linux-toradex.git/kernel/params.c, branch tegra-10.7.1

param: fix setting arrays of bool

2009-10-28T22:26:20+00:00

We create a dummy struct kernel_param on the stack for parsing each
array element, but we didn't initialize the flags word.  This matters
for arrays of type "bool", where the flag indicates if it really is
an array of bools or unsigned int (old-style).

Reported-by: Takashi Iwai 
Signed-off-by: Rusty Russell 
Cc: stable@kernel.org

param: fix NULL comparison on oom

2009-10-28T22:26:18+00:00

kp->arg is always true: it's the contents of that pointer we care about.

Reported-by: Takashi Iwai 
Signed-off-by: Rusty Russell 
Cc: stable@kernel.org

param: fix lots of bugs with writing charp params from sysfs, by leaking mem.

2009-10-28T22:26:17+00:00

e180a6b7759a "param: fix charp parameters set via sysfs" fixed the case
where charp parameters written via sysfs were freed, leaving drivers
accessing random memory.

Unfortunately, storing a flag in the kparam struct was a bad idea: it's
rodata so setting it causes an oops on some archs.  But that's not all:

1) module_param_array() on charp doesn't work reliably, since we use an
   uninitialized temporary struct kernel_param.
2) there's a fundamental race if a module uses this parameter and then
   it's changed: they will still access the old, freed, memory.

The simplest fix (ie. for 2.6.32) is to never free the memory.  This
prevents all these problems, at cost of a memory leak.  In practice, there
are only 18 places where a charp is writable via sysfs, and all are
root-only writable.

Reported-by: Takashi Iwai 
Cc: Sitsofe Wheeler 
Cc: Frederic Weisbecker 
Cc: Christof Schmitt 
Signed-off-by: Rusty Russell 
Cc: stable@kernel.org

param: allow whitespace as kernel parameter separator

2009-09-24T15:02:58+00:00

Some boot mechanisms require that kernel parameters are stored in a
separate file which is loaded to memory without further processing
(e.g. the "Load from FTP" method on s390). When such a file contains
newline characters, the kernel parameter preceding the newline might
not be correctly parsed (due to the newline being stuck to the end of
the actual parameter value) which can lead to boot failures.

This patch improves kernel command line usability in such a situation
by allowing generic whitespace characters as separators between kernel
parameters.

Signed-off-by: Peter Oberparleiter 
Signed-off-by: Rusty Russell

module_param: allow 'bool' module_params to be bool, not just int.

2009-06-12T12:16:58+00:00

Impact: API cleanup

For historical reasons, 'bool' parameters must be an int, not a bool.
But there are around 600 users, so a conversion seems like useless churn.

So we use __same_type() to distinguish, and handle both cases.

Signed-off-by: Rusty Russell

module_param: split perm field into flags and perm

2009-06-12T12:16:56+00:00

Impact: cleanup

Rather than hack KPARAM_KMALLOCED into the perm field, separate it out.
Since the perm field was 32 bits and only needs 16, we don't add bloat.

Signed-off-by: Rusty Russell

module_param: invbool should take a 'bool', not an 'int'

2009-06-12T12:16:56+00:00

It takes an 'int' for historical reasons, and there are only two
users: simply switch it over to bool.

The other user (uvesafb.c) will get a (harmless-on-x86) warning until
the next patch is applied.

Cc: Brad Douglas 
Cc: Michal Januszewski 
Signed-off-by: Rusty Russell

param: fix charp parameters set via sysfs

2009-03-31T02:35:30+00:00

Impact: fix crash on reading from /sys/module/.../ieee80211_default_rc_algo

The module_param type "charp" simply sets a char * pointer in the
module to the parameter in the commandline string: this is why we keep
the (mangled) module command line around.  But when set via sysfs (as
about 11 charp parameters can be) this memory is freed on the way
out of the write().  Future reads hit random mem.

So we kstrdup instead: we have to check we're not in early commandline
parsing, and we have to note when we've used it so we can reliably
kfree the parameter when it's next overwritten, and also on module
unload.

(Thanks to Randy Dunlap for CONFIG_SYSFS=n fixes)

Reported-by: Sitsofe Wheeler 
Diagnosed-by: Frederic Weisbecker 
Tested-by: Frederic Weisbecker 
Tested-by: Christof Schmitt 
Signed-off-by: Rusty Russell

Fix compile warning in kernel/params.c

2008-10-23T19:09:00+00:00

Move free_module_param_attrs() into the CONFIG_MODULES section, since
it's only used inside there. Thus avoiding the warning

  kernel/params.c:514: warning: 'free_module_param_attrs' defined but not used

Signed-off-by: Linus Torvalds

core_param() for genuinely core kernel parameters

2008-10-21T23:00:23+00:00

There are a lot of one-liner uses of __setup() in the kernel: they're
cumbersome and not queryable (definitely not settable) via /sys.  Yet
it's ugly to simplify them to module_param(), because by default that
inserts a prefix of the module name (usually filename).

So, introduce a "core_param".  The parameter gets no prefix, but
appears in /sys/module/kernel/parameters/ (if non-zero perms arg).  I
thought about using the name "core", but that's more common than
"kernel".  And if you create a module called "kernel", you will die
a horrible death.

Signed-off-by: Rusty Russell