linux-stable.git/Documentation, branch v5.4.76

linkage: Introduce new macros for assembler symbols

2020-11-10T11:37:24+00:00

commit ffedeeb780dc554eff3d3b16e6a462a26a41d7ec upstream.

Introduce new C macros for annotations of functions and data in
assembly. There is a long-standing mess in macros like ENTRY, END,
ENDPROC and similar. They are used in different manners and sometimes
incorrectly.

So introduce macros with clear use to annotate assembly as follows:

a) Support macros for the ones below
   SYM_T_FUNC -- type used by assembler to mark functions
   SYM_T_OBJECT -- type used by assembler to mark data
   SYM_T_NONE -- type used by assembler to mark entries of unknown type

   They are defined as STT_FUNC, STT_OBJECT, and STT_NOTYPE
   respectively. According to the gas manual, this is the most portable
   way. I am not sure about other assemblers, so this can be switched
   back to %function and %object if this turns into a problem.
   Architectures can also override them by something like ", @function"
   if they need.

   SYM_A_ALIGN, SYM_A_NONE -- align the symbol?
   SYM_L_GLOBAL, SYM_L_WEAK, SYM_L_LOCAL -- linkage of symbols

b) Mostly internal annotations, used by the ones below
   SYM_ENTRY -- use only if you have to (for non-paired symbols)
   SYM_START -- use only if you have to (for paired symbols)
   SYM_END -- use only if you have to (for paired symbols)

c) Annotations for code
   SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code
   SYM_INNER_LABEL -- only for labels in the middle of code

   SYM_FUNC_START_LOCAL_ALIAS -- use where there are two local names for
	one function
   SYM_FUNC_START_ALIAS -- use where there are two global names for one
	function
   SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function

   SYM_FUNC_START -- use for global functions
   SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment
   SYM_FUNC_START_LOCAL -- use for local functions
   SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o
	alignment
   SYM_FUNC_START_WEAK -- use for weak functions
   SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment
   SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START,
	SYM_FUNC_START_WEAK, ...

   For functions with special (non-C) calling conventions:
   SYM_CODE_START -- use for non-C (special) functions
   SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o
	alignment
   SYM_CODE_START_LOCAL -- use for local non-C (special) functions
   SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special)
	functions, w/o alignment
   SYM_CODE_END -- the end of SYM_CODE_START_LOCAL or SYM_CODE_START

d) For data
   SYM_DATA_START -- global data symbol
   SYM_DATA_START_LOCAL -- local data symbol
   SYM_DATA_END -- the end of the SYM_DATA_START symbol
   SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol
   SYM_DATA -- start+end wrapper around simple global data
   SYM_DATA_LOCAL -- start+end wrapper around simple local data

==========

The macros allow to pair starts and ends of functions and mark functions
correctly in the output ELF objects.

All users of the old macros in x86 are converted to use these in further
patches.

Signed-off-by: Jiri Slaby 
Signed-off-by: Borislav Petkov 
Acked-by: Rafael J. Wysocki 
Cc: Andrew Morton 
Cc: Andrey Ryabinin 
Cc: Boris Ostrovsky 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Jonathan Corbet 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Len Brown 
Cc: Linus Torvalds 
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: Mark Rutland 
Cc: Pavel Machek 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: x86-ml 
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20191011115108.12392-2-jslaby@suse.cz
Cc: Jian Cai 
Signed-off-by: Greg Kroah-Hartman

media: videodev2.h: RGB BT2020 and HSV are always full range

2020-11-05T10:43:15+00:00

[ Upstream commit b305dfe2e93434b12d438434461b709641f62af4 ]

The default RGB quantization range for BT.2020 is full range (just as for
all the other RGB pixel encodings), not limited range.

Update the V4L2_MAP_QUANTIZATION_DEFAULT macro and documentation
accordingly.

Also mention that HSV is always full range and cannot be limited range.

When RGB BT2020 was introduced in V4L2 it was not clear whether it should
be limited or full range, but full range is the right (and consistent)
choice.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Sasha Levin

xen/events: defer eoi in case of excessive number of events

2020-11-05T10:43:12+00:00

commit e99502f76271d6bc4e374fe368c50c67a1fd3070 upstream.

In case rogue guests are sending events at high frequency it might
happen that xen_evtchn_do_upcall() won't stop processing events in
dom0. As this is done in irq handling a crash might be the result.

In order to avoid that, delay further inter-domain events after some
time in xen_evtchn_do_upcall() by forcing eoi processing into a
worker on the same cpu, thus inhibiting new events coming in.

The time after which eoi processing is to be delayed is configurable
via a new module parameter "event_loop_timeout" which specifies the
maximum event loop time in jiffies (default: 2, the value was chosen
after some tests showing that a value of 2 was the lowest with an
only slight drop of dom0 network throughput while multiple guests
performed an event storm).

How long eoi processing will be delayed can be specified via another
parameter "event_eoi_delay" (again in jiffies, default 10, again the
value was chosen after testing with different delay values).

This is part of XSA-332.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall 
Signed-off-by: Juergen Gross 
Reviewed-by: Stefano Stabellini 
Reviewed-by: Wei Liu 
Signed-off-by: Greg Kroah-Hartman

x86/fpu: Allow multiple bits in clearcpuid= parameter

2020-10-29T08:57:29+00:00

[ Upstream commit 0a4bb5e5507a585532cc413125b921c8546fc39f ]

Commit

  0c2a3913d6f5 ("x86/fpu: Parse clearcpuid= as early XSAVE argument")

changed clearcpuid parsing from __setup() to cmdline_find_option().
While the __setup() function would have been called for each clearcpuid=
parameter on the command line, cmdline_find_option() will only return
the last one, so the change effectively made it impossible to disable
more than one bit.

Allow a comma-separated list of bit numbers as the argument for
clearcpuid to allow multiple bits to be disabled again. Log the bits
being disabled for informational purposes.

Also fix the check on the return value of cmdline_find_option(). It
returns -1 when the option is not found, so testing as a boolean is
incorrect.

Fixes: 0c2a3913d6f5 ("x86/fpu: Parse clearcpuid= as early XSAVE argument")
Signed-off-by: Arvind Sankar 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20200907213919.2423441-1-nivedita@alum.mit.edu
Signed-off-by: Sasha Levin

icmp: randomize the global rate limiter

2020-10-29T08:57:27+00:00

[ Upstream commit b38e7819cae946e2edf869e604af1e65a5d241c5 ]

Keyu Man reported that the ICMP rate limiter could be used
by attackers to get useful signal. Details will be provided
in an upcoming academic publication.

Our solution is to add some noise, so that the attackers
no longer can get help from the predictable token bucket limiter.

Fixes: 4cdf507d5452 ("icmp: add a global rate limitation")
Signed-off-by: Eric Dumazet 
Reported-by: Keyu Man 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

block/diskstats: more accurate approximation of io_ticks for slow disks

2020-10-07T06:01:29+00:00

commit 2b8bd423614c595540eaadcfbc702afe8e155e50 upstream.

Currently io_ticks is approximated by adding one at each start and end of
requests if jiffies counter has changed. This works perfectly for requests
shorter than a jiffy or if one of requests starts/ends at each jiffy.

If disk executes just one request at a time and they are longer than two
jiffies then only first and last jiffies will be accounted.

Fix is simple: at the end of request add up into io_ticks jiffies passed
since last update rather than just one jiffy.

Example: common HDD executes random read 4k requests around 12ms.

fio --name=test --filename=/dev/sdb --rw=randread --direct=1 --runtime=30 &
iostat -x 10 sdb

Note changes of iostat's "%util" 8,43% -> 99,99% before/after patch:

Before:

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
sdb               0,00     0,00   82,60    0,00   330,40     0,00     8,00     0,96   12,09   12,09    0,00   1,02   8,43

After:

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
sdb               0,00     0,00   82,50    0,00   330,00     0,00     8,00     1,00   12,10   12,10    0,00  12,12  99,99

Now io_ticks does not loose time between start and end of requests, but
for queue-depth > 1 some I/O time between adjacent starts might be lost.

For load estimation "%util" is not as useful as average queue length,
but it clearly shows how often disk queue is completely empty.

Fixes: 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting")
Signed-off-by: Konstantin Khlebnikov 
Reviewed-by: Ming Lei 
Signed-off-by: Jens Axboe 
From: "Banerjee, Debabrata" 
Signed-off-by: Greg Kroah-Hartman

gpio/aspeed-sgpio: enable access to all 80 input & output sgpios

2020-10-07T06:01:28+00:00

[ Upstream commit ac67b07e268d46eba675a60c37051bb3e59fd201 ]

Currently, the aspeed-sgpio driver exposes up to 80 GPIO lines,
corresponding to the 80 status bits available in hardware. Each of these
lines can be configured as either an input or an output.

However, each of these GPIOs is actually an input *and* an output; we
actually have 80 inputs plus 80 outputs.

This change expands the maximum number of GPIOs to 160; the lower half
of this range are the input-only GPIOs, the upper half are the outputs.
We fix the GPIO directions to correspond to this mapping.

This also fixes a bug when setting GPIOs - we were reading from the
input register, making it impossible to set more than one output GPIO.

Signed-off-by: Jeremy Kerr 
Fixes: 7db47faae79b ("gpio: aspeed: Add SGPIO driver")
Reviewed-by: Joel Stanley 
Reviewed-by: Andrew Jeffery 
Acked-by: Rob Herring 
Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Sasha Levin

ata: make qc_prep return ata_completion_errors

2020-10-01T11:18:26+00:00

commit 95364f36701e62dd50eee91e1303187fd1a9f567 upstream.

In case a driver wants to return an error from qc_prep, return enum
ata_completion_errors. sata_mv is one of those drivers -- see the next
patch. Other drivers return the newly defined AC_ERR_OK.

[v2] use enum ata_completion_errors and AC_ERR_OK.

Signed-off-by: Jiri Slaby 
Cc: Jens Axboe 
Cc: linux-ide@vger.kernel.org
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

dt-bindings: sound: wm8994: Correct required supplies based on actual implementaion

2020-10-01T11:17:58+00:00

[ Upstream commit 8c149b7d75e53be47648742f40fc90d9fc6fa63a ]

The required supplies in bindings were actually not matching
implementation making the bindings incorrect and misleading.  The Linux
kernel driver requires all supplies to be present.  Also for wlf,wm8994
uses just DBVDD-supply instead of DBVDDn-supply (n: <1,3>).

Reported-by: Jonathan Bakker 
Signed-off-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20200501133534.6706-1-krzk@kernel.org
Signed-off-by: Mark Brown 
Signed-off-by: Sasha Levin

affs: fix basic permission bits to actually work

2020-09-09T17:12:34+00:00

commit d3a84a8d0dde4e26bc084b36ffcbdc5932ac85e2 upstream.

The basic permission bits (protection bits in AmigaOS) have been broken
in Linux' AFFS - it would only set bits, but never delete them.
Also, contrary to the documentation, the Archived bit was not handled.

Let's fix this for good, and set the bits such that Linux and classic
AmigaOS can coexist in the most peaceful manner.

Also, update the documentation to represent the current state of things.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Max Staudt 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman