linux-toradex.git/lib/test_printf.c, branch v5.6-rc6

Merge tag 'devprop-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2019-11-27T03:45:12+00:00

Pull device properties framework updates from Rafael Wysocki:
 "Add support for printing fwnode names using a new conversion specifier
  "%pfw" (Sakari Ailus), clean up the software node and
  efi/apple-properties code in preparation for improved software node
  reference properties handling (Dmitry Torokhov) and fix the struct
  fwnode_operations description (Heikki Krogerus)"

* tag 'devprop-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (22 commits)
  software node: simplify property_entry_read_string_array()
  software node: unify PROPERTY_ENTRY_XXX macros
  software node: remove property_entry_read_uNN_array functions
  software node: get rid of property_set_pointer()
  software node: clean up property_copy_string_array()
  software node: mark internal macros with double underscores
  efi/apple-properties: use PROPERTY_ENTRY_U8_ARRAY_LEN
  software node: introduce PROPERTY_ENTRY_XXX_ARRAY_LEN()
  software node: remove DEV_PROP_MAX
  device property: Fix the description of struct fwnode_operations
  lib/test_printf: Add tests for %pfw printk modifier
  lib/vsprintf: Add %pfw conversion specifier for printing fwnode names
  lib/vsprintf: OF nodes are first and foremost, struct device_nodes
  lib/vsprintf: Make use of fwnode API to obtain node names and separators
  lib/vsprintf: Add a note on re-using %pf or %pF
  lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps
  device property: Add a function to obtain a node's prefix
  device property: Add fwnode_get_name for returning the name of a node
  device property: Add functions for accessing node's parents
  device property: Move fwnode_get_parent() up
  ...

printf: add support for printing symbolic error names

2019-10-17T14:23:25+00:00

It has been suggested several times to extend vsnprintf() to be able
to convert the numeric value of ENOSPC to print "ENOSPC". This
implements that as a %p extension: With %pe, one can do

  if (IS_ERR(foo)) {
    pr_err("Sorry, can't do that: %pe\n", foo);
    return PTR_ERR(foo);
  }

instead of what is seen in quite a few places in the kernel:

  if (IS_ERR(foo)) {
    pr_err("Sorry, can't do that: %ld\n", PTR_ERR(foo));
    return PTR_ERR(foo);
  }

If the value passed to %pe is an ERR_PTR, but the library function
errname() added here doesn't know about the value, the value is simply
printed in decimal. If the value passed to %pe is not an ERR_PTR, we
treat it as an ordinary %p and thus print the hashed value (passing
non-ERR_PTR values to %pe indicates a bug in the caller, but we can't
do much about that).

With my embedded hat on, and because it's not very invasive to do,
I've made it possible to remove this. The errname() function and
associated lookup tables take up about 3K. For most, that's probably
quite acceptable and a price worth paying for more readable
dmesg (once this starts getting used), while for those that disable
printk() it's of very little use - I don't see a
procfs/sysfs/seq_printf() file reasonably making use of this - and
they clearly want to squeeze vmlinux as much as possible. Hence the
default y if PRINTK.

The symbols to include have been found by massaging the output of

  find arch include -iname 'errno*.h' | xargs grep -E 'define\s*E'

In the cases where some common aliasing exists
(e.g. EAGAIN=EWOULDBLOCK on all platforms, EDEADLOCK=EDEADLK on most),
I've moved the more popular one (in terms of 'git grep -w Efoo | wc)
to the bottom so that one takes precedence.

Link: http://lkml.kernel.org/r/20191015190706.15989-1-linux@rasmusvillemoes.dk
To: "Jonathan Corbet" 
To: linux-kernel@vger.kernel.org
Cc: "Andy Shevchenko" 
Cc: "Andrew Morton" 
Cc: "Joe Perches" 
Cc: linux-doc@vger.kernel.org
Signed-off-by: Rasmus Villemoes 
Acked-by: Uwe Kleine-König 
Reviewed-by: Petr Mladek 
[andy.shevchenko@gmail.com: use abs()]
Acked-by: Andy Shevchenko 
Signed-off-by: Petr Mladek

lib/test_printf: Add tests for %pfw printk modifier

2019-10-11T09:26:55+00:00

Add a test for the %pfw printk modifier using software nodes.

Signed-off-by: Sakari Ailus 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Petr Mladek 
Signed-off-by: Rafael J. Wysocki

lib/test_printf: Remove obvious comments from %pd and %pD tests

2019-08-15T15:03:16+00:00

Signed-off-by: Petr Mladek

lib/test_printf: Add test of null/invalid pointer dereference for dentry

2019-08-15T14:58:06+00:00

This add some additional test cases of null/invalid pointer dereference
for dentry and file (%pd and %pD)

Link: http://lkml.kernel.org/r/20190809012457.56685-2-justin.he@arm.com
To: Geert Uytterhoeven 
To: Sergey Senozhatsky 
To: Thomas Gleixner 
To: Andy Shevchenko 
To: Petr Mladek 
To: linux-kernel@vger.kernel.org
Cc: Kees Cook 
Cc: "Steven Rostedt (VMware)" 
Cc: Shuah Khan 
Cc: "Tobin C. Harding" 
Signed-off-by: Jia He 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Sergey Senozhatsky 
Signed-off-by: Petr Mladek

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have MODULE_LICENCE("GPL*") inside which was used in the initial
   scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

2019-05-07T16:18:12+00:00

Pull printk updates from Petr Mladek:

 - Allow state reset of printk_once() calls.

 - Prevent crashes when dereferencing invalid pointers in vsprintf().
   Only the first byte is checked for simplicity.

 - Make vsprintf warnings consistent and inlined.

 - Treewide conversion of obsolete %pf, %pF to %ps, %pF printf
   modifiers.

 - Some clean up of vsprintf and test_printf code.

* tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  lib/vsprintf: Make function pointer_string static
  vsprintf: Limit the length of inlined error messages
  vsprintf: Avoid confusion between invalid address and value
  vsprintf: Prevent crash when dereferencing invalid pointers
  vsprintf: Consolidate handling of unknown pointer specifiers
  vsprintf: Factor out %pO handler as kobject_string()
  vsprintf: Factor out %pV handler as va_format()
  vsprintf: Factor out %p[iI] handler as ip_addr_string()
  vsprintf: Do not check address of well-known strings
  vsprintf: Consistent %pK handling for kptr_restrict == 0
  vsprintf: Shuffle restricted_pointer()
  printk: Tie printk_once / printk_deferred_once into .data.once for reset
  treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
  lib/test_printf: Switch to bitmap_zalloc()

Merge branch 'for-5.2-vsprintf-hardening' into for-linus

2019-05-06T08:32:45+00:00

vsprintf: Prevent crash when dereferencing invalid pointers

2019-04-26T14:20:43+00:00

We already prevent crash when dereferencing some obviously broken
pointers. But the handling is not consistent. Sometimes we print "(null)"
only for pure NULL pointer, sometimes for pointers in the first
page and sometimes also for pointers in the last page (error codes).

Note that printk() call this code under logbuf_lock. Any recursive
printks are redirected to the printk_safe implementation and the messages
are stored into per-CPU buffers. These buffers might be eventually flushed
in printk_safe_flush_on_panic() but it is not guaranteed.

This patch adds a check using probe_kernel_read(). It is not a full-proof
test. But it should help to see the error message in 99% situations where
the kernel would silently crash otherwise.

Also it makes the error handling unified for "%s" and the many %p*
specifiers that need to read the data from a given address. We print:

   + (null)   when accessing data on pure pure NULL address
   + (efault) when accessing data on an invalid address

It does not affect the %p* specifiers that just print the given address
in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p.

Note that we print (efault) from security reasons. In fact, the real
address can be seen only by %px or eventually %pK.

Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com
To: Rasmus Villemoes 
Cc: Linus Torvalds 
Cc: "Tobin C . Harding" 
Cc: Joe Perches 
Cc: Andrew Morton 
Cc: Michal Hocko 
Cc: Steven Rostedt 
Cc: Sergey Senozhatsky 
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Petr Mladek

vsprintf: Consolidate handling of unknown pointer specifiers

2019-04-26T14:20:20+00:00

There are few printk formats that make sense only with two or more
specifiers. Also some specifiers make sense only when a kernel feature
is enabled.

The handling of unknown specifiers is inconsistent and not helpful.
Using WARN() looks like an overkill for this type of error. pr_warn()
is not good either. It would by handled via printk_safe buffer and
it might be hard to match it with the problematic string.

A reasonable compromise seems to be writing the unknown format specifier
into the original string with a question mark, for example (%pC?).
It should be self-explaining enough. Note that it is in brackets
to follow the (null) style.

Note that it introduces a warning about that test_hashed() function
is unused. It is going to be used again by a later patch.

Link: http://lkml.kernel.org/r/20190417115350.20479-8-pmladek@suse.com
To: Rasmus Villemoes 
Cc: Linus Torvalds 
Cc: "Tobin C . Harding" 
Cc: Joe Perches 
Cc: Andrew Morton 
Cc: Michal Hocko 
Cc: Steven Rostedt 
Cc: Sergey Senozhatsky 
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Petr Mladek