kernel/linux.git/init/main.c, branch v6.1.168

init: handle bootloader identifier in kernel parameters

2025-10-19T14:23:13+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

smp: Provide 'setup_max_cpus' definition on UP too

2024-06-16T11:41:42+00:00

commit 3c2f8859ae1ce53f2a89c8e4ca4092101afbff67 upstream. This was already defined locally by init/main.c, but let's make it generic, as arch/x86/kernel/cpu/topology.c is going to make use of it to have more uniform code. Reviewed-by: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

init/main.c: Fix potential static_command_line memory overflow

2024-04-27T15:07:16+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

modules: wait do_free_init correctly

2024-03-26T22:20:52+00:00

[ Upstream commit 8f8cd6c0a43ed637e620bbe45a8d0e0c2f4d5130 ] The synchronization here is to ensure the ordering of freeing of a module init so that it happens before W+X checking. It is worth noting it is not that the freeing was not happening, it is just that our sanity checkers raced against the permission checkers which assume init memory is already gone. Commit 1a7b7d922081 ("modules: Use vmalloc special flag") moved calling do_free_init() into a global workqueue instead of relying on it being called through call_rcu(..., do_free_init), which used to allowed us call do_free_init() asynchronously after the end of a subsequent grace period. The move to a global workqueue broke the gaurantees for code which needed to be sure the do_free_init() would complete with rcu_barrier(). To fix this callers which used to rely on rcu_barrier() must now instead use flush_work(&init_free_wq). Without this fix, we still could encounter false positive reports in W+X checking since the rcu_barrier() here can not ensure the ordering now. Even worse, the rcu_barrier() can introduce significant delay. Eric Chanudet reported that the rcu_barrier introduces ~0.1s delay on a PREEMPT_RT kernel. [ 0.291444] Freeing unused kernel memory: 5568K [ 0.402442] Run /sbin/init as init process With this fix, the above delay can be eliminated. Link: https://lkml.kernel.org/r/20240227023546.2490667-1-changbin.du@huawei.com Fixes: 1a7b7d922081 ("modules: Use vmalloc special flag") Signed-off-by: Changbin Du Tested-by: Eric Chanudet Acked-by: Luis Chamberlain Cc: Xiaoyi Su Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

proc: sysctl: prevent aliased sysctls from getting passed to init

2023-11-28T17:07:08+00:00

commit 8001f49394e353f035306a45bcf504f06fca6355 upstream. The code that checks for unknown boot options is unaware of the sysctl alias facility, which maps bootparams to sysctl values. If a user sets an old value that has a valid alias, a message about an invalid parameter will be printed during boot, and the parameter will get passed to init. Fix by checking for the existence of aliased parameters in the unknown boot parameter code. If an alias exists, don't return an error or pass the value to init. Signed-off-by: Krister Johansen Cc: stable@vger.kernel.org Fixes: 0a477e1ae21b ("kernel/sysctl: support handling command line aliases") Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman

x86/mm: Initialize text poking earlier

2023-08-08T18:03:49+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()

2023-08-08T18:03:49+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()

2023-08-08T18:03:47+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

2023-08-08T18:03:47+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

2023-08-08T18:03:47+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