[PATCH 2/2] mm: vmalloc: Refactor vmalloc_dump_obj() function

From: Uladzislau Rezki (Sony)
Date: Wed Jan 24 2024 - 13:09:39 EST


This patch tends to simplify the function in question,
by removing an extra stack "objp" variable, returning
back to an early exit approach if spin_trylock() fails
or VA was not found.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
---
mm/vmalloc.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index b8be601b056d..449f45b0e474 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -4696,34 +4696,35 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
#ifdef CONFIG_PRINTK
bool vmalloc_dump_obj(void *object)
{
- void *objp = (void *)PAGE_ALIGN((unsigned long)object);
const void *caller;
+ struct vm_struct *vm;
struct vmap_area *va;
struct vmap_node *vn;
unsigned long addr;
unsigned int nr_pages;
- bool success = false;
-
- vn = addr_to_node((unsigned long)objp);

- if (spin_trylock(&vn->busy.lock)) {
- va = __find_vmap_area((unsigned long)objp, &vn->busy.root);
+ addr = PAGE_ALIGN((unsigned long) object);
+ vn = addr_to_node(addr);

- if (va && va->vm) {
- addr = (unsigned long)va->vm->addr;
- caller = va->vm->caller;
- nr_pages = va->vm->nr_pages;
- success = true;
- }
+ if (!spin_trylock(&vn->busy.lock))
+ return false;

+ va = __find_vmap_area(addr, &vn->busy.root);
+ if (!va || !va->vm) {
spin_unlock(&vn->busy.lock);
+ return false;
}

- if (success)
- pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
- nr_pages, addr, caller);
+ vm = va->vm;
+ addr = (unsigned long) vm->addr;
+ caller = vm->caller;
+ nr_pages = vm->nr_pages;
+ spin_unlock(&vn->busy.lock);

- return success;
+ pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
+ nr_pages, addr, caller);
+
+ return true;
}
#endif

--
2.39.2