Re: [PATCH] jump_label: mark __start/stop___jump_table const

[kbuild test robot]

Hi Michael,

[auto build test WARNING on linus/master]
[also build test WARNING on v4.10-rc7 next-20170209]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Michael-S-Tsirkin/jump_label-mark-__start-stop___jump_table-const/20170210-104623
config: x86_64-rhel (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   kernel/jump_label.c: In function 'jump_label_init':
>> kernel/jump_label.c:284:34: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
     struct jump_entry *iter_start = __start___jump_table;
                                     ^~~~~~~~~~~~~~~~~~~~
   kernel/jump_label.c:285:33: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
     struct jump_entry *iter_stop = __stop___jump_table;
                                    ^~~~~~~~~~~~~~~~~~~
   kernel/jump_label.c: In function 'jump_label_text_reserved':
>> kernel/jump_label.c:549:39: warning: passing argument 1 of '__jump_label_text_reserved' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
     int ret = __jump_label_text_reserved(__start___jump_table,
                                          ^~~~~~~~~~~~~~~~~~~~
   kernel/jump_label.c:210:12: note: expected 'struct jump_entry *' but argument is of type 'const struct jump_entry *'
    static int __jump_label_text_reserved(struct jump_entry *iter_start,
               ^~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/jump_label.c:550:4: warning: passing argument 2 of '__jump_label_text_reserved' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
       __stop___jump_table, start, end);
       ^~~~~~~~~~~~~~~~~~~
   kernel/jump_label.c:210:12: note: expected 'struct jump_entry *' but argument is of type 'const struct jump_entry *'
    static int __jump_label_text_reserved(struct jump_entry *iter_start,
               ^~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/jump_label.c: In function 'jump_label_update':
   kernel/jump_label.c:563:28: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
     struct jump_entry *stop = __stop___jump_table;
                               ^~~~~~~~~~~~~~~~~~~

vim +/const +284 kernel/jump_label.c

706249c22 Peter Zijlstra      2015-07-24  268  				struct jump_entry *entry,
706249c22 Peter Zijlstra      2015-07-24  269  				struct jump_entry *stop)
706249c22 Peter Zijlstra      2015-07-24  270  {
706249c22 Peter Zijlstra      2015-07-24  271  	for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
706249c22 Peter Zijlstra      2015-07-24  272  		/*
706249c22 Peter Zijlstra      2015-07-24  273  		 * entry->code set to 0 invalidates module init text sections
706249c22 Peter Zijlstra      2015-07-24  274  		 * kernel_text_address() verifies we are not in core kernel
706249c22 Peter Zijlstra      2015-07-24  275  		 * init code, see jump_label_invalidate_module_init().
706249c22 Peter Zijlstra      2015-07-24  276  		 */
706249c22 Peter Zijlstra      2015-07-24  277  		if (entry->code && kernel_text_address(entry->code))
706249c22 Peter Zijlstra      2015-07-24  278  			arch_jump_label_transform(entry, jump_label_type(entry));
706249c22 Peter Zijlstra      2015-07-24  279  	}
706249c22 Peter Zijlstra      2015-07-24  280  }
706249c22 Peter Zijlstra      2015-07-24  281  
97ce2c88f Jeremy Fitzhardinge 2011-10-12  282  void __init jump_label_init(void)
bf5438fca Jason Baron         2010-09-17  283  {
bf5438fca Jason Baron         2010-09-17 @284  	struct jump_entry *iter_start = __start___jump_table;
bf5438fca Jason Baron         2010-09-17  285  	struct jump_entry *iter_stop = __stop___jump_table;
c5905afb0 Ingo Molnar         2012-02-24  286  	struct static_key *key = NULL;
bf5438fca Jason Baron         2010-09-17  287  	struct jump_entry *iter;
bf5438fca Jason Baron         2010-09-17  288  
1f69bf9c6 Jason Baron         2016-08-03  289  	/*
1f69bf9c6 Jason Baron         2016-08-03  290  	 * Since we are initializing the static_key.enabled field with
1f69bf9c6 Jason Baron         2016-08-03  291  	 * with the 'raw' int values (to avoid pulling in atomic.h) in
1f69bf9c6 Jason Baron         2016-08-03  292  	 * jump_label.h, let's make sure that is safe. There are only two

:::::: The code at line 284 was first introduced by commit
:::::: bf5438fca2950b03c21ad868090cc1a8fcd49536 jump label: Base patch for jump label

:::::: TO: Jason Baron <jbaron@xxxxxxxxxx>
:::::: CC: Steven Rostedt <rostedt@xxxxxxxxxxx>

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