linux-stable.git/arch/arc, branch v4.4.185

ARC: handle gcc generated __builtin_trap for older compiler

2019-07-10T07:56:44+00:00

commit af1be2e21203867cb958aaceed5366e2e24b88e8 upstream.

ARC gcc prior to GNU 2018.03 release didn't have a target specific
__builtin_trap() implementation, generating default abort() call.

Implement the abort() call - emulating what newer gcc does for the same,
as suggested by Arnd.

Acked-by: Arnd Bergmann 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

bug.h: work around GCC PR82365 in BUG()

2019-07-10T07:56:42+00:00

[ Upstream commit 173a3efd3edb2ef6ef07471397c5f542a360e9c1 ]

Looking at functions with large stack frames across all architectures
led me discovering that BUG() suffers from the same problem as
fortify_panic(), which I've added a workaround for already.

In short, variables that go out of scope by calling a noreturn function
or __builtin_unreachable() keep using stack space in functions
afterwards.

A workaround that was identified is to insert an empty assembler
statement just before calling the function that doesn't return.  I'm
adding a macro "barrier_before_unreachable()" to document this, and
insert calls to that in all instances of BUG() that currently suffer
from this problem.

The files that saw the largest change from this had these frame sizes
before, and much less with my patch:

  fs/ext4/inode.c:82:1: warning: the frame size of 1672 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/namei.c:434:1: warning: the frame size of 904 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/super.c:2279:1: warning: the frame size of 1160 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/xattr.c:146:1: warning: the frame size of 1168 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/f2fs/inode.c:152:1: warning: the frame size of 1424 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:1195:1: warning: the frame size of 1068 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:395:1: warning: the frame size of 1084 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:298:1: warning: the frame size of 928 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:418:1: warning: the frame size of 908 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_lblcr.c:718:1: warning: the frame size of 960 bytes is larger than 800 bytes [-Wframe-larger-than=]
  drivers/net/xen-netback/netback.c:1500:1: warning: the frame size of 1088 bytes is larger than 800 bytes [-Wframe-larger-than=]

In case of ARC and CRIS, it turns out that the BUG() implementation
actually does return (or at least the compiler thinks it does),
resulting in lots of warnings about uninitialized variable use and
leaving noreturn functions, such as:

  block/cfq-iosched.c: In function 'cfq_async_queue_prio':
  block/cfq-iosched.c:3804:1: error: control reaches end of non-void function [-Werror=return-type]
  include/linux/dmaengine.h: In function 'dma_maxpq':
  include/linux/dmaengine.h:1123:1: error: control reaches end of non-void function [-Werror=return-type]

This makes them call __builtin_trap() instead, which should normally
dump the stack and kill the current process, like some of the other
architectures already do.

I tried adding barrier_before_unreachable() to panic() and
fortify_panic() as well, but that had very little effect, so I'm not
submitting that patch.

Vineet said:

: For ARC, it is double win.
:
: 1. Fixes 3 -Wreturn-type warnings
:
: | ../net/core/ethtool.c:311:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../kernel/sched/core.c:3246:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../include/linux/sunrpc/svc_xprt.h:180:1: warning: control reaches end of
: non-void function [-Wreturn-type]
:
: 2.  bloat-o-meter reports code size improvements as gcc elides the
:    generated code for stack return.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
Link: http://lkml.kernel.org/r/20171219114112.939391-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann 
Acked-by: Vineet Gupta 	[arch/arc]
Tested-by: Vineet Gupta 	[arch/arc]
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Geert Uytterhoeven 
Cc: "David S. Miller" 
Cc: Christopher Li 
Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Kees Cook 
Cc: Ingo Molnar 
Cc: Josh Poimboeuf 
Cc: Will Deacon 
Cc: "Steven Rostedt (VMware)" 
Cc: Mark Rutland 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
[ removed cris changes - gregkh]
Signed-off-by: Greg Kroah-Hartman

ARC: fix build warning in elf.h

2019-07-10T07:56:41+00:00

[ Upstream commit 1dec78585328db00e33fb18dc1a6deed0e2095a5 ]

The cast valid since TASK_SIZE * 2 will never actually cause overflow.

|   CC      fs/binfmt_elf.o
| In file included from ../include/linux/elf.h:4:0,
|                  from ../include/linux/module.h:15,
|                  from ../fs/binfmt_elf.c:12:
| ../fs/binfmt_elf.c: In function load_elf_binar:
| ../arch/arc/include/asm/elf.h:57:29: warning: integer overflow in expression [-Woverflow]
|  #define ELF_ET_DYN_BASE  (2 * TASK_SIZE / 3)
|                              ^
| ../fs/binfmt_elf.c:921:16: note: in expansion of macro ELF_ET_DYN_BASE
|     load_bias = ELF_ET_DYN_BASE - vaddr;

Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: Assume multiplier is always present

2019-07-10T07:56:41+00:00

[ Upstream commit 0eca6fdb3193410fbe66b6f064431cc394513e82 ]

It is unlikely that designs running Linux will not have multiplier.
Further the current support is not complete as tool don't generate a
multilib w/o multiplier.

Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: uacces: remove lp_start, lp_end from clobber list

2019-03-23T07:44:34+00:00

[ Upstream commit d5e3c55e01d8b1774b37b4647c30fb22f1d39077 ]

Newer ARC gcc handles lp_start, lp_end in a different way and doesn't
like them in the clobber list.

Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: fix __ffs return value to avoid build warnings

2019-03-23T07:44:19+00:00

[ Upstream commit 4e868f8419cb4cb558c5d428e7ab5629cef864c7 ]

|  CC      mm/nobootmem.o
|In file included from ./include/asm-generic/bug.h:18:0,
|                 from ./arch/arc/include/asm/bug.h:32,
|                 from ./include/linux/bug.h:5,
|                 from ./include/linux/mmdebug.h:5,
|                 from ./include/linux/gfp.h:5,
|                 from ./include/linux/slab.h:15,
|                 from mm/nobootmem.c:14:
|mm/nobootmem.c: In function '__free_pages_memory':
|./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast
|   (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
|                             ^
|./include/linux/kernel.h:859:4: note: in expansion of macro '__typecheck'
|   (__typecheck(x, y) && __no_side_effects(x, y))
|    ^~~~~~~~~~~
|./include/linux/kernel.h:869:24: note: in expansion of macro '__safe_cmp'
|  __builtin_choose_expr(__safe_cmp(x, y), \
|                        ^~~~~~~~~~
|./include/linux/kernel.h:878:19: note: in expansion of macro '__careful_cmp'
| #define min(x, y) __careful_cmp(x, y, <)
|                   ^~~~~~~~~~~~~
|mm/nobootmem.c:104:11: note: in expansion of macro 'min'
|   order = min(MAX_ORDER - 1UL, __ffs(start));

Change __ffs return value from 'int' to 'unsigned long' as it
is done in other implementations (like asm-generic, x86, etc...)
to avoid build-time warnings in places where type is strictly
checked.

As __ffs may return values in [0-31] interval changing return
type to unsigned is valid.

Signed-off-by: Eugeniy Paltsev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARCv2: Enable unaligned access in early ASM code

2019-03-23T07:44:18+00:00

commit 252f6e8eae909bc075a1b1e3b9efb095ae4c0b56 upstream.

It is currently done in arc_init_IRQ() which might be too late
considering gcc 7.3.1 onwards (GNU 2018.03) generates unaligned
memory accesses by default

Cc: stable@vger.kernel.org #4.4+
Signed-off-by: Eugeniy Paltsev 
Signed-off-by: Vineet Gupta 
[vgupta: rewrote changelog]
Signed-off-by: Greg Kroah-Hartman

ARC: perf: map generic branches to correct hardware condition

2019-02-06T18:43:03+00:00

commit 3affbf0e154ee351add6fcc254c59c3f3947fa8f upstream.

So far we've mapped branches to "ijmp" which also counts conditional
branches NOT taken. This makes us different from other architectures
such as ARM which seem to be counting only taken branches.

So use "ijmptak" hardware condition which only counts (all jump
instructions that are taken)

'ijmptak' event is available on both ARCompact and ARCv2 ISA based
cores.

Signed-off-by: Eugeniy Paltsev 
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta 
[vgupta: reworked changelog]
Signed-off-by: Greg Kroah-Hartman

ARC: io.h: Implement reads{x}()/writes{x}()

2018-12-21T13:09:52+00:00

[ Upstream commit 10d443431dc2bb733cf7add99b453e3fb9047a2e ]

Some ARC CPU's do not support unaligned loads/stores. Currently, generic
implementation of reads{b/w/l}()/writes{b/w/l}() is being used with ARC.
This can lead to misfunction of some drivers as generic functions do a
plain dereference of a pointer that can be unaligned.

Let's use {get/put}_unaligned() helpers instead of plain dereference of
pointer in order to fix. The helpers allow to get and store data from an
unaligned address whilst preserving the CPU internal alignment.
According to [1], the use of these helpers are costly in terms of
performance so we added an initial check for a buffer already aligned so
that the usage of the helpers can be avoided, when possible.

[1] Documentation/unaligned-memory-access.txt

Cc: Alexey Brodkin 
Cc: Joao Pinto 
Cc: David Laight 
Tested-by: Vitor Soares 
Signed-off-by: Jose Abreu 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

arc: [devboards] Add support of NFSv3 ACL

2018-12-13T08:21:33+00:00

commit 6b04114f6fae5e84d33404c2970b1949c032546e upstream.

By default NFSv3 doesn't support ACL (Access Control Lists)
which might be quite convenient to have so that
mounted NFS behaves exactly as any other local file-system.

In particular missing support of ACL makes umask useless.
This among other thigs fixes Glibc's "nptl/tst-umask1".

Signed-off-by: Alexey Brodkin 
Cc: Cupertino Miranda 
Cc: stable@vger.kernel.org	#4.14+
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman