kernel/linux.git/arch/um/include/shared, branch v6.6.131

um: remove copy_from_kernel_nofault_allowed

2025-04-10T12:37:34+00:00

[ Upstream commit 84a6fc378471fbeaf48f8604566a5a33a3d63c18 ] There is no need to override the default version of this function anymore as UML now has proper _nofault memory access functions. Doing this also fixes the fact that the implementation was incorrect as using mincore() will incorrectly flag pages as inaccessible if they were swapped out by the host. Fixes: f75b1b1bedfb ("um: Implement probe_kernel_read()") Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20250210160926.420133-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

um: Fix the declaration of kasan_map_memory

2024-06-12T09:12:42+00:00

[ Upstream commit 6a85e34c4d07d2ec0c153067baff338ac0db55ca ] Make it match its definition (size_t vs unsigned long). And declare it in a shared header to fix the -Wmissing-prototypes warning, as it is defined in the user code and called in the kernel code. Fixes: 5b301409e8bc ("UML: add support for KASAN under x86_64") Signed-off-by: Tiwei Bie Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

um: Fix the -Wmissing-prototypes warning for __switch_mm

2024-06-12T09:12:42+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

2024-02-05T20:14:30+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: fix 3 instances of -Wmissing-prototypes

2023-08-26T20:45:05+00:00

Fixes the following build errors observed from W=1 builds: arch/um/drivers/xterm_kern.c:35:5: warning: no previous prototype for function 'xterm_fd' [-Wmissing-prototypes] 35 | int xterm_fd(int socket, int *pid_out) | ^ arch/um/drivers/xterm_kern.c:35:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 35 | int xterm_fd(int socket, int *pid_out) | ^ | static arch/um/drivers/chan_kern.c:183:6: warning: no previous prototype for function 'free_irqs' [-Wmissing-prototypes] 183 | void free_irqs(void) | ^ arch/um/drivers/chan_kern.c:183:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 183 | void free_irqs(void) | ^ | static arch/um/drivers/slirp_kern.c:18:6: warning: no previous prototype for function 'slirp_init' [-Wmissing-prototypes] 18 | void slirp_init(struct net_device *dev, void *data) | ^ arch/um/drivers/slirp_kern.c:18:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 18 | void slirp_init(struct net_device *dev, void *data) | ^ | static Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202308081050.sZEw4cQ5-lkp@intel.com/ Signed-off-by: Nick Desaulniers Signed-off-by: Richard Weinberger

um: Remove strlcpy usage

2023-08-19T20:24:39+00:00

strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh [rw: Massaged subject] Signed-off-by: Richard Weinberger

uml: Replace strlcpy with strscpy

2023-06-20T20:35:37+00:00

strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20230614003604.1021205-1-azeemshaikh38@gmail.com

um: make stub data pages size tweakable

2023-04-20T21:08:43+00:00

There's a lot of code here that hard-codes that the data is a single page, and right now that seems to be sufficient, but to make it easier to change this in the future, add a new STUB_DATA_PAGES constant and use it throughout the code. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

Merge tag 'for-linus-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

2022-08-05T21:03:11+00:00

Pull UML updates from Richard Weinberger: - KASAN support for x86_64 - noreboot command line option, just like qemu's -no-reboot - Various fixes and cleanups * tag 'for-linus-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: include sys/types.h for size_t um: Replace to_phys() and to_virt() with less generic function names um: Add missing apply_returns() um: add "noreboot" command line option for PANIC_TIMEOUT=-1 setups um: include linux/stddef.h for __always_inline UML: add support for KASAN under x86_64 mm: Add PAGE_ALIGN_DOWN macro um: random: Don't initialise hwrng struct with zero um: remove unused mm_copy_segments um: remove unused variable um: Remove straying parenthesis um: x86: print RIP with symbol arch: um: Fix build for statically linked UML w/ constructors x86/um: Kconfig: Fix indentation um/drivers: Kconfig: Fix indentation um: Kconfig: Fix indentation

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