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

rss_stat: add support to detect RSS updates of external mm

2019-12-01T14:29:18+00:00

When a process updates the RSS of a different process, the rss_stat
tracepoint appears in the context of the process doing the update.  This
can confuse userspace that the RSS of process doing the update is
updated, while in reality a different process's RSS was updated.

This issue happens in reclaim paths such as with direct reclaim or
background reclaim.

This patch adds more information to the tracepoint about whether the mm
being updated belongs to the current process's context (curr field).  We
also include a hash of the mm pointer so that the process who the mm
belongs to can be uniquely identified (mm_id field).

Also vsprintf.c is refactored a bit to allow reuse of hashing code.

[akpm@linux-foundation.org: remove unused local `str']
[joelaf@google.com: inline call to ptr_to_hashval]
  Link: http://lore.kernel.org/r/20191113153816.14b95acd@gandalf.local.home
  Link: http://lkml.kernel.org/r/20191114164622.GC233237@google.com
Link: http://lkml.kernel.org/r/20191106024452.81923-1-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) 
Reported-by: Ioannis Ilkos 
Acked-by: Petr Mladek 	[lib/vsprintf.c]
Cc: Tim Murray 
Cc: Michal Hocko 
Cc: Carmen Jackson 
Cc: Mayank Gupta 
Cc: Daniel Colascione 
Cc: Steven Rostedt (VMware) 
Cc: Minchan Kim 
Cc: "Aneesh Kumar K.V" 
Cc: Dan Williams 
Cc: Jerome Glisse 
Cc: Matthew Wilcox 
Cc: Ralph Campbell 
Cc: Vlastimil Babka 
Cc: Steven Rostedt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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/vsprintf: Add %pfw conversion specifier for printing fwnode names

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

Add support for %pfw conversion specifier (with "f" and "P" modifiers) to
support printing full path of the node, including its name ("f") and only
the node's name ("P") in the printk family of functions. The two flags
have equivalent functionality to existing %pOF with the same two modifiers
("f" and "P") on OF based systems. The ability to do the same on ACPI
based systems is added by this patch.

On ACPI based systems the resulting strings look like

	\_SB.PCI0.CIO2.port@1.endpoint@0

where the nodes are separated by a dot (".") and the first three are
ACPI device nodes and the latter two ACPI data nodes.

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

lib/vsprintf: OF nodes are first and foremost, struct device_nodes

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

Factor out static kobject_string() function that simply calls
device_node_string(), and thus remove references to kobjects (as these are
struct device_node).

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

lib/vsprintf: Make use of fwnode API to obtain node names and separators

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

Instead of implementing our own means of discovering parent nodes, node
names or counting how many parents a node has, use the newly added
functions in the fwnode API to obtain that information.

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

lib/vsprintf: Add a note on re-using %pf or %pF

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

Add a note warning of re-use of obsolete %pf or %pF extensions.

Signed-off-by: Sakari Ailus 
Suggested-by: Steven Rostedt (VMware) 
Reviewed-by: Petr Mladek 
Signed-off-by: Rafael J. Wysocki

lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps

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

%pS and %ps are now the preferred conversion specifiers to print function
names. The functionality is equivalent; remove the old, deprecated %pF
and %pf support.

Depends-on: commit 2d44d165e939 ("scsi: lpfc: Convert existing %pf users to %ps")
Depends-on: commit b295c3e39c13 ("tools lib traceevent: Convert remaining %p[fF] users to %p[sS]")
Signed-off-by: Sakari Ailus 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Petr Mladek 
Signed-off-by: Rafael J. Wysocki

vsprintf: Prevent crash when dereferencing invalid pointers for %pD

2019-08-15T14:40:10+00:00

Commit 3e5903eb9cff ("vsprintf: Prevent crash when dereferencing invalid
pointers") prevents most crash except for %pD.
There is an additional pointer dereferencing before dentry_name.

At least, vma->file can be NULL and be passed to printk %pD in
print_bad_pte, which can cause crash.

This patch fixes it with introducing a new file_dentry_name.

Link: http://lkml.kernel.org/r/20190809012457.56685-1-justin.he@arm.com
Fixes: 3e5903eb9cff ("vsprintf: Prevent crash when dereferencing invalid pointers")
To: Geert Uytterhoeven 
To: Thomas Gleixner 
To: Andy Shevchenko 
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

Merge tag 'printk-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

2019-07-09T19:25:58+00:00

Pull printk updates from Petr Mladek:

 - distinguish different legacy clocks again

 - small clean up

* tag 'printk-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  lib/vsprintf: Reinstate printing of legacy clock IDs
  vsprintf: fix data type of variable in string_nocheck()