Le 11/03/2024 à 17:46, Pasha Tatashin a écrit :
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
code confusing to read.
Change the code so the naming is consisent:
Nit: consistent
struct vm_struct is always called vm_area
struct vm_stack is always called vm_stack
Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
---
kernel/fork.c | 38 ++++++++++++++++++--------------------
1 file changed, 18 insertions(+), 20 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index 32600bf2422a..60e812825a7a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -192,12 +192,12 @@ 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++) {
- if (this_cpu_cmpxchg(cached_stacks[i], NULL, vm) != NULL)
+ if (this_cpu_cmpxchg(cached_stacks[i], NULL, vm_area) != NULL)
continue;
return true;
}
@@ -207,11 +207,12 @@ static bool try_release_thread_stack_to_cache(struct vm_struct *vm)
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);
This does not look like only a renaming of a variable. Is it?
If no, should there be a Fixes tag and should it be detailed in the
commit description?
CJ
}
static void thread_stack_delayed_free(struct task_struct *tsk)
@@ -228,12 +229,12 @@ static int free_vm_stack_cache(unsigned int 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_stacks[i];
- if (!vm_stack)
+ if (!vm_area)
continue;
- vfree(vm_stack->addr);
+ vfree(vm_area->addr);
cached_vm_stacks[i] = NULL;
}
@@ -263,32 +264,29 @@ static int memcg_charge_kernel_stack(struct vm_struct *vm)
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;
}
@@ -306,8 +304,8 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node)
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;
}
@@ -316,7 +314,7 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node)
* 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;
