kernel/arch/um/os-Linux/main.c, branch linux-rolling-stable

um: Always set up AT_HWCAP and AT_PLATFORM

2025-11-06T12:02:34Z

Historically the code to set up AT_HWCAP and AT_PLATFORM was only built for 32bit x86 as it was intermingled with the vDSO passthrough code. Now that vDSO passthrough has been removed, always pass through AT_HWCAP and AT_PLATFORM. Signed-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20251028-uml-remove-32bit-pseudo-vdso-v1-10-e930063eff5f@weissschuh.net Signed-off-by: Johannes Berg

um: Define timers on a per-CPU basis

2025-10-27T15:41:15Z

Define timers on a per-CPU basis to enable each CPU to have its own timer. This is a preparation for adding SMP support. Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20251027001815.1666872-5-tiwei.bie@linux.dev Signed-off-by: Johannes Berg

um: Remove unused THREAD_NAME_LEN macro

2025-01-10T12:49:57Z

It's no longer used since commit 42fda66387da ("uml: throw out CONFIG_MODE_TT"). Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20241128083137.2219830-9-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg

um: Remove unused PGD_BOUND macro

2025-01-10T12:49:57Z

It's no longer used since commit 11100b1dfb6e ("uml: delete unused code"). Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20241128083137.2219830-8-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg

um: Mark setup_env_path as __init

2025-01-10T12:49:57Z

It's only invoked during boot from main(). Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20241128083137.2219830-7-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg

um: Mark install_fatal_handler as __init

2025-01-10T12:49:56Z

It's only invoked during boot from main(). Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20241128083137.2219830-6-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg

um: Mark set_stklim as __init

2025-01-10T12:49:56Z

It's only invoked during boot from main(). Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20241128083137.2219830-5-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg

um: remove PATH_MAX use

2024-10-24T07:52:51Z

Evidently, PATH_MAX isn't always defined, at least not via . Simply remove the use and replace it by a constant 4k. As stat::st_size is zero for /proc/self/exe we can't even size it automatically, and it seems unlikely someone's going to try to run UML with such a path. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202410240553.gYNIXN8i-lkp@intel.com/ Fixes: 031acdcfb566 ("um: restore process name") Signed-off-by: Johannes Berg

um: restore process name

2024-10-23T07:25:55Z

After the execve() to disable ASLR, comm is now "exe", which is a bit confusing. Use readlink() to get this to the right name again. Disable stack frame size warnings on main.o since it's part of the initial userspace and can use larger stack. Fixes: 68b9883cc16e ("um: Discover host_task_size from envp") Link: https://patch.msgid.link/20241010161411.c576e2aeb3e5.I244d4f34b8a8555ee5bec0e1cf5027bce4cc491b@changeid Signed-off-by: Johannes Berg

um: Discover host_task_size from envp

2024-10-10T11:37:22Z

When loading the UML binary, the host kernel will place the stack at the highest possible address. It will then map the program name and environment variables onto the start of the stack. As such, an easy way to figure out the host_task_size is to use the highest pointer to an environment variable as a reference. Ensure that this works by disabling address layout randomization and re-executing UML in case it was enabled. This increases the available TASK_SIZE for 64 bit UML considerably. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240919124511.282088-9-benjamin@sipsolutions.net Signed-off-by: Johannes Berg