diff options
Diffstat (limited to 'include/linux/init.h')
| -rw-r--r-- | include/linux/init.h | 135 |
1 files changed, 102 insertions, 33 deletions
diff --git a/include/linux/init.h b/include/linux/init.h index 212fc9e2f691..077d7f93b402 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -47,11 +47,11 @@ /* These are for everybody (although not all archs will actually discard it in modules) */ -#define __init __section(.init.text) __cold __latent_entropy __noinitretpoline -#define __initdata __section(.init.data) -#define __initconst __section(.init.rodata) -#define __exitdata __section(.exit.data) -#define __exit_call __used __section(.exitcall.exit) +#define __init __section(".init.text") __cold __latent_entropy __noinitretpoline +#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. @@ -70,9 +70,9 @@ * * The markers follow same syntax rules as __init / __initdata. */ -#define __ref __section(.ref.text) noinline -#define __refdata __section(.ref.data) -#define __refconst __section(.ref.rodata) +#define __ref __section(".ref.text") noinline +#define __refdata __section(".ref.data") +#define __refconst __section(".ref.rodata") #ifdef MODULE #define __exitused @@ -80,16 +80,16 @@ #define __exitused __used #endif -#define __exit __section(.exit.text) __exitused __cold notrace +#define __exit __section(".exit.text") __exitused __cold notrace /* Used for MEMORY_HOTPLUG */ -#define __meminit __section(.meminit.text) __cold notrace \ +#define __meminit __section(".meminit.text") __cold notrace \ __latent_entropy -#define __meminitdata __section(.meminit.data) -#define __meminitconst __section(.meminit.rodata) -#define __memexit __section(.memexit.text) __exitused __cold notrace -#define __memexitdata __section(.memexit.data) -#define __memexitconst __section(.memexit.rodata) +#define __meminitdata __section(".meminit.data") +#define __meminitconst __section(".meminit.rodata") +#define __memexit __section(".memexit.text") __exitused __cold notrace +#define __memexitdata __section(".memexit.data") +#define __memexitconst __section(".memexit.rodata") /* For assembly routines */ #define __HEAD .section ".head.text","ax" @@ -134,7 +134,7 @@ static inline initcall_t initcall_from_entry(initcall_entry_t *entry) 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; @@ -184,19 +184,81 @@ extern bool initcall_debug; * as KEEP() in the linker script. */ +/* Format: <modname>__<counter>_<line>_<fn> */ +#define __initcall_id(fn) \ + __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, id, __sec) \ - __ADDRESSABLE(fn) \ - asm(".section \"" #__sec ".init\", \"a\" \n" \ - "__initcall_" #fn #id ": \n" \ - ".long " #fn " - . \n" \ - ".previous \n"); +#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, id, __sec) \ - static initcall_t __initcall_##fn##id __used \ - __attribute__((__section__(#__sec ".init"))) = fn; +#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) /* @@ -236,7 +298,7 @@ extern bool initcall_debug; #define __exitcall(fn) \ static exitcall_t __exitcall_##fn __exit_call = fn -#define console_initcall(fn) ___define_initcall(fn,, .con_initcall) +#define console_initcall(fn) ___define_initcall(fn, con, .con_initcall) struct obs_kernel_param { const char *str; @@ -254,16 +316,23 @@ struct obs_kernel_param { 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))))) \ + __used __section(".init.setup") \ + __aligned(__alignof__(struct obs_kernel_param)) \ = { __setup_str_##unique_id, fn, early } +/* + * 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. + * 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) @@ -277,14 +346,14 @@ struct obs_kernel_param { var = 1; \ return 0; \ } \ - __setup_param(str_on, parse_##var##_on, parse_##var##_on, 1); \ + early_param(str_on, parse_##var##_on); \ \ static int __init parse_##var##_off(char *arg) \ { \ var = 0; \ return 0; \ } \ - __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1) + early_param(str_off, parse_##var##_off) /* Relies on boot_command_line being set */ void __init parse_early_param(void); @@ -298,7 +367,7 @@ void __init parse_early_options(char *cmdline); #endif /* Data marked not to be saved by software suspend */ -#define __nosavedata __section(.data..nosave) +#define __nosavedata __section(".data..nosave") #ifdef MODULE #define __exit_p(x) x |