linux-stable.git/drivers/mtd/mtdcore.c, branch v6.2

mtd: core: Fix refcount error in del_mtd_device()

2022-11-24T11:32:16+00:00

del_mtd_device() will call of_node_put() to mtd_get_of_node(mtd), which
is mtd->dev.of_node. However, memset(&mtd->dev, 0) is called before
of_node_put(). As the result, of_node_put() won't do anything in
del_mtd_device(), and causes the refcount leak.

del_mtd_device()
    memset(&mtd->dev, 0, sizeof(mtd->dev) # clear mtd->dev
    of_node_put()
        mtd_get_of_node(mtd) # mtd->dev is cleared, can't locate of_node
                             # of_node_put(NULL) won't do anything

Fix the error by caching the pointer of the device_node.

OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry: attach
overlay node /spi/spi-sram@0
CPU: 3 PID: 275 Comm: python3 Tainted: G N 6.1.0-rc3+ #54
    0d8a1edddf51f172ff5226989a7565c6313b08e2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
Call Trace:

    dump_stack_lvl+0x67/0x83
    kobject_get+0x155/0x160
    of_node_get+0x1f/0x30
    of_fwnode_get+0x43/0x70
    fwnode_handle_get+0x54/0x80
    fwnode_get_nth_parent+0xc9/0xe0
    fwnode_full_name_string+0x3f/0xa0
    device_node_string+0x30f/0x750
    pointer+0x598/0x7a0
    vsnprintf+0x62d/0x9b0
    ...
    cfs_overlay_release+0x30/0x90
    config_item_release+0xbe/0x1a0
    config_item_put+0x5e/0x80
    configfs_rmdir+0x3bd/0x540
    vfs_rmdir+0x18c/0x320
    do_rmdir+0x198/0x330
    __x64_sys_rmdir+0x2c/0x40
    do_syscall_64+0x37/0x90
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 00596576a051 ("mtd: core: clear out unregistered devices a bit more")
Signed-off-by: Shang XiaoJing 
[: Light reword of the commit log]
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20221119063915.11108-1-shangxiaojing@huawei.com

mtd: core: fix possible resource leak in init_mtd()

2022-11-07T16:14:20+00:00

I got the error report while inject fault in init_mtd():

sysfs: cannot create duplicate filename '/devices/virtual/bdi/mtd-0'
Call Trace:
 
 dump_stack_lvl+0x67/0x83
 sysfs_warn_dup+0x60/0x70
 sysfs_create_dir_ns+0x109/0x120
 kobject_add_internal+0xce/0x2f0
 kobject_add+0x98/0x110
 device_add+0x179/0xc00
 device_create_groups_vargs+0xf4/0x100
 device_create+0x7b/0xb0
 bdi_register_va.part.13+0x58/0x2d0
 bdi_register+0x9b/0xb0
 init_mtd+0x62/0x171 [mtd]
 do_one_initcall+0x6c/0x3c0
 do_init_module+0x58/0x222
 load_module+0x268e/0x27d0
 __do_sys_finit_module+0xd5/0x140
 do_syscall_64+0x37/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
 
kobject_add_internal failed for mtd-0 with -EEXIST, don't try to register
	things with the same name in the same directory.
Error registering mtd class or bdi: -17

If init_mtdchar() fails in init_mtd(), mtd_bdi will not be unregistered,
as a result, we can't load the mtd module again, to fix this by calling
bdi_unregister(mtd_bdi) after out_procfs label.

Fixes: 445caaa20c4d ("mtd: Allocate bdi objects dynamically")
Signed-off-by: Gaosheng Cui 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20221024065109.2050705-1-cuigaosheng1@huawei.com

mtd: core: set ROOT_DEV for partitions marked as rootfs in DT

2022-11-07T16:14:18+00:00

This adds support for "linux,rootfs" binding that is used to mark flash
partition containing rootfs. It's useful for devices using device tree
that don't have bootloader passing root info in cmdline.

Signed-off-by: Rafał Miłecki 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20221022211318.32009-2-zajec5@gmail.com

mtd: Fix device name leak when register device failed in add_mtd_device()

2022-11-07T16:14:16+00:00

There is a kmemleak when register device failed:
  unreferenced object 0xffff888101aab550 (size 8):
    comm "insmod", pid 3922, jiffies 4295277753 (age 925.408s)
    hex dump (first 8 bytes):
      6d 74 64 30 00 88 ff ff                          mtd0....
    backtrace:
      [<00000000bde26724>] __kmalloc_node_track_caller+0x4e/0x150
      [<000000003c32b416>] kvasprintf+0xb0/0x130
      [<000000001f7a8f15>] kobject_set_name_vargs+0x2f/0xb0
      [<000000006e781163>] dev_set_name+0xab/0xe0
      [<00000000e30d0c78>] add_mtd_device+0x4bb/0x700
      [<00000000f3d34de7>] mtd_device_parse_register+0x2ac/0x3f0
      [<00000000c0d88488>] 0xffffffffa0238457
      [<00000000b40d0922>] 0xffffffffa02a008f
      [<0000000023d17b9d>] do_one_initcall+0x87/0x2a0
      [<00000000770f6ca6>] do_init_module+0xdf/0x320
      [<000000007b6768fe>] load_module+0x2f98/0x3330
      [<00000000346bed5a>] __do_sys_finit_module+0x113/0x1b0
      [<00000000674c2290>] do_syscall_64+0x35/0x80
      [<000000004c6a8d97>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

If register device failed, should call put_device() to give up the
reference.

Fixes: 1f24b5a8ecbb ("[MTD] driver model updates")
Signed-off-by: Zhang Xiaoxu 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20221022121352.2534682-1-zhangxiaoxu5@huawei.com

mtd: core: try to find OF node for every MTD partition

2022-11-07T16:07:56+00:00

So far this feature was limited to the top-level "nvmem-cells" node.
There are multiple parsers creating partitions and subpartitions
dynamically. Extend that code to handle them too.

This allows finding partition-* node for every MTD (sub)partition.

Random example:

partitions {
	compatible = "brcm,bcm947xx-cfe-partitions";

	partition-firmware {
		compatible = "brcm,trx";

		partition-loader {
		};
	};
};

Cc: Christian Marangi 
Signed-off-by: Rafał Miłecki 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-2-zajec5@gmail.com

mtd: core: simplify (a bit) code find partition-matching dynamic OF node

2022-11-07T16:06:30+00:00

1. Don't hardcode "partition-" string twice
2. Use simpler logic & use ->name to avoid of_property_read_string()
3. Use mtd_get_of_node() helper

Cc: Christian Marangi 
Signed-off-by: Rafał Miłecki 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20221004083710.27704-1-zajec5@gmail.com

mtd: core: add missing of_node_get() in dynamic partitions code

2022-10-18T08:16:38+00:00

This fixes unbalanced of_node_put():
[    1.078910] 6 cmdlinepart partitions found on MTD device gpmi-nand
[    1.085116] Creating 6 MTD partitions on "gpmi-nand":
[    1.090181] 0x000000000000-0x000008000000 : "nandboot"
[    1.096952] 0x000008000000-0x000009000000 : "nandfit"
[    1.103547] 0x000009000000-0x00000b000000 : "nandkernel"
[    1.110317] 0x00000b000000-0x00000c000000 : "nanddtb"
[    1.115525] ------------[ cut here ]------------
[    1.120141] refcount_t: addition on 0; use-after-free.
[    1.125328] WARNING: CPU: 0 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0xdc/0x148
[    1.133528] Modules linked in:
[    1.136589] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.0.0-rc7-next-20220930-04543-g8cf3f7
[    1.146342] Hardware name: Freescale i.MX8DXL DDR3L EVK (DT)
[    1.151999] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    1.158965] pc : refcount_warn_saturate+0xdc/0x148
[    1.163760] lr : refcount_warn_saturate+0xdc/0x148
[    1.168556] sp : ffff800009ddb080
[    1.171866] x29: ffff800009ddb080 x28: ffff800009ddb35a x27: 0000000000000002
[    1.179015] x26: ffff8000098b06ad x25: ffffffffffffffff x24: ffff0a00ffffff05
[    1.186165] x23: ffff00001fdf6470 x22: ffff800009ddb367 x21: 0000000000000000
[    1.193314] x20: ffff00001fdfebe8 x19: ffff00001fdfec50 x18: ffffffffffffffff
[    1.200464] x17: 0000000000000000 x16: 0000000000000118 x15: 0000000000000004
[    1.207614] x14: 0000000000000fff x13: ffff800009bca248 x12: 0000000000000003
[    1.214764] x11: 00000000ffffefff x10: c0000000ffffefff x9 : 4762cb2ccb52de00
[    1.221914] x8 : 4762cb2ccb52de00 x7 : 205d313431303231 x6 : 312e31202020205b
[    1.229063] x5 : ffff800009d55c1f x4 : 0000000000000001 x3 : 0000000000000000
[    1.236213] x2 : 0000000000000000 x1 : ffff800009954be6 x0 : 000000000000002a
[    1.243365] Call trace:
[    1.245806]  refcount_warn_saturate+0xdc/0x148
[    1.250253]  kobject_get+0x98/0x9c
[    1.253658]  of_node_get+0x20/0x34
[    1.257072]  of_fwnode_get+0x3c/0x54
[    1.260652]  fwnode_get_nth_parent+0xd8/0xf4
[    1.264926]  fwnode_full_name_string+0x3c/0xb4
[    1.269373]  device_node_string+0x498/0x5b4
[    1.273561]  pointer+0x41c/0x5d0
[    1.276793]  vsnprintf+0x4d8/0x694
[    1.280198]  vprintk_store+0x164/0x528
[    1.283951]  vprintk_emit+0x98/0x164
[    1.287530]  vprintk_default+0x44/0x6c
[    1.291284]  vprintk+0xf0/0x134
[    1.294428]  _printk+0x54/0x7c
[    1.297486]  of_node_release+0xe8/0x128
[    1.301326]  kobject_put+0x98/0xfc
[    1.304732]  of_node_put+0x1c/0x28
[    1.308137]  add_mtd_device+0x484/0x6d4
[    1.311977]  add_mtd_partitions+0xf0/0x1d0
[    1.316078]  parse_mtd_partitions+0x45c/0x518
[    1.320439]  mtd_device_parse_register+0xb0/0x274
[    1.325147]  gpmi_nand_probe+0x51c/0x650
[    1.329074]  platform_probe+0xa8/0xd0
[    1.332740]  really_probe+0x130/0x334
[    1.336406]  __driver_probe_device+0xb4/0xe0
[    1.340681]  driver_probe_device+0x3c/0x1f8
[    1.344869]  __driver_attach+0xdc/0x1a4
[    1.348708]  bus_for_each_dev+0x80/0xcc
[    1.352548]  driver_attach+0x24/0x30
[    1.356127]  bus_add_driver+0x108/0x1f4
[    1.359967]  driver_register+0x78/0x114
[    1.363807]  __platform_driver_register+0x24/0x30
[    1.368515]  gpmi_nand_driver_init+0x1c/0x28
[    1.372798]  do_one_initcall+0xbc/0x238
[    1.376638]  do_initcall_level+0x94/0xb4
[    1.380565]  do_initcalls+0x54/0x94
[    1.384058]  do_basic_setup+0x1c/0x28
[    1.387724]  kernel_init_freeable+0x110/0x188
[    1.392084]  kernel_init+0x20/0x1a0
[    1.395578]  ret_from_fork+0x10/0x20
[    1.399157] ---[ end trace 0000000000000000 ]---
[    1.403782] ------------[ cut here ]------------

Reported-by: Han Xu 
Fixes: ad9b10d1eaada169 ("mtd: core: introduce of support for dynamic partitions")
Signed-off-by: Rafał Miłecki 
Tested-by: Han Xu 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20221018051822.28685-1-zajec5@gmail.com

Merge tag 'char-misc-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2022-10-08T15:56:37+00:00

Pull char/misc and other driver updates from Greg KH:
 "Here is the large set of char/misc and other small driver subsystem
  changes for 6.1-rc1. Loads of different things in here:

   - IIO driver updates, additions, and changes. Probably the largest
     part of the diffstat

   - habanalabs driver update with support for new hardware and
     features, the second largest part of the diff.

   - fpga subsystem driver updates and additions

   - mhi subsystem updates

   - Coresight driver updates

   - gnss subsystem updates

   - extcon driver updates

   - icc subsystem updates

   - fsi subsystem updates

   - nvmem subsystem and driver updates

   - misc driver updates

   - speakup driver additions for new features

   - lots of tiny driver updates and cleanups

  All of these have been in the linux-next tree for a while with no
  reported issues"

* tag 'char-misc-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (411 commits)
  w1: Split memcpy() of struct cn_msg flexible array
  spmi: pmic-arb: increase SPMI transaction timeout delay
  spmi: pmic-arb: block access for invalid PMIC arbiter v5 SPMI writes
  spmi: pmic-arb: correct duplicate APID to PPID mapping logic
  spmi: pmic-arb: add support to dispatch interrupt based on IRQ status
  spmi: pmic-arb: check apid against limits before calling irq handler
  spmi: pmic-arb: do not ack and clear peripheral interrupts in cleanup_irq
  spmi: pmic-arb: handle spurious interrupt
  spmi: pmic-arb: add a print in cleanup_irq
  drivers: spmi: Directly use ida_alloc()/free()
  MAINTAINERS: add TI ECAP driver info
  counter: ti-ecap-capture: capture driver support for ECAP
  Documentation: ABI: sysfs-bus-counter: add frequency & num_overflows items
  dt-bindings: counter: add ti,am62-ecap-capture.yaml
  counter: Introduce the COUNTER_COMP_ARRAY component type
  counter: Consolidate Counter extension sysfs attribute creation
  counter: Introduce the Count capture component
  counter: 104-quad-8: Add Signal polarity component
  counter: Introduce the Signal polarity component
  counter: interrupt-cnt: Implement watch_validate callback
  ...

mtd: allow getting MTD device associated with a specific DT node

2022-09-24T12:54:37+00:00

MTD subsystem API allows interacting with MTD devices (e.g. reading,
writing, handling bad blocks). So far a random driver could get MTD
device only by its name (get_mtd_device_nm()). This change allows
getting them also by a DT node.

This API is required for drivers handling DT defined MTD partitions in a
specific way (e.g. U-Boot (sub)partition with environment variables).

Acked-by: Miquel Raynal 
Signed-off-by: Rafał Miłecki 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20220916122100.170016-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

mtd: track maximum number of bitflips for each read request

2022-09-21T08:38:05+00:00

mtd_read_oob() callers are currently oblivious to the details of ECC
errors detected during the read operation - they only learn (through the
return value) whether any corrected bitflips or uncorrectable errors
occurred.  More detailed ECC information can be useful to user-space
applications for making better-informed choices about moving data
around.

Extend struct mtd_oob_ops with a pointer to a newly-introduced struct
mtd_req_stats and set its 'max_bitflips' field to the maximum number of
bitflips found in a single ECC step during the read operation performed
by mtd_read_oob().  This is a prerequisite for ultimately passing that
value back to user space.

Suggested-by: Boris Brezillon 
Signed-off-by: Michał Kępień 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20220629125737.14418-2-kernel@kempniu.pl