linux-stable.git/arch/um, branch linux-5.4.y Linux kernel stable tree um: ubd: Add missing error check in start_io_thread() 2025-07-17T16:24:53+00:00 Tiwei Bie tiwei.btw@antgroup.com 2025-06-06T12:44:25+00:00 a304adc2c7226545ae689285bce31146be984667 [ Upstream commit c55c7a85e02a7bfee20a3ffebdff7cbeb41613ef ] The subsequent call to os_set_fd_block() overwrites the previous return value. OR the two return values together to fix it. Fixes: f88f0bdfc32f ("um: UBD Improvements") Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20250606124428.148164-2-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c55c7a85e02a7bfee20a3ffebdff7cbeb41613ef ]

The subsequent call to os_set_fd_block() overwrites the previous
return value. OR the two return values together to fix it.

Fixes: f88f0bdfc32f ("um: UBD Improvements")
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20250606124428.148164-2-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: let 'make clean' properly clean underlying SUBARCH as well 2025-06-04T12:32:37+00:00 Masahiro Yamada masahiroy@kernel.org 2025-05-07T07:49:33+00:00 dd1283d756a9f37f4aa441854dcb187481aef603 [ Upstream commit ab09da75700e9d25c7dfbc7f7934920beb5e39b9 ] Building the kernel with O= is affected by stale in-tree build artifacts. So, if the source tree is not clean, Kbuild displays the following: $ make ARCH=um O=build defconfig make[1]: Entering directory '/.../linux/build' *** *** The source tree is not clean, please run 'make ARCH=um mrproper' *** in /.../linux *** make[2]: *** [/.../linux/Makefile:673: outputmakefile] Error 1 make[1]: *** [/.../linux/Makefile:248: __sub-make] Error 2 make[1]: Leaving directory '/.../linux/build' make: *** [Makefile:248: __sub-make] Error 2 Usually, running 'make mrproper' is sufficient for cleaning the source tree for out-of-tree builds. However, building UML generates build artifacts not only in arch/um/, but also in the SUBARCH directory (i.e., arch/x86/). If in-tree stale files remain under arch/x86/, Kbuild will reuse them instead of creating new ones under the specified build directory. This commit makes 'make ARCH=um clean' recurse into the SUBARCH directory. Reported-by: Shuah Khan <skhan@linuxfoundation.org> Closes: https://lore.kernel.org/lkml/20250502172459.14175-1-skhan@linuxfoundation.org/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Johannes Berg <johannes@sipsolutions.net> Reviewed-by: David Gow <davidgow@google.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ab09da75700e9d25c7dfbc7f7934920beb5e39b9 ]

Building the kernel with O= is affected by stale in-tree build artifacts.

So, if the source tree is not clean, Kbuild displays the following:

  $ make ARCH=um O=build defconfig
  make[1]: Entering directory '/.../linux/build'
  ***
  *** The source tree is not clean, please run 'make ARCH=um mrproper'
  *** in /.../linux
  ***
  make[2]: *** [/.../linux/Makefile:673: outputmakefile] Error 1
  make[1]: *** [/.../linux/Makefile:248: __sub-make] Error 2
  make[1]: Leaving directory '/.../linux/build'
  make: *** [Makefile:248: __sub-make] Error 2

Usually, running 'make mrproper' is sufficient for cleaning the source
tree for out-of-tree builds.

However, building UML generates build artifacts not only in arch/um/,
but also in the SUBARCH directory (i.e., arch/x86/). If in-tree stale
files remain under arch/x86/, Kbuild will reuse them instead of creating
new ones under the specified build directory.

This commit makes 'make ARCH=um clean' recurse into the SUBARCH directory.

Reported-by: Shuah Khan <skhan@linuxfoundation.org>
Closes: https://lore.kernel.org/lkml/20250502172459.14175-1-skhan@linuxfoundation.org/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: Update min_low_pfn to match changes in uml_reserved 2025-06-04T12:32:30+00:00 Tiwei Bie tiwei.btw@antgroup.com 2025-02-21T04:18:55+00:00 874553032a8336070781cc635e540f7ab85b12dc [ 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 <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20250221041855.1156109-1-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20250221041855.1156109-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: Always dump trace for specified task in show_stack 2024-12-14T18:44:40+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-06T10:39:33+00:00 9e497ef3a6cfa1b211626b24312b440339509893 [ 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 <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241106103933.1132365-1-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241106103933.1132365-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: Clean up stacktrace dump 2024-12-14T18:44:40+00:00 Johannes Berg johannes.berg@intel.com 2020-09-21T11:43:25+00:00 115e3e51b14a2637058d1bc95b68710f9dc709fd [ Upstream commit 273fe1b676cb59d41e177980a981e27806872954 ] We currently get a few stray newlines, due to the interaction between printk() and the code here. Remove a few explicit newline prints to neaten the output. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at> Stable-dep-of: 0f659ff362ea ("um: Always dump trace for specified task in show_stack") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 273fe1b676cb59d41e177980a981e27806872954 ]

We currently get a few stray newlines, due to the interaction
between printk() and the code here. Remove a few explicit
newline prints to neaten the output.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Stable-dep-of: 0f659ff362ea ("um: Always dump trace for specified task in show_stack")
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: add show_stack_loglvl() 2024-12-14T18:44:39+00:00 Dmitry Safonov dima@arista.com 2020-06-09T04:31:45+00:00 abf08999d994f10534bf0ceb615629221c8930af [ Upstream commit 1ad87824f4cf16a7f381e1f94943a96bb7a99062 ] Currently, the log-level of show_stack() depends on a platform realization. It creates situations where the headers are printed with lower log level or higher than the stacktrace (depending on a platform or user). Furthermore, it forces the logic decision from user to an architecture side. In result, some users as sysrq/kdb/etc are doing tricks with temporary rising console_loglevel while printing their messages. And in result it not only may print unwanted messages from other CPUs, but also omit printing at all in the unlucky case where the printk() was deferred. Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier approach than introducing more printk buffers. Also, it will consolidate printings with headers. Introduce show_stack_loglvl(), that eventually will substitute show_stack(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Link: http://lkml.kernel.org/r/20200418201944.482088-37-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Stable-dep-of: 0f659ff362ea ("um: Always dump trace for specified task in show_stack") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1ad87824f4cf16a7f381e1f94943a96bb7a99062 ]

Currently, the log-level of show_stack() depends on a platform
realization.  It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side.  In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages.  And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers.  Also, it will consolidate
printings with headers.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/20200418201944.482088-37-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 0f659ff362ea ("um: Always dump trace for specified task in show_stack")
Signed-off-by: Sasha Levin <sashal@kernel.org>
um/sysrq: remove needless variable sp 2024-12-14T18:44:39+00:00 Dmitry Safonov dima@arista.com 2020-06-09T04:31:42+00:00 3103837c507ebdad6ddace363d5670de49be5d3c [ Upstream commit 3dd923f39a03dede001afe0edcc08613d5f403e5 ] `sp' is a needless excercise here. Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Link: http://lkml.kernel.org/r/20200418201944.482088-36-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Stable-dep-of: 0f659ff362ea ("um: Always dump trace for specified task in show_stack") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3dd923f39a03dede001afe0edcc08613d5f403e5 ]

`sp' is a needless excercise here.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/20200418201944.482088-36-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 0f659ff362ea ("um: Always dump trace for specified task in show_stack")
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: Fix the return value of elf_core_copy_task_fpregs 2024-12-14T18:44:39+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-09-13T02:33:02+00:00 ea8b2f3718db5836ee9ca53fcda0d51055e06555 [ 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 <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20240913023302.130300-1-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20240913023302.130300-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: Fix potential integer overflow during physmem setup 2024-12-14T18:44:39+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-09-16T04:59:48+00:00 5c710f45811e7e2bfcf703980c306f19c7e1ecfe [ 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 <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20240916045950.508910-3-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20240916045950.508910-3-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
um: vector: Do not use drvdata in release 2024-12-14T18:44:37+00:00 Tiwei Bie tiwei.btw@antgroup.com 2024-11-04T16:32:03+00:00 376c7f0beb8f6f3800fc3013ef2f422d0cbfbf92 commit 51b39d741970742a5c41136241a9c48ac607cf82 upstream. The drvdata is not available in release. Let's just use container_of() to get the vector_device instance. Otherwise, removing a vector device will result in a crash: RIP: 0033:vector_device_release+0xf/0x50 RSP: 00000000e187bc40 EFLAGS: 00010202 RAX: 0000000060028f61 RBX: 00000000600f1baf RCX: 00000000620074e0 RDX: 000000006220b9c0 RSI: 0000000060551c80 RDI: 0000000000000000 RBP: 00000000e187bc50 R08: 00000000603ad594 R09: 00000000e187bb70 R10: 000000000000135a R11: 00000000603ad422 R12: 00000000623ae028 R13: 000000006287a200 R14: 0000000062006d30 R15: 00000000623700b6 Kernel panic - not syncing: Segfault with no mm CPU: 0 UID: 0 PID: 16 Comm: kworker/0:1 Not tainted 6.12.0-rc6-g59b723cd2adb #1 Workqueue: events mc_work_proc Stack: 60028f61 623ae028 e187bc80 60276fcd 6220b9c0 603f5820 623ae028 00000000 e187bcb0 603a2bcd 623ae000 62370010 Call Trace: [<60028f61>] ? vector_device_release+0x0/0x50 [<60276fcd>] device_release+0x70/0xba [<603a2bcd>] kobject_put+0xba/0xe7 [<60277265>] put_device+0x19/0x1c [<60281266>] platform_device_put+0x26/0x29 [<60281e5f>] platform_device_unregister+0x2c/0x2e [<60029422>] vector_remove+0x52/0x58 [<60031316>] ? mconsole_reply+0x0/0x50 [<600310c8>] mconsole_remove+0x160/0x1cc [<603b19f4>] ? strlen+0x0/0x15 [<60066611>] ? __dequeue_entity+0x1a9/0x206 [<600666a7>] ? set_next_entity+0x39/0x63 [<6006666e>] ? set_next_entity+0x0/0x63 [<60038fa6>] ? um_set_signals+0x0/0x43 [<6003070c>] mc_work_proc+0x77/0x91 [<60057664>] process_scheduled_works+0x1b3/0x2dd [<60055f32>] ? assign_work+0x0/0x58 [<60057f0a>] worker_thread+0x1e9/0x293 [<6005406f>] ? set_pf_worker+0x0/0x64 [<6005d65d>] ? arch_local_irq_save+0x0/0x2d [<6005d748>] ? kthread_exit+0x0/0x3a [<60057d21>] ? worker_thread+0x0/0x293 [<6005dbf1>] kthread+0x126/0x12b [<600219c5>] new_thread_handler+0x85/0xb6 Cc: stable@vger.kernel.org Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Link: https://patch.msgid.link/20241104163203.435515-5-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 51b39d741970742a5c41136241a9c48ac607cf82 upstream.

The drvdata is not available in release. Let's just use container_of()
to get the vector_device instance. Otherwise, removing a vector device
will result in a crash:

RIP: 0033:vector_device_release+0xf/0x50
RSP: 00000000e187bc40  EFLAGS: 00010202
RAX: 0000000060028f61 RBX: 00000000600f1baf RCX: 00000000620074e0
RDX: 000000006220b9c0 RSI: 0000000060551c80 RDI: 0000000000000000
RBP: 00000000e187bc50 R08: 00000000603ad594 R09: 00000000e187bb70
R10: 000000000000135a R11: 00000000603ad422 R12: 00000000623ae028
R13: 000000006287a200 R14: 0000000062006d30 R15: 00000000623700b6
Kernel panic - not syncing: Segfault with no mm
CPU: 0 UID: 0 PID: 16 Comm: kworker/0:1 Not tainted 6.12.0-rc6-g59b723cd2adb #1
Workqueue: events mc_work_proc
Stack:
 60028f61 623ae028 e187bc80 60276fcd
 6220b9c0 603f5820 623ae028 00000000
 e187bcb0 603a2bcd 623ae000 62370010
Call Trace:
 [<60028f61>] ? vector_device_release+0x0/0x50
 [<60276fcd>] device_release+0x70/0xba
 [<603a2bcd>] kobject_put+0xba/0xe7
 [<60277265>] put_device+0x19/0x1c
 [<60281266>] platform_device_put+0x26/0x29
 [<60281e5f>] platform_device_unregister+0x2c/0x2e
 [<60029422>] vector_remove+0x52/0x58
 [<60031316>] ? mconsole_reply+0x0/0x50
 [<600310c8>] mconsole_remove+0x160/0x1cc
 [<603b19f4>] ? strlen+0x0/0x15
 [<60066611>] ? __dequeue_entity+0x1a9/0x206
 [<600666a7>] ? set_next_entity+0x39/0x63
 [<6006666e>] ? set_next_entity+0x0/0x63
 [<60038fa6>] ? um_set_signals+0x0/0x43
 [<6003070c>] mc_work_proc+0x77/0x91
 [<60057664>] process_scheduled_works+0x1b3/0x2dd
 [<60055f32>] ? assign_work+0x0/0x58
 [<60057f0a>] worker_thread+0x1e9/0x293
 [<6005406f>] ? set_pf_worker+0x0/0x64
 [<6005d65d>] ? arch_local_irq_save+0x0/0x2d
 [<6005d748>] ? kthread_exit+0x0/0x3a
 [<60057d21>] ? worker_thread+0x0/0x293
 [<6005dbf1>] kthread+0x126/0x12b
 [<600219c5>] new_thread_handler+0x85/0xb6

Cc: stable@vger.kernel.org
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://patch.msgid.link/20241104163203.435515-5-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>