linux-stable.git/arch/arc, branch v4.4.166

ARC: build: Get rid of toolchain check

2018-10-20T07:52:38+00:00

commit 615f64458ad890ef94abc879a66d8b27236e733a upstream.

This check is very naive: we simply test if GCC invoked without
"-mcpu=XXX" has ARC700 define set. In that case we think that GCC
was built with "--with-cpu=arc700" and has libgcc built for ARC700.

Otherwise if ARC700 is not defined we think that everythng was built
for ARCv2.

But in reality our life is much more interesting.

1. Regardless of GCC configuration (i.e. what we pass in "--with-cpu"
   it may generate code for any ARC core).

2. libgcc might be built with explicitly specified "--mcpu=YYY"

That's exactly what happens in case of multilibbed toolchains:
 - GCC is configured with default settings
 - All the libs built for many different CPU flavors

I.e. that check gets in the way of usage of multilibbed
toolchains. And even non-multilibbed toolchains are affected.
OpenEmbedded also builds GCC without "--with-cpu" because
each and every target component later is compiled with explicitly
set "-mcpu=ZZZ".

Acked-by: Rob Herring 
Signed-off-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: clone syscall to setp r25 as thread pointer

2018-10-13T07:11:34+00:00

commit c58a584f05e35d1d4342923cd7aac07d9c3d3d16 upstream.

Per ARC TLS ABI, r25 is designated TP (thread pointer register).
However so far kernel didn't do any special treatment, like setting up
usermode r25, even for CLONE_SETTLS. We instead relied on libc runtime
to do this, in say clone libc wrapper [1]. This was deliberate to keep
kernel ABI agnostic (userspace could potentially change TP, specially
for different ARC ISA say ARCompact vs. ARCv2 with different spare
registers etc)

However userspace setting up r25, after clone syscall opens a race, if
child is not scheduled and gets a signal instead. It starts off in
userspace not in clone but in a signal handler and anything TP sepcific
there such as pthread_self() fails which showed up with uClibc
testsuite nptl/tst-kill6 [2]

Fix this by having kernel populate r25 to TP value. So this locks in
ABI, but it was not going to change anyways, and fwiw is same for both
ARCompact (arc700 core) and ARCvs (HS3x cores)

[1] https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/tree/libc/sysdeps/linux/arc/clone.S
[2] https://github.com/wbx-github/uclibc-ng-test/blob/master/test/nptl/tst-kill6.c

Fixes: ARC STAR 9001378481
Cc: stable@vger.kernel.org
Reported-by: Nikita Sobolev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: [plat-axs*]: Enable SWAP

2018-09-19T20:48:56+00:00

commit c83532fb0fe053d2e43e9387354cb1b52ba26427 upstream.

SWAP support on ARC was fixed earlier by
commit 6e3761145a9b ("ARC: Fix CONFIG_SWAP")
so now we may safely enable it on platforms that
have external media like USB and SD-card.

Note: it was already allowed for HSDK

Signed-off-by: Alexey Brodkin 
Cc: stable@vger.kernel.org # 6e3761145a9b: ARC: Fix CONFIG_SWAP
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

arc: fix type warnings in arc/mm/cache.c

2018-09-05T07:18:36+00:00

[ Upstream commit ec837d620c750c0d4996a907c8c4f7febe1bbeee ]

Fix type warnings in arch/arc/mm/cache.c.

../arch/arc/mm/cache.c: In function 'flush_anon_page':
../arch/arc/mm/cache.c:1062:55: warning: passing argument 2 of '__flush_dcache_page' makes integer from pointer without a cast [-Wint-conversion]
  __flush_dcache_page((phys_addr_t)page_address(page), page_address(page));
                                                       ^~~~~~~~~~~~~~~~~~
../arch/arc/mm/cache.c:1013:59: note: expected 'long unsigned int' but argument is of type 'void *'
 void __flush_dcache_page(phys_addr_t paddr, unsigned long vaddr)
                                             ~~~~~~~~~~~~~~^~~~~

Signed-off-by: Randy Dunlap 
Cc: Vineet Gupta 
Cc: linux-snps-arc@lists.infradead.org
Cc: Elad Kanfi 
Cc: Leon Romanovsky 
Cc: Ofer Levi 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

arc: fix build errors in arc/include/asm/delay.h

2018-09-05T07:18:36+00:00

[ Upstream commit 2423665ec53f2a29191b35382075e9834288a975 ]

Fix build errors in arch/arc/'s delay.h:
- add "extern unsigned long loops_per_jiffy;"
- add  for "u64"

In file included from ../drivers/infiniband/hw/cxgb3/cxio_hal.c:32:
../arch/arc/include/asm/delay.h: In function '__udelay':
../arch/arc/include/asm/delay.h:61:12: error: 'u64' undeclared (first use in this function)
  loops = ((u64) usecs * 4295 * HZ * loops_per_jiffy) >> 32;
            ^~~

In file included from ../drivers/infiniband/hw/cxgb3/cxio_hal.c:32:
../arch/arc/include/asm/delay.h: In function '__udelay':
../arch/arc/include/asm/delay.h:63:37: error: 'loops_per_jiffy' undeclared (first use in this function)
  loops = ((u64) usecs * 4295 * HZ * loops_per_jiffy) >> 32;
                                     ^~~~~~~~~~~~~~~

Signed-off-by: Randy Dunlap 
Cc: Vineet Gupta 
Cc: linux-snps-arc@lists.infradead.org
Cc: Elad Kanfi 
Cc: Leon Romanovsky 
Cc: Ofer Levi 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARC: Enable machine_desc->init_per_cpu for !CONFIG_SMP

2018-08-24T11:26:55+00:00

[ Upstream commit 2f24ef7413a4d91657ef04e77c27ce0b313e6c95 ]

machine_desc->init_per_cpu() hook is supposed to be per cpu
initialization and would seem to apply  equally to UP and/or SMP.
Infact the comment in header file seems to suggest it works for
UP too, which was not the case and this patch.

This enables !CONFIG_SMP build for platforms such as hsdk.

Signed-off-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 
[vgupta: trimmeed changelog]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARC: Explicitly add -mmedium-calls to CFLAGS

2018-08-24T11:26:53+00:00

[ Upstream commit 74c11e300c103af47db5b658fdcf28002421e250 ]

GCC built for arc*-*-linux has "-mmedium-calls" implicitly enabled by default
thus we don't see any problems during Linux kernel compilation.
----------------------------->8------------------------
arc-linux-gcc -mcpu=arc700 -Q --help=target | grep calls
  -mlong-calls                          [disabled]
  -mmedium-calls                        [enabled]
----------------------------->8------------------------

But if we try to use so-called Elf32 toolchain with GCC configured for
arc*-*-elf* then we'd see the following failure:
----------------------------->8------------------------
init/do_mounts.o: In function 'init_rootfs':
do_mounts.c:(.init.text+0x108): relocation truncated to fit: R_ARC_S21W_PCREL
against symbol 'unregister_filesystem' defined in .text section in fs/filesystems.o

arc-elf32-ld: final link failed: Symbol needs debug section which does not exist
make: *** [vmlinux] Error 1
----------------------------->8------------------------

That happens because neither "-mmedium-calls" nor "-mlong-calls" are enabled in
Elf32 GCC:
----------------------------->8------------------------
arc-elf32-gcc -mcpu=arc700 -Q --help=target | grep calls
  -mlong-calls                          [disabled]
  -mmedium-calls                        [disabled]
----------------------------->8------------------------

Now to make it possible to use Elf32 toolchain for building Linux kernel
we're explicitly add "-mmedium-calls" to CFLAGS.

And since we add "-mmedium-calls" to the global CFLAGS there's no point in
having per-file copies thus removing them.

Signed-off-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 

Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARC: mm: allow mprotect to make stack mappings executable

2018-07-25T08:18:16+00:00

commit 93312b6da4df31e4102ce5420e6217135a16c7ea upstream.

mprotect(EXEC) was failing for stack mappings as default vm flags was
missing MAYEXEC.

This was triggered by glibc test suite nptl/tst-execstack testcase

What is surprising is that despite running LTP for years on, we didn't
catch this issue as it lacks a directed test case.

gcc dejagnu tests with nested functions also requiring exec stack work
fine though because they rely on the GNU_STACK segment spit out by
compiler and handled in kernel elf loader.

This glibc case is different as the stack is non exec to begin with and
a dlopen of shared lib with GNU_STACK segment triggers the exec stack
proceedings using a mprotect(PROT_EXEC) which was broken.

CC: stable@vger.kernel.org
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: Fix CONFIG_SWAP

2018-07-25T08:18:15+00:00

commit 6e3761145a9ba3ce267c330b6bff51cf6a057b06 upstream.

swap was broken on ARC due to silly copy-paste issue.

We encode offset from swapcache page in __swp_entry() as (off << 13) but
were not decoding back in __swp_offset() as (off >> 13) - it was still
(off << 13).

This finally fixes swap usage on ARC.

| # mkswap /dev/sda2
|
| # swapon -a -e /dev/sda2
| Adding 500728k swap on /dev/sda2.  Priority:-2 extents:1 across:500728k
|
| # free
|              total       used       free     shared    buffers     cached
| Mem:        765104      13456     751648       4736          8       4736
| -/+ buffers/cache:       8712     756392
| Swap:       500728          0     500728

Cc: stable@vger.kernel.org
Signed-off-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: Fix malformed ARC_EMUL_UNALIGNED default

2018-05-30T05:48:58+00:00

[ Upstream commit 827cc2fa024dd6517d62de7a44c7b42f32af371b ]

'default N' should be 'default n', though they happen to have the same
effect here, due to undefined symbols (N in this case) evaluating to n
in a tristate sense.

Remove the default from ARC_EMUL_UNALIGNED instead of changing it. bool
and tristate symbols implicitly default to n.

Discovered with the
https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_ulfalizer_Kconfiglib_blob_master_examples_list-5Fundefined.py&d=DwIBAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=c14YS-cH-kdhTOW89KozFhBtBJgs1zXscZojEZQ0THs&m=WxxD8ozR7QQUVzNCBksiznaisBGO_crN7PBOvAoju8s&s=1LmxsNqxwT-7wcInVpZ6Z1J27duZKSoyKxHIJclXU_M&e=
script.

Signed-off-by: Ulf Magnusson 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman