kernel.git/arch/um/kernel, branch linux-rolling-stable

kbuild: Split .modinfo out from ELF_DETAILS

2026-03-12T11:09:39Z

commit 8678591b47469fe16357234efef9b260317b8be4 upstream. Commit 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped") added .modinfo to ELF_DETAILS while removing it from COMMON_DISCARDS, as it was needed in vmlinux.unstripped and ELF_DETAILS was present in all architecture specific vmlinux linker scripts. While this shuffle is fine for vmlinux, ELF_DETAILS and COMMON_DISCARDS may be used by other linker scripts, such as the s390 and x86 compressed boot images, which may not expect to have a .modinfo section. In certain circumstances, this could result in a bootloader failing to load the compressed kernel [1]. Commit ddc6cbef3ef1 ("s390/boot/vmlinux.lds.S: Ensure bzImage ends with SecureBoot trailer") recently addressed this for the s390 bzImage but the same bug remains for arm, parisc, and x86. The presence of .modinfo in the x86 bzImage was the root cause of the issue worked around with commit d50f21091358 ("kbuild: align modinfo section for Secureboot Authenticode EDK2 compat"). misc.c in arch/x86/boot/compressed includes lib/decompress_unzstd.c, which in turn includes lib/xxhash.c and its MODULE_LICENSE / MODULE_DESCRIPTION macros due to the STATIC definition. Split .modinfo out from ELF_DETAILS into its own macro and handle it in all vmlinux linker scripts. Discard .modinfo in the places where it was previously being discarded from being in COMMON_DISCARDS, as it has never been necessary in those uses. Cc: stable@vger.kernel.org Fixes: 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped") Reported-by: Ed W Closes: https://lore.kernel.org/587f25e0-a80e-46a5-9f01-87cb40cfa377@wildgooses.com/ [1] Tested-by: Ed W # x86_64 Link: https://patch.msgid.link/20260225-separate-modinfo-from-elf-details-v1-1-387ced6baf4b@kernel.org Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

Merge tag 'objtool-urgent-2025-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-12-06T19:56:51Z

Pull objtool fixes from Ingo Molnar: "Address various objtool scalability bugs/inefficiencies exposed by allmodconfig builds, plus improve the quality of alternatives instructions generated code and disassembly" * tag 'objtool-urgent-2025-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Simplify .annotate_insn code generation output some more objtool: Add more robust signal error handling, detect and warn about stack overflows objtool: Remove newlines and tabs from annotation macros objtool: Consolidate annotation macros x86/asm: Remove ANNOTATE_DATA_SPECIAL usage x86/alternative: Remove ANNOTATE_DATA_SPECIAL usage objtool: Fix stack overflow in validate_branch()

Merge tag 'uml-for-linux-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

2025-12-06T00:30:56Z

Pull UML updates from Johannes Berg: "Apart from the usual small churn, we have - initial SMP support (only kernel) - major vDSO cleanups (and fixes for 32-bit)" * tag 'uml-for-linux-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (33 commits) um: Disable KASAN_INLINE when STATIC_LINK is selected um: Don't rename vmap to kernel_vmap um: drivers: virtio: use string choices helper um: Always set up AT_HWCAP and AT_PLATFORM x86/um: Remove FIXADDR_USER_START and FIXADDR_USE_END um: Remove __access_ok_vsyscall() um: Remove redundant range check from __access_ok_vsyscall() um: Remove fixaddr_user_init() x86/um: Drop gate area handling x86/um: Do not inherit vDSO from host um: Split out default elf_aux_hwcap x86/um: Move ELF_PLATFORM fallback to x86-specific code um: Split out default elf_aux_platform um: Avoid circular dependency on asm-offsets in pgtable.h um: Enable SMP support on x86 asm-generic: percpu: Add assembly guard um: vdso: Remove getcpu support on x86 um: Add initial SMP support um: Define timers on a per-CPU basis um: Determine sleep based on need_resched() ...

Merge tag 'printk-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2025-12-03T20:42:36Z

Pull printk updates from Petr Mladek: - Allow creaing nbcon console drivers with an unsafe write_atomic() callback that can only be called by the final nbcon_atomic_flush_unsafe(). Otherwise, the driver would rely on the kthread. It is going to be used as the-best-effort approach for an experimental nbcon netconsole driver, see https://lore.kernel.org/r/20251121-nbcon-v1-2-503d17b2b4af@debian.org Note that a safe .write_atomic() callback is supposed to work in NMI context. But some networking drivers are not safe even in IRQ context: https://lore.kernel.org/r/oc46gdpmmlly5o44obvmoatfqo5bhpgv7pabpvb6sjuqioymcg@gjsma3ghoz35 In an ideal world, all networking drivers would be fixed first and the atomic flush would be blocked only in NMI context. But it brings the question how reliable networking drivers are when the system is in a bad state. They might block flushing more reliable serial consoles which are more suitable for serious debugging anyway. - Allow to use the last 4 bytes of the printk ring buffer. - Prevent queuing IRQ work and block printk kthreads when consoles are suspended. Otherwise, they create non-necessary churn or even block the suspend. - Release console_lock() between each record in the kthread used for legacy consoles on RT. It might significantly speed up the boot. - Release nbcon context between each record in the atomic flush. It prevents stalls of the related printk kthread after it has lost the ownership in the middle of a record - Add support for NBCON consoles into KDB - Add %ptsP modifier for printing struct timespec64 and use it where possible - Misc code clean up * tag 'printk-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (48 commits) printk: Use console_is_usable on console_unblank arch: um: kmsg_dump: Use console_is_usable drivers: serial: kgdboc: Drop checks for CON_ENABLED and CON_BOOT lib/vsprintf: Unify FORMAT_STATE_NUM handlers printk: Avoid irq_work for printk_deferred() on suspend printk: Avoid scheduling irq_work on suspend printk: Allow printk_trigger_flush() to flush all types tracing: Switch to use %ptSp scsi: snic: Switch to use %ptSp scsi: fnic: Switch to use %ptSp s390/dasd: Switch to use %ptSp ptp: ocp: Switch to use %ptSp pps: Switch to use %ptSp PCI: epf-test: Switch to use %ptSp net: dsa: sja1105: Switch to use %ptSp mmc: mmc_test: Switch to use %ptSp media: av7110: Switch to use %ptSp ipmi: Switch to use %ptSp igb: Switch to use %ptSp e1000e: Switch to use %ptSp ...

arch: um: kmsg_dump: Use console_is_usable

2025-11-27T14:54:50Z

All consoles found on for_each_console are registered, meaning that all of them have the CON_ENABLED flag set. Since NBCON was introduced it's important to check if a given console also implements the NBCON callbacks. The function console_is_usable does exactly that. Signed-off-by: Marcos Paulo de Souza Reviewed-by: Petr Mladek Link: https://patch.msgid.link/20251121-printk-cleanup-part2-v2-2-57b8b78647f4@suse.com Signed-off-by: Petr Mladek

um: Remove fixaddr_user_init()

2025-11-06T12:02:33Z

With the removal of the vDSO passthrough from the host, FIXADDR_USER_START is always 0 and fixaddr_user_init() is dead code. Remove it. Signed-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20251028-uml-remove-32bit-pseudo-vdso-v1-6-e930063eff5f@weissschuh.net Signed-off-by: Johannes Berg

um: Add initial SMP support

2025-10-27T15:41:15Z

Add initial symmetric multi-processing (SMP) support to UML. With this support enabled, users can tell UML to start multiple virtual processors, each represented as a separate host thread. In UML, kthreads and normal threads (when running in kernel mode) can be scheduled and executed simultaneously on different virtual processors. However, the userspace code of normal threads still runs within their respective single-threaded stubs. That is, SMP support is currently available both within the kernel and across different processes, but still remains limited within threads of the same process in userspace. Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20251027001815.1666872-6-tiwei.bie@linux.dev 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: Determine sleep based on need_resched()

2025-10-27T15:41:15Z

With SMP and NO_HZ enabled, the CPU may still need to sleep even if the timer is disarmed. Switch to deciding whether to sleep based on pending resched. Additionally, because disabling IRQs does not block SIGALRM, it is also necessary to check for any pending timer alarms. This is a preparation for adding SMP support. Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20251027001815.1666872-4-tiwei.bie@linux.dev Signed-off-by: Johannes Berg

um: Turn signals_* into thread-local variables

2025-10-27T15:41:15Z

Turn signals_enabled, signals_pending and signals_active into thread-local variables. This enables us to control and track signals independently on each CPU thread. This is a preparation for adding SMP support. Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20251027001815.1666872-3-tiwei.bie@linux.dev Signed-off-by: Johannes Berg