linux-stable.git/arch/um/os-Linux, branch linux-6.14.y Linux kernel stable tree um: remove copy_from_kernel_nofault_allowed 2025-04-10T12:44:33+00:00 Benjamin Berg benjamin.berg@intel.com 2025-02-10T16:09:26+00:00 bb758c41bda94cbe73f36aea06f98ad8202e3bd2 [ Upstream commit 84a6fc378471fbeaf48f8604566a5a33a3d63c18 ] There is no need to override the default version of this function anymore as UML now has proper _nofault memory access functions. Doing this also fixes the fact that the implementation was incorrect as using mincore() will incorrectly flag pages as inaccessible if they were swapped out by the host. Fixes: f75b1b1bedfb ("um: Implement probe_kernel_read()") Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20250210160926.420133-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 84a6fc378471fbeaf48f8604566a5a33a3d63c18 ]

There is no need to override the default version of this function
anymore as UML now has proper _nofault memory access functions.

Doing this also fixes the fact that the implementation was incorrect as
using mincore() will incorrectly flag pages as inaccessible if they were
swapped out by the host.

Fixes: f75b1b1bedfb ("um: Implement probe_kernel_read()")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20250210160926.420133-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: fix execve stub execution on old host OSs 2025-02-12T22:40:45+00:00 Benjamin Berg benjamin.berg@intel.com 2025-01-13T09:41:07+00:00 f82a9e7b9fa922bb9cccb00aae684a27b79e6df7 The stub execution uses the somewhat new close_range and execveat syscalls. Of these two, the execveat call is essential, but the close_range call is more about stub process hygiene rather than safety (and its result is ignored). Replace both calls with a raw syscall as older machines might not have a recent enough kernel for close_range (with CLOSE_RANGE_CLOEXEC) or a libc that does not yet expose both of the syscalls. Fixes: 32e8eaf263d9 ("um: use execveat to create userspace MMs") Reported-by: Glenn Washburn <development@efficientek.com> Closes: https://lore.kernel.org/20250108022404.05e0de1e@crass-HP-ZBook-15-G2 Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20250113094107.674738-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> 
The stub execution uses the somewhat new close_range and execveat
syscalls. Of these two, the execveat call is essential, but the
close_range call is more about stub process hygiene rather than safety
(and its result is ignored).

Replace both calls with a raw syscall as older machines might not have a
recent enough kernel for close_range (with CLOSE_RANGE_CLOEXEC) or a
libc that does not yet expose both of the syscalls.

Fixes: 32e8eaf263d9 ("um: use execveat to create userspace MMs")
Reported-by: Glenn Washburn <development@efficientek.com>
Closes: https://lore.kernel.org/20250108022404.05e0de1e@crass-HP-ZBook-15-G2
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20250113094107.674738-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
um: Remove unused THREAD_NAME_LEN macro 2025-01-10T12:49:57+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-28T08:31:36+00:00 c5e78b8d408add9d3562c7c44a727336ecb5d48b It's no longer used since commit 42fda66387da ("uml: throw out CONFIG_MODE_TT"). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128083137.2219830-9-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
It's no longer used since commit 42fda66387da ("uml: throw out
CONFIG_MODE_TT").

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241128083137.2219830-9-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
um: Remove unused PGD_BOUND macro 2025-01-10T12:49:57+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-28T08:31:35+00:00 3c68810e150b80b9282e854142922b39489a54a5 It's no longer used since commit 11100b1dfb6e ("uml: delete unused code"). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128083137.2219830-8-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
It's no longer used since commit 11100b1dfb6e ("uml: delete
unused code").

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241128083137.2219830-8-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
um: Mark setup_env_path as __init 2025-01-10T12:49:57+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-28T08:31:34+00:00 0c5258efd69b73bd12f3e68cfe72e1396fdb857c It's only invoked during boot from main(). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128083137.2219830-7-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
It's only invoked during boot from main().

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241128083137.2219830-7-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
um: Mark install_fatal_handler as __init 2025-01-10T12:49:56+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-28T08:31:33+00:00 c2fdfd779717bf1d4bb569c7cb64502143144cad It's only invoked during boot from main(). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128083137.2219830-6-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
It's only invoked during boot from main().

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241128083137.2219830-6-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
um: Mark set_stklim as __init 2025-01-10T12:49:56+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-28T08:31:32+00:00 f0c76bc82d4544bde874497e830b2c9fa04bafe1 It's only invoked during boot from main(). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128083137.2219830-5-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
It's only invoked during boot from main().

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241128083137.2219830-5-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
um: move thread info into task 2024-11-12T13:50:31+00:00 Benjamin Berg benjamin.berg@intel.com 2024-11-11T10:29:10+00:00 2f681ba4b352cdd5658ed2a96062375a12839755 This selects the THREAD_INFO_IN_TASK option for UM and changes the way that the current task is discovered. This is trivial though, as UML already tracks the current task in cpu_tasks[] and this can be used to retrieve it. Also remove the signal handler code that copies the thread information into the IRQ stack. It is obsolete now, which also means that the mentioned race condition cannot happen anymore. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Reviewed-by: Hajime Tazaki <thehajime@gmail.com> Link: https://patch.msgid.link/20241111102910.46512-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
This selects the THREAD_INFO_IN_TASK option for UM and changes the way
that the current task is discovered. This is trivial though, as UML
already tracks the current task in cpu_tasks[] and this can be used to
retrieve it.

Also remove the signal handler code that copies the thread information
into the IRQ stack. It is obsolete now, which also means that the
mentioned race condition cannot happen anymore.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Reviewed-by: Hajime Tazaki <thehajime@gmail.com>
Link: https://patch.msgid.link/20241111102910.46512-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
um: remove broken double fault detection 2024-11-07T16:36:31+00:00 Benjamin Berg benjamin.berg@intel.com 2024-11-03T15:05:06+00:00 ce6e85a186c28ab0ca024580cba93fa19147c72b The show_stack function had some code to detect double faults. However, the logic is wrong and it would e.g. trigger if a WARNING happened inside an IRQ. Remove it without trying to add a new logic. The current behaviour, which will just fault repeatedly until the IRQ stack is used up and the host kills UML, seems to be good enough. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241103150506.1367695-5-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
The show_stack function had some code to detect double faults. However,
the logic is wrong and it would e.g. trigger if a WARNING happened
inside an IRQ.

Remove it without trying to add a new logic. The current behaviour,
which will just fault repeatedly until the IRQ stack is used up and the
host kills UML, seems to be good enough.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241103150506.1367695-5-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
um: remove file sync for stub data 2024-11-07T16:36:30+00:00 Benjamin Berg benjamin.berg@intel.com 2024-11-03T15:05:04+00:00 37c691151e52f7762afa147ffb6e412ee0b5e8ac There is no need to sync the stub code to "disk" for the other process to see the correct memory. Drop the fsync there and remove the helper function. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241103150506.1367695-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> 
There is no need to sync the stub code to "disk" for the other process
to see the correct memory. Drop the fsync there and remove the helper
function.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241103150506.1367695-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>