diff options
| author | Kefeng Wang <wangkefeng.wang@huawei.com> | 2021-11-05 13:39:41 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 13:30:37 -0700 |
| commit | 0eb68437a7f9dfef9c218873310c66c714f2fa99 (patch) | |
| tree | 8f13b34decb2b67f5a2db002f3d97e909797e484 /mm/vmalloc.c | |
| parent | dd544141b9eb8f3c58dedc9c1dcc4803de0eed45 (diff) | |
vmalloc: choose a better start address in vm_area_register_early()
Percpu embedded first chunk allocator is the firstly option, but it
could fail on ARM64, eg,
percpu: max_distance=0x5fcfdc640000 too large for vmalloc space 0x781fefff0000
percpu: max_distance=0x600000540000 too large for vmalloc space 0x7dffb7ff0000
percpu: max_distance=0x5fff9adb0000 too large for vmalloc space 0x5dffb7ff0000
then we could get to
WARNING: CPU: 15 PID: 461 at vmalloc.c:3087 pcpu_get_vm_areas+0x488/0x838
and the system cannot boot successfully.
Let's implement page mapping percpu first chunk allocator as a fallback
to the embedding allocator to increase the robustness of the system.
Also fix a crash when both NEED_PER_CPU_PAGE_FIRST_CHUNK and
KASAN_VMALLOC enabled.
Tested on ARM64 qemu with cmdline "percpu_alloc=page".
This patch (of 3):
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.
Link: https://lkml.kernel.org/r/20210910053354.26721-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20210910053354.26721-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 2cd23fa00a13..74da45a8beec 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2276,15 +2276,21 @@ 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) |