From 1b1eeca7e4c19fa76d409d4c7b338dba21f2df45 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 21 Aug 2018 21:56:13 -0700 Subject: [PATCH] init: allow initcall tables to be emitted using relative references Allow the initcall tables to be emitted using relative references that are only half the size on 64-bit architectures and don't require fixups at runtime on relocatable kernels. Link: http://lkml.kernel.org/r/20180704083651.24360-5-ard.biesheuvel@linaro.org Acked-by: James Morris Acked-by: Sergey Senozhatsky Acked-by: Petr Mladek Acked-by: Michael Ellerman Acked-by: Ingo Molnar Signed-off-by: Ard Biesheuvel Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Bjorn Helgaas Cc: Catalin Marinas Cc: James Morris Cc: Jessica Yu Cc: Josh Poimboeuf Cc: Kees Cook Cc: Nicolas Pitre Cc: Paul Mackerras Cc: Russell King Cc: "Serge E. Hallyn" Cc: Steven Rostedt Cc: Thomas Garnier Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init.h | 44 +++++++++++++++++++++++++++++++----------- init/main.c | 32 +++++++++++++++--------------- kernel/printk/printk.c | 16 ++++++++------- security/security.c | 17 +++++++++------- 4 files changed, 68 insertions(+), 41 deletions(-) diff --git a/include/linux/init.h b/include/linux/init.h index bc27cf03c41e..2538d176dd1f 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -116,8 +116,24 @@ 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[]; +extern initcall_entry_t __security_initcall_start[], __security_initcall_end[]; /* Used for contructor calls. */ typedef void (*ctor_fn_t)(void); @@ -167,9 +183,20 @@ extern bool initcall_debug; * as KEEP() in the linker script. */ -#define __define_initcall(fn, id) \ +#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"); +#else +#define ___define_initcall(fn, id, __sec) \ static initcall_t __initcall_##fn##id __used \ - __attribute__((__section__(".initcall" #id ".init"))) = fn; + __attribute__((__section__(#__sec ".init"))) = fn; +#endif + +#define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id) /* * Early initcalls run before initializing SMP. @@ -208,13 +235,8 @@ extern bool initcall_debug; #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_initcall) +#define security_initcall(fn) ___define_initcall(fn,, .security_initcall) struct obs_kernel_param { const char *str; diff --git a/init/main.c b/init/main.c index b729e1f22838..3a6ce89e128f 100644 --- a/init/main.c +++ b/init/main.c @@ -902,18 +902,18 @@ int __init_or_module do_one_initcall(initcall_t fn) } -extern initcall_t __initcall_start[]; -extern initcall_t __initcall0_start[]; -extern initcall_t __initcall1_start[]; -extern initcall_t __initcall2_start[]; -extern initcall_t __initcall3_start[]; -extern initcall_t __initcall4_start[]; -extern initcall_t __initcall5_start[]; -extern initcall_t __initcall6_start[]; -extern initcall_t __initcall7_start[]; -extern initcall_t __initcall_end[]; - -static initcall_t *initcall_levels[] __initdata = { +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[]; + +static initcall_entry_t *initcall_levels[] __initdata = { __initcall0_start, __initcall1_start, __initcall2_start, @@ -939,7 +939,7 @@ static char *initcall_level_names[] __initdata = { static void __init do_initcall_level(int level) { - initcall_t *fn; + initcall_entry_t *fn; strcpy(initcall_command_line, saved_command_line); parse_args(initcall_level_names[level], @@ -950,7 +950,7 @@ static void __init do_initcall_level(int level) trace_initcall_level(initcall_level_names[level]); for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) - do_one_initcall(*fn); + do_one_initcall(initcall_from_entry(fn)); } static void __init do_initcalls(void) @@ -981,11 +981,11 @@ static void __init do_basic_setup(void) static void __init do_pre_smp_initcalls(void) { - initcall_t *fn; + initcall_entry_t *fn; trace_initcall_level("early"); for (fn = __initcall_start; fn < __initcall0_start; fn++) - do_one_initcall(*fn); + do_one_initcall(initcall_from_entry(fn)); } /* diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 90b6ab01db59..918f386b2f6e 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2788,7 +2788,8 @@ EXPORT_SYMBOL(unregister_console); void __init console_init(void) { int ret; - initcall_t *call; + initcall_t call; + initcall_entry_t *ce; /* Setup the default TTY line discipline. */ n_tty_init(); @@ -2797,13 +2798,14 @@ void __init console_init(void) * set up the console device so that later boot sequences can * inform about problems etc.. */ - call = __con_initcall_start; + ce = __con_initcall_start; trace_initcall_level("console"); - while (call < __con_initcall_end) { - trace_initcall_start((*call)); - ret = (*call)(); - trace_initcall_finish((*call), ret); - call++; + while (ce < __con_initcall_end) { + call = initcall_from_entry(ce); + trace_initcall_start(call); + ret = call(); + trace_initcall_finish(call, ret); + ce++; } } diff --git a/security/security.c b/security/security.c index 47cfff01d7ec..736e78da1ab9 100644 --- a/security/security.c +++ b/security/security.c @@ -48,14 +48,17 @@ static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] = static void __init do_security_initcalls(void) { int ret; - initcall_t *call; - call = __security_initcall_start; + initcall_t call; + initcall_entry_t *ce; + + ce = __security_initcall_start; trace_initcall_level("security"); - while (call < __security_initcall_end) { - trace_initcall_start((*call)); - ret = (*call) (); - trace_initcall_finish((*call), ret); - call++; + while (ce < __security_initcall_end) { + call = initcall_from_entry(ce); + trace_initcall_start(call); + ret = call(); + trace_initcall_finish(call, ret); + ce++; } } -- 2.34.1