Re: [PATCH v2] drivers: char: ipmi: ipmi_msghandler: Pass lockdep expression to RCU lists

From: kbuild test robot
Date: Sun Jan 12 2020 - 00:31:48 EST


Hi Amol,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on ipmi/for-next arm-soc/for-next v5.5-rc5]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url: https://github.com/0day-ci/linux/commits/Amol-Grover/drivers-char-ipmi-ipmi_msghandler-Pass-lockdep-expression-to-RCU-lists/20200111-081002
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git 16bb7abc4a6b9defffa294e4dc28383e62a1dbcf
config: x86_64-randconfig-a003-20200109 (attached as .config)
compiler: gcc-5 (Ubuntu 5.5.0-12ubuntu1) 5.5.0 20171010
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

In file included from include/linux/export.h:43:0,
from include/linux/linkage.h:7,
from include/linux/kernel.h:8,
from include/linux/list.h:9,
from include/linux/module.h:12,
from drivers/char/ipmi/ipmi_msghandler.c:17:
drivers/char/ipmi/ipmi_msghandler.c: In function 'find_cmd_rcvr':
include/linux/rculist.h:53:25: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
RCU_LOCKDEP_WARN(!cond && !rcu_read_lock_any_held(), \
^
include/linux/compiler.h:58:52: note: in definition of macro '__trace_if_var'
#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
^
>> include/linux/rcupdate.h:263:3: note: in expansion of macro 'if'
if (debug_lockdep_rcu_enabled() && !__warned && (c)) { \
^
>> include/linux/rculist.h:53:2: note: in expansion of macro 'RCU_LOCKDEP_WARN'
RCU_LOCKDEP_WARN(!cond && !rcu_read_lock_any_held(), \
^
include/linux/rculist.h:371:7: note: in expansion of macro '__list_check_rcu'
for (__list_check_rcu(dummy, ## cond, 0), \
^
drivers/char/ipmi/ipmi_msghandler.c:1607:2: note: in expansion of macro 'list_for_each_entry_rcu'
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
^
include/linux/rculist.h:53:25: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
RCU_LOCKDEP_WARN(!cond && !rcu_read_lock_any_held(), \
^
include/linux/compiler.h:58:61: note: in definition of macro '__trace_if_var'
#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
^
>> include/linux/rcupdate.h:263:3: note: in expansion of macro 'if'
if (debug_lockdep_rcu_enabled() && !__warned && (c)) { \
^
>> include/linux/rculist.h:53:2: note: in expansion of macro 'RCU_LOCKDEP_WARN'
RCU_LOCKDEP_WARN(!cond && !rcu_read_lock_any_held(), \
^
include/linux/rculist.h:371:7: note: in expansion of macro '__list_check_rcu'
for (__list_check_rcu(dummy, ## cond, 0), \
^
drivers/char/ipmi/ipmi_msghandler.c:1607:2: note: in expansion of macro 'list_for_each_entry_rcu'
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
^
include/linux/rculist.h:53:25: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
RCU_LOCKDEP_WARN(!cond && !rcu_read_lock_any_held(), \
^
include/linux/compiler.h:69:3: note: in definition of macro '__trace_if_value'
(cond) ? \
^
include/linux/compiler.h:56:28: note: in expansion of macro '__trace_if_var'
#define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
^
>> include/linux/rcupdate.h:263:3: note: in expansion of macro 'if'
if (debug_lockdep_rcu_enabled() && !__warned && (c)) { \
^
>> include/linux/rculist.h:53:2: note: in expansion of macro 'RCU_LOCKDEP_WARN'
RCU_LOCKDEP_WARN(!cond && !rcu_read_lock_any_held(), \
^
include/linux/rculist.h:371:7: note: in expansion of macro '__list_check_rcu'
for (__list_check_rcu(dummy, ## cond, 0), \
^
drivers/char/ipmi/ipmi_msghandler.c:1607:2: note: in expansion of macro 'list_for_each_entry_rcu'
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
^

vim +/if +263 include/linux/rcupdate.h

632ee200130899 Paul E. McKenney 2010-02-22 254
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 255 /**
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 256 * RCU_LOCKDEP_WARN - emit lockdep splat if specified condition is met
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 257 * @c: condition to check
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 258 * @s: informative message
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 259 */
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 260 #define RCU_LOCKDEP_WARN(c, s) \
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 261 do { \
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 262 static bool __section(.data.unlikely) __warned; \
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 @263 if (debug_lockdep_rcu_enabled() && !__warned && (c)) { \
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 264 __warned = true; \
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 265 lockdep_rcu_suspicious(__FILE__, __LINE__, s); \
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 266 } \
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 267 } while (0)
f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 268

:::::: The code at line 263 was first introduced by commit
:::::: f78f5b90c4ffa559e400c3919a02236101f29f3f rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN()

:::::: TO: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
:::::: CC: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

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