linux.git/arch/arc/kernel, branch v5.10.258 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git ARC: fix spare error 2024-01-25T22:37:38+00:00 Vineet Gupta vgupta@kernel.org 2023-12-08T23:57:07+00:00 86e4e2eea4ea47e44a85d5c43c24400c71245075 [ Upstream commit aca02d933f63ba8bc84258bf35f9ffaf6b664336 ] Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202312082320.VDN5A9hb-lkp@intel.com/ Signed-off-by: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aca02d933f63ba8bc84258bf35f9ffaf6b664336 ]

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312082320.VDN5A9hb-lkp@intel.com/
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
arch: setup PF_IO_WORKER threads like PF_KTHREAD 2023-01-04T10:39:22+00:00 Jens Axboe axboe@kernel.dk 2021-02-17T15:48:00+00:00 320c8057eceb18c5d836fcbe0ffb0035fcfe28ff [ Upstream commit 4727dc20e0422211a0e0c72b1ace4ed6096df8a6 ] PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the sense that we don't assign ->set_child_tid with our own structure. Just ensure that every arch sets up the PF_IO_WORKER threads like kthreads in the arch implementation of copy_thread(). Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 4727dc20e0422211a0e0c72b1ace4ed6096df8a6 ]

PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: unbork 5.11 bootup: fix snafu in _TIF_NOTIFY_SIGNAL handling 2023-01-04T10:39:21+00:00 Vineet Gupta vgupta@synopsys.com 2021-01-06T20:34:36+00:00 db911277a2b38b4ef98c7192728d5f4cba7863fe [ Upstream commit bb12433bf56e76789c6b08b36c546f745a6aa6e1 ] Linux 5.11.rcX was failing to boot on ARC HSDK board. Turns out we have a couple of issues, this being the first one, and I'm to blame as I didn't pay attention during review. TIF_NOTIFY_SIGNAL support requires checking multiple TIF_* bits in kernel return code path. Old code only needed to check a single bit so BBIT0 <TIF_SIGPENDING> worked. New code needs to check multiple bits so AND <bit-mask> instruction. So needs to use bit mask variant _TIF_SIGPENDING Cc: Jens Axboe <axboe@kernel.dk> Fixes: 53855e12588743ea128 ("arc: add support for TIF_NOTIFY_SIGNAL") Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/34 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit bb12433bf56e76789c6b08b36c546f745a6aa6e1 ]

Linux 5.11.rcX was failing to boot on ARC HSDK board. Turns out we have
a couple of issues, this being the first one, and I'm to blame as I
didn't pay attention during review.

TIF_NOTIFY_SIGNAL support requires checking multiple TIF_* bits in
kernel return code path. Old code only needed to check a single bit so
BBIT0 <TIF_SIGPENDING> worked. New code needs to check multiple bits so
AND <bit-mask> instruction. So needs to use bit mask variant _TIF_SIGPENDING

Cc: Jens Axboe <axboe@kernel.dk>
Fixes: 53855e12588743ea128 ("arc: add support for TIF_NOTIFY_SIGNAL")
Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/34
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arc: add support for TIF_NOTIFY_SIGNAL 2023-01-04T10:39:18+00:00 Jens Axboe axboe@kernel.dk 2020-10-12T13:15:37+00:00 2dbb0354517b1ebef40890d05ce8362e99b86179 [ Upstream commit 53855e12588743ea128ee31f913d1c6e2f1d32c8 ] Wire up TIF_NOTIFY_SIGNAL handling for arc. Cc: linux-snps-arc@lists.infradead.org Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 53855e12588743ea128ee31f913d1c6e2f1d32c8 ]

Wire up TIF_NOTIFY_SIGNAL handling for arc.

Cc: linux-snps-arc@lists.infradead.org
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: entry: fix syscall_trace_exit argument 2022-04-27T11:53:55+00:00 Sergey Matyukevich sergey.matyukevich@synopsys.com 2022-04-14T08:17:22+00:00 5580b974a84b30f6da90a3a562ea0dbfb0038110 commit b1c6ecfdd06907554518ec384ce8e99889d15193 upstream. Function syscall_trace_exit expects pointer to pt_regs. However r0 is also used to keep syscall return value. Restore pointer to pt_regs before calling syscall_trace_exit. Cc: <stable@vger.kernel.org> Signed-off-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b1c6ecfdd06907554518ec384ce8e99889d15193 upstream.

Function syscall_trace_exit expects pointer to pt_regs. However
r0 is also used to keep syscall return value. Restore pointer
to pt_regs before calling syscall_trace_exit.

Cc: <stable@vger.kernel.org>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uaccess: fix type mismatch warnings from access_ok() 2022-04-08T12:40:35+00:00 Arnd Bergmann arnd@arndb.de 2022-02-14T19:22:10+00:00 40a5c93a747389de01ee7195c414cb424710ea6f [ Upstream commit 23fc539e81295b14b50c6ccc5baeb4f3d59d822d ] On some architectures, access_ok() does not do any argument type checking, so replacing the definition with a generic one causes a few warnings for harmless issues that were never caught before. Fix the ones that I found either through my own test builds or that were reported by the 0-day bot. Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 23fc539e81295b14b50c6ccc5baeb4f3d59d822d ]

On some architectures, access_ok() does not do any argument type
checking, so replacing the definition with a generic one causes
a few warnings for harmless issues that were never caught before.

Fix the ones that I found either through my own test builds or
that were reported by the 0-day bot.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ARC: Fix CONFIG_STACKDEPOT 2021-09-03T08:09:21+00:00 Guenter Roeck linux@roeck-us.net 2021-07-10T14:50:33+00:00 a13a2df0b14910eea92229aadb209bdc86e23600 [ Upstream commit bf79167fd86f3b97390fe2e70231d383526bd9cc ] Enabling CONFIG_STACKDEPOT results in the following build error. arc-elf-ld: lib/stackdepot.o: in function `filter_irq_stacks': stackdepot.c:(.text+0x456): undefined reference to `__irqentry_text_start' arc-elf-ld: stackdepot.c:(.text+0x456): undefined reference to `__irqentry_text_start' arc-elf-ld: stackdepot.c:(.text+0x476): undefined reference to `__irqentry_text_end' arc-elf-ld: stackdepot.c:(.text+0x476): undefined reference to `__irqentry_text_end' arc-elf-ld: stackdepot.c:(.text+0x484): undefined reference to `__softirqentry_text_start' arc-elf-ld: stackdepot.c:(.text+0x484): undefined reference to `__softirqentry_text_start' arc-elf-ld: stackdepot.c:(.text+0x48c): undefined reference to `__softirqentry_text_end' arc-elf-ld: stackdepot.c:(.text+0x48c): undefined reference to `__softirqentry_text_end' Other architectures address this problem by adding IRQENTRY_TEXT and SOFTIRQENTRY_TEXT to the text segment, so do the same here. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit bf79167fd86f3b97390fe2e70231d383526bd9cc ]

Enabling CONFIG_STACKDEPOT results in the following build error.

arc-elf-ld: lib/stackdepot.o: in function `filter_irq_stacks':
stackdepot.c:(.text+0x456): undefined reference to `__irqentry_text_start'
arc-elf-ld: stackdepot.c:(.text+0x456): undefined reference to `__irqentry_text_start'
arc-elf-ld: stackdepot.c:(.text+0x476): undefined reference to `__irqentry_text_end'
arc-elf-ld: stackdepot.c:(.text+0x476): undefined reference to `__irqentry_text_end'
arc-elf-ld: stackdepot.c:(.text+0x484): undefined reference to `__softirqentry_text_start'
arc-elf-ld: stackdepot.c:(.text+0x484): undefined reference to `__softirqentry_text_start'
arc-elf-ld: stackdepot.c:(.text+0x48c): undefined reference to `__softirqentry_text_end'
arc-elf-ld: stackdepot.c:(.text+0x48c): undefined reference to `__softirqentry_text_end'

Other architectures address this problem by adding IRQENTRY_TEXT and
SOFTIRQENTRY_TEXT to the text segment, so do the same here.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ARC: fp: set FPU_STATUS.FWE to enable FPU_STATUS update on context switch 2021-08-18T06:59:06+00:00 Vineet Gupta vgupta@synopsys.com 2021-07-09T00:13:48+00:00 ca6dea44bd8cf953a11866fd63d1a5fd9eec81a9 commit 3a715e80400f452b247caa55344f4f60250ffbcf upstream. FPU_STATUS register contains FP exception flags bits which are updated by core as side-effect of FP instructions but can also be manually wiggled such as by glibc C99 functions fe{raise,clear,test}except() etc. To effect the update, the programming model requires OR'ing FWE bit (31). This bit is write-only and RAZ, meaning it is effectively auto-cleared after write and thus needs to be set everytime: which is how glibc implements this. However there's another usecase of FPU_STATUS update, at the time of Linux task switch when incoming task value needs to be programmed into the register. This was added as part of f45ba2bd6da0dc ("ARCv2: fpu: preserve userspace fpu state") which missed OR'ing FWE bit, meaning the new value is effectively not being written at all. This patch remedies that. Interestingly, this snafu was not caught in interm glibc testing as the race window which relies on a specific exception bit to be set/clear is really small specially when it nvolves context switch. Fortunately this was caught by glibc's math/test-fenv-tls test which repeatedly set/clear exception flags in a big loop, concurrently in main program and also in a thread. Fixes: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/54 Fixes: f45ba2bd6da0dc ("ARCv2: fpu: preserve userspace fpu state") Cc: stable@vger.kernel.org #5.6+ Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3a715e80400f452b247caa55344f4f60250ffbcf upstream.

FPU_STATUS register contains FP exception flags bits which are updated
by core as side-effect of FP instructions but can also be manually
wiggled such as by glibc C99 functions fe{raise,clear,test}except() etc.
To effect the update, the programming model requires OR'ing FWE
bit (31). This bit is write-only and RAZ, meaning it is effectively
auto-cleared after write and thus needs to be set everytime: which
is how glibc implements this.

However there's another usecase of FPU_STATUS update, at the time of
Linux task switch when incoming task value needs to be programmed into
the register. This was added as part of f45ba2bd6da0dc ("ARCv2:
fpu: preserve userspace fpu state") which missed OR'ing FWE bit,
meaning the new value is effectively not being written at all.
This patch remedies that.

Interestingly, this snafu was not caught in interm glibc testing as the
race window which relies on a specific exception bit to be set/clear is
really small specially when it nvolves context switch.
Fortunately this was caught by glibc's math/test-fenv-tls test which
repeatedly set/clear exception flags in a big loop, concurrently in main
program and also in a thread.

Fixes: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/54
Fixes: f45ba2bd6da0dc ("ARCv2: fpu: preserve userspace fpu state")
Cc: stable@vger.kernel.org	#5.6+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sched/core: Initialize the idle task with preemption disabled 2021-07-14T14:55:50+00:00 Valentin Schneider valentin.schneider@arm.com 2021-05-12T09:46:36+00:00 3c51d82d0b7862d7d246016c74b4390fb1fa1f11 [ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ] As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ]

As pointed out by commit

  de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread")

init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.

As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().

Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().

Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().

Secondary startups were patched via coccinelle:

  @begone@
  @@

  -preempt_disable();
  ...
  cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
ARCv2: save ABI registers across signal handling 2021-06-23T12:42:51+00:00 Vineet Gupta vgupta@synopsys.com 2021-06-09T02:39:25+00:00 f6bcb1a6281d4ea03b98e26501b88439baa007c6 commit 96f1b00138cb8f04c742c82d0a7c460b2202e887 upstream. ARCv2 has some configuration dependent registers (r30, r58, r59) which could be targetted by the compiler. To keep the ABI stable, these were unconditionally part of the glibc ABI (sysdeps/unix/sysv/linux/arc/sys/ucontext.h:mcontext_t) however we missed populating them (by saving/restoring them across signal handling). This patch fixes the issue by - adding arcv2 ABI regs to kernel struct sigcontext - populating them during signal handling Change to struct sigcontext might seem like a glibc ABI change (although it primarily uses ucontext_t:mcontext_t) but the fact is - it has only been extended (existing fields are not touched) - the old sigcontext was ABI incomplete to begin with anyways Fixes: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/53 Cc: <stable@vger.kernel.org> Tested-by: kernel test robot <lkp@intel.com> Reported-by: Vladimir Isaev <isaev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 96f1b00138cb8f04c742c82d0a7c460b2202e887 upstream.

ARCv2 has some configuration dependent registers (r30, r58, r59) which
could be targetted by the compiler. To keep the ABI stable, these were
unconditionally part of the glibc ABI
(sysdeps/unix/sysv/linux/arc/sys/ucontext.h:mcontext_t) however we
missed populating them (by saving/restoring them across signal
handling).

This patch fixes the issue by
 - adding arcv2 ABI regs to kernel struct sigcontext
 - populating them during signal handling

Change to struct sigcontext might seem like a glibc ABI change (although
it primarily uses ucontext_t:mcontext_t) but the fact is
 - it has only been extended (existing fields are not touched)
 - the old sigcontext was ABI incomplete to begin with anyways

Fixes: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/53
Cc: <stable@vger.kernel.org>
Tested-by: kernel test robot <lkp@intel.com>
Reported-by: Vladimir Isaev <isaev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>