linux-toradex.git/fs/debugfs, branch v5.19-rc8

debugfs: Document that debugfs_create functions need not be error checked

2022-02-25T10:56:13+00:00

As talked about in commit b792e64021ec ("drm: no need to check return
value of debugfs_create functions"), in many cases we can get away
with totally skipping checking the errors of debugfs functions. Let's
document that so people don't add new code that needlessly checks
these errors.

Probably this note could be added to a boatload of functions, but
that's a lot of duplication.  Let's just add it to the two most
frequent ones and hope people will get the idea.

Suggested-by: Javier Martinez Canillas 
Reviewed-by: Javier Martinez Canillas 
Signed-off-by: Douglas Anderson 
Link: https://lore.kernel.org/r/20220222154555.1.I26d364db7a007f8995e8f0dac978673bc8e9f5e2@changeid
Signed-off-by: Greg Kroah-Hartman

debugfs: lockdown: Allow reading debugfs files that are not world readable

2022-01-06T14:47:41+00:00

When the kernel is locked down the kernel allows reading only debugfs
files with mode 444. Mode 400 is also valid but is not allowed.

Make the 444 into a mask.

Fixes: 5496197f9b08 ("debugfs: Restrict debugfs when the kernel is locked down")
Signed-off-by: Michal Suchanek 
Link: https://lore.kernel.org/r/20220104170505.10248-1-msuchanek@suse.de
Signed-off-by: Greg Kroah-Hartman

debugfs: debugfs_create_file_size(): use IS_ERR to check for error

2021-09-21T07:09:06+00:00

debugfs_create_file() returns encoded error so use IS_ERR for checking
return value.

Reviewed-by: Christian König 
Signed-off-by: Nirmoy Das 
Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL")
Cc: stable 
References: https://gitlab.freedesktop.org/drm/amd/-/issues/1686
Link: https://lore.kernel.org/r/20210902102917.2233-1-nirmoy.das@amd.com
Signed-off-by: Greg Kroah-Hartman

debugfs: Return error during {full/open}_proxy_open() on rmmod

2021-08-05T12:42:40+00:00

If a kernel module gets unloaded then it printed report about a leak before
commit 275678e7a9be ("debugfs: Check module state before warning in
{full/open}_proxy_open()"). An additional check was added in this commit to
avoid this printing. But it was forgotten that the function must return an
error in this case because it was not actually opened.

As result, the systems started to crash or to hang when a module was
unloaded while something was trying to open a file.

Fixes: 275678e7a9be ("debugfs: Check module state before warning in {full/open}_proxy_open()")
Cc: Taehee Yoo 
Reported-by: Mário Lopes 
Signed-off-by: Sven Eckelmann 
Link: https://lore.kernel.org/r/20210802162444.7848-1-sven@narfation.org
Signed-off-by: Greg Kroah-Hartman

Merge tag 'v5.13-rc6' into driver-core-next

2021-06-14T07:07:45+00:00

We need the driver core fix in here as well.

Signed-off-by: Greg Kroah-Hartman

debugfs: Fix debugfs_read_file_str()

2021-06-04T13:01:08+00:00

Read the entire size of the buffer, including the trailing new line
character.
Discovered while reading the sched domain names of CPU0:

before:

cat /sys/kernel/debug/sched/domains/cpu0/domain*/name
SMTMCDIE

after:

cat /sys/kernel/debug/sched/domains/cpu0/domain*/name
SMT
MC
DIE

Fixes: 9af0440ec86eb ("debugfs: Implement debugfs_create_str()")
Reviewed-by: Steven Rostedt (VMware) 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Dietmar Eggemann 
Link: https://lore.kernel.org/r/20210527091105.258457-1-dietmar.eggemann@arm.com
Signed-off-by: Greg Kroah-Hartman

Merge 5.13-rc4 into driver-core-next

2021-05-31T07:10:03+00:00

We need the driver core fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

debugfs: remove return value of debugfs_create_ulong()

2021-05-21T18:59:55+00:00

No one checks the return value of debugfs_create_ulong(), as it's not
needed, so make the return value void, so that no one tries to do so in
the future.

Link: https://lore.kernel.org/r/20210521184340.1348539-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

debugfs: remove return value of debugfs_create_bool()

2021-05-21T18:59:03+00:00

No one checks the return value of debugfs_create_bool(), as it's not
needed, so make the return value void, so that no one tries to do so in
the future.

Link: https://lore.kernel.org/r/20210521184519.1356639-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

debugfs: fix security_locked_down() call for SELinux

2021-05-18T16:05:59+00:00

When (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) is zero, then
the SELinux implementation of the locked_down hook might report a denial
even though the operation would actually be allowed.

To fix this, make sure that security_locked_down() is called only when
the return value will be taken into account (i.e. when changing one of
the problematic attributes).

Note: this was introduced by commit 5496197f9b08 ("debugfs: Restrict
debugfs when the kernel is locked down"), but it didn't matter at that
time, as the SELinux support came in later.

Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown")
Cc: stable 
Signed-off-by: Ondrej Mosnacek 
Link: https://lore.kernel.org/r/20210507125304.144394-1-omosnace@redhat.com
Signed-off-by: Greg Kroah-Hartman