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Date: Thu, 21 Dec 2023 05:35:55 +0800
From: kernel test robot <lkp@intel.com>
To: Sven Schnelle <svens@linux.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>
Cc: oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org,
	Heiko Carstens <hca@linux.ibm.com>
Subject: Re: [PATCH v2 1/3] entry: move exit to usermode functions to header
 file
Message-ID: <202312210535.lQDyVDDW-lkp@intel.com>
References: <20231218074520.1998026-2-svens@linux.ibm.com>
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MIME-Version: 1.0
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In-Reply-To: <20231218074520.1998026-2-svens@linux.ibm.com>

Hi Sven,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tip/core/entry]
[also build test WARNING on linus/master v6.7-rc6 next-20231220]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Sven-Schnelle/entry-move-exit-to-usermode-functions-to-header-file/20231218-154733
base:   tip/core/entry
patch link:    https://lore.kernel.org/r/20231218074520.1998026-2-svens%40linux.ibm.com
patch subject: [PATCH v2 1/3] entry: move exit to usermode functions to header file
config: x86_64-rhel-8.3-kunit (https://download.01.org/0day-ci/archive/20231221/202312210535.lQDyVDDW-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231221/202312210535.lQDyVDDW-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312210535.lQDyVDDW-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/entry/common.c:134: warning: Function parameter or struct member 'regs' not described in 'exit_to_user_mode_loop'
>> kernel/entry/common.c:134: warning: Function parameter or struct member 'ti_work' not described in 'exit_to_user_mode_loop'


vim +134 kernel/entry/common.c

a9f3a74a29af09 Thomas Gleixner     2020-07-22  128  
af18f155cb4bda Sven Schnelle       2023-12-18  129  /**
af18f155cb4bda Sven Schnelle       2023-12-18  130   * exit_to_user_mode_loop - do any pending work before leaving to user space
af18f155cb4bda Sven Schnelle       2023-12-18  131   */
af18f155cb4bda Sven Schnelle       2023-12-18  132  __always_inline unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
a9f3a74a29af09 Thomas Gleixner     2020-07-22  133  						     unsigned long ti_work)
a9f3a74a29af09 Thomas Gleixner     2020-07-22 @134  {
a9f3a74a29af09 Thomas Gleixner     2020-07-22  135  	/*
a9f3a74a29af09 Thomas Gleixner     2020-07-22  136  	 * Before returning to user space ensure that all pending work
a9f3a74a29af09 Thomas Gleixner     2020-07-22  137  	 * items have been completed.
a9f3a74a29af09 Thomas Gleixner     2020-07-22  138  	 */
a9f3a74a29af09 Thomas Gleixner     2020-07-22  139  	while (ti_work & EXIT_TO_USER_MODE_WORK) {
a9f3a74a29af09 Thomas Gleixner     2020-07-22  140  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  141  		local_irq_enable_exit_to_user(ti_work);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  142  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  143  		if (ti_work & _TIF_NEED_RESCHED)
a9f3a74a29af09 Thomas Gleixner     2020-07-22  144  			schedule();
a9f3a74a29af09 Thomas Gleixner     2020-07-22  145  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  146  		if (ti_work & _TIF_UPROBE)
a9f3a74a29af09 Thomas Gleixner     2020-07-22  147  			uprobe_notify_resume(regs);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  148  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  149  		if (ti_work & _TIF_PATCH_PENDING)
a9f3a74a29af09 Thomas Gleixner     2020-07-22  150  			klp_update_patch_state(current);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  151  
12db8b690010cc Jens Axboe          2020-10-26  152  		if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
8ba62d37949e24 Eric W. Biederman   2022-02-09  153  			arch_do_signal_or_restart(regs);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  154  
a68de80f61f6af Sean Christopherson 2021-09-01  155  		if (ti_work & _TIF_NOTIFY_RESUME)
03248addadf1a5 Eric W. Biederman   2022-02-09  156  			resume_user_mode_work(regs);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  157  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  158  		/* Architecture specific TIF work */
a9f3a74a29af09 Thomas Gleixner     2020-07-22  159  		arch_exit_to_user_mode_work(regs, ti_work);
a9f3a74a29af09 Thomas Gleixner     2020-07-22  160  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  161  		/*
a9f3a74a29af09 Thomas Gleixner     2020-07-22  162  		 * Disable interrupts and reevaluate the work flags as they
a9f3a74a29af09 Thomas Gleixner     2020-07-22  163  		 * might have changed while interrupts and preemption was
a9f3a74a29af09 Thomas Gleixner     2020-07-22  164  		 * enabled above.
a9f3a74a29af09 Thomas Gleixner     2020-07-22  165  		 */
a9f3a74a29af09 Thomas Gleixner     2020-07-22  166  		local_irq_disable_exit_to_user();
47b8ff194c1fd7 Frederic Weisbecker 2021-02-01  167  
47b8ff194c1fd7 Frederic Weisbecker 2021-02-01  168  		/* Check if any of the above work has queued a deferred wakeup */
f268c3737ecaef Frederic Weisbecker 2021-05-27  169  		tick_nohz_user_enter_prepare();
47b8ff194c1fd7 Frederic Weisbecker 2021-02-01  170  
6ce895128b3bff Mark Rutland        2021-11-29  171  		ti_work = read_thread_flags();
a9f3a74a29af09 Thomas Gleixner     2020-07-22  172  	}
a9f3a74a29af09 Thomas Gleixner     2020-07-22  173  
a9f3a74a29af09 Thomas Gleixner     2020-07-22  174  	/* Return the latest work state for arch_exit_to_user_mode() */
a9f3a74a29af09 Thomas Gleixner     2020-07-22  175  	return ti_work;
a9f3a74a29af09 Thomas Gleixner     2020-07-22  176  }
a9f3a74a29af09 Thomas Gleixner     2020-07-22  177  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki