The patch titled
Subject: mm: vmalloc: bail out early in find_vmap_area() if vmap is not init
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-vmalloc-bail-out-early-in-find_vmap_area-if-vmap-is-not-init.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmalloc-bail-out-early-in-find_vmap_area-if-vmap-is-not-init.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Uladzislau Rezki (Sony)" <urezki@xxxxxxxxx>
Subject: mm: vmalloc: bail out early in find_vmap_area() if vmap is not init
Date: Sat, 23 Mar 2024 15:15:44 +0100
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@xxxxxxxxx
Fixes: 72210662c5a2 ("mm: vmalloc: offload free_vmap_area_lock lock")
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Reviewed-by: Baoquan He <bhe@xxxxxxxxxx>
Acked-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 3 +++
1 file changed, 3 insertions(+)
--- a/mm/vmalloc.c~mm-vmalloc-bail-out-early-in-find_vmap_area-if-vmap-is-not-init
+++ a/mm/vmalloc.c
@@ -2343,6 +2343,9 @@ struct vmap_area *find_vmap_area(unsigne
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
_
Patches currently in -mm which might be from urezki@xxxxxxxxx are
mm-vmalloc-bail-out-early-in-find_vmap_area-if-vmap-is-not-init.patch
