kernel/git/stable/linux.git/arch/um/os-Linux, branch linux-5.19.y

um: add "noreboot" command line option for PANIC_TIMEOUT=-1 setups

2022-08-25T09:45:45+00:00

[ Upstream commit dda520d07b95072a0b63f6c52a8eb566d08ea897 ] QEMU has a -no-reboot option, which halts instead of reboots when the guest asks to reboot. This is invaluable when used with CONFIG_PANIC_TIMEOUT=-1 (and panic_on_warn), because it allows panics and warnings to be caught immediately in CI. Implement this in UML too, by way of a basic setup param. Signed-off-by: Jason A. Donenfeld Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

um: seed rng using host OS rng

2022-08-17T13:13:53+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: Replace to_phys() and to_virt() with less generic function names

2022-07-14T18:57:27+00:00

The UML function names to_virt() and to_phys() are exposed by UML headers, and are very generic and may be defined by drivers. As it turns out, commit 9409c9b6709e ("pmem: refactor pmem_clear_poison()") did exactly that. This results in build errors such as the following when trying to build um:allmodconfig: drivers/nvdimm/pmem.c: In function ‘pmem_dax_zero_page_range’: ./arch/um/include/asm/page.h:105:20: error: too few arguments to function ‘to_phys’ 105 | #define __pa(virt) to_phys((void *) (unsigned long) (virt)) | ^~~~~~~ Use less generic function names for the um specific to_phys() and to_virt() functions to fix the problem and to avoid similar problems in the future. Fixes: 9409c9b6709e ("pmem: refactor pmem_clear_poison()") Cc: Dan Williams Cc: Christoph Hellwig Signed-off-by: Guenter Roeck Signed-off-by: Linus Torvalds

Merge tag 'for-linus-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

2022-03-31T23:16:58+00:00

Pull UML updates from Richard Weinberger: - Devicetree support (for testing) - Various cleanups and fixes: UBD, port_user, uml_mconsole - Maintainer update * tag 'for-linus-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: run_helper: Write error message to kernel log on exec failure on host um: port_user: Improve error handling when port-helper is not found um: port_user: Allow setting path to port-helper using UML_PORT_HELPER envvar um: port_user: Search for in.telnetd in PATH um: clang: Strip out -mno-global-merge from USER_CFLAGS docs: UML: Mention telnetd for port channel um: Remove unused timeval_to_ns() function um: Fix uml_mconsole stop/go um: Cleanup syscall_handler_t definition/cast, fix warning uml: net: vector: fix const issue um: Fix WRITE_ZEROES in the UBD Driver um: Migrate vector drivers to NAPI um: Fix order of dtb unflatten/early init um: fix and optimize xor select template for CONFIG64 and timetravel mode um: Document dtb command line option lib/logic_iomem: correct fallback config references um: Remove duplicated include in syscalls_64.c MAINTAINERS: Update UserModeLinux entry

um: Allow builds with Clang

2022-03-21T15:13:03+00:00

Add SUBARCH target for Clang+um (which must go last, not alphabetically, so the other SUBARCHes are assigned). Remove open-coded "DEFINE" macro, instead using linux/kbuild.h's version which was updated to use Clang-friendly assembly in commit cf0c3e68aa81 ("kbuild: fix asm-offset generation to work with clang"). Redefine "DEFINE_LONGS" in terms of "COMMENT" and "DEFINE" so that the intended coment actually has useful content. Add a missed "break" to avoid implicit fall-through warnings. This lets me run KUnit tests with Clang: $ ./tools/testing/kunit/kunit.py run --make_options LLVM=1 ... Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: Masahiro Yamada Cc: Nick Desaulniers Cc: Nathan Chancellor Cc: David Gow Cc: linux-um@lists.infradead.org Cc: linux-kbuild@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: kunit-dev@googlegroups.com Cc: llvm@lists.linux.dev Reviewed-by: Nathan Chancellor Link: https://lore.kernel.org/lkml/Yg2YubZxvYvx7%2Fnm@dev-arch.archlinux-ax161/ Tested-by: David Gow Link: https://lore.kernel.org/lkml/CABVgOSk=oFxsbSbQE-v65VwR2+mXeGXDDjzq8t7FShwjJ3+kUg@mail.gmail.com/ Signed-off-by: Kees Cook --- v1: https://lore.kernel.org/lkml/20220217002843.2312603-1-keescook@chromium.org v2: https://lore.kernel.org/lkml/20220224055831.1854786-1-keescook@chromium.org v3: - use kbuild.h to avoid duplication (Masahiro) - fix intended comments (Masahiro) - use SUBARCH (Nathan)

um: run_helper: Write error message to kernel log on exec failure on host

2022-03-11T09:56:17+00:00

The best place to log errors from the host side is in the kernel log within the UML guest. Letting the user now that exec() failed and why is very helpful when the user is trying to determine why some aspect of UML is not working. For instance, when telneting into the UML instance, if the connection is established and then immediately dropped, this may be due to exec() failing because in.telnetd is not found. Signed-off-by: Glenn Washburn Signed-off-by: Richard Weinberger

um: Remove unused timeval_to_ns() function

2022-03-11T09:49:50+00:00

The timeval_to_ns() function doesn't appear to be used anywhere, as far as I (or git grep) can tell, and clang throws up a warning about it: ../arch/um/os-Linux/time.c:21:25: warning: unused function 'timeval_to_ns' [-Wunused-function] static inline long long timeval_to_ns(const struct timeval *tv) ^ 1 warning generated. Signed-off-by: David Gow Acked-By: Anton Ivanov Signed-off-by: Richard Weinberger

um: Fix WRITE_ZEROES in the UBD Driver

2022-03-11T09:46:34+00:00

Call to fallocate with FALLOC_FL_PUNCH_HOLE on a device backed by a sparse file can end up by missing data, zeroes data range, if the underlying file is used with a tool like bmaptool which will referenced only used spaces. Signed-off-by: Frédéric Danis Acked-by: Anton Ivanov Signed-off-by: Richard Weinberger

um: Use swap() to make code cleaner

2021-12-21T20:41:04+00:00

Use the macro 'swap()' defined in 'include/linux/minmax.h' to avoid opencoding it. Reported-by: Zeal Robot Signed-off-by: Yang Guang Signed-off-by: Richard Weinberger

um: registers: Rename function names to avoid conflicts and build problems

2021-12-21T20:22:19+00:00

The function names init_registers() and restore_registers() are used in several net/ethernet/ and gpu/drm/ drivers for other purposes (not calls to UML functions), so rename them. This fixes multiple build errors. Signed-off-by: Randy Dunlap Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: linux-um@lists.infradead.org Signed-off-by: Richard Weinberger