Commit 8c620d05 authored by Uladzislau Rezki (Sony)'s avatar Uladzislau Rezki (Sony) Committed by Peng Zhang
Browse files

mm: vmalloc: refactor vmalloc_dump_obj() function 

mainline inclusion
from mainline-v6.9-rc1
commit 8be4d46e12af32342569840d958272dbb3be3f4c
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9CHG1
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8be4d46e12af32342569840d958272dbb3be3f4c

-------------------------------------------------

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.

Link: https://lkml.kernel.org/r/20240124180920.50725-2-urezki@gmail.com


Signed-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: default avatarLorenzo Stoakes <lstoakes@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 8be4d46e12af32342569840d958272dbb3be3f4c)
Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
parent b0c82817

mm/vmalloc.c

+17 −16
Original line number Diff line number Diff line
@@ -4773,34 +4773,35 @@ 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);

	addr = PAGE_ALIGN((unsigned long) object);

	vn = addr_to_node(addr);



	if (spin_trylock(&vn->busy.lock)) {

		va = __find_vmap_area((unsigned long)objp, &vn->busy.root);

	if (!spin_trylock(&vn->busy.lock))

		return false;



		if (va && va->vm) {

			addr = (unsigned long)va->vm->addr;

			caller = va->vm->caller;

			nr_pages = va->vm->nr_pages;

			success = true;

	va = __find_vmap_area(addr, &vn->busy.root);

	if (!va || !va->vm) {

		spin_unlock(&vn->busy.lock);

		return false;

	}



	vm = va->vm;

	addr = (unsigned long) vm->addr;

	caller = vm->caller;

	nr_pages = vm->nr_pages;

	spin_unlock(&vn->busy.lock);

	}



	if (success)

	pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",

		nr_pages, addr, caller);



	return success;

	return true;

}

#endif