On 03/21/2016 07:14 PM, Rasmus Villemoes wrote: > Using kasprintf to get the function name makes us look up the name > twice, along with all the vsnprintf overhead of parsing the format > string etc. It also means there is an allocation failure case to deal > with. Since symbol_string in vsprintf.c would anyway allocate an array > of size KSYM_SYMBOL_LEN on the stack, that might as well be done up > here. > > Moreover, since this is a debug feature and the blacklisted_initcalls > list is usually empty, we might as well test that and thus avoid > looking up the symbol name even once in the common case. > > Signed-off-by: Rasmus Villemoes <[email protected]>
Acked-by: Prarit Bhargava <[email protected]> P. > --- > init/main.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/init/main.c b/init/main.c > index b3c6e363ae18..d76d94cd537c 100644 > --- a/init/main.c > +++ b/init/main.c > @@ -706,21 +706,20 @@ static int __init initcall_blacklist(char *str) > static bool __init_or_module initcall_blacklisted(initcall_t fn) > { > struct blacklist_entry *entry; > - char *fn_name; > + char fn_name[KSYM_SYMBOL_LEN]; > > - fn_name = kasprintf(GFP_KERNEL, "%pf", fn); > - if (!fn_name) > + if (list_empty(&blacklisted_initcalls)) > return false; > > + sprint_symbol_no_offset(fn_name, (unsigned long)fn); > + > list_for_each_entry(entry, &blacklisted_initcalls, next) { > if (!strcmp(fn_name, entry->buf)) { > pr_debug("initcall %s blacklisted\n", fn_name); > - kfree(fn_name); > return true; > } > } > > - kfree(fn_name); > return false; > } > #else >
