kernel/linux.git/arch/um/os-Linux/util.c, branch v6.12.80

um: Don't use vfprintf() for os_info()

2024-01-04T22:45:17+00:00

The threads allocated inside the kernel have only a single page of stack. Unfortunately, the vfprintf function in standard glibc may use too much stack-space, overflowing it. To make os_info safe to be used by helper threads, use the kernel vscnprintf function into a smallish buffer and write out the information to stderr. Signed-off-by: Benjamin Berg Signed-off-by: Richard Weinberger

um: seed rng using host OS rng

2022-07-18T13:04:04+00:00

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

isystem: trim/fixup stdarg.h and other headers

2021-08-19T00:02:55+00:00

Delete/fixup few includes in anticipation of global -isystem compile option removal. Note: crypto/aegis128-neon-inner.c keeps due to redefinition of uintptr_t error (one definition comes from , another from ). Signed-off-by: Alexey Dobriyan Signed-off-by: Masahiro Yamada

um: Some fixes to build UML with musl

2020-10-11T21:13:06+00:00

musl toolchain and headers are a bit more strict. These fixes enable building UML with musl as well as seem not to break on glibc. Signed-off-by: Ignat Korchagin Tested-by: Brendan Higgins Signed-off-by: Richard Weinberger

um: Add SPDX headers for files in arch/um/os-Linux

2019-09-15T19:37:17+00:00

Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar Signed-off-by: Richard Weinberger

um: Add os_warn() for pre-boot warning/error messages

2017-07-05T21:18:02+00:00

Add os_warn() for printing out pre-boot warning/error messages in stderr. The messages via os_warn() are not suppressed by quiet option. Signed-off-by: Masami Hiramatsu Signed-off-by: Richard Weinberger

um: Add os_info() for pre-boot information messages

2017-07-05T21:17:16+00:00

Add os_info() for printing out pre-boot information level messages in stderr. The messages via os_info() are suppressed by "quiet" kernel command line. Signed-off-by: Masami Hiramatsu Signed-off-by: Richard Weinberger

um: Cleanup SIGTERM handling

2013-09-07T08:56:58+00:00

Richard reported that some UML processes survive if the UML main process receives a SIGTERM. This issue was caused by a wrongly placed signal(SIGTERM, SIG_DFL) in init_new_thread_signals(). It disabled the UML exit handler accidently for some processes. The correct solution is to disable the fatal handler for all UML helper threads/processes. Such that last_ditch_exit() does not get called multiple times and all processes can exit due to SIGTERM. Reported-and-tested-by: Richard W.M. Jones Signed-off-by: Richard Weinberger

um: get rid of pointless include "..." where include <...> will do

2012-10-09T20:28:45+00:00

Signed-off-by: Al Viro Signed-off-by: Richard Weinberger

um: -include user.h for USER_OBJ, trim includes

2011-11-02T13:14:44+00:00

Signed-off-by: Al Viro Signed-off-by: Richard Weinberger