linux-stable.git/drivers/base/regmap/regmap-debugfs.c, branch linux-5.1.y

regmap: debugfs: Fix memory leak in regmap_debugfs_init

2019-07-26T07:12:23+00:00

[ Upstream commit 2899872b627e99b7586fe3b6c9f861da1b4d5072 ]

As detected by kmemleak running on i.MX6ULL board:

nreferenced object 0xd8366600 (size 64):
  comm "swapper/0", pid 1, jiffies 4294937370 (age 933.220s)
  hex dump (first 32 bytes):
    64 75 6d 6d 79 2d 69 6f 6d 75 78 63 2d 67 70 72  dummy-iomuxc-gpr
    40 32 30 65 34 30 30 30 00 e3 f3 ab fe d1 1b dd  @20e4000........
  backtrace:
    [] kasprintf+0x2c/0x54
    [] regmap_debugfs_init+0x7c/0x31c
    [<9c8d91fa>] __regmap_init+0xb5c/0xcf4
    [<5b1c3d2a>] of_syscon_register+0x164/0x2c4
    [<596a5d80>] syscon_node_to_regmap+0x64/0x90
    [<49bd597b>] imx6ul_init_machine+0x34/0xa0
    [<250a4dac>] customize_machine+0x1c/0x30
    [<2d19fdaf>] do_one_initcall+0x7c/0x398
    [] kernel_init_freeable+0x328/0x448
    [<168c9101>] kernel_init+0x8/0x114
    [<913268aa>] ret_from_fork+0x14/0x20
    [] 0x0

Root cause is that map->debugfs_name is allocated using kasprintf
and then the pointer is lost by assigning it other memory address.

Reported-by: Stefan Wahren 
Signed-off-by: Daniel Baluta 
Signed-off-by: Mark Brown 
Signed-off-by: Sasha Levin

regmap: debugfs: convert to DEFINE_SHOW_ATTRIBUTE

2018-12-17T19:06:13+00:00

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.

Signed-off-by: Yangtao Li 
Signed-off-by: Mark Brown

regmap: debugfs: Improve warning message on debugfs_create_dir() failure

2018-03-06T14:49:28+00:00

Currently when debugfs_create_dir() fails we receive a warning message
that provides no indication as to what was the directory entry that
failed to be created.

Improve the warning message by printing the directory name that failed
in order to help debugging.

Signed-off-by: Fabio Estevam 
Signed-off-by: Mark Brown

regmap: debugfs: Free map->debugfs_name when debugfs_create_dir() failed

2018-03-06T14:20:50+00:00

Free map->debugfs_name when debugfs_create_dir() failed to avoid memory
leak.

Signed-off-by: Jeffy Chen 
Signed-off-by: Mark Brown

regmap: debugfs: Don't leak dummy names

2018-03-05T20:26:51+00:00

When allocating dummy names we need to store a pointer to the string we
allocate so that we don't leak it on free.

Signed-off-by: Mark Brown

regmap: debugfs: Disambiguate dummy debugfs file name

2018-03-05T19:23:26+00:00

Since commit 9b947a13e7f6 ("regmap: use debugfs even when no device")
allows the usage of regmap debugfs even when there is no device
associated, which causes several warnings like this:

(NULL device *): Failed to create debugfs directory

This happens when the debugfs file name is 'dummy'.

The first dummy debugfs creation works fine, but subsequent creations
fail as they have all the same name.

Disambiguate the 'dummy' debugfs file name by adding a suffix entry,
so that the names become dummy0, dummy1, dummy2, etc.

Signed-off-by: Fabio Estevam 
Signed-off-by: Mark Brown

regmap: Allow missing device in regmap_name_read_file()

2018-02-20T12:07:43+00:00

This fixes a possible NULL pointer dereference oops in
regmap_name_read_file() when the regmap does not have a device
associated with it. For example syscon regmaps retrieved with
syscon_regmap_lookup_by_compatible() don't have a device.

Signed-off-by: David Lechner 
Signed-off-by: Mark Brown

regmap: debugfs: document why we don't create the debugfs entries

2017-12-27T10:33:24+00:00

This is a follow-up to commit a5ba91c380b8 ("regmap: debugfs: emit a
debug message when locking is disabled"). I figured that a user may
see this message, grep the code, come to this place and he still won't
know why we actually disabled debugfs.

Add a comment explaining the reason.

Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Mark Brown

regmap: debugfs: emit a debug message when locking is disabled

2017-12-21T12:27:25+00:00

We currently silently omit creating the debugfs entries when regmap
locking is disabled. Users may not be aware of the reason for which
regmap files don't show up in debugfs. Add a dev_dbg() message
explaining that.

Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Mark Brown

regmap: Disable debugfs when locking is disabled

2017-12-13T16:22:31+00:00

The recently added support for disabling the regmap internal locking left
debugfs enabled for devices with the locking disabled. This is a problem
since debugfs allows userspace to do things like initiate reads from the
hardware which will use the scratch buffers protected by the regmap locking
so could cause data corruption.

For safety address this by just disabling debugfs for these devices. That
is overly conservative since some of the debugfs files just read internal
data structures but it's much simpler to implmement and less likely to
lead to problems with tooling that works with debugfs.

Reported-by: Lars-Peter Clausen 
Signed-off-by: Mark Brown