similar to: [PATCH] Fix: buffer overflow during hvc_alloc().

From: Andrew Melnychenko <andrew at daynix.com> 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

Fix the polling section of the hvc driver to use the global "last_hvc" variable, rather than the ttys. With this change debugging a xen dom0 kernel is possible via the following kernel parameter: kgdboc=hvc0 Signed-off-by: Ben Guthro <Benjamin.Guthro@citrix.com> diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index 2d691eb..3750e74 100644 ---

> > Description of problem: > Guest get 'Call Trace' when loading module "virtio_console" and unloading > it frequently > > > Version-Release number of selected component (if applicable): > Guest > kernel-4.18.0-167.el8.x86_64 > seabios-bin-1.11.1-4.module+el8.1.0+4066+0f1aadab.noarch > # modinfo virtio_console >

Hey Rusty, This series adds support for generic ports with each port getting two vqs: one for input and one for output. The host notifies us via the config space of the max. number of ports that can be added for a particular device. As a result of that change, the buffer management for find_readbufs and send_bufs is moved to the vqs. Only one outbuf per port is used so we bide away some time in

Hey Rusty, This series adds support for generic ports with each port getting two vqs: one for input and one for output. The host notifies us via the config space of the max. number of ports that can be added for a particular device. As a result of that change, the buffer management for find_readbufs and send_bufs is moved to the vqs. Only one outbuf per port is used so we bide away some time in

(Amit pointed out that the patches never went out. This is a resend of the series meant to go out on 11/2/2011; I've marked it "v2".) This patchset applies to linux-next/next-20111102. This series implements support for multiple virtio_consoles using KVM. This patchset addresses several issues associated with trying to establish multiple virtio consoles. I'm trying to

(Amit pointed out that the patches never went out. This is a resend of the series meant to go out on 11/2/2011; I've marked it "v2".) This patchset applies to linux-next/next-20111102. This series implements support for multiple virtio_consoles using KVM. This patchset addresses several issues associated with trying to establish multiple virtio consoles. I'm trying to

(Amit pointed out that the patches never went out. This was a resend of the series meant to go out on 11/2/2011; Now it's a resend of the mail this morning, with everyone copied on the same mail. So sorry for the spam! This is v3.) This patchset applies to linux-next/next-20111102. This series implements support for multiple virtio_consoles using KVM. This patchset addresses several issues

(Amit pointed out that the patches never went out. This was a resend of the series meant to go out on 11/2/2011; Now it's a resend of the mail this morning, with everyone copied on the same mail. So sorry for the spam! This is v3.) This patchset applies to linux-next/next-20111102. This series implements support for multiple virtio_consoles using KVM. This patchset addresses several issues

(Amit pointed out that the patches never went out. This was a resend of the series meant to go out on 11/2/2011; Now it's a resend of the mail this morning, with everyone copied on the same mail. So sorry for the spam! This is v3.) This patchset applies to linux-next/next-20111102. This series implements support for multiple virtio_consoles using KVM. This patchset addresses several issues

(Amit pointed out that the patches never went out. This is a resend of the series meant to go out on 11/2/2011; I''ve marked it "v2".) This patchset applies to linux-next/next-20111102. This series implements support for multiple virtio_consoles using KVM. This patchset addresses several issues associated with trying to establish multiple virtio consoles. I''m

Expose multiple char devices ("ports") for simple communication between the host userspace and guest. Sample offline usages can be: poking around in a guest to find out the file systems used, applications installed, etc. Online usages can be sharing of clipboard data between the guest and the host, sending information about logged-in users to the host, locking the screen or session when

Expose multiple char devices ("ports") for simple communication between the host userspace and guest. Sample offline usages can be: poking around in a guest to find out the file systems used, applications installed, etc. Online usages can be sharing of clipboard data between the guest and the host, sending information about logged-in users to the host, locking the screen or session when

From: Francois Diakhate <fdiakh at gmail.com> Currently early_put_chars is not used by virtio_console because it can only be used once a port has been found, at which point it's too late because it is no longer needed. This patch should fix it. Acked-by: Christian Borntraeger <borntraeger at de.ibm.com> Signed-off-by: Amit Shah <amit.shah at redhat.com> Signed-off-by: Rusty

From: Francois Diakhate <fdiakh at gmail.com> Currently early_put_chars is not used by virtio_console because it can only be used once a port has been found, at which point it's too late because it is no longer needed. This patch should fix it. Acked-by: Christian Borntraeger <borntraeger at de.ibm.com> Signed-off-by: Amit Shah <amit.shah at redhat.com> Signed-off-by: Rusty

For regular serial ports we do not initialize value of vtermno variable. A garbage value is assigned for non console ports. The value can be observed as a random integer with [1]. [1] vim /sys/kernel/debug/virtio-ports/vport*p* This patch initialize the value of vtermno for console serial ports to '1' and regular serial ports are initiaized to '0'. Reported-by: siliu at

From: Omar Sandoval <osandov at fb.com> put_chars() stuffs the buffer it gets into an sg, but that buffer may be on the stack. This breaks with CONFIG_VMAP_STACK=y (for me, it manifested as printks getting turned into NUL bytes). Signed-off-by: Omar Sandoval <osandov at fb.com> --- Patch based on v4.10-rc6. drivers/char/virtio_console.c | 12 ++++++++++-- 1 file changed, 10

From: Omar Sandoval <osandov at fb.com> put_chars() stuffs the buffer it gets into an sg, but that buffer may be on the stack. This breaks with CONFIG_VMAP_STACK=y (for me, it manifested as printks getting turned into NUL bytes). Signed-off-by: Omar Sandoval <osandov at fb.com> --- Patch based on v4.10-rc6. drivers/char/virtio_console.c | 12 ++++++++++-- 1 file changed, 10

From: Christian Borntraeger <borntraeger at de.ibm.com> In case the registration of the hvc tty never happens AND the kernel thinks that hvc0 is the preferred console we should keep the early printk function to avoid a kernel panic due to code being removed. Signed-off-by: Christian Borntraeger <borntraeger at de.ibm.com> Signed-off-by: Jing Liu <liujbjl at linux.vnet.ibm.com>

From: Rusty Russell <rusty@rustcorp.com.au> A simple console driver for lguest. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- drivers/char/Makefile | 1 drivers/char/hvc_lguest.c | 99 ++++++++++++++++++++++++++++++++++++ 2 files changed, 100 insertions(+) diff