diff mbox series

[v4,1/3] vmalloc: Choose a better start address in vm_area_register_early()

Message ID 20210910053354.26721-2-wangkefeng.wang@huawei.com (mailing list archive)
State New
Headers show
Series arm64: support page mapping percpu first chunk allocator | expand

Commit Message

Kefeng Wang Sept. 10, 2021, 5:33 a.m. UTC
There are some fixed locations in the vmalloc area be reserved
in ARM(see iotable_init()) and ARM64(see map_kernel()), but for
pcpu_page_first_chunk(), it calls vm_area_register_early() and
choose VMALLOC_START as the start address of vmap area which
could be conflicted with above address, then could trigger a
BUG_ON in vm_area_add_early().

Let's choose a suit start address by traversing the vmlist.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/vmalloc.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

Comments

Catalin Marinas Oct. 12, 2021, 6:21 p.m. UTC | #1
On Fri, Sep 10, 2021 at 01:33:52PM +0800, Kefeng Wang wrote:
> There are some fixed locations in the vmalloc area be reserved
> in ARM(see iotable_init()) and ARM64(see map_kernel()), but for
> pcpu_page_first_chunk(), it calls vm_area_register_early() and
> choose VMALLOC_START as the start address of vmap area which
> could be conflicted with above address, then could trigger a
> BUG_ON in vm_area_add_early().
> 
> Let's choose a suit start address by traversing the vmlist.
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff mbox series

Patch

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d77830ff604c..5ee3cbeffa26 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2272,15 +2272,21 @@  void __init vm_area_add_early(struct vm_struct *vm)
  */
 void __init vm_area_register_early(struct vm_struct *vm, size_t align)
 {
-	static size_t vm_init_off __initdata;
-	unsigned long addr;
+	unsigned long addr = ALIGN(VMALLOC_START, align);
+	struct vm_struct *cur, **p;
 
-	addr = ALIGN(VMALLOC_START + vm_init_off, align);
-	vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
+	BUG_ON(vmap_initialized);
 
-	vm->addr = (void *)addr;
+	for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) {
+		if ((unsigned long)cur->addr - addr >= vm->size)
+			break;
+		addr = ALIGN((unsigned long)cur->addr + cur->size, align);
+	}
 
-	vm_area_add_early(vm);
+	BUG_ON(addr > VMALLOC_END - vm->size);
+	vm->addr = (void *)addr;
+	vm->next = *p;
+	*p = vm;
 }
 
 static void vmap_init_free_space(void)