[frederic-dynticks:rcu/context-tracking-v2 17/21] kernel/context_tracking.c:91:4: error: call to undeclared function 'rcu_irq_work_resched'; ISO C99 and later do not support implicit function declarations
From: kernel test robot
Date: Fri May 13 2022 - 01:43:09 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git rcu/context-tracking-v2
head: 0364ddb8830db4d4b78f7bfd9344e12d22e9cd32
commit: 0fe61091f9b097b9f0ccc4ffe3333d7e80093392 [17/21] rcu/context-tracking: Move deferred nocb resched to context tracking
config: arm-randconfig-r023-20220512 (https://download.01.org/0day-ci/archive/20220513/202205131353.DZ30D5rD-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 9519dacab7b8afd537811fc2abaceb4d14f4e16a)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm cross compiling tool for clang build
# apt-get install binutils-arm-linux-gnueabi
# https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git/commit/?id=0fe61091f9b097b9f0ccc4ffe3333d7e80093392
git remote add frederic-dynticks https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
git fetch --no-tags frederic-dynticks rcu/context-tracking-v2
git checkout 0fe61091f9b097b9f0ccc4ffe3333d7e80093392
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
All errors (new ones prefixed by >>):
In file included from kernel/context_tracking.c:18:
In file included from include/linux/context_tracking.h:6:
In file included from include/linux/vtime.h:5:
include/linux/context_tracking_state.h:51:29: error: incompatible pointer types passing 'enum ctx_state *' to parameter of type 'const atomic_t *' [-Werror,-Wincompatible-pointer-types]
return atomic_read_acquire(&ct->state);
^~~~~~~~~~
include/linux/atomic/atomic-instrumented.h:32:37: note: passing argument to parameter 'v' here
atomic_read_acquire(const atomic_t *v)
^
>> kernel/context_tracking.c:91:4: error: call to undeclared function 'rcu_irq_work_resched'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
rcu_irq_work_resched();
^
2 errors generated.
vim +/rcu_irq_work_resched +91 kernel/context_tracking.c
> 18 #include <linux/context_tracking.h>
19 #include <linux/rcupdate.h>
20 #include <linux/sched.h>
21 #include <linux/hardirq.h>
22 #include <linux/export.h>
23 #include <linux/kprobes.h>
24
25 #ifdef CONFIG_CONTEXT_TRACKING_USER
26
27 #define CREATE_TRACE_POINTS
28 #include <trace/events/context_tracking.h>
29
30 DEFINE_STATIC_KEY_FALSE(context_tracking_key);
31 EXPORT_SYMBOL_GPL(context_tracking_key);
32
33 static noinstr bool context_tracking_recursion_enter(void)
34 {
35 int recursion;
36
37 recursion = __this_cpu_inc_return(context_tracking.recursion);
38 if (recursion == 1)
39 return true;
40
41 WARN_ONCE((recursion < 1), "Invalid context tracking recursion value %d\n", recursion);
42 __this_cpu_dec(context_tracking.recursion);
43
44 return false;
45 }
46
47 static __always_inline void context_tracking_recursion_exit(void)
48 {
49 __this_cpu_dec(context_tracking.recursion);
50 }
51
52 /**
53 * __ct_user_enter - Inform the context tracking that the CPU is going
54 * to enter user or guest space mode.
55 *
56 * This function must be called right before we switch from the kernel
57 * to user or guest space, when it's guaranteed the remaining kernel
58 * instructions to execute won't use any RCU read side critical section
59 * because this function sets RCU in extended quiescent state.
60 */
61 void noinstr __ct_user_enter(enum ctx_state state)
62 {
63 lockdep_assert_irqs_disabled();
64
65 /* Kernel threads aren't supposed to go to userspace */
66 WARN_ON_ONCE(!current->mm);
67
68 if (!context_tracking_recursion_enter())
69 return;
70
71 if ( __this_cpu_read(context_tracking.state) != state) {
72 if (__this_cpu_read(context_tracking.active)) {
73 /*
74 * At this stage, only low level arch entry code remains and
75 * then we'll run in userspace. We can assume there won't be
76 * any RCU read-side critical section until the next call to
77 * user_exit() or ct_irq_enter(). Let's remove RCU's dependency
78 * on the tick.
79 */
80 if (state == CONTEXT_USER) {
81 instrumentation_begin();
82 trace_user_enter(0);
83 vtime_user_enter(current);
84 instrumentation_end();
85 }
86 /*
87 * Other than generic entry implementation, we may be past the last
88 * rescheduling opportunity in the entry code. Trigger a self IPI
89 * that will fire and reschedule once we resume in user/guest mode.
90 */
> 91 rcu_irq_work_resched();
92 rcu_user_enter();
93 }
94 /*
95 * Even if context tracking is disabled on this CPU, because it's outside
96 * the full dynticks mask for example, we still have to keep track of the
97 * context transitions and states to prevent inconsistency on those of
98 * other CPUs.
99 * If a task triggers an exception in userspace, sleep on the exception
100 * handler and then migrate to another CPU, that new CPU must know where
101 * the exception returns by the time we call exception_exit().
102 * This information can only be provided by the previous CPU when it called
103 * exception_enter().
104 * OTOH we can spare the calls to vtime and RCU when context_tracking.active
105 * is false because we know that CPU is not tickless.
106 */
107 __this_cpu_write(context_tracking.state, state);
108 }
109 context_tracking_recursion_exit();
110 }
111 EXPORT_SYMBOL_GPL(__ct_user_enter);
112
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