kernel/linux.git/arch/um/include, branch v5.15.208

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: Add cmpxchg8b_emu and checksum functions to asm-prototypes.h

2025-07-10T13:57:33+00:00

[ Upstream commit 674d03f6bd6b0f8327f1a4920ff5893557facfbd ] With CONFIG_GENDWARFKSYMS, um builds fail due to missing prototypes in asm/asm-prototypes.h. Add declarations for cmpxchg8b_emu and the exported checksum functions, including csum_partial_copy_generic as it's also exported. Cc: Masahiro Yamada Cc: linux-kbuild@vger.kernel.org Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202503251216.lE4t9Ikj-lkp@intel.com/ Signed-off-by: Sami Tolvanen Link: https://patch.msgid.link/20250326190500.847236-2-samitolvanen@google.com Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

um: Fix the -Wmissing-prototypes warning for __switch_mm

2024-06-16T11:39:44+00:00

[ Upstream commit 2cbade17b18c0f0fd9963f26c9fc9b057eb1cb3a ] The __switch_mm function is defined in the user code, and is called by the kernel code. It should be declared in a shared header. Fixes: 4dc706c2f292 ("um: take um_mmu.h to asm/mmu.h, clean asm/mmu_context.h a bit") Signed-off-by: Tiwei Bie 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

um: seed rng using host OS rng

2022-08-17T12:22:55+00:00

commit 0b9ba6135d7f18b82f3d8bebb55ded725ba88e0e upstream. UML generally does not provide access to special CPU instructions like RDRAND, and execution tends to be rather deterministic, with no real hardware interrupts, making good randomness really very hard, if not all together impossible. Not only is this a security eyebrow raiser, but it's also quite annoying when trying to do various pieces of UML-based automation that takes a long time to boot, if ever. Fix this by trivially calling getrandom() in the host and using that seed as "bootloader randomness", which initializes the rng immediately at UML boot. The old behavior can be restored the same way as on any other arch, by way of CONFIG_TRUST_BOOTLOADER_RANDOMNESS=n or random.trust_bootloader=0. So seen from that perspective, this just makes UML act like other archs, which is positive in its own right. Additionally, wire up arch_get_random_{int,long}() in the same way, so that reseeds can also make use of the host RNG, controllable by CONFIG_TRUST_CPU_RANDOMNESS and random.trust_cpu, per usual. Cc: stable@vger.kernel.org Acked-by: Johannes Berg Acked-By: Anton Ivanov Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

um: Remove straying parenthesis

2022-08-17T12:22:55+00:00

commit c6496e0a4a90d8149203c16323cff3fa46e422e7 upstream. Commit e3a33af812c6 ("um: fix and optimize xor select template for CONFIG64 and timetravel mode") caused a build regression when CONFIG_XOR_BLOCKS and CONFIG_UML_TIME_TRAVEL_SUPPORT are selected. Fix it by removing the straying parenthesis. Cc: stable@vger.kernel.org Fixes: e3a33af812c6 ("um: fix and optimize xor select template for CONFIG64 and timetravel mode") Signed-off-by: Benjamin Beichler [rw: Added commit message] Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

um: line: Use separate IRQs per line

2022-06-14T16:36:23+00:00

[ Upstream commit d5a9597d6916a76663085db984cb8fe97f0a5c56 ] Today, all possible serial lines (ssl*=) as well as all possible consoles (con*=) each share a single interrupt (with a fixed number) with others of the same type. Now, if you have two lines, say ssl0 and ssl1, and one of them is connected to an fd you cannot read (e.g. a file), but the other gets a read interrupt, then both of them get the interrupt since it's shared. Then, the read() call will return EOF, since it's a file being written and there's nothing to read (at least not at the current offset, at the end). Unfortunately, this is treated as a read error, and we close this line, losing all the possible output. It might be possible to work around this and make the IRQ sharing work, however, now that we have dynamically allocated IRQs that are easy to use, simply use that to achieve separating between the events; then there's no interrupt for that line and we never attempt the read in the first place, thus not closing the line. This manifested itself in the wifi hostap/hwsim tests where the parallel script communicates via one serial console and the kernel messages go to another (a file) and sending data on the communication console caused the kernel messages to stop flowing into the file. Reported-by: Jouni Malinen Signed-off-by: Johannes Berg Acked-By: anton ivanov Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

um: Use asm-generic/dma-mapping.h

2022-06-09T08:23:26+00:00

commit 365719035526e8eda214a1cedb2e1c96e969a0d7 upstream. If DMA (PCI over virtio) is enabled, then some drivers may enable CONFIG_DMA_OPS as well, and then we pull in the x86 definition of get_arch_dma_ops(), which uses the dma_ops symbol, which isn't defined. Since we don't have real DMA ops nor any kind of IOMMU fix this in the simplest possible way: pull in the asm-generic file instead of inheriting the x86 one. It's not clear why those drivers that do (e.g. VDPA) "select DMA_OPS", and if they'd even work with this, but chances are nobody will be wanting to do that anyway, so fixing the build failure is good enough. Reported-by: Randy Dunlap Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver") Signed-off-by: Johannes Berg Tested-by: Randy Dunlap Acked-by: Randy Dunlap Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP

2022-06-09T08:22:29+00:00

commit c200e4bb44e80b343c09841e7caaaca0aac5e5fa upstream. User mode linux is the last user of the PT_DTRACE flag. Using the flag to indicate single stepping is a little confusing and worse changing tsk->ptrace without locking could potentionally cause problems. So use a thread info flag with a better name instead of flag in tsk->ptrace. Remove the definition PT_DTRACE as uml is the last user. Cc: stable@vger.kernel.org Acked-by: Johannes Berg Tested-by: Kees Cook Reviewed-by: Oleg Nesterov Link: https://lkml.kernel.org/r/20220505182645.497868-3-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman