diff options
Diffstat (limited to 'include/linux/init.h')
| -rw-r--r-- | include/linux/init.h | 341 |
1 files changed, 199 insertions, 142 deletions
diff --git a/include/linux/init.h b/include/linux/init.h index e73f2b708525..40331923b9f4 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -1,7 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_INIT_H #define _LINUX_INIT_H +#include <linux/build_bug.h> #include <linux/compiler.h> +#include <linux/stringify.h> #include <linux/types.h> /* These macros are used to mark some functions or @@ -26,8 +29,8 @@ * extern int initialize_foobar_device(int, int, int) __init; * * For initialized data: - * You should insert __initdata between the variable name and equal - * sign followed by value, e.g.: + * You should insert __initdata or __initconst between the variable name + * and equal sign followed by value, e.g.: * * static int init_variable __initdata = 0; * static const char linux_logo[] __initconst = { 0x32, 0x36, ... }; @@ -35,28 +38,16 @@ * Don't forget to initialize data not at file scope, i.e. within a function, * as gcc otherwise puts the data into the bss section and not into the init * section. - * - * Also note, that this data cannot be "const". */ /* These are for everybody (although not all archs will actually discard it in modules) */ -#define __init __section(.init.text) __cold notrace -#define __initdata __section(.init.data) -#define __initconst __constsection(.init.rodata) -#define __exitdata __section(.exit.data) -#define __exit_call __used __section(.exitcall.exit) - -/* - * Some architecture have tool chains which do not handle rodata attributes - * correctly. For those disable special sections for const, so that other - * architectures can annotate correctly. - */ -#ifdef CONFIG_BROKEN_RODATA -#define __constsection(x) -#else -#define __constsection(x) __section(x) -#endif +#define __init __section(".init.text") __cold __latent_entropy \ + __no_kstack_erase +#define __initdata __section(".init.data") +#define __initconst __section(".init.rodata") +#define __exitdata __section(".exit.data") +#define __exit_call __used __section(".exitcall.exit") /* * modpost check for section mismatches during the kernel build. @@ -75,15 +66,9 @@ * * The markers follow same syntax rules as __init / __initdata. */ -#define __ref __section(.ref.text) noinline -#define __refdata __section(.ref.data) -#define __refconst __constsection(.ref.rodata) - -/* compatibility defines */ -#define __init_refok __ref -#define __initdata_refok __refdata -#define __exit_refok __ref - +#define __ref __section(".ref.text") noinline +#define __refdata __section(".ref.data") +#define __refconst __section(".ref.rodata") #ifdef MODULE #define __exitused @@ -91,23 +76,17 @@ #define __exitused __used #endif -#define __exit __section(.exit.text) __exitused __cold notrace +#define __exit __section(".exit.text") __exitused __cold notrace -/* temporary, until all users are removed */ -#define __cpuinit -#define __cpuinitdata -#define __cpuinitconst -#define __cpuexit -#define __cpuexitdata -#define __cpuexitconst - -/* Used for MEMORY_HOTPLUG */ -#define __meminit __section(.meminit.text) __cold notrace -#define __meminitdata __section(.meminit.data) -#define __meminitconst __constsection(.meminit.rodata) -#define __memexit __section(.memexit.text) __exitused __cold notrace -#define __memexitdata __section(.memexit.data) -#define __memexitconst __constsection(.memexit.rodata) +#ifdef CONFIG_MEMORY_HOTPLUG +#define __meminit +#define __meminitdata +#define __meminitconst +#else +#define __meminit __init +#define __meminitdata __initdata +#define __meminitconst __initconst +#endif /* For assembly routines */ #define __HEAD .section ".head.text","ax" @@ -118,13 +97,6 @@ #define __INITRODATA .section ".init.rodata","a",%progbits #define __FINITDATA .previous -/* temporary, until all users are removed */ -#define __CPUINIT - -#define __MEMINIT .section ".meminit.text", "ax" -#define __MEMINITDATA .section ".meminit.data", "aw" -#define __MEMINITRODATA .section ".meminit.rodata", "a" - /* silence warnings when references are OK */ #define __REF .section ".ref.text", "ax" #define __REFDATA .section ".ref.data", "aw" @@ -137,34 +109,81 @@ typedef int (*initcall_t)(void); typedef void (*exitcall_t)(void); -extern initcall_t __con_initcall_start[], __con_initcall_end[]; -extern initcall_t __security_initcall_start[], __security_initcall_end[]; +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS +typedef int initcall_entry_t; + +static inline initcall_t initcall_from_entry(initcall_entry_t *entry) +{ + return offset_to_ptr(entry); +} +#else +typedef initcall_t initcall_entry_t; + +static inline initcall_t initcall_from_entry(initcall_entry_t *entry) +{ + return *entry; +} +#endif + +extern initcall_entry_t __con_initcall_start[], __con_initcall_end[]; -/* Used for contructor calls. */ +/* Used for constructor calls. */ typedef void (*ctor_fn_t)(void); +struct file_system_type; + /* Defined in init/main.c */ extern int do_one_initcall(initcall_t fn); extern char __initdata boot_command_line[]; extern char *saved_command_line; +extern unsigned int saved_command_line_len; extern unsigned int reset_devices; /* used by init/main.c */ void setup_arch(char **); void prepare_namespace(void); -void __init load_default_modules(void); +void __init init_rootfs(void); + +void init_IRQ(void); +void time_init(void); +void poking_init(void); +void pgtable_cache_init(void); + +extern initcall_entry_t __initcall_start[]; +extern initcall_entry_t __initcall0_start[]; +extern initcall_entry_t __initcall1_start[]; +extern initcall_entry_t __initcall2_start[]; +extern initcall_entry_t __initcall3_start[]; +extern initcall_entry_t __initcall4_start[]; +extern initcall_entry_t __initcall5_start[]; +extern initcall_entry_t __initcall6_start[]; +extern initcall_entry_t __initcall7_start[]; +extern initcall_entry_t __initcall_end[]; + +extern struct file_system_type rootfs_fs_type; + +extern bool rodata_enabled; +void mark_rodata_ro(void); extern void (*late_time_init)(void); extern bool initcall_debug; +#ifdef MODULE +extern struct module __this_module; +#define THIS_MODULE (&__this_module) +#else +#define THIS_MODULE ((struct module *)0) +#endif + #endif #ifndef MODULE #ifndef __ASSEMBLY__ -/* initcalls are now grouped by functionality into separate +/* + * initcalls are now grouped by functionality into separate * subsections. Ordering inside the subsections is determined * by link order. * For backwards compatibility, initcall() puts the call in @@ -172,11 +191,90 @@ extern bool initcall_debug; * * The `id' arg to __define_initcall() is needed so that multiple initcalls * can point at the same handler without causing duplicate-symbol build errors. + * + * Initcalls are run by placing pointers in initcall sections that the + * kernel iterates at runtime. The linker can do dead code / data elimination + * and remove that completely, so the initcall sections have to be marked + * as KEEP() in the linker script. */ -#define __define_initcall(fn, id) \ - static initcall_t __initcall_##fn##id __used \ - __attribute__((__section__(".initcall" #id ".init"))) = fn +/* Format: <modname>__<counter>_<line>_<fn> */ +#define __initcall_id(fn) \ + __PASTE(kmod_, \ + __PASTE(__KBUILD_MODNAME, \ + __PASTE(__, \ + __PASTE(__COUNTER__, \ + __PASTE(_, \ + __PASTE(__LINE__, \ + __PASTE(_, fn))))))) + +/* Format: __<prefix>__<iid><id> */ +#define __initcall_name(prefix, __iid, id) \ + __PASTE(__, \ + __PASTE(prefix, \ + __PASTE(__, \ + __PASTE(__iid, id)))) + +#ifdef CONFIG_LTO_CLANG +/* + * With LTO, the compiler doesn't necessarily obey link order for + * initcalls. In order to preserve the correct order, we add each + * variable into its own section and generate a linker script (in + * scripts/link-vmlinux.sh) to specify the order of the sections. + */ +#define __initcall_section(__sec, __iid) \ + #__sec ".init.." #__iid + +/* + * With LTO, the compiler can rename static functions to avoid + * global naming collisions. We use a global stub function for + * initcalls to create a stable symbol name whose address can be + * taken in inline assembly when PREL32 relocations are used. + */ +#define __initcall_stub(fn, __iid, id) \ + __initcall_name(initstub, __iid, id) + +#define __define_initcall_stub(__stub, fn) \ + int __init __stub(void); \ + int __init __stub(void) \ + { \ + return fn(); \ + } \ + __ADDRESSABLE(__stub) +#else +#define __initcall_section(__sec, __iid) \ + #__sec ".init" + +#define __initcall_stub(fn, __iid, id) fn + +#define __define_initcall_stub(__stub, fn) \ + __ADDRESSABLE(fn) +#endif + +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS +#define ____define_initcall(fn, __stub, __name, __sec) \ + __define_initcall_stub(__stub, fn) \ + asm(".section \"" __sec "\", \"a\" \n" \ + __stringify(__name) ": \n" \ + ".long " __stringify(__stub) " - . \n" \ + ".previous \n"); \ + static_assert(__same_type(initcall_t, &fn)); +#else +#define ____define_initcall(fn, __unused, __name, __sec) \ + static initcall_t __name __used \ + __attribute__((__section__(__sec))) = fn; +#endif + +#define __unique_initcall(fn, id, __sec, __iid) \ + ____define_initcall(fn, \ + __initcall_stub(fn, __iid, id), \ + __initcall_name(initcall, __iid, id), \ + __initcall_section(__sec, __iid)) + +#define ___define_initcall(fn, id, __sec) \ + __unique_initcall(fn, id, __sec, __initcall_id(fn)) + +#define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id) /* * Early initcalls run before initializing SMP. @@ -212,16 +310,10 @@ extern bool initcall_debug; #define __initcall(fn) device_initcall(fn) -#define __exitcall(fn) \ +#define __exitcall(fn) \ static exitcall_t __exitcall_##fn __exit_call = fn -#define console_initcall(fn) \ - static initcall_t __initcall_##fn \ - __used __section(.con_initcall.init) = fn - -#define security_initcall(fn) \ - static initcall_t __initcall_##fn \ - __used __section(.security_initcall.init) = fn +#define console_initcall(fn) ___define_initcall(fn, con, .con_initcall) struct obs_kernel_param { const char *str; @@ -229,6 +321,8 @@ struct obs_kernel_param { int early; }; +extern const struct obs_kernel_param __setup_start[], __setup_end[]; + /* * Only for really core code. See moduleparam.h for the normal way. * @@ -236,98 +330,61 @@ struct obs_kernel_param { * obs_kernel_param "array" too far apart in .init.setup. */ #define __setup_param(str, unique_id, fn, early) \ - static const char __setup_str_##unique_id[] __initconst \ - __aligned(1) = str; \ - static struct obs_kernel_param __setup_##unique_id \ - __used __section(.init.setup) \ - __attribute__((aligned((sizeof(long))))) \ + static const char __setup_str_##unique_id[] __initconst \ + __aligned(1) = str; \ + static struct obs_kernel_param __setup_##unique_id \ + __used __section(".init.setup") \ + __aligned(__alignof__(struct obs_kernel_param)) \ = { __setup_str_##unique_id, fn, early } -#define __setup(str, fn) \ +/* + * NOTE: __setup functions return values: + * @fn returns 1 (or non-zero) if the option argument is "handled" + * and returns 0 if the option argument is "not handled". + */ +#define __setup(str, fn) \ __setup_param(str, fn, fn, 0) -/* NOTE: fn is as per module_param, not __setup! Emits warning if fn - * returns non-zero. */ -#define early_param(str, fn) \ +/* + * NOTE: @fn is as per module_param, not __setup! + * I.e., @fn returns 0 for no error or non-zero for error + * (possibly @fn returns a -errno value, but it does not matter). + * Emits warning if @fn returns non-zero. + */ +#define early_param(str, fn) \ __setup_param(str, fn, fn, 1) +#define early_param_on_off(str_on, str_off, var, config) \ + \ + int var = IS_ENABLED(config); \ + \ + static int __init parse_##var##_on(char *arg) \ + { \ + var = 1; \ + return 0; \ + } \ + early_param(str_on, parse_##var##_on); \ + \ + static int __init parse_##var##_off(char *arg) \ + { \ + var = 0; \ + return 0; \ + } \ + early_param(str_off, parse_##var##_off) + /* Relies on boot_command_line being set */ void __init parse_early_param(void); void __init parse_early_options(char *cmdline); #endif /* __ASSEMBLY__ */ -/** - * module_init() - driver initialization entry point - * @x: function to be run at kernel boot time or module insertion - * - * module_init() will either be called during do_initcalls() (if - * builtin) or at module insertion time (if a module). There can only - * be one per module. - */ -#define module_init(x) __initcall(x); - -/** - * module_exit() - driver exit entry point - * @x: function to be run when driver is removed - * - * module_exit() will wrap the driver clean-up code - * with cleanup_module() when used with rmmod when - * the driver is a module. If the driver is statically - * compiled into the kernel, module_exit() has no effect. - * There can only be one per module. - */ -#define module_exit(x) __exitcall(x); - #else /* MODULE */ -/* Don't use these in loadable modules, but some people do... */ -#define early_initcall(fn) module_init(fn) -#define core_initcall(fn) module_init(fn) -#define postcore_initcall(fn) module_init(fn) -#define arch_initcall(fn) module_init(fn) -#define subsys_initcall(fn) module_init(fn) -#define fs_initcall(fn) module_init(fn) -#define device_initcall(fn) module_init(fn) -#define late_initcall(fn) module_init(fn) - -#define security_initcall(fn) module_init(fn) - -/* Each module must use one module_init(). */ -#define module_init(initfn) \ - static inline initcall_t __inittest(void) \ - { return initfn; } \ - int init_module(void) __attribute__((alias(#initfn))); - -/* This is only required if you want to be unloadable. */ -#define module_exit(exitfn) \ - static inline exitcall_t __exittest(void) \ - { return exitfn; } \ - void cleanup_module(void) __attribute__((alias(#exitfn))); - #define __setup_param(str, unique_id, fn) /* nothing */ #define __setup(str, func) /* nothing */ #endif /* Data marked not to be saved by software suspend */ -#define __nosavedata __section(.data..nosave) - -/* This means "can be init if no module support, otherwise module load - may call it." */ -#ifdef CONFIG_MODULES -#define __init_or_module -#define __initdata_or_module -#define __initconst_or_module -#define __INIT_OR_MODULE .text -#define __INITDATA_OR_MODULE .data -#define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits -#else -#define __init_or_module __init -#define __initdata_or_module __initdata -#define __initconst_or_module __initconst -#define __INIT_OR_MODULE __INIT -#define __INITDATA_OR_MODULE __INITDATA -#define __INITRODATA_OR_MODULE __INITRODATA -#endif /*CONFIG_MODULES*/ +#define __nosavedata __section(".data..nosave") #ifdef MODULE #define __exit_p(x) x |