linux-stable.git/arch/arc/kernel, branch v4.4.201 Linux kernel stable tree ARC: export "abort" for modules 2019-09-21T05:12:54+00:00 Vineet Gupta Vineet.Gupta1@synopsys.com 2019-09-19T20:58:47+00:00 6b011ece4cdfb018d067b6c72a1237e52c73c41c This is a custom patch (no mainline equivalent) for stable backport only to address 0-Day kernel test infra ARC 4.x.y builds errors. The reason for this custom patch as that it is a single patch, touches only ARC, vs. atleast two 7c2c11b208be09c1, dc8635b78cd8669 which touch atleast 3 other arches (one long removed) and could potentially have a fallout. Reported-by: kbuild test robot <lkp@intel.com> CC: stable@vger.kernel.org # 4.4, 4.9 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This is a custom patch (no mainline equivalent) for stable backport only
to address 0-Day kernel test infra ARC 4.x.y builds errors.

The reason for this custom patch as that it is a single patch, touches
only ARC, vs. atleast two 7c2c11b208be09c1, dc8635b78cd8669 which touch
atleast 3 other arches (one long removed) and could potentially have a
fallout.

Reported-by: kbuild test robot <lkp@intel.com>
CC: stable@vger.kernel.org	# 4.4, 4.9
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: hide unused function unw_hdr_alloc 2019-07-21T07:07:14+00:00 Arnd Bergmann arnd@arndb.de 2019-07-03T13:39:25+00:00 07724b2fad568c08578df99067a226c958fb532a commit fd5de2721ea7d16e2b16c4049ac49f229551b290 upstream. As kernelci.org reports, this function is not used in vdk_hs38_defconfig: arch/arc/kernel/unwind.c:188:14: warning: 'unw_hdr_alloc' defined but not used [-Wunused-function] Fixes: bc79c9a72165 ("ARC: dw2 unwind: Reinstante unwinding out of modules") Link: https://kernelci.org/build/id/5d1cae3f59b514300340c132/logs/ Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fd5de2721ea7d16e2b16c4049ac49f229551b290 upstream.

As kernelci.org reports, this function is not used in
vdk_hs38_defconfig:

arch/arc/kernel/unwind.c:188:14: warning: 'unw_hdr_alloc' defined but not used [-Wunused-function]

Fixes: bc79c9a72165 ("ARC: dw2 unwind: Reinstante unwinding out of modules")
Link: https://kernelci.org/build/id/5d1cae3f59b514300340c132/logs/
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: handle gcc generated __builtin_trap for older compiler 2019-07-10T07:56:44+00:00 Vineet Gupta vgupta@synopsys.com 2017-12-08T16:45:57+00:00 a62a40c8a3ff18d255d2a325c7780708d54fadc1 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 <arnd@arndb.de> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <arnd@arndb.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: Assume multiplier is always present 2019-07-10T07:56:41+00:00 Vineet Gupta vgupta@synopsys.com 2016-02-16T04:12:57+00:00 a414c474578a1ac097a1da0875b02b431f60a4e6 [ 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 <vgupta@synopsys.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ARCv2: Enable unaligned access in early ASM code 2019-03-23T07:44:18+00:00 Eugeniy Paltsev Eugeniy.Paltsev@synopsys.com 2019-01-16T11:29:50+00:00 2c2433eba19a9762ff8d151777f6fd5774b5bff4 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 <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: rewrote changelog] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: rewrote changelog]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: clone syscall to setp r25 as thread pointer 2018-10-13T07:11:34+00:00 Vineet Gupta vgupta@synopsys.com 2018-10-05T19:48:48+00:00 b4dd80c33338df403868222045d6427295ff54e5 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 <sobolev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <sobolev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: Enable machine_desc->init_per_cpu for !CONFIG_SMP 2018-08-24T11:26:55+00:00 Alexey Brodkin Alexey.Brodkin@synopsys.com 2017-11-29T08:21:45+00:00 d68db3d9974fdc31664a46bbd12a98915eeec1f6 [ 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 <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: trimmeed changelog] Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ 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 <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: trimmeed changelog]
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: Re-enable MMU upon Machine Check exception 2017-09-27T09:00:16+00:00 Jose Abreu Jose.Abreu@synopsys.com 2017-09-01T16:00:23+00:00 81306fc3dbb53b11f9c42d31403df3655d50f935 commit 1ee55a8f7f6b7ca4c0c59e0b4b4e3584a085c2d3 upstream. I recently came upon a scenario where I would get a double fault machine check exception tiriggered by a kernel module. However the ensuing crash stacktrace (ksym lookup) was not working correctly. Turns out that machine check auto-disables MMU while modules are allocated in kernel vaddr spapce. This patch re-enables the MMU before start printing the stacktrace making stacktracing of modules work upon a fatal exception. Signed-off-by: Jose Abreu <joabreu@synopsys.com> Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: moved code into low level handler to avoid in 2 places] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1ee55a8f7f6b7ca4c0c59e0b4b4e3584a085c2d3 upstream.

I recently came upon a scenario where I would get a double fault
machine check exception tiriggered by a kernel module.
However the ensuing crash stacktrace (ksym lookup) was not working
correctly.

Turns out that machine check auto-disables MMU while modules are allocated
in kernel vaddr spapce.

This patch re-enables the MMU before start printing the stacktrace
making stacktracing of modules work upon a fatal exception.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: moved code into low level handler to avoid in 2 places]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: [arcompact] brown paper bag bug in unaligned access delay slot fixup 2017-02-14T23:22:50+00:00 Vineet Gupta Vineet.Gupta1@synopsys.com 2017-02-07T17:44:58+00:00 e871ea6bcf99097731fceff3e8e1c5ed05b04ae2 commit a524c218bc94c705886a0e0fedeee45d1931da32 upstream. Reported-by: Jo-Philipp Wich <jo@mein.io> Fixes: 9aed02feae57bf7 ("ARC: [arcompact] handle unaligned access delay slot") Cc: linux-kernel@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a524c218bc94c705886a0e0fedeee45d1931da32 upstream.

Reported-by: Jo-Philipp Wich <jo@mein.io>
Fixes: 9aed02feae57bf7 ("ARC: [arcompact] handle unaligned access delay slot")
Cc: linux-kernel@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: [arcompact] handle unaligned access delay slot corner case 2017-02-01T07:30:53+00:00 Vineet Gupta vgupta@synopsys.com 2017-01-27T18:45:27+00:00 acb63c8b576d9a853ffae2f25f21447be6f5c347 commit 9aed02feae57bf7a40cb04ea0e3017cb7a998db4 upstream. After emulating an unaligned access in delay slot of a branch, we pretend as the delay slot never happened - so return back to actual branch target (or next PC if branch was not taken). Curently we did this by handling STATUS32.DE, we also need to clear the BTA.T bit, which is disregarded when returning from original misaligned exception, but could cause weirdness if it took the interrupt return path (in case interrupt was acive too) One ARC700 customer ran into this when enabling unaligned access fixup for kernel mode accesses as well Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9aed02feae57bf7a40cb04ea0e3017cb7a998db4 upstream.

After emulating an unaligned access in delay slot of a branch, we
pretend as the delay slot never happened - so return back to actual
branch target (or next PC if branch was not taken).

Curently we did this by handling STATUS32.DE, we also need to clear the
BTA.T bit, which is disregarded when returning from original misaligned
exception, but could cause weirdness if it took the interrupt return
path (in case interrupt was acive too)

One ARC700 customer ran into this when enabling unaligned access fixup
for kernel mode accesses as well

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>