linux-stable.git/arch/um/kernel, branch linux-5.15.y

sched: Add wrapper for get_wchan() to keep task blocked

2025-08-28T14:24:03+00:00

commit 42a20f86dc19f9282d974df0ba4d226c865ab9dd upstream.

Having a stable wchan means the process must be blocked and for it to
stay that way while performing stack unwinding.

Suggested-by: Peter Zijlstra 
Signed-off-by: Kees Cook 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Geert Uytterhoeven 
Acked-by: Russell King (Oracle)  [arm]
Tested-by: Mark Rutland  [arm64]
Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
Signed-off-by: Siddhi Katage 
Signed-off-by: Greg Kroah-Hartman

um: Update min_low_pfn to match changes in uml_reserved

2025-06-04T12:37:56+00:00

[ Upstream commit e82cf3051e6193f61e03898f8dba035199064d36 ]

When uml_reserved is updated, min_low_pfn must also be updated
accordingly. Otherwise, min_low_pfn will not accurately reflect
the lowest available PFN.

Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20250221041855.1156109-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg 
Signed-off-by: Sasha Levin

um: Always dump trace for specified task in show_stack

2024-12-14T18:51:19+00:00

[ Upstream commit 0f659ff362eac69777c4c191b7e5ccb19d76c67d ]

Currently, show_stack() always dumps the trace of the current task.
However, it should dump the trace of the specified task if one is
provided. Otherwise, things like running "echo t > sysrq-trigger"
won't work as expected.

Fixes: 970e51feaddb ("um: Add support for CONFIG_STACKTRACE")
Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20241106103933.1132365-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg 
Signed-off-by: Sasha Levin

um: Fix the return value of elf_core_copy_task_fpregs

2024-12-14T18:51:19+00:00

[ Upstream commit 865e3845eeaa21e9a62abc1361644e67124f1ec0 ]

This function is expected to return a boolean value, which should be
true on success and false on failure.

Fixes: d1254b12c93e ("uml: fix x86_64 core dump crash")
Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20240913023302.130300-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg 
Signed-off-by: Sasha Levin

um: Fix potential integer overflow during physmem setup

2024-12-14T18:51:19+00:00

[ Upstream commit a98b7761f697e590ed5d610d87fa12be66f23419 ]

This issue happens when the real map size is greater than LONG_MAX,
which can be easily triggered on UML/i386.

Fixes: fe205bdd1321 ("um: Print minimum physical memory requirement")
Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20240916045950.508910-3-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg 
Signed-off-by: Sasha Levin

um: time-travel: fix time-travel-start option

2024-08-19T03:45:23+00:00

[ Upstream commit 7d0a8a490aa3a2a82de8826aaf1dfa38575cb77a ]

We need to have the = as part of the option so that the
value can be parsed properly. Also document that it must
be given in nanoseconds, not seconds.

Fixes: 065038706f77 ("um: Support time travel mode")
Link: https://patch.msgid.link/20240417102744.14b9a9d4eba0.Ib22e9136513126b2099d932650f55f193120cd97@changeid
Signed-off-by: Johannes Berg 
Signed-off-by: Sasha Levin

um: time-travel: fix time corruption

2024-02-23T07:54:50+00:00

[ Upstream commit abe4eaa8618bb36c2b33e9cdde0499296a23448c ]

In 'basic' time-travel mode (without =inf-cpu or =ext), we
still get timer interrupts. These can happen at arbitrary
points in time, i.e. while in timer_read(), which pushes
time forward just a little bit. Then, if we happen to get
the interrupt after calculating the new time to push to,
but before actually finishing that, the interrupt will set
the time to a value that's incompatible with the forward,
and we'll crash because time goes backwards when we do the
forwarding.

Fix this by reading the time_travel_time, calculating the
adjustment, and doing the adjustment all with interrupts
disabled.

Reported-by: Vincent Whitchurch 
Signed-off-by: Johannes Berg 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: Fix naming clash between UML and scheduler

2024-02-23T07:54:49+00:00

[ Upstream commit 541d4e4d435c8b9bfd29f70a1da4a2db97794e0a ]

__cant_sleep was already used and exported by the scheduler.
The name had to be changed to a UML specific one.

Signed-off-by: Anton Ivanov 
Reviewed-by: Peter Lafreniere 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um/cpu: Switch to arch_cpu_finalize_init()

2023-08-08T17:58:31+00:00

commit 9349b5cd0908f8afe95529fc7a8cbb1417df9b0c upstream

check_bugs() is about to be phased out. Switch over to the new
arch_cpu_finalize_init() implementation.

No functional change.

Signed-off-by: Thomas Gleixner 
Acked-by: Richard Weinberger 
Link: https://lore.kernel.org/r/20230613224545.493148694@linutronix.de
Signed-off-by: Daniel Sneddon 
Signed-off-by: Greg Kroah-Hartman

UML: define RUNTIME_DISCARD_EXIT

2023-03-17T07:49:04+00:00

commit b99ddbe8336ee680257c8ab479f75051eaa49dcf upstream.

With CONFIG_VIRTIO_UML=y, GNU ld < 2.36 fails to link UML vmlinux
(w/wo CONFIG_LD_SCRIPT_STATIC).

  `.exit.text' referenced in section `.uml.exitcall.exit' of arch/um/drivers/virtio_uml.o: defined in discarded section `.exit.text' of arch/um/drivers/virtio_uml.o
  collect2: error: ld returned 1 exit status

This fix is similar to the following commits:

- 4b9880dbf3bd ("powerpc/vmlinux.lds: Define RUNTIME_DISCARD_EXIT")
- a494398bde27 ("s390: define RUNTIME_DISCARD_EXIT to fix link error
  with GNU ld < 2.36")
- c1c551bebf92 ("sh: define RUNTIME_DISCARD_EXIT")

Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Reported-by: SeongJae Park 
Signed-off-by: Masahiro Yamada 
Tested-by: SeongJae Park 
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman