mm: vmalloc: bail out early in find_vmap_area() if vmap is not init

During the boot the s390 system triggers "spinlock bad magic" messages
if the spinlock debugging is enabled:

[    0.465445] BUG: spinlock bad magic on CPU#0, swapper/0
[    0.465490]  lock: single+0x1860/0x1958, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[    0.466067] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-12955-g8e938e398669 #1
[    0.466188] Hardware name: QEMU 8561 QEMU (KVM/Linux)
[    0.466270] Call Trace:
[    0.466470]  [<00000000011f26c8>] dump_stack_lvl+0x98/0xd8
[    0.466516]  [<00000000001dcc6a>] do_raw_spin_lock+0x8a/0x108
[    0.466545]  [<000000000042146c>] find_vmap_area+0x6c/0x108
[    0.466572]  [<000000000042175a>] find_vm_area+0x22/0x40
[    0.466597]  [<000000000012f152>] __set_memory+0x132/0x150
[    0.466624]  [<0000000001cc0398>] vmem_map_init+0x40/0x118
[    0.466651]  [<0000000001cc0092>] paging_init+0x22/0x68
[    0.466677]  [<0000000001cbbed2>] setup_arch+0x52a/0x708
[    0.466702]  [<0000000001cb6140>] start_kernel+0x80/0x5c8
[    0.466727]  [<0000000000100036>] startup_continue+0x36/0x40

it happens because such system tries to access some vmap areas
whereas the vmalloc initialization is not even yet done:

[    0.465490] lock: single+0x1860/0x1958, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[    0.466067] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-12955-g8e938e398669 #1
[    0.466188] Hardware name: QEMU 8561 QEMU (KVM/Linux)
[    0.466270] Call Trace:
[    0.466470] dump_stack_lvl (lib/dump_stack.c:117)
[    0.466516] do_raw_spin_lock (kernel/locking/spinlock_debug.c:87 kernel/locking/spinlock_debug.c:115)
[    0.466545] find_vmap_area (mm/vmalloc.c:1059 mm/vmalloc.c:2364)
[    0.466572] find_vm_area (mm/vmalloc.c:3150)
[    0.466597] __set_memory (arch/s390/mm/pageattr.c:360 arch/s390/mm/pageattr.c:393)
[    0.466624] vmem_map_init (./arch/s390/include/asm/set_memory.h:55 arch/s390/mm/vmem.c:660)
[    0.466651] paging_init (arch/s390/mm/init.c:97)
[    0.466677] setup_arch (arch/s390/kernel/setup.c:972)
[    0.466702] start_kernel (init/main.c:899)
[    0.466727] startup_continue (arch/s390/kernel/head64.S:35)
[    0.466811] INFO: lockdep is turned off.
...
[    0.718250] vmalloc init - busy lock init 0000000002871860
[    0.718328] vmalloc init - busy lock init 00000000028731b8

Some background. It worked before because the lock that is in question
was statically defined and initialized. As of now, the locks and data
structures are initialized in the vmalloc_init() function.

To address that issue add the check whether the "vmap_initialized"
variable is set, if not find_vmap_area() bails out on entry returning NULL.

Link: https://lkml.kernel.org/r/20240323141544.4150-1-urezki@gmail.com
Fixes: 72210662c5a2 ("mm: vmalloc: offload free_vmap_area_lock lock")
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 22aa63f4ef6322a71030c5dd163706c83ef5cd8d..0d77d171b5d9f74f5b6ef968e37f55bc853508cd 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2343,6 +2343,9 @@ struct vmap_area *find_vmap_area(unsigned long addr)
        struct vmap_area *va;
        int i, j;
 
+       if (unlikely(!vmap_initialized))
+               return NULL;
+
        /*
         * An addr_to_node_id(addr) converts an address to a node index
         * where a VA is located. If VA spans several zones and passed