linux-toradex.git/drivers/edac/edac_mc_sysfs.c, branch v4.8-rc2

EDAC: Correct channel count limit

2016-06-16T08:06:35+00:00

c44696fff04f ("EDAC: Remove arbitrary limit on number of channels")
lifted the arbitrary limit on memory controller channels in EDAC.
However, the dynamic channel attributes dynamic_csrow_dimm_attr and
dynamic_csrow_ce_count_attr remained 6.

This wasn't a problem except channels 6 and 7 weren't visible in sysfs
on machines with more than 6 channels after the conversion to static
attr groups with

  2c1946b6d629 ("EDAC: Use static attribute groups for managing sysfs entries")

 [ without that, we're exploding in edac_create_sysfs_mci_device()
   because we're dereferencing out of the bounds of the
   dynamic_csrow_dimm_attr array. ]

Add attributes for channels 6 and 7 along with a guard for the
future, should more channels be required and/or to sanity check for
misconfigured machines.

We still need to check against the number of channels present on the MC
first, as Thor reported.

Signed-off-by: Borislav Petkov 
Reported-by: Hironobu Ishii 
Tested-by: Thor Thayer 
Cc:  # 4.2

EDAC: Fix used after kfree() error in edac_unregister_sysfs()

2016-04-23T11:23:54+00:00

Code flow looks like this:

  device_unregister(&mci->dev);
   -> kobject_put+0x25/0x50
    -> kobject_cleanup+0x77/0x190
      -> device_release+0x32/0xa0
	-> mci_attr_release+0x36/0x70
	  -> kfree(mci);
  bus_unregister(mci->bus);

Fix is to grab a local copy of "mci->bus" and use that when we call
bus_unregister().

Signed-off-by: Tony Luck 
Acked-by: Aristeu Rozanski 
Cc: Mauro Carvalho Chehab 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/21d595b0ab3d718d9cb206647f4ec91c05e62ec4.1461261078.git.tony.luck@intel.com
Signed-off-by: Borislav Petkov

EDAC: Remove edac_get_sysfs_subsys() error handling

2015-12-11T15:56:41+00:00

It cannot fail now. We either load EDAC core after having successfully
initialized edac_subsys or we don't.

Signed-off-by: Borislav Petkov

EDAC: Rip out the edac_subsys reference counting

2015-12-11T15:56:39+00:00

This was really dumb - reference counting for the main EDAC sysfs
object. While we could've simply registered it as the first thing in the
module init path and then hand it around to what needs it.

Do that and rip out all the code around it, thus simplifying the whole
handling significantly.

Move the edac_subsys node back to edac_module.c.

Signed-off-by: Borislav Petkov

EDAC, mc_sysfs: Fix freeing bus' name

2015-12-11T15:56:38+00:00

I get the splat below when modprobing/rmmoding EDAC drivers. It happens
because bus->name is invalid after bus_unregister() has run. The Code: section
below corresponds to:

  .loc 1 1108 0
  movq    672(%rbx), %rax # mci_1(D)->bus, mci_1(D)->bus
  .loc 1 1109 0
  popq    %rbx    #

  .loc 1 1108 0
  movq    (%rax), %rdi    # _7->name,
  jmp     kfree   #

and %rax has some funky stuff 2030203020312030 which looks a lot like
something walked over it.

Fix that by saving the name ptr before doing stuff to string it points to.

  general protection fault: 0000 [#1] SMP
  Modules linked in: ...
  CPU: 4 PID: 10318 Comm: modprobe Tainted: G          I EN  3.12.51-11-default+ #48
  Hardware name: HP ProLiant DL380 G7, BIOS P67 05/05/2011
  task: ffff880311320280 ti: ffff88030da3e000 task.ti: ffff88030da3e000
  RIP: 0010:[]  [] edac_unregister_sysfs+0x22/0x30 [edac_core]
  RSP: 0018:ffff88030da3fe28  EFLAGS: 00010292
  RAX: 2030203020312030 RBX: ffff880311b4e000 RCX: 000000000000095c
  RDX: 0000000000000001 RSI: ffff880327bb9600 RDI: 0000000000000286
  RBP: ffff880311b4e750 R08: 0000000000000000 R09: ffffffff81296110
  R10: 0000000000000400 R11: 0000000000000000 R12: ffff88030ba1ac68
  R13: 0000000000000001 R14: 00000000011b02f0 R15: 0000000000000000
  FS:  00007fc9bf8f5700(0000) GS:ffff8801a7c40000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000403c90 CR3: 000000019ebdf000 CR4: 00000000000007e0
  Stack:
  Call Trace:
    i7core_unregister_mci.isra.9
    i7core_remove
    pci_device_remove
    __device_release_driver
    driver_detach
    bus_remove_driver
    pci_unregister_driver
    i7core_exit
    SyS_delete_module
    system_call_fastpath
    0x7fc9bf426536
  Code: 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 53 48 89 fb e8 52 2a 1f e1 48 8b bb a0 02 00 00 e8 46 59 1f e1 48 8b 83 a0 02 00 00 5b <48> 8b 38 e9 26 9a fe e0 66 0f 1f 44 00 00 66 66 66 66 90 48 8b
  RIP  [] edac_unregister_sysfs+0x22/0x30 [edac_core]
   RSP 

Signed-off-by: Borislav Petkov 
Cc: Mauro Carvalho Chehab 
Cc:  # v3.6..
Fixes: 7a623c039075 ("edac: rewrite the sysfs code to use struct device")

EDAC: Use edac_debugfs_remove_recursive()

2015-10-14T16:50:32+00:00

debugfs_remove() is used to remove a file or a directory from the
debugfs filesystem, but mci->debugfs might not empty.

This can be triggered by the following sequence:

1) Enable CONFIG_EDAC_DEBUG
2) insmod an EDAC module (like i3000_edac or similar)
3) rmmod this module
4) we can see files remaining under /edac/ like
   "fake_inject", for example.

Removing edac_core then, causes a NULL pointer dereference.

Reported-by: Yun Wu (Abel) 
Signed-off-by: Tan Xiaojun 
Cc: Doug Thompson 
Cc: Mauro Carvalho Chehab 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/1444787364-104353-1-git-send-email-tanxiaojun@huawei.com
Signed-off-by: Borislav Petkov

EDAC: Don't allow empty DIMM labels

2015-09-28T14:39:05+00:00

Updating dimm_label to an empty string does not make much sense. Change
the sysfs dimm_label store operation to fail a request when an input
string is empty.

Suggested-by: Borislav Petkov 
Signed-off-by: Toshi Kani 
Cc: elliott@hpe.com
Cc: Mauro Carvalho Chehab 
Cc: Tony Luck 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/1443124767.25474.172.camel@hpe.com
Signed-off-by: Borislav Petkov

EDAC: Fix sysfs dimm_label store operation

2015-09-25T17:45:59+00:00

Sysfs "dimm_label" and "chX_dimm_label" nodes have the following issues
in their store operation:

 1) A newline-terminated input string causes redundant newlines:

  # echo "test" > /sys/bus/mc0/devices/dimm0/dimm_label
  # cat  /sys/bus/mc0/devices/dimm0/dimm_label
  test

  #  od -bc /sys/bus/mc0/devices/dimm0/dimm_label
  0000000 164 145 163 164 012 012
            t   e   s   t  \n  \n
  0000006

 2) The original label string (31 characters) cannot be stored due to
    an improper size check:

  # echo "CPU_SrcID#0_Ha#0_Chan#0_DIMM#0" > /sys/bus/mc0/devices/dimm0/dimm_label
  # cat /sys/bus/mc0/devices/dimm0/dimm_label

  # od -bc /sys/bus/mc0/devices/dimm0/dimm_label
   0000000 012 012
            \n  \n
   0000002

 3) An input string longer than the buffer size results a wrong label
    info as it allows a retry with the remaining string:

  # echo "CPU_SrcID#0_Ha#0_Chan#0_DIMM#0_TEST" > /sys/bus/mc0/devices/dimm0/dimm_label
  # cat  /sys/bus/mc0/devices/dimm0/dimm_label
  _TEST

Fix these issues by making the following changes:
 1) Replace a newline character at the end by setting a null. It also
    assures that the string is null-terminated in the label buffer.
 2) Check the label buffer size with 'sizeof(dimm->label)'.
 3) Fail a request if its string exceeds the label buffer size.

Signed-off-by: Toshi Kani 
Acked-by: Tony Luck 
Cc: linux-edac 
Cc: Mauro Carvalho Chehab 
Cc: Robert Elliott 
Link: http://lkml.kernel.org/r/1443121564.25474.160.camel@hpe.com
Signed-off-by: Borislav Petkov

EDAC: Fix sysfs dimm_label show operation

2015-09-25T17:19:21+00:00

After

  7d375bffa524 ("sb_edac: Fix support for systems with two home agents per socket")

sysfs "dimm_label" and "chX_dimm_label" show their label string without a
newline "\n" at the end.

  [root@orange ~]# cat /sys/bus/mc0/devices/dimm0/dimm_label
  CPU_SrcID#0_Ha#0_Chan#0_DIMM#0[root@orange ~]#

  [root@orange ~]# cat /sys/devices/system/edac/mc/mc0/csrow0/ch0_dimm_label
  CPU_SrcID#0_Ha#0_Chan#0_DIMM#0[root@orange ~]#

The label strings now have 31 characters, which are the same as
EDAC_MC_LABEL_LEN. Since the snprintf()s in channel_dimm_label_show()
and dimmdev_label_show() limit the whole length by EDAC_MC_LABEL_LEN,
the newline in the format "%s\n" is ignored.

  [root@orange ~]# od -bc /sys/bus/mc0/devices/dimm0/dimm_label
  0000000 103 120 125 137 123 162 143 111 104 043 060 137 110 141 043 060
            C   P   U   _   S   r   c   I   D   #   0   _   H   a   #   0
  0000020 137 103 150 141 156 043 060 137 104 111 115 115 043 060 000
            _   C   h   a   n   #   0   _   D   I   M   M   #   0  \0
  0000037

Fix it by using 'sizeof(dimm->label) + 1' as the whole length in the
snprintf()s in channel_dimm_label_show() and dimmdev_label_show().

Reported-by: Robert Elliott 
Signed-off-by: Toshi Kani 
Acked-by: Tony Luck 
Cc: linux-edac 
Cc: Mauro Carvalho Chehab 
Link: http://lkml.kernel.org/r/1442933883-21587-2-git-send-email-toshi.kani@hpe.com
Signed-off-by: Borislav Petkov

EDAC: Carve out debugfs functionality

2015-09-22T10:29:46+00:00

... into a separate compilation unit and drop a couple of
CONFIG_EDAC_DEBUG ifdefferies. Rename edac_create_debug_nodes() to
edac_create_debugfs_nodes(), while at it.

No functionality change.

Cc: 
Signed-off-by: Borislav Petkov