++)
- memcg_kmem_uncharge_page(vm->pages[i], 0);
+ memcg_kmem_uncharge_page(vm_area->pages[i], 0);
return ret;
}
static int alloc_thread_stack_node(struct task_struct *tsk, int node)
{
- struct vm_struct *vm;
+ struct vm_struct *vm_area;
void *stack;
int i;
for (i = 0; i < NR_CACHED_STACKS; i++) {
- struct vm_struct *s;
-
- s = this_cpu_xchg(cached_stacks[i], NULL);
-
- if (!s)
+ vm_area = this_cpu_xchg(cached_stacks[i], NULL);
+ if (!vm_area)
continue;
/* Reset stack metadata. */
- kasan_unpoison_range(s->addr, THREAD_SIZE);
+ kasan_unpoison_range(vm_area->addr, THREAD_SIZE);
- stack = kasan_reset_tag(s->addr);
+ stack = kasan_reset_tag(vm_area->addr);
/* Clear stale pointers from reused stack. */
memset(stack, 0, THREAD_SIZE);
- if (memcg_charge_kernel_stack(s)) {
- vfree(s->addr);
+ if (memcg_charge_kernel_stack(vm_area)) {
+ vfree(vm_area->addr);
return -ENOMEM;
}
- tsk->stack_vm_area = s;
+ tsk->stack_vm_area = vm_area;
tsk->stack = stack;
return 0;
}
@@ -320,8 +318,8 @@ static int alloc_thread_stack_node(struc
if (!stack)
return -ENOMEM;
- vm = find_vm_area(stack);
- if (memcg_charge_kernel_stack(vm)) {
+ vm_area = find_vm_area(stack);
+ if (memcg_charge_kernel_stack(vm_area)) {
vfree(stack);
return -ENOMEM;
}
@@ -330,7 +328,7 @@ static int alloc_thread_stack_node(struc
* free_thread_stack() can be called in interrupt context,
* so cache the vm_struct.
*/
- tsk->stack_vm_area = vm;
+ tsk->stack_vm_area = vm_area;
stack = kasan_reset_tag(stack);
tsk->stack = stack;
return 0;
@@ -437,11 +435,11 @@ static struct kmem_cache *mm_cachep;
static void account_kernel_stack(struct task_struct *tsk, int account)
{
if (IS_ENABLED(CONFIG_VMAP_STACK)) {
- struct vm_struct *vm = task_stack_vm_area(tsk);
+ struct vm_struct *vm_area = task_stack_vm_area(tsk);
int i;
for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++)
- mod_lruvec_page_state(vm->pages[i], NR_KERNEL_STACK_KB,
+ mod_lruvec_page_state(vm_area->pages[i], NR_KERNEL_STACK_KB,
account * (PAGE_SIZE / 1024));
} else {
void *stack = task_stack_page(tsk);
@@ -457,12 +455,12 @@ void exit_task_stack_account(struct task
account_kernel_stack(tsk, -1);
if (IS_ENABLED(CONFIG_VMAP_STACK)) {
- struct vm_struct *vm;
+ struct vm_struct *vm_area;
int i;
- vm = task_stack_vm_area(tsk);
+ vm_area = task_stack_vm_area(tsk);
for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++)
- memcg_kmem_uncharge_page(vm->pages[i], 0);
+ memcg_kmem_uncharge_page(vm_area->pages[i], 0);
}
}
_
Patches currently in -mm which might be from pasha.tatashin@soleen.com are
fork-clean-up-naming-of-vm_stack-vm_struct-variables-in-vmap-stacks-code.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
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