[PATCH v4 1/3] vmalloc: Choose a better start address in vm_area_register_early()
From: Kefeng Wang <hidden>
Date: 2021-09-10 05:30:21
Also in:
linux-mm, lkml
Subsystem:
memory management, the rest, vmalloc · Maintainers:
Andrew Morton, Linus Torvalds, Uladzislau Rezki
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 <redacted> --- mm/vmalloc.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
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)
--
2.26.2
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