linux-toradex.git/kernel/params.c, branch v5.1-rc1

kernel/params.c: downgrade warning for unsafe parameters

2018-04-11T17:28:37+00:00

As using an unsafe module parameter is, by its very definition, an
expected user action, emitting a warning is overkill.  Nothing has yet
gone wrong, and we add a taint flag for any future oops should something
actually go wrong.  So instead of having a user controllable pr_warn,
downgrade it to a pr_notice for "a normal, but significant condition".

We make use of unsafe kernel parameters in igt
(https://cgit.freedesktop.org/drm/igt-gpu-tools/) (we have not yet
succeeded in removing all such debugging options), which generates a
warning and taints the kernel.  The warning is unhelpful as we then need
to filter it out again as we check that every test themselves do not
provoke any kernel warnings.

Link: http://lkml.kernel.org/r/20180226151919.9674-1-chris@chris-wilson.co.uk
Fixes: 91f9d330cc14 ("module: make it possible to have unsafe, tainting module params")
Signed-off-by: Chris Wilson 
Acked-by: Jani Nikula 
Reviewed-by: Andrew Morton 
Cc: Rusty Russell 
Cc: Jean Delvare 
Cc: Li Zhong 
Cc: Petri Latvala 
Cc: Daniel Vetter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/params.c: improve STANDARD_PARAM_DEF readability

2017-10-04T00:54:26+00:00

Align the parameters passed to STANDARD_PARAM_DEF for clarity.

Link: http://lkml.kernel.org/r/20170928162728.756143cc@endymion
Signed-off-by: Jean Delvare 
Suggested-by: Ingo Molnar 
Acked-by: Ingo Molnar 
Cc: Baoquan He 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/params.c: fix an overflow in param_attr_show

2017-10-04T00:54:26+00:00

Function param_attr_show could overflow the buffer it is operating on.

The buffer size is PAGE_SIZE, and the string returned by
attribute->param->ops->get is generated by scnprintf(buffer, PAGE_SIZE,
...) so it could be PAGE_SIZE - 1 long, with the terminating '\0' at the
very end of the buffer.  Calling strcat(..., "\n") on this isn't safe, as
the '\0' will be replaced by '\n' (OK) and then another '\0' will be added
past the end of the buffer (not OK.)

Simply add the trailing '\n' when writing the attribute contents to the
buffer originally.  This is safe, and also faster.

Credits to Teradata for discovering this issue.

Link: http://lkml.kernel.org/r/20170928162602.60c379c7@endymion
Signed-off-by: Jean Delvare 
Acked-by: Ingo Molnar 
Cc: Baoquan He 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/params.c: fix the maximum length in param_get_string

2017-10-04T00:54:26+00:00

The length parameter of strlcpy() is supposed to reflect the size of the
target buffer, not of the source string.  Harmless in this case as the
buffer is PAGE_SIZE long and the source string is always much shorter than
this, but conceptually wrong, so let's fix it.

Link: http://lkml.kernel.org/r/20170928162515.24846b4f@endymion
Signed-off-by: Jean Delvare 
Acked-by: Ingo Molnar 
Cc: Baoquan He 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/params.c: align add_sysfs_param documentation with code

2017-10-04T00:54:23+00:00

This parameter is named kp, so the documentation should use that.

Fixes: 9b473de87209 ("param: Fix duplicate module prefixes")
Link: http://lkml.kernel.org/r/20170919142656.64aea59e@endymion
Signed-off-by: Jean Delvare 
Acked-by: Rusty Russell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

boot/param: Move next_arg() function to lib/cmdline.c for later reuse

2017-04-18T08:37:13+00:00

next_arg() will be used to parse boot parameters in the x86/boot/compressed code,
so move it to lib/cmdline.c for better code reuse.

No change in functionality.

Signed-off-by: Baoquan He 
Cc: Andrew Morton 
Cc: Gustavo Padovan 
Cc: Jens Axboe 
Cc: Jessica Yu 
Cc: Johannes Berg 
Cc: Josh Triplett 
Cc: Larry Finger 
Cc: Linus Torvalds 
Cc: Niklas Söderlund 
Cc: Peter Zijlstra 
Cc: Petr Mladek 
Cc: Rasmus Villemoes 
Cc: Thomas Gleixner 
Cc: dan.j.williams@intel.com
Cc: dave.jiang@intel.com
Cc: dyoung@redhat.com
Cc: keescook@chromium.org
Cc: zijun_hu 
Link: http://lkml.kernel.org/r/1492436099-4017-2-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2015-11-09T23:53:39+00:00

Pull module updates from Rusty Russell:
 "Nothing exciting, minor tweaks and cleanups"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  scripts: [modpost] add new sections to white list
  modpost: Add flag -E for making section mismatches fatal
  params: don't ignore the rest of cmdline if parse_one() fails
  modpost: abort if a module symbol is too long

module: export param_free_charp()

2015-11-07T01:50:42+00:00

Change the param_free_charp() function from static to exported.

It is used by zswap in the next patch ("zswap: use charp for zswap param
strings").

Signed-off-by: Dan Streetman 
Acked-by: Rusty Russell 
Cc: Seth Jennings 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

params: don't ignore the rest of cmdline if parse_one() fails

2015-08-26T01:06:19+00:00

parse_args() just aborts after it hits an error, so other args
at the same initcall level are simply ignored. This can lead to
other hard-to-understand problems, for example my testing machine
panics during the boot if I pass "locktorture.verbose=true".

Change parse_args() to save the err code for return and continue.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Rusty Russell

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2015-07-01T17:49:25+00:00

Pull module updates from Rusty Russell:
 "Main excitement here is Peter Zijlstra's lockless rbtree optimization
  to speed module address lookup.  He found some abusers of the module
  lock doing that too.

  A little bit of parameter work here too; including Dan Streetman's
  breaking up the big param mutex so writing a parameter can load
  another module (yeah, really).  Unfortunately that broke the usual
  suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were
  appended too"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits)
  modules: only use mod->param_lock if CONFIG_MODULES
  param: fix module param locks when !CONFIG_SYSFS.
  rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()
  module: add per-module param_lock
  module: make perm const
  params: suppress unused variable error, warn once just in case code changes.
  modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'.
  kernel/module.c: avoid ifdefs for sig_enforce declaration
  kernel/workqueue.c: remove ifdefs over wq_power_efficient
  kernel/params.c: export param_ops_bool_enable_only
  kernel/params.c: generalize bool_enable_only
  kernel/module.c: use generic module param operaters for sig_enforce
  kernel/params: constify struct kernel_param_ops uses
  sysfs: tightened sysfs permission checks
  module: Rework module_addr_{min,max}
  module: Use __module_address() for module_address_lookup()
  module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING
  module: Optimize __module_address() using a latched RB-tree
  rbtree: Implement generic latch_tree
  seqlock: Introduce raw_read_seqcount_latch()
  ...