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[ Upstream commit 6214894f49a967c749ee6c07cb00f9cede748df4 ]
The hvc machinery registers both a console and a tty device based on
the hv ops provided by the specific implementation. Those two
interfaces however have different locks, and there's no single locks
that's shared between the tty and the console implementations, hence
the driver needs to protect itself against concurrent accesses.
Otherwise concurrent calls using the split interfaces are likely to
corrupt the ring indexes, leaving the console unusable.
Introduce a lock to xencons_info to serialize accesses to the shared
ring. This is only required when using the shared memory console,
concurrent accesses to the hypercall based console implementation are
not an issue.
Note the conditional logic in domU_read_console() is slightly modified
so the notify_daemon() call can be done outside of the locked region:
it's an hypercall and there's no need for it to be done with the lock
held.
Fixes: b536b4b96230 ('xen: use the hvc console infrastructure for Xen console')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221130150919.13935-1-roger.pau@citrix.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 2704c9a5593f4a47620c12dad78838ca62b52f48 upstream.
The xen_hvc_init() function should always register the frontend driver,
even when there's no primary console — as there may be secondary consoles.
(Qemu can always add secondary consoles, but only the toolstack can add
the primary because it's special.)
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231020161529.355083-3-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a30badfd7c13fc8763a9e10c5a12ba7f81515a55 upstream.
On unplug of a Xen console, xencons_disconnect_backend() unconditionally
calls free_irq() via unbind_from_irqhandler(), causing a warning of
freeing an already-free IRQ:
(qemu) device_del con1
[ 32.050919] ------------[ cut here ]------------
[ 32.050942] Trying to free already-free IRQ 33
[ 32.050990] WARNING: CPU: 0 PID: 51 at kernel/irq/manage.c:1895 __free_irq+0x1d4/0x330
It should be using evtchn_put() to tear down the event channel binding,
and let the Linux IRQ side of it be handled by notifier_del_irq() through
the HVC code.
On which topic... xencons_disconnect_backend() should call hvc_remove()
*first*, rather than tearing down the event channel and grant mapping
while they are in use. And then the IRQ is guaranteed to be freed by
the time it's torn down by evtchn_put().
Since evtchn_put() also closes the actual event channel, avoid calling
xenbus_free_evtchn() except in the failure path where the IRQ was not
successfully set up.
However, calling hvc_remove() at the start of xencons_disconnect_backend()
still isn't early enough. An unplug request is indicated by the backend
setting its state to XenbusStateClosing, which triggers a notification
to xencons_backend_changed(), which... does nothing except set its own
frontend state directly to XenbusStateClosed without *actually* tearing
down the HVC device or, you know, making sure it isn't actively in use.
So the backend sees the guest frontend set its state to XenbusStateClosed
and stops servicing the interrupt... and the guest spins for ever in the
domU_write_console() function waiting for the ring to drain.
Fix that one by calling hvc_remove() from xencons_backend_changed() before
signalling to the backend that it's OK to proceed with the removal.
Tested with 'dd if=/dev/zero of=/dev/hvc1' while telling Qemu to remove
the console device.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231020161529.355083-4-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit c0dccad87cf68fc6012aec7567e354353097ec1a ]
The currently lockless access to the xen console list in
vtermno_to_xencons() is incorrect, as additions and removals from the
list can happen anytime, and as such the traversal of the list to get
the private console data for a given termno needs to happen with the
lock held. Note users that modify the list already do so with the
lock taken.
Adjust current lock takers to use the _irq{save,restore} helpers,
since the context in which vtermno_to_xencons() is called can have
interrupts disabled. Use the _irq{save,restore} set of helpers to
switch the current callers to disable interrupts in the locked region.
I haven't checked if existing users could instead use the _irq
variant, as I think it's safer to use _irq{save,restore} upfront.
While there switch from using list_for_each_entry_safe to
list_for_each_entry: the current entry cursor won't be removed as
part of the code in the loop body, so using the _safe variant is
pointless.
Fixes: 02e19f9c7cac ('hvc_xen: implement multiconsole support')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20221130163611.14686-1-roger.pau@citrix.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 53819a0d97aace1425bb042829e3446952a9e8a9 ]
__setup() handlers should return 1 to indicate that the boot option
has been handled or 0 to indicate that it was not handled.
Add a pr_warn() message if the option value is invalid and then
always return 1.
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Fixes: 86b40567b917 ("tty: replace strict_strtoul() with kstrtoul()")
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Julian Wiedmann <jwi@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220308024228.20477-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit fe415186b43df0db1f17fa3a46275fd92107fe71 upstream.
The Xen console driver is still vulnerable for an attack via excessive
number of events sent by the backend. Fix that by using a lateeoi event
channel.
For the normal domU initial console this requires the introduction of
bind_evtchn_to_irq_lateeoi() as there is no xenbus device available
at the time the event channel is bound to the irq.
As the decision whether an interrupt was spurious or not requires to
test for bytes having been read from the backend, move sending the
event into the if statement, as sending an event without having found
any bytes to be read is making no sense at all.
This is part of XSA-391
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e679004dec37566f658a255157d3aed9d762a2b7 upstream.
Xen frontends shouldn't BUG() in case of illegal data received from
their backends. So replace the BUG_ON()s when reading illegal data from
the ring page with negative return values.
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20210707091045.460-1-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 7ccbdcc4d08a6d7041e4849219bbb12ffa45db4c ]
The alloc_tty_driver failure is handled gracefully in hvsi_init. But
tty_register_driver is not. panic is called if that one fails.
So handle the failure of tty_register_driver gracefully too. This will
keep at least the console functional as it was enabled earlier by
console_initcall in hvsi_console_init. Instead of shooting down the
whole system.
This means, we disable interrupts and restore hvsi_wait back to
poll_for_state().
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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aarch64-linux-gnu-ld: drivers/tty/hvc/hvc_dcc.o: in function `dcc_early_write':
hvc_dcc.c:(.text+0x164): undefined reference to `uart_console_write'
The driver uses the uart_console_write(), but SERIAL_CORE_CONSOLE is not
selected, so uart_console_write is not defined, then we get the error.
Fix this by selecting SERIAL_CORE_CONSOLE.
Fixes: d1a1af2cdf19 ("hvc: dcc: Add earlycon support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20200919063535.2809707-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The code currently NULLs tty->driver_data in hvcs_close() with the
intent of informing the next call to hvcs_open() that device needs to be
reconfigured. However, when hvcs_cleanup() is called we copy hvcsd from
tty->driver_data which was previoulsy NULLed by hvcs_close() and our
call to tty_port_put(&hvcsd->port) doesn't actually do anything since
&hvcsd->port ends up translating to NULL by chance. This has the side
effect that when hvcs_remove() is called we have one too many port
references preventing hvcs_destuct_port() from ever being called. This
also prevents us from reusing the /dev/hvcsX node in a future
hvcs_probe() and we can eventually run out of /dev/hvcsX devices.
Fix this by waiting to NULL tty->driver_data in hvcs_cleanup().
Fixes: 27bf7c43a19c ("TTY: hvcs, add tty install")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20200820234643.70412-1-tyreld@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.
[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
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Use the 'common' foo_console_setup() naming scheme. There are 71
foo_console_setup() callbacks and only one foo_setup_console().
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200619172240.754910-1-sergey.senozhatsky@gmail.com
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For unifying console ->setup() handling, which is poorly documented,
return error code, rather than non-zero arbitrary number.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200618164751.56828-5-andriy.shevchenko@linux.intel.com
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hvc_open sets tty->driver_data to NULL when open fails at some point.
Typically, the failure happens in hp->ops->notifier_add(). If there is
a racing process which tries to open such mangled tty, which was not
closed yet, the process will crash in hvc_open as tty->driver_data is
NULL.
All this happens because close wants to know whether open failed or not.
But ->open should not NULL this and other tty fields for ->close to be
happy. ->open should call tty_port_set_initialized(true) and close
should check by tty_port_initialized() instead. So do this properly in
this driver.
So this patch removes these from ->open:
* tty_port_tty_set(&hp->port, NULL). This happens on last close.
* tty->driver_data = NULL. Dtto.
* tty_port_put(&hp->port). This happens in shutdown and until now, this
must have been causing a reference underflow, if I am not missing
something.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: stable <stable@vger.kernel.org>
Reported-and-tested-by: Raghavendra <rananta@codeaurora.org>
Link: https://lore.kernel.org/r/20200526145632.13879-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This reverts commit e2bd1dcbe1aa34ff5570b3427c530e4332ecf0fe.
In discussion on the mailing list, it has been determined that this is
not the correct type of fix for this issue. Revert it so that we can do
this correctly.
Reported-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200428032601.22127-1-rananta@codeaurora.org
Cc: Raghavendra Rao Ananta <rananta@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the tty fixes in here too.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
"A handful of fixes.
Specifically:
- fix linker argument to allow linking with lld
- build fix for configurations without a frame pointer
- a handful of build fixes related the SBI 0.1 vs 0.2 split
- remove STRICT_KERNEL_RWX for !MMU, which isn't useful"
* tag 'riscv-for-linus-5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: select ARCH_HAS_STRICT_KERNEL_RWX only if MMU
riscv: sbi: Fix undefined reference to sbi_shutdown
tty: riscv: Using RISCV_SBI_V01 instead of RISCV_SBI
riscv: sbi: Correct sbi_shutdown() and sbi_clear_ipi() export
riscv: fix vdso build with lld
RISC-V: stacktrace: Declare sp_in_global outside ifdef
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Potentially, hvc_open() can be called in parallel when two tasks calls
open() on /dev/hvcX. In such a scenario, if the hp->ops->notifier_add()
callback in the function fails, where it sets the tty->driver_data to
NULL, the parallel hvc_open() can see this NULL and cause a memory abort.
Hence, serialize hvc_open and check if tty->private_data is NULL before
proceeding ahead.
The issue can be easily reproduced by launching two tasks simultaneously
that does nothing but open() and close() on /dev/hvcX.
For example:
$ ./simple_open_close /dev/hvc0 & ./simple_open_close /dev/hvc0 &
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>
Link: https://lore.kernel.org/r/20200428032601.22127-1-rananta@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the tty/serial fixes in here too.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If there is a lot(more then 16) of virtio-console devices
or virtio_console module is reloaded
- buffers 'vtermnos' and 'cons_ops' are overflowed.
In older kernels it overruns spinlock which leads to kernel freezing:
https://bugzilla.redhat.com/show_bug.cgi?id=1786239
To reproduce the issue, you can try simple script that
loads/unloads module. Something like this:
while [ 1 ]
do
modprobe virtio_console
sleep 2
modprobe -r virtio_console
sleep 2
done
Description of problem:
Guest get 'Call Trace' when loading module "virtio_console"
and unloading it frequently - clearly reproduced on kernel-4.18.0:
[ 81.498208] ------------[ cut here ]------------
[ 81.499263] pvqspinlock: lock 0xffffffff92080020 has corrupted value 0xc0774ca0!
[ 81.501000] WARNING: CPU: 0 PID: 785 at kernel/locking/qspinlock_paravirt.h:500 __pv_queued_spin_unlock_slowpath+0xc0/0xd0
[ 81.503173] Modules linked in: virtio_console fuse xt_CHECKSUM ipt_MASQUERADE xt_conntrack ipt_REJECT nft_counter nf_nat_tftp nft_objref nf_conntrack_tftp tun bridge stp llc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_tables_set nft_chain_nat_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 nft_chain_route_ipv6 nft_chain_nat_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack nft_chain_route_ipv4 ip6_tables nft_compat ip_set nf_tables nfnetlink sunrpc bochs_drm drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm i2c_piix4 pcspkr crct10dif_pclmul crc32_pclmul joydev ghash_clmulni_intel ip_tables xfs libcrc32c sd_mod sg ata_generic ata_piix virtio_net libata crc32c_intel net_failover failover serio_raw virtio_scsi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: virtio_console]
[ 81.517019] CPU: 0 PID: 785 Comm: kworker/0:2 Kdump: loaded Not tainted 4.18.0-167.el8.x86_64 #1
[ 81.518639] Hardware name: Red Hat KVM, BIOS 1.12.0-5.scrmod+el8.2.0+5159+d8aa4d83 04/01/2014
[ 81.520205] Workqueue: events control_work_handler [virtio_console]
[ 81.521354] RIP: 0010:__pv_queued_spin_unlock_slowpath+0xc0/0xd0
[ 81.522450] Code: 07 00 48 63 7a 10 e8 bf 64 f5 ff 66 90 c3 8b 05 e6 cf d6 01 85 c0 74 01 c3 8b 17 48 89 fe 48 c7 c7 38 4b 29 91 e8 3a 6c fa ff <0f> 0b c3 0f 0b 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48
[ 81.525830] RSP: 0018:ffffb51a01ffbd70 EFLAGS: 00010282
[ 81.526798] RAX: 0000000000000000 RBX: 0000000000000010 RCX: 0000000000000000
[ 81.528110] RDX: ffff9e66f1826480 RSI: ffff9e66f1816a08 RDI: ffff9e66f1816a08
[ 81.529437] RBP: ffffffff9153ff10 R08: 000000000000026c R09: 0000000000000053
[ 81.530732] R10: 0000000000000000 R11: ffffb51a01ffbc18 R12: ffff9e66cd682200
[ 81.532133] R13: ffffffff9153ff10 R14: ffff9e6685569500 R15: ffff9e66cd682000
[ 81.533442] FS: 0000000000000000(0000) GS:ffff9e66f1800000(0000) knlGS:0000000000000000
[ 81.534914] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 81.535971] CR2: 00005624c55b14d0 CR3: 00000003a023c000 CR4: 00000000003406f0
[ 81.537283] Call Trace:
[ 81.537763] __raw_callee_save___pv_queued_spin_unlock_slowpath+0x11/0x20
[ 81.539011] .slowpath+0x9/0xe
[ 81.539585] hvc_alloc+0x25e/0x300
[ 81.540237] init_port_console+0x28/0x100 [virtio_console]
[ 81.541251] handle_control_message.constprop.27+0x1c4/0x310 [virtio_console]
[ 81.542546] control_work_handler+0x70/0x10c [virtio_console]
[ 81.543601] process_one_work+0x1a7/0x3b0
[ 81.544356] worker_thread+0x30/0x390
[ 81.545025] ? create_worker+0x1a0/0x1a0
[ 81.545749] kthread+0x112/0x130
[ 81.546358] ? kthread_flush_work_fn+0x10/0x10
[ 81.547183] ret_from_fork+0x22/0x40
[ 81.547842] ---[ end trace aa97649bd16c8655 ]---
[ 83.546539] general protection fault: 0000 [#1] SMP NOPTI
[ 83.547422] CPU: 5 PID: 3225 Comm: modprobe Kdump: loaded Tainted: G W --------- - - 4.18.0-167.el8.x86_64 #1
[ 83.549191] Hardware name: Red Hat KVM, BIOS 1.12.0-5.scrmod+el8.2.0+5159+d8aa4d83 04/01/2014
[ 83.550544] RIP: 0010:__pv_queued_spin_lock_slowpath+0x19a/0x2a0
[ 83.551504] Code: c4 c1 ea 12 41 be 01 00 00 00 4c 8d 6d 14 41 83 e4 03 8d 42 ff 49 c1 e4 05 48 98 49 81 c4 40 a5 02 00 4c 03 24 c5 60 48 34 91 <49> 89 2c 24 b8 00 80 00 00 eb 15 84 c0 75 0a 41 0f b6 54 24 14 84
[ 83.554449] RSP: 0018:ffffb51a0323fdb0 EFLAGS: 00010202
[ 83.555290] RAX: 000000000000301c RBX: ffffffff92080020 RCX: 0000000000000001
[ 83.556426] RDX: 000000000000301d RSI: 0000000000000000 RDI: 0000000000000000
[ 83.557556] RBP: ffff9e66f196a540 R08: 000000000000028a R09: ffff9e66d2757788
[ 83.558688] R10: 0000000000000000 R11: 0000000000000000 R12: 646e61725f770b07
[ 83.559821] R13: ffff9e66f196a554 R14: 0000000000000001 R15: 0000000000180000
[ 83.560958] FS: 00007fd5032e8740(0000) GS:ffff9e66f1940000(0000) knlGS:0000000000000000
[ 83.562233] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 83.563149] CR2: 00007fd5022b0da0 CR3: 000000038c334000 CR4: 00000000003406e0
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200414191503.3471783-1-andrew@daynix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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No users of hvcs_driver_string, remove it. This fixes the following gcc
warning:
drivers/tty/hvc/hvcs.c:199:19: warning: ‘hvcs_driver_string’ defined but
not used [-Wunused-const-variable=]
static const char hvcs_driver_string[]
^~~~~~~~~~~~~~~~~~
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200403071325.3721-1-yanaijie@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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As shown in SBI v0.2, the legacy console SBI functions (sbi_console_getchar()
and sbi_console_putchar()) are expected to be deprecated; they have no replacement.
Let's HVC_RISCV_SBI and SERIAL_EARLYCON_RISCV_SBI depends on RISCV_SBI_V01.
Fixes: efca13989250 ("RISC-V: Introduce a new config for SBI v0.1")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the big set of char/misc/other driver patches for 5.7-rc1.
Lots of things in here, and it's later than expected due to some
reverts to resolve some reported issues. All is now clean with no
reported problems in linux-next.
Included in here is:
- interconnect updates
- mei driver updates
- uio updates
- nvmem driver updates
- soundwire updates
- binderfs updates
- coresight updates
- habanalabs updates
- mhi new bus type and core
- extcon driver updates
- some Kconfig cleanups
- other small misc driver cleanups and updates
As mentioned, all have been in linux-next for a while, and with the
last two reverts, all is calm and good"
* tag 'char-misc-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (174 commits)
Revert "driver core: platform: Initialize dma_parms for platform devices"
Revert "amba: Initialize dma_parms for amba devices"
amba: Initialize dma_parms for amba devices
driver core: platform: Initialize dma_parms for platform devices
bus: mhi: core: Drop the references to mhi_dev in mhi_destroy_device()
bus: mhi: core: Initialize bhie field in mhi_cntrl for RDDM capture
bus: mhi: core: Add support for reading MHI info from device
misc: rtsx: set correct pcr_ops for rts522A
speakup: misc: Use dynamic minor numbers for speakup devices
mei: me: add cedar fork device ids
coresight: do not use the BIT() macro in the UAPI header
Documentation: provide IBM contacts for embargoed hardware
nvmem: core: remove nvmem_sysfs_get_groups()
nvmem: core: use is_bin_visible for permissions
nvmem: core: use device_register and device_unregister
nvmem: core: add root_only member to nvmem device struct
extcon: axp288: Add wakeup support
extcon: Mark extcon_get_edev_name() function as exported symbol
extcon: palmas: Hide error messages if gpio returns -EPROBE_DEFER
dt-bindings: extcon: usbc-cros-ec: convert extcon-usbc-cros-ec.txt to yaml format
...
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This patch corrects the SPDX License Identifier style in
header file related to the HVC driver.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).
Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Link: https://lore.kernel.org/r/20200301170419.GA7125@nishad
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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'source' (include) all of the tty/*/Kconfig files from
drivers/tty/Kconfig instead of from drivers/char/Kconfig.
This consolidates them both in source code and in menu
presentation to the user.
Move hvc/Kconfig and serial/Kconfig 'source' lines into the
if TTY/endif block and remove the if TTY/endif blocks from
those 2 files.
Cc: linux-serial@vger.kernel.org
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Jiri Slaby <jslaby@suse.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20200311225736.32147-3-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial updates from Greg KH:
"Here is the "big" tty and serial driver patches for 5.5-rc1.
It's a bit later in the merge window than normal as I wanted to make
sure some last-minute patches applied to it were all sane. They seem
to be :)
There's a lot of little stuff in here, for the tty core, and for lots
of serial drivers:
- reverts of uartlite serial driver patches that were wrong
- msm-serial driver fixes
- serial core updates and fixes
- tty core fixes
- serial driver dma mapping api changes
- lots of other tiny fixes and updates for serial drivers
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (58 commits)
Revert "serial/8250: Add support for NI-Serial PXI/PXIe+485 devices"
vcs: prevent write access to vcsu devices
tty: vt: keyboard: reject invalid keycodes
tty: don't crash in tty_init_dev when missing tty_port
serial: stm32: fix clearing interrupt error flags
tty: Fix Kconfig indentation, continued
serial: serial_core: Perform NULL checks for break_ctl ops
tty: remove unused argument from tty_open_by_driver()
tty: Fix Kconfig indentation
{tty: serial, nand: onenand}: samsung: rename to fix build warning
serial: ifx6x60: add missed pm_runtime_disable
serial: pl011: Fix DMA ->flush_buffer()
Revert "serial-uartlite: Move the uart register"
Revert "serial-uartlite: Add get serial id if not provided"
Revert "serial-uartlite: Do not use static struct uart_driver out of probe()"
Revert "serial-uartlite: Add runtime support"
Revert "serial-uartlite: Change logic how console_port is setup"
Revert "serial-uartlite: Use allocated structure instead of static ones"
tty: serial: msm_serial: Use dma_request_chan() directly for channel request
tty: serial: tegra: Use dma_request_chan() directly for channel request
...
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Adjust indentation from seven spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20191121132847.29015-1-krzk@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20191120133843.13189-1-krzk@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When running in M-mode we can't use SBI based drivers. Add a new
CONFIG_RISCV_SBI that drivers that do SBI calls can depend on
instead.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
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Add DCC earlycon support for early printks. The patch is useful for SoC
bringup where HW serial console is broken.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/41e2920a6348e65b2e986b0e65b66531e87cd756.1570543923.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Use the typical style of array, not the equivalent &array[0].
Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/1be432798311378947ec4e6051cad1235b6eccbb.1562283944.git.joe@perches.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Convert docs to ReST and add them to the arch-specific
book.
The conversion here was trivial, as almost every file there
was already using an elegant format close to ReST standard.
The changes were mostly to mark literal blocks and add a few
missing section title identifiers.
One note with regards to "--": on Sphinx, this can't be used
to identify a list, as it will format it badly. This can be
used, however, to identify a long hyphen - and "---" is an
even longer one.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> # cxl
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While developing KASAN for 64-bit book3s, I hit the following stack
over-read.
It occurs because the hypercall to put characters onto the terminal
takes 2 longs (128 bits/16 bytes) of characters at a time, and so
hvc_put_chars() would unconditionally copy 16 bytes from the argument
buffer, regardless of supplied length. However, udbg_hvc_putc() can
call hvc_put_chars() with a single-byte buffer, leading to the error.
==================================================================
BUG: KASAN: stack-out-of-bounds in hvc_put_chars+0xdc/0x110
Read of size 8 at addr c0000000023e7a90 by task swapper/0
CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc2-next-20190528-02824-g048a6ab4835b #113
Call Trace:
dump_stack+0x104/0x154 (unreliable)
print_address_description+0xa0/0x30c
__kasan_report+0x20c/0x224
kasan_report+0x18/0x30
__asan_report_load8_noabort+0x24/0x40
hvc_put_chars+0xdc/0x110
hvterm_raw_put_chars+0x9c/0x110
udbg_hvc_putc+0x154/0x200
udbg_write+0xf0/0x240
console_unlock+0x868/0xd30
register_console+0x970/0xe90
register_early_udbg_console+0xf8/0x114
setup_arch+0x108/0x790
start_kernel+0x104/0x784
start_here_common+0x1c/0x534
Memory state around the buggy address:
c0000000023e7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0000000023e7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1
>c0000000023e7a80: f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00 00 00
^
c0000000023e7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0000000023e7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Document that a 16-byte buffer is requred, and provide it in udbg.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux
Pull RISC-V updates from Palmer Dabbelt:
"This contains an assortment of RISC-V related patches that I'd like to
target for the 5.2 merge window. Most of the patches are cleanups, but
there are a handful of user-visible changes:
- The nosmp and nr_cpus command-line arguments are now supported,
which work like normal.
- The SBI console no longer installs itself as a preferred console,
we rely on standard mechanisms (/chosen, command-line, hueristics)
instead.
- sfence_remove_sfence_vma{,_asid} now pass their arguments along to
the SBI call.
- Modules now support BUG().
- A missing sfence.vma during boot has been added. This bug only
manifests during boot.
- The arch/riscv support for SiFive's L2 cache controller has been
merged, which should un-block the EDAC framework work.
I've only tested this on QEMU again, as I didn't have time to get
things running on the Unleashed. The latest master from this morning
merges in cleanly and passes the tests as well"
* tag 'riscv-for-linus-5.2-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (31 commits)
riscv: fix locking violation in page fault handler
RISC-V: sifive_l2_cache: Add L2 cache controller driver for SiFive SoCs
RISC-V: Add DT documentation for SiFive L2 Cache Controller
RISC-V: Avoid using invalid intermediate translations
riscv: Support BUG() in kernel module
riscv: Add the support for c.ebreak check in is_valid_bugaddr()
riscv: support trap-based WARN()
riscv: fix sbi_remote_sfence_vma{,_asid}.
riscv: move switch_mm to its own file
riscv: move flush_icache_{all,mm} to cacheflush.c
tty: Don't force RISCV SBI console as preferred console
RISC-V: Access CSRs using CSR numbers
RISC-V: Add interrupt related SCAUSE defines in asm/csr.h
RISC-V: Use tabs to align macro values in asm/csr.h
RISC-V: Fix minor checkpatch issues.
RISC-V: Support nr_cpus command line option.
RISC-V: Implement nosmp commandline option.
RISC-V: Add RISC-V specific arch_match_cpu_phys_id
riscv: vdso: drop unnecessary cc-ldoption
riscv: call pm_power_off from machine_halt / machine_power_off
...
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The Linux kernel will auto-disables all boot consoles whenever it
gets a preferred real console.
Currently on RISC-V systems, if we have a real console which is not
RISCV SBI console then boot consoles (such as earlycon=sbi) are not
auto-disabled when a real console (ttyS0 or ttySIF0) is available.
This results in duplicate prints at boot-time after kernel starts
using real console (i.e. ttyS0 or ttySIF0) if "earlycon=" kernel
parameter was passed by bootloader.
The reason for above issue is that RISCV SBI console always adds
itself as preferred console which is causing other real consoles
to be not used as preferred console.
Ideally "console=" kernel parameter passed by bootloaders should
be the one selecting a preferred real console.
This patch fixes above issue by not forcing RISCV SBI console as
preferred console.
Fixes: afa6b1ccfad5 ("tty: New RISC-V SBI console driver")
Cc: stable@vger.kernel.org
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
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'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.
Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:
...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:
config FOO
bool
config FOO
bool
default n
With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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There were a few Kconfig and Makefiles under drivers/tty/ that were
missing a SPDX identifier. Fix that up so that automated tools can
properly classify all kernel source files.
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
This patch fixes the following warning:
drivers/tty/hvc/hvc_xen.c: In function ‘xencons_backend_changed’:
drivers/tty/hvc/hvc_xen.c:493:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (dev->state == XenbusStateClosed)
^
drivers/tty/hvc/hvc_xen.c:496:2: note: here
case XenbusStateClosing:
^~~~
Warning level 3 was used: -Wimplicit-fallthrough=3
Notice that, in this particular case, the code comment is modified
in accordance with what GCC is expecting to find.
This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.
For hvc, the code can also be simplified by using of_stdout pointer
instead of searching again for the stdout node.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-serial@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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Commit 550ddadcc758 ("tty: hvc: hvc_write() may sleep") broke the
termination condition in case the driver stops accepting characters.
This can result in unnecessary polling of the busy driver.
Restore it by testing the hvc_push return code.
Tested-by: Matteo Croce <mcroce@redhat.com>
Tested-by: Jason Gunthorpe <jgg@mellanox.com>
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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Commit ec97eaad1383 ("tty: hvc: hvc_poll() break hv read loop")
removes get_chars batching entirely, which slows down large console
operations like paste -- virtio console "feels worse than a 9600 baud
serial line," reports Matteo.
This adds back batching in a more latency friendly way. If the caller
can sleep then we try to fill the entire flip buffer, releasing the
lock and scheduling between each iteration. If it can not sleep, then
batches are limited to 128 bytes. Matteo confirms this fixes the
performance problem.
Latency testing the powerpc OPAL console with OpenBMC UART with a
large paste shows about 0.25ms latency, which seems reasonable. 10ms
latencies were typical for this case before the latency breaking work,
so we still see most of the benefit.
kopald-1204 0d.h. 5us : hvc_poll <-hvc_handle_interrupt
kopald-1204 0d.h. 5us : __hvc_poll <-hvc_handle_interrupt
kopald-1204 0d.h. 5us : _raw_spin_lock_irqsave <-__hvc_poll
kopald-1204 0d.h. 5us : tty_port_tty_get <-__hvc_poll
kopald-1204 0d.h. 6us : _raw_spin_lock_irqsave <-tty_port_tty_get
kopald-1204 0d.h. 6us : _raw_spin_unlock_irqrestore <-tty_port_tty_get
kopald-1204 0d.h. 6us : tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 7us : __tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 7us+: opal_get_chars <-__hvc_poll
kopald-1204 0d.h. 36us : tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 36us : __tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 36us+: opal_get_chars <-__hvc_poll
kopald-1204 0d.h. 65us : tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 65us : __tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 66us+: opal_get_chars <-__hvc_poll
kopald-1204 0d.h. 94us : tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 95us : __tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 95us+: opal_get_chars <-__hvc_poll
kopald-1204 0d.h. 124us : tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 124us : __tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 125us+: opal_get_chars <-__hvc_poll
kopald-1204 0d.h. 154us : tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 154us : __tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 154us+: opal_get_chars <-__hvc_poll
kopald-1204 0d.h. 183us : tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 184us : __tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 184us+: opal_get_chars <-__hvc_poll
kopald-1204 0d.h. 213us : tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 213us : __tty_buffer_request_room <-__hvc_poll
kopald-1204 0d.h. 213us+: opal_get_chars <-__hvc_poll
kopald-1204 0d.h. 242us : _raw_spin_unlock_irqrestore <-__hvc_poll
kopald-1204 0d.h. 242us : tty_flip_buffer_push <-__hvc_poll
kopald-1204 0d.h. 243us : queue_work_on <-tty_flip_buffer_push
kopald-1204 0d.h. 243us : tty_kref_put <-__hvc_poll
kopald-1204 0d.h. 243us : hvc_kick <-hvc_handle_interrupt
kopald-1204 0d.h. 243us : wake_up_process <-hvc_kick
kopald-1204 0d.h. 244us : try_to_wake_up <-hvc_kick
kopald-1204 0d.h. 244us : _raw_spin_lock_irqsave <-try_to_wake_up
kopald-1204 0d.h. 244us : _raw_spin_unlock_irqrestore <-try_to_wake_up
Reported-by: Matteo Croce <mcroce@redhat.com>
Tested-by: Matteo Croce <mcroce@redhat.com>
Tested-by: Jason Gunthorpe <jgg@mellanox.com>
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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Commit ec97eaad1383 ("tty: hvc: hvc_poll() break hv read loop") causes
the virtio console to hang at times (e.g., if you paste a bunch of
characters to it.
The reason is that get_chars must return 0 before we can be sure the
driver will kick or poll input again, but this change only scheduled a
poll if get_chars had returned a full count. Change this to poll on
any > 0 count.
Reported-by: Matteo Croce <mcroce@redhat.com>
Reported-by: Jason Gunthorpe <jgg@mellanox.com>
Tested-by: Matteo Croce <mcroce@redhat.com>
Tested-by: Jason Gunthorpe <jgg@mellanox.com>
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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Provide the flush hv_op for the opal hvc driver. This will flush the
firmware console buffers without spinning with interrupts disabled.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|
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This branch held some hvc related commits (Hypervisor Virtual Console)
so that they could get some wider testing in linux-next before merging.
|
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This delay was in the very first OPAL console commit 6.5 years ago,
and came from the vio hvc driver. The firmware console has hardened
sufficiently to remove it.
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|
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The RAW console does not need writes to be atomic, so relax
opal_put_chars to be able to do partial writes, and implement an
_atomic variant which does not take a spinlock. This API is used
in xmon, so the less locking that is used, the better chance there
is that a crash can be debugged.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|
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OPAL console writes do not have to synchronously flush firmware /
hardware buffers unless they are going through the udbg path.
Remove the unconditional flushing from opal_put_chars. Flush if
there was no space in the buffer as an optimisation (callers loop
waiting for success in that case). udbg flushing is moved to
udbg_opal_putc.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|
|
Use .flush to wait for drivers to flush their console outside of
the spinlock, to reduce lock/irq latencies.
Flush the hvc console driver after each write, which can help
messages make it out to the console after a crash.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|
|
Rework the hvc_write loop to drop and re-take the spinlock on each
iteration, add a cond_resched. Don't bother with an initial hvc_push
initially, which makes the logic simpler -- just do a hvc_push on
each time around the loop.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|
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Introduce points where hvc_poll drops the lock, enables interrupts,
and reschedules.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|
Roger Pau Monne
David Woodhouse
Randy Dunlap
Juergen Gross
Jiri Slaby
Yang Yingliang
Tyrel Datwyler
Gustavo A. R. Silva
Sergey Senozhatsky
Andy Shevchenko
Greg Kroah-Hartman
Linus Torvalds
Raghavendra Rao Ananta
Andrew Melnychenko
Jason Yan
Kefeng Wang
Nishad Kamdar
Krzysztof Kozlowski
Damien Le Moal
Michal Simek
Joe Perches
Mauro Carvalho Chehab
Daniel Axtens
Anup Patel
Bartlomiej Zolnierkiewicz
Gustavo A. R. Silva
Rob Herring
Nicholas Piggin
Michael Ellerman