diff options
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 22 | ||||
| -rw-r--r-- | init/main.c | 18 |
2 files changed, 31 insertions, 9 deletions
diff --git a/init/Kconfig b/init/Kconfig index 54c655ce9c04..a23da9f01803 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1079,6 +1079,28 @@ config SLOB endchoice +config MMAP_ALLOW_UNINITIALIZED + bool "Allow mmapped anonymous memory to be uninitialized" + depends on EMBEDDED && !MMU + default n + help + Normally, and according to the Linux spec, anonymous memory obtained + from mmap() has it's contents cleared before it is passed to + userspace. Enabling this config option allows you to request that + mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus + providing a huge performance boost. If this option is not enabled, + then the flag will be ignored. + + This is taken advantage of by uClibc's malloc(), and also by + ELF-FDPIC binfmt's brk and stack allocator. + + Because of the obvious security issues, this option should only be + enabled on embedded devices where you control what is run in + userspace. Since that isn't generally a problem on no-MMU systems, + it is normally safe to say Y here. + + See Documentation/nommu-mmap.txt for more information. + config PROFILING bool "Profiling support (EXPERIMENTAL)" help diff --git a/init/main.c b/init/main.c index 4051d75dd2d6..c3db4a98b369 100644 --- a/init/main.c +++ b/init/main.c @@ -691,10 +691,10 @@ asmlinkage void __init start_kernel(void) static void __init do_ctors(void) { #ifdef CONFIG_CONSTRUCTORS - ctor_fn_t *call = (ctor_fn_t *) __ctors_start; + ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; - for (; call < (ctor_fn_t *) __ctors_end; call++) - (*call)(); + for (; fn < (ctor_fn_t *) __ctors_end; fn++) + (*fn)(); #endif } @@ -755,10 +755,10 @@ extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[]; static void __init do_initcalls(void) { - initcall_t *call; + initcall_t *fn; - for (call = __early_initcall_end; call < __initcall_end; call++) - do_one_initcall(*call); + for (fn = __early_initcall_end; fn < __initcall_end; fn++) + do_one_initcall(*fn); /* Make sure there is no pending stuff from the initcall sequence */ flush_scheduled_work(); @@ -785,10 +785,10 @@ static void __init do_basic_setup(void) static void __init do_pre_smp_initcalls(void) { - initcall_t *call; + initcall_t *fn; - for (call = __initcall_start; call < __early_initcall_end; call++) - do_one_initcall(*call); + for (fn = __initcall_start; fn < __early_initcall_end; fn++) + do_one_initcall(*fn); } static void run_init_process(char *init_filename) |