linux-stable.git/arch/alpha/kernel, branch v4.9.331

tty: the rest, stop using tty_schedule_flip()

2022-07-29T15:05:47+00:00

commit b68b914494df4f79b4e9b58953110574af1cb7a2 upstream.

Since commit a9c3f68f3cd8d (tty: Fix low_latency BUG) in 2014,
tty_flip_buffer_push() is only a wrapper to tty_schedule_flip(). We are
going to remove the latter (as it is used less), so call the former in
the rest of the users.

Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: William Hubbs 
Cc: Chris Brannon 
Cc: Kirk Reiser 
Cc: Samuel Thibault 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Cc: Alexander Gordeev 
Reviewed-by: Johan Hovold 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211122111648.30379-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

alpha: Send stop IPI to send to online CPUs

2021-08-15T11:01:04+00:00

[ Upstream commit caace6ca4e06f09413fb8f8a63319594cfb7d47d ]

This issue was noticed while debugging a shutdown issue where some
secondary CPUs are not being shutdown correctly.  A fix for that [1] requires
that secondary cpus be offlined using the cpu_online_mask so that the
stop operation is a no-op if CPU HOTPLUG is disabled.  I, like the author in
[1] looked at the architectures and found that alpha is one of two
architectures that executes smp_send_stop() on all possible CPUs.

On alpha, smp_send_stop() sends an IPI to all possible CPUs but only needs
to send them to online CPUs.

Send the stop IPI to only the online CPUs.

[1] https://lkml.org/lkml/2020/1/10/250

Signed-off-by: Prarit Bhargava 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Signed-off-by: Matt Turner 
Signed-off-by: Sasha Levin

sys: don't hold uts_sem while accessing userspace memory

2018-09-09T18:01:24+00:00

commit 42a0cc3478584d4d63f68f2f5af021ddbea771fa upstream.

Holding uts_sem as a writer while accessing userspace memory allows a
namespace admin to stall all processes that attempt to take uts_sem.
Instead, move data through stack buffers and don't access userspace memory
while uts_sem is held.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jann Horn 
Signed-off-by: Eric W. Biederman 
Signed-off-by: Greg Kroah-Hartman

osf_getdomainname(): use copy_to_user()

2018-09-09T18:01:24+00:00

commit 9ba3eb5103cf56f0daaf07de4507df76e7813ed7 upstream.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

vgacon: Set VGA struct resource types

2018-03-24T10:00:25+00:00

[ Upstream commit c82084117f79bcae085e40da526253736a247120 ]

Set the resource type when we reserve VGA-related I/O port resources.

The resource code doesn't actually look at the type, so it inserts
resources without a type in the tree correctly even without this change.
But if we ever print a resource without a type, it looks like this:

  vga+ [??? 0x000003c0-0x000003df flags 0x0]

Setting the type means it will be printed correctly as:

  vga+ [io  0x000003c0-0x000003df]

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

alpha: fix formating of stack content

2018-02-17T12:21:19+00:00

commit 4b01abdb32fc36abe877503bfbd33019159fad71 upstream.

Since version 4.9, the kernel automatically breaks printk calls into
multiple newlines unless pr_cont is used. Fix the alpha stacktrace code,
so that it prints stack trace in four columns, as it was initially
intended.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Matt Turner 
Signed-off-by: Greg Kroah-Hartman

alpha: fix reboot on Avanti platform

2018-02-17T12:21:19+00:00

commit 55fc633c41a08ce9244ff5f528f420b16b1e04d6 upstream.

We need to define NEED_SRM_SAVE_RESTORE on the Avanti, otherwise we get
machine check exception when attempting to reboot the machine.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Matt Turner 
Signed-off-by: Greg Kroah-Hartman

alpha: fix crash if pthread_create races with signal delivery

2018-02-17T12:21:19+00:00

commit 21ffceda1c8b3807615c40d440d7815e0c85d366 upstream.

On alpha, a process will crash if it attempts to start a thread and a
signal is delivered at the same time. The crash can be reproduced with
this program: https://cygwin.com/ml/cygwin/2014-11/msg00473.html

The reason for the crash is this:
* we call the clone syscall
* we go to the function copy_process
* copy process calls copy_thread_tls, it is a wrapper around copy_thread
* copy_thread sets the tls pointer: childti->pcb.unique = regs->r20
* copy_thread sets regs->r20 to zero
* we go back to copy_process
* copy process checks "if (signal_pending(current))" and returns
  -ERESTARTNOINTR
* the clone syscall is restarted, but this time, regs->r20 is zero, so
  the new thread is created with zero tls pointer
* the new thread crashes in start_thread when attempting to access tls

The comment in the code says that setting the register r20 is some
compatibility with OSF/1. But OSF/1 doesn't use the CLONE_SETTLS flag, so
we don't have to zero r20 if CLONE_SETTLS is set. This patch fixes the bug
by zeroing regs->r20 only if CLONE_SETTLS is not set.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Matt Turner 
Signed-off-by: Greg Kroah-Hartman

osf_wait4(): fix infoleak

2017-05-25T13:44:47+00:00

commit a8c39544a6eb2093c04afd5005b6192bd0e880c6 upstream.

failing sys_wait4() won't fill struct rusage...

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

ptrace: Don't allow accessing an undumpable mm

2017-01-06T09:40:13+00:00

commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3 upstream.

It is the reasonable expectation that if an executable file is not
readable there will be no way for a user without special privileges to
read the file.  This is enforced in ptrace_attach but if ptrace
is already attached before exec there is no enforcement for read-only
executables.

As the only way to read such an mm is through access_process_vm
spin a variant called ptrace_access_vm that will fail if the
target process is not being ptraced by the current process, or
the current process did not have sufficient privileges when ptracing
began to read the target processes mm.

In the ptrace implementations replace access_process_vm by
ptrace_access_vm.  There remain several ptrace sites that still use
access_process_vm as they are reading the target executables
instructions (for kernel consumption) or register stacks.  As such it
does not appear necessary to add a permission check to those calls.

This bug has always existed in Linux.

Fixes: v1.0
Reported-by: Andy Lutomirski 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman