[PATCH] maple_tree: use KMEM_CACHE to create maple

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* [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches
@ 2024-11-04  6:16 Ke Sun
  2024-11-04 13:27 ` Matthew Wilcox
  2024-11-05  2:34 ` kernel test robot
  0 siblings, 2 replies; 5+ messages in thread
From: Ke Sun @ 2024-11-04  6:16 UTC (permalink / raw)
  To: Andrew Morton, Liam R. Howlett; +Cc: maple-tree, linux-mm, Ke Sun

Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
the creation of SLAB caches.

Signed-off-by: Ke Sun <sunke@kylinos.cn>
---
 lib/maple_tree.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 3619301dda2e..60be142e35c6 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -6299,9 +6299,7 @@ bool mas_nomem(struct ma_state *mas, gfp_t gfp)
 
 void __init maple_tree_init(void)
 {
-	maple_node_cache = kmem_cache_create("maple_node",
-			sizeof(struct maple_node), sizeof(struct maple_node),
-			SLAB_PANIC, NULL);
+	maple_node_cache = KMEM_CACHE(maple_node, SLAB_PANIC);
 }
 
 /**
-- 
2.34.1



^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches
  2024-11-04  6:16 [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches Ke Sun
@ 2024-11-04 13:27 ` Matthew Wilcox
  2024-11-05  2:21   ` Ke Sun
  2024-11-05  2:34 ` kernel test robot
  1 sibling, 1 reply; 5+ messages in thread
From: Matthew Wilcox @ 2024-11-04 13:27 UTC (permalink / raw)
  To: Ke Sun; +Cc: Andrew Morton, Liam R. Howlett, maple-tree, linux-mm

On Mon, Nov 04, 2024 at 02:16:17PM +0800, Ke Sun wrote:
> Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
> the creation of SLAB caches.

Did you even test this?  It is REQUIRED that maple_node be aligned to
its size (eg 256 bytes) as the bottom bits of pointers to nodes are used
for other purposes.  KMEM_CACHE() does not give us this guarantee.

NACK.


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches
  2024-11-04 13:27 ` Matthew Wilcox
@ 2024-11-05  2:21   ` Ke Sun
  2024-11-05  4:17     ` Matthew Wilcox
  0 siblings, 1 reply; 5+ messages in thread
From: Ke Sun @ 2024-11-05  2:21 UTC (permalink / raw)
  To: Matthew Wilcox; +Cc: Andrew Morton, Liam R. Howlett, maple-tree, linux-mm

[-- Attachment #1: Type: text/plain, Size: 1202 bytes --]

Matthew Wilcox <willy@infradead.org> 于2024年11月4日周一 21:27写道：

> On Mon, Nov 04, 2024 at 02:16:17PM +0800, Ke Sun wrote:
> > Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
> > the creation of SLAB caches.
>
> Did you even test this?  It is REQUIRED that maple_node be aligned to
>

I have tests on an ARM64 QEMU VM and enabled some Maple Tree debugging
configs:
CONFIG_DEBUG_VM_MAPLE_TREE=y
CONFIG_DEBUG_MAPLE_TREE=y
CONFIG_TEST_MAPLE_TREE=y

The results show:
[    1.434017][    T1] TEST STARTING
[    1.434017][    T1]
[   78.257756][    T1] maple_tree: 172860522 of 172860522 tests passed
[   78.271770][    T1] atomic64_test: passed


> its size (eg 256 bytes) as the bottom bits of pointers to nodes are used
> for other purposes.  KMEM_CACHE() does not give us this guarantee.
>

The code comments of kmem_cache say: 'The alignment of the struct
determines object alignment.'
 #define KMEM_CACHE(__struct, __flags)                                   \
__kmem_cache_create_args(#__struct, sizeof(struct __struct),    \
&(struct kmem_cache_args) { \
.align = __alignof__(struct __struct), \
}, (__flags))


>
> NACK.
>
>

[-- Attachment #2: Type: text/html, Size: 2053 bytes --]

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches
  2024-11-05  2:21   ` Ke Sun
@ 2024-11-05  4:17     ` Matthew Wilcox
  0 siblings, 0 replies; 5+ messages in thread
From: Matthew Wilcox @ 2024-11-05  4:17 UTC (permalink / raw)
  To: Ke Sun; +Cc: Andrew Morton, Liam R. Howlett, maple-tree, linux-mm

On Tue, Nov 05, 2024 at 10:21:00AM +0800, Ke Sun wrote:
> > its size (eg 256 bytes) as the bottom bits of pointers to nodes are used
> > for other purposes.  KMEM_CACHE() does not give us this guarantee.
> 
> The code comments of kmem_cache say: 'The alignment of the struct
> determines object alignment.'
>  #define KMEM_CACHE(__struct, __flags)                                   \
> __kmem_cache_create_args(#__struct, sizeof(struct __struct),    \
> &(struct kmem_cache_args) { \
> .align = __alignof__(struct __struct), \
> }, (__flags))

You're looking right at your bug, and you don't see it.


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches
  2024-11-04  6:16 [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches Ke Sun
  2024-11-04 13:27 ` Matthew Wilcox
@ 2024-11-05  2:34 ` kernel test robot
  1 sibling, 0 replies; 5+ messages in thread
From: kernel test robot @ 2024-11-05  2:34 UTC (permalink / raw)
  To: Ke Sun
  Cc: oe-lkp, lkp, maple-tree, linux-mm, Andrew Morton,
	Liam R. Howlett, Ke Sun, oliver.sang



Hello,


we noticed Matthew Wilcox NACKed this patch in
https://lore.kernel.org/all/ZyjLpXKx5qcLYQ3S@casper.infradead.org/

we send below report FYI in case it could supply some useful information to
you. just ignore otherwise. thanks


kernel test robot noticed "BUG:KASAN:slab-out-of-bounds_in_mas_store_gfp" on:

commit: 6fa40fae6ea5ad7990555fa7460739ee44088111 ("[PATCH] maple_tree: use KMEM_CACHE to create maple_node caches")
url: https://github.com/intel-lab-lkp/linux/commits/Ke-Sun/maple_tree-use-KMEM_CACHE-to-create-maple_node-caches/20241104-141720
base: https://git.kernel.org/cgit/linux/kernel/git/akpm/mm.git mm-nonmm-unstable
patch link: https://lore.kernel.org/all/20241104061617.450907-1-sunke@kylinos.cn/
patch subject: [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches

in testcase: boot

config: x86_64-rhel-8.3-kselftests
compiler: gcc-12
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

(please refer to attached dmesg/kmsg for entire log/backtrace)


+----------------------------------------------------------------------------------------------+------------+------------+
|                                                                                              | d61ee4ec5d | 6fa40fae6e |
+----------------------------------------------------------------------------------------------+------------+------------+
| boot_successes                                                                               | 18         | 0          |
| boot_failures                                                                                | 0          | 18         |
| BUG:KASAN:slab-out-of-bounds_in_mas_store_gfp                                                | 0          | 14         |
| Oops:general_protection_fault,probably_for_non-canonical_address#:#[##]PREEMPT_SMP_KASAN_PTI | 0          | 18         |
| KASAN:null-ptr-deref_in_range[#-#]                                                           | 0          | 18         |
| RIP:mas_wr_store_type                                                                        | 0          | 11         |
| Kernel_panic-not_syncing:Fatal_exception                                                     | 0          | 18         |
| BUG:KASAN:slab-out-of-bounds_in_mas_put_in_tree                                              | 0          | 4          |
| RIP:mas_put_in_tree                                                                          | 0          | 4          |
| RIP:mas_ascend                                                                               | 0          | 3          |
+----------------------------------------------------------------------------------------------+------------+------------+


If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202411051011.b1d218e6-oliver.sang@intel.com


[ 3.482690][ T0] BUG: KASAN: slab-out-of-bounds in mas_store_gfp (lib/maple_tree.c:546 lib/maple_tree.c:578 lib/maple_tree.c:1368 lib/maple_tree.c:4132 lib/maple_tree.c:4266 lib/maple_tree.c:5477) 
[    3.483624][    T0] Read of size 8 at addr ffff88810028b600 by task swapper/0/0
[    3.484595][    T0]
[    3.484906][    T0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc5-00131-g6fa40fae6ea5 #1
[    3.486154][    T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[    3.487534][    T0] Call Trace:
[    3.487952][    T0]  <TASK>
[ 3.488337][ T0] dump_stack_lvl (lib/dump_stack.c:124) 
[ 3.488949][ T0] print_address_description+0x2c/0x3a0 
[ 3.489867][ T0] ? mas_store_gfp (lib/maple_tree.c:546 lib/maple_tree.c:578 lib/maple_tree.c:1368 lib/maple_tree.c:4132 lib/maple_tree.c:4266 lib/maple_tree.c:5477) 
[ 3.490508][ T0] print_report (mm/kasan/report.c:489) 
[ 3.491108][ T0] ? kasan_addr_to_slab (mm/kasan/common.c:37) 
[ 3.491762][ T0] ? mas_store_gfp (lib/maple_tree.c:546 lib/maple_tree.c:578 lib/maple_tree.c:1368 lib/maple_tree.c:4132 lib/maple_tree.c:4266 lib/maple_tree.c:5477) 
[ 3.492391][ T0] kasan_report (mm/kasan/report.c:603) 
[ 3.492999][ T0] ? mas_store_gfp (lib/maple_tree.c:546 lib/maple_tree.c:578 lib/maple_tree.c:1368 lib/maple_tree.c:4132 lib/maple_tree.c:4266 lib/maple_tree.c:5477) 
[ 3.493672][ T0] mas_store_gfp (lib/maple_tree.c:546 lib/maple_tree.c:578 lib/maple_tree.c:1368 lib/maple_tree.c:4132 lib/maple_tree.c:4266 lib/maple_tree.c:5477) 
[ 3.494258][ T0] ? __pfx_mas_store_gfp (lib/maple_tree.c:5470) 
[ 3.494930][ T0] ? init_desc (kernel/irq/irqdesc.c:213) 
[ 3.495526][ T0] early_irq_init (kernel/irq/irqdesc.c:174 kernel/irq/irqdesc.c:585) 
[ 3.496148][ T0] ? __pfx_early_irq_init (kernel/irq/irqdesc.c:563) 
[ 3.496833][ T0] ? __trace_define_field (include/linux/list.h:150 include/linux/list.h:169 kernel/trace/trace_events.c:138) 
[ 3.497557][ T0] start_kernel (init/main.c:1008) 
[ 3.498161][ T0] x86_64_start_reservations (arch/x86/kernel/head64.c:495) 
[ 3.498918][ T0] x86_64_start_kernel (arch/x86/kernel/head64.c:437 (discriminator 17)) 
[ 3.499599][ T0] common_startup_64 (arch/x86/kernel/head_64.S:414) 
[    3.500276][    T0]  </TASK>
[    3.500684][    T0]
[    3.500996][    T0] The buggy address belongs to the object at ffff88810028b500
[    3.500996][    T0]  which belongs to the cache maple_node of size 256
[    3.502884][    T0] The buggy address is located 0 bytes to the right of
[    3.502884][    T0]  allocated 256-byte region [ffff88810028b500, ffff88810028b600)
[    3.504826][    T0]
[    3.505139][    T0] The buggy address belongs to the physical page:
[    3.506009][    T0] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10028b
[    3.507141][    T0] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
[    3.508110][    T0] page_type: f5(slab)
[    3.508638][    T0] raw: 0017ffffc0000000 ffff88810004fdc0 dead000000000122 0000000000000000
[    3.509777][    T0] raw: 0000000000000000 00000000800c000c 00000001f5000000 0000000000000000
[    3.510920][    T0] page dumped because: kasan: bad access detected
[    3.511773][    T0]
[    3.512072][    T0] Memory state around the buggy address:
[    3.512839][    T0]  ffff88810028b500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[    3.513930][    T0]  ffff88810028b580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[    3.514979][    T0] >ffff88810028b600: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
[    3.516054][    T0]                    ^
[    3.516582][    T0]  ffff88810028b680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[    3.517681][    T0]  ffff88810028b700: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
[    3.518763][    T0] ==================================================================
[    3.519871][    T0] Disabling lock debugging due to kernel taint
[    3.520761][    T0] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
[    3.522464][    T0] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[    3.523522][    T0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G    B              6.12.0-rc5-00131-g6fa40fae6ea5 #1
[    3.524900][    T0] Tainted: [B]=BAD_PAGE
[    3.525438][    T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 3.526808][ T0] RIP: 0010:mas_wr_store_type (lib/maple_tree.c:795 lib/maple_tree.c:808 lib/maple_tree.c:3526 lib/maple_tree.c:4198) 
[ 3.527581][ T0] Code: 00 0f 85 a9 0e 00 00 4d 8b 75 00 e8 3a d0 0a 00 85 c0 0f 85 33 02 00 00 44 0f b6 74 24 20 4a 8d 6c f5 00 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 6e 0e 00 00 49 8d 7f 48 4c 8b 75 00 48 89 f8
All code
========
   0:	00 0f                	add    %cl,(%rdi)
   2:	85 a9 0e 00 00 4d    	test   %ebp,0x4d00000e(%rcx)
   8:	8b 75 00             	mov    0x0(%rbp),%esi
   b:	e8 3a d0 0a 00       	callq  0xad04a
  10:	85 c0                	test   %eax,%eax
  12:	0f 85 33 02 00 00    	jne    0x24b
  18:	44 0f b6 74 24 20    	movzbl 0x20(%rsp),%r14d
  1e:	4a 8d 6c f5 00       	lea    0x0(%rbp,%r14,8),%rbp
  23:	48 89 e8             	mov    %rbp,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
  2a:*	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)		<-- trapping instruction
  2f:	0f 85 6e 0e 00 00    	jne    0xea3
  35:	49 8d 7f 48          	lea    0x48(%r15),%rdi
  39:	4c 8b 75 00          	mov    0x0(%rbp),%r14
  3d:	48 89 f8             	mov    %rdi,%rax

Code starting with the faulting instruction
===========================================
   0:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
   5:	0f 85 6e 0e 00 00    	jne    0xe79
   b:	49 8d 7f 48          	lea    0x48(%r15),%rdi
   f:	4c 8b 75 00          	mov    0x0(%rbp),%r14
  13:	48 89 f8             	mov    %rdi,%rax
[    3.530219][    T0] RSP: 0000:ffffffffa8a07bf8 EFLAGS: 00010046
[    3.531055][    T0] RAX: 0000000000000000 RBX: ffffffffa8a07e8d RCX: 1ffffffff5140faa
[    3.532126][    T0] RDX: 0000000000000005 RSI: 0000000000000002 RDI: ffffffffa8a07e60
[    3.533193][    T0] RBP: 0000000000000000 R08: 0000000000000001 R09: 1ffffffff5140fcc
[    3.534285][    T0] R10: 0000000000000000 R11: ffffffffa8a07d40 R12: dffffc0000000000
[    3.535366][    T0] R13: ffffffffa8a07e50 R14: 0000000000000000 R15: ffffffffa8a07d38
[    3.536432][    T0] FS:  0000000000000000(0000) GS:ffff8883aee00000(0000) knlGS:0000000000000000
[    3.537616][    T0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    3.538481][    T0] CR2: ffff88843ffff000 CR3: 00000000aec7e000 CR4: 00000000000000b0
[    3.539544][    T0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    3.540540][    T0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    3.541553][    T0] Call Trace:
[    3.541978][    T0]  <TASK>
[ 3.542348][ T0] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 3.542896][ T0] ? exc_general_protection (arch/x86/kernel/traps.c:751 arch/x86/kernel/traps.c:693) 
[ 3.543641][ T0] ? asm_exc_general_protection (arch/x86/include/asm/idtentry.h:617) 
[ 3.544411][ T0] ? mas_wr_store_type (lib/maple_tree.c:795 lib/maple_tree.c:808 lib/maple_tree.c:3526 lib/maple_tree.c:4198) 
[ 3.545114][ T0] ? mas_wr_store_type (lib/maple_tree.c:795 lib/maple_tree.c:808 lib/maple_tree.c:3526 lib/maple_tree.c:4198) 
[ 3.545833][ T0] mas_store_gfp (lib/maple_tree.c:212 lib/maple_tree.c:4145 lib/maple_tree.c:4268 lib/maple_tree.c:5477) 
[ 3.546457][ T0] ? __pfx_mas_store_gfp (lib/maple_tree.c:5470) 
[ 3.547141][ T0] ? init_desc (kernel/irq/irqdesc.c:213) 
[ 3.547738][ T0] early_irq_init (kernel/irq/irqdesc.c:174 kernel/irq/irqdesc.c:585) 
[ 3.548380][ T0] ? __pfx_early_irq_init (kernel/irq/irqdesc.c:563) 
[ 3.549074][ T0] ? __trace_define_field (include/linux/list.h:150 include/linux/list.h:169 kernel/trace/trace_events.c:138) 
[ 3.549825][ T0] start_kernel (init/main.c:1008) 
[ 3.550392][ T0] x86_64_start_reservations (arch/x86/kernel/head64.c:495) 
[ 3.551107][ T0] x86_64_start_kernel (arch/x86/kernel/head64.c:437 (discriminator 17)) 
[ 3.551765][ T0] common_startup_64 (arch/x86/kernel/head_64.S:414) 
[    3.552417][    T0]  </TASK>
[    3.552804][    T0] Modules linked in:
[    3.553314][    T0] ---[ end trace 0000000000000000 ]---
[ 3.554036][ T0] RIP: 0010:mas_wr_store_type (lib/maple_tree.c:795 lib/maple_tree.c:808 lib/maple_tree.c:3526 lib/maple_tree.c:4198) 
[ 3.554798][ T0] Code: 00 0f 85 a9 0e 00 00 4d 8b 75 00 e8 3a d0 0a 00 85 c0 0f 85 33 02 00 00 44 0f b6 74 24 20 4a 8d 6c f5 00 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 6e 0e 00 00 49 8d 7f 48 4c 8b 75 00 48 89 f8
All code
========
   0:	00 0f                	add    %cl,(%rdi)
   2:	85 a9 0e 00 00 4d    	test   %ebp,0x4d00000e(%rcx)
   8:	8b 75 00             	mov    0x0(%rbp),%esi
   b:	e8 3a d0 0a 00       	callq  0xad04a
  10:	85 c0                	test   %eax,%eax
  12:	0f 85 33 02 00 00    	jne    0x24b
  18:	44 0f b6 74 24 20    	movzbl 0x20(%rsp),%r14d
  1e:	4a 8d 6c f5 00       	lea    0x0(%rbp,%r14,8),%rbp
  23:	48 89 e8             	mov    %rbp,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
  2a:*	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)		<-- trapping instruction
  2f:	0f 85 6e 0e 00 00    	jne    0xea3
  35:	49 8d 7f 48          	lea    0x48(%r15),%rdi
  39:	4c 8b 75 00          	mov    0x0(%rbp),%r14
  3d:	48 89 f8             	mov    %rdi,%rax

Code starting with the faulting instruction
===========================================
   0:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
   5:	0f 85 6e 0e 00 00    	jne    0xe79
   b:	49 8d 7f 48          	lea    0x48(%r15),%rdi
   f:	4c 8b 75 00          	mov    0x0(%rbp),%r14
  13:	48 89 f8             	mov    %rdi,%rax


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20241105/202411051011.b1d218e6-oliver.sang@intel.com



-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki



^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2024-11-05  4:17 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-11-04  6:16 [PATCH] maple_tree: use KMEM_CACHE to create maple_node caches Ke Sun
2024-11-04 13:27 ` Matthew Wilcox
2024-11-05  2:21   ` Ke Sun
2024-11-05  4:17     ` Matthew Wilcox
2024-11-05  2:34 ` kernel test robot

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