kernel/linux.git/init/main.c, branch v5.10.257

init: handle bootloader identifier in kernel parameters

2025-10-29T13:01:11+00:00

commit e416f0ed3c500c05c55fb62ee62662717b1c7f71 upstream. BootLoaders (Grub, LILO, etc) may pass an identifier such as "BOOT_IMAGE= /boot/vmlinuz-x.y.z" to kernel parameters. But these identifiers are not recognized by the kernel itself so will be passed to userspace. However user space init program also don't recognize it. KEXEC/KDUMP (kexec-tools) may also pass an identifier such as "kexec" on some architectures. We cannot change BootLoader's behavior, because this behavior exists for many years, and there are already user space programs search BOOT_IMAGE= in /proc/cmdline to obtain the kernel image locations: https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/util.go (search getBootOptions) https://github.com/linuxdeepin/deepin-ab-recovery/blob/master/main.go (search getKernelReleaseWithBootOption) So the the best way is handle (ignore) it by the kernel itself, which can avoid such boot warnings (if we use something like init=/bin/bash, bootloader identifier can even cause a crash): Kernel command line: BOOT_IMAGE=(hd0,1)/vmlinuz-6.x root=/dev/sda3 ro console=tty Unknown kernel command line parameters "BOOT_IMAGE=(hd0,1)/vmlinuz-6.x", will be passed to user space. [chenhuacai@loongson.cn: use strstarts()] Link: https://lkml.kernel.org/r/20250815090120.1569947-1-chenhuacai@loongson.cn Link: https://lkml.kernel.org/r/20250721101343.3283480-1-chenhuacai@loongson.cn Signed-off-by: Huacai Chen Cc: Al Viro Cc: Christian Brauner Cc: Jan Kara Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

init/main.c: Fix potential static_command_line memory overflow

2024-05-02T14:23:39+00:00

commit 46dad3c1e57897ab9228332f03e1c14798d2d3b9 upstream. We allocate memory of size 'xlen + strlen(boot_command_line) + 1' for static_command_line, but the strings copied into static_command_line are extra_command_line and command_line, rather than extra_command_line and boot_command_line. When strlen(command_line) > strlen(boot_command_line), static_command_line will overflow. This patch just recovers strlen(command_line) which was miss-consolidated with strlen(boot_command_line) in the commit f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()") Link: https://lore.kernel.org/all/20240412081733.35925-2-ytcoode@gmail.com/ Fixes: f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()") Cc: stable@vger.kernel.org Signed-off-by: Yuntao Wang Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Greg Kroah-Hartman

x86/mm: Initialize text poking earlier

2023-08-08T17:57:39+00:00

commit 5b93a83649c7cba3a15eb7e8959b250841acb1b1 upstream. Move poking_init() up a bunch; specifically move it right after mm_init() which is right before ftrace_init(). This will allow simplifying ftrace text poking which currently has a bunch of exceptions for early boot. Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20221025201057.881703081@infradead.org Signed-off-by: Greg Kroah-Hartman

mm: Move mm_cachep initialization to mm_init()

2023-08-08T17:57:39+00:00

commit af80602799681c78f14fbe20b6185a56020dedee upstream. In order to allow using mm_alloc() much earlier, move initializing mm_cachep into mm_init(). Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20221025201057.751153381@infradead.org Signed-off-by: Greg Kroah-Hartman

init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()

2023-08-08T17:57:37+00:00

commit 439e17576eb47f26b78c5bbc72e344d4206d2327 upstream Invoke the X86ism mem_encrypt_init() from X86 arch_cpu_finalize_init() and remove the weak fallback from the core code. No functional change. Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230613224545.670360645@linutronix.de Signed-off-by: Daniel Sneddon Signed-off-by: Greg Kroah-Hartman

init: Invoke arch_cpu_finalize_init() earlier

2023-08-08T17:57:37+00:00

commit 9df9d2f0471b4c4702670380b8d8a45b40b23a7d upstream X86 is reworking the boot process so that initializations which are not required during early boot can be moved into the late boot process and out of the fragile and restricted initial boot phase. arch_cpu_finalize_init() is the obvious place to do such initializations, but arch_cpu_finalize_init() is invoked too late in start_kernel() e.g. for initializing the FPU completely. fork_init() requires that the FPU is initialized as the size of task_struct on X86 depends on the size of the required FPU register buffer. Fortunately none of the init calls between calibrate_delay() and arch_cpu_finalize_init() is relevant for the functionality of arch_cpu_finalize_init(). Invoke it right after calibrate_delay() where everything which is relevant for arch_cpu_finalize_init() has been set up already. No functional change intended. Signed-off-by: Thomas Gleixner Reviewed-by: Rick Edgecombe Link: https://lore.kernel.org/r/20230613224545.612182854@linutronix.de Signed-off-by: Daniel Sneddon Signed-off-by: Greg Kroah-Hartman

init: Remove check_bugs() leftovers

2023-08-08T17:57:37+00:00

commit 61235b24b9cb37c13fcad5b9596d59a1afdcec30 upstream Everything is converted over to arch_cpu_finalize_init(). Remove the check_bugs() leftovers including the empty stubs in asm-generic, alpha, parisc, powerpc and xtensa. Signed-off-by: Thomas Gleixner Reviewed-by: Richard Henderson Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de Signed-off-by: Daniel Sneddon Signed-off-by: Greg Kroah-Hartman

init: Provide arch_cpu_finalize_init()

2023-08-08T17:57:36+00:00

commit 7725acaa4f0c04fbefb0e0d342635b967bb7d414 upstream check_bugs() has become a dumping ground for all sorts of activities to finalize the CPU initialization before running the rest of the init code. Most are empty, a few do actual bug checks, some do alternative patching and some cobble a CPU advertisement string together.... Aside of that the current implementation requires duplicated function declaration and mostly empty header files for them. Provide a new function arch_cpu_finalize_init(). Provide a generic declaration if CONFIG_ARCH_HAS_CPU_FINALIZE_INIT is selected and a stub inline otherwise. This requires a temporary #ifdef in start_kernel() which will be removed along with check_bugs() once the architectures are converted over. Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230613224544.957805717@linutronix.de Signed-off-by: Daniel Sneddon Signed-off-by: Greg Kroah-Hartman

random: handle latent entropy and command line from random_init()

2022-05-30T07:33:44+00:00

commit 2f14062bb14b0fcfcc21e6dc7d5b5c0d25966164 upstream. Currently, start_kernel() adds latent entropy and the command line to the entropy bool *after* the RNG has been initialized, deferring when it's actually used by things like stack canaries until the next time the pool is seeded. This surely is not intended. Rather than splitting up which entropy gets added where and when between start_kernel() and random_init(), just do everything in random_init(), which should eliminate these kinds of bugs in the future. While we're at it, rename the awkwardly titled "rand_initialize()" to the more standard "random_init()" nomenclature. Reviewed-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

init: call time_init() before rand_initialize()

2022-05-30T07:33:40+00:00

commit fe222a6ca2d53c38433cba5d3be62a39099e708e upstream. Currently time_init() is called after rand_initialize(), but rand_initialize() makes use of the timer on various platforms, and sometimes this timer needs to be initialized by time_init() first. In order for random_get_entropy() to not return zero during early boot when it's potentially used as an entropy source, reverse the order of these two calls. The block doing random initialization was right before time_init() before, so changing the order shouldn't have any complicated effects. Cc: Andrew Morton Reviewed-by: Stafford Horne Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman