Hi Sergey, [auto build test ERROR on linus/master] [also build test ERROR on next-20161221] [cannot apply to v4.9] [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/Sergey-Senozhatsky/printk-use-vprintk_func-in-vprintk/20161222-075616 config: ia64-allmodconfig (attached as .config) compiler: ia64-linux-gcc (GCC) 6.2.0 reproduce: wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=ia64 Note: the linux-review/Sergey-Senozhatsky/printk-use-vprintk_func-in-vprintk/20161222-075616 HEAD 43ffcdc67ed0e40d3cf6137a37fbe557bfee4fb7 builds fine. It only hurts bisectibility. All error/warnings (new ones prefixed by >>): In file included from arch/ia64/include/asm/intrinsics.h:10:0, from arch/ia64/include/asm/bitops.h:18, from include/linux/bitops.h:36, from include/linux/kernel.h:10, from include/linux/list.h:8, from include/linux/preempt.h:10, from kernel/printk/printk_safe.c:18: kernel/printk/printk_safe.c: In function 'printk_safe_log_store': >> kernel/printk/printk_safe.c:82:15: error: 'nmi_message_lost' undeclared (first use in this function) atomic_inc(&nmi_message_lost); ^ arch/ia64/include/uapi/asm/intrinsics.h:60:24: note: in definition of macro 'ia64_fetchadd' volatile __typeof__(*(v)) *_v = (v); \ ^ >> arch/ia64/include/asm/atomic.h:75:5: note: in expansion of macro 'ia64_fetch_and_add' ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \ ^~~~~~~~~~~~~~~~~~ >> arch/ia64/include/asm/atomic.h:316:33: note: in expansion of macro 'atomic_add_return' #define atomic_add(i,v) (void)atomic_add_return((i), (v)) ^~~~~~~~~~~~~~~~~ >> arch/ia64/include/asm/atomic.h:318:25: note: in expansion of macro 'atomic_add' #define atomic_inc(v) atomic_add(1, (v)) ^~~~~~~~~~ >> kernel/printk/printk_safe.c:82:3: note: in expansion of macro 'atomic_inc' atomic_inc(&nmi_message_lost); ^~~~~~~~~~ kernel/printk/printk_safe.c:82:15: note: each undeclared identifier is reported only once for each function it appears in atomic_inc(&nmi_message_lost); ^ arch/ia64/include/uapi/asm/intrinsics.h:60:24: note: in definition of macro 'ia64_fetchadd' volatile __typeof__(*(v)) *_v = (v); \ ^ >> arch/ia64/include/asm/atomic.h:75:5: note: in expansion of macro 'ia64_fetch_and_add' ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter) \ ^~~~~~~~~~~~~~~~~~ >> arch/ia64/include/asm/atomic.h:316:33: note: in expansion of macro 'atomic_add_return' #define atomic_add(i,v) (void)atomic_add_return((i), (v)) ^~~~~~~~~~~~~~~~~ >> arch/ia64/include/asm/atomic.h:318:25: note: in expansion of macro 'atomic_add' #define atomic_inc(v) atomic_add(1, (v)) ^~~~~~~~~~ >> kernel/printk/printk_safe.c:82:3: note: in expansion of macro 'atomic_inc' atomic_inc(&nmi_message_lost); ^~~~~~~~~~ vim +/nmi_message_lost +82 kernel/printk/printk_safe.c 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 12 * GNU General Public License for more details. 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 13 * 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 14 * You should have received a copy of the GNU General Public License 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 15 * along with this program; if not, see . 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 16 */ 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 17 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 @18 #include 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 19 #include cf9b1106 kernel/printk/nmi.c Petr Mladek 2016-05-20 20 #include 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 21 #include 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 22 #include 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 23 #include 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 24 #include 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 25 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 26 #include "internal.h" 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 27 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 28 /* 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 29 * printk() could not take logbuf_lock in NMI context. Instead, 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 30 * it uses an alternative implementation that temporary stores 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 31 * the strings into a per-CPU buffer. The content of the buffer 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 32 * is later flushed into the main ring buffer via IRQ work. 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 33 * 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 34 * The alternative implementation is chosen transparently 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 35 * by examinig current printk() context mask stored in @printk_context 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 36 * per-CPU variable. 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 37 * 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 38 * The implementation allows to flush the strings also from another CPU. 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 39 * There are situations when we want to make sure that all buffers 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 40 * were handled or when IRQs are blocked. 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 41 */ c178cb8a kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 42 static int printk_safe_irq_ready; 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 43 c178cb8a kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 44 #define SAFE_LOG_BUF_LEN ((1 << CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT) - \ 427934b8 kernel/printk/nmi.c Petr Mladek 2016-05-20 45 sizeof(atomic_t) - sizeof(struct irq_work)) 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 46 c178cb8a kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 47 struct printk_safe_seq_buf { 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 48 atomic_t len; /* length of written data */ 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 49 struct irq_work work; /* IRQ work that flushes the buffer */ c178cb8a kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 50 unsigned char buffer[SAFE_LOG_BUF_LEN]; 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 51 }; 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 52 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 53 static DEFINE_PER_CPU(struct printk_safe_seq_buf, safe_print_seq); 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 54 static DEFINE_PER_CPU(int, printk_context); 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 55 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 56 #ifdef CONFIG_PRINTK_NMI c178cb8a kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 57 static DEFINE_PER_CPU(struct printk_safe_seq_buf, nmi_print_seq); 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 58 atomic_t nmi_message_lost; 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 59 #endif 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 60 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 61 /* 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 62 * Add a message to per-CPU context-dependent buffer. NMI and printk-safe 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 63 * have dedicated buffers, because otherwise printk-safe preempted by 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 64 * NMI-printk would have overwritten the NMI messages. 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 65 * 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 66 * The messages are fushed from irq work (of from panic()), possibly, 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 67 * from other CPU, concurrently with printk_safe_log_store(). Should this 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 68 * happen, printk_safe_log_store() will notice the buffer->len mismatch 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 69 * and repeat the write. 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 70 */ 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 71 static int printk_safe_log_store(struct printk_safe_seq_buf *s, 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 72 const char *fmt, va_list args) 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 73 { 927f128d kernel/printk/printk_safe.c Sergey Senozhatsky 2016-12-21 74 int add; 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 75 size_t len; 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 76 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 77 again: 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 78 len = atomic_read(&s->len); 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 79 4a998e32 kernel/printk/nmi.c Petr Mladek 2016-12-12 80 /* The trailing '\0' is not counted into len. */ 4a998e32 kernel/printk/nmi.c Petr Mladek 2016-12-12 81 if (len >= sizeof(s->buffer) - 1) { b522deab kernel/printk/nmi.c Petr Mladek 2016-05-20 @82 atomic_inc(&nmi_message_lost); 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 83 return 0; b522deab kernel/printk/nmi.c Petr Mladek 2016-05-20 84 } 42a0bb3f kernel/printk/nmi.c Petr Mladek 2016-05-20 85 :::::: The code at line 82 was first introduced by commit :::::: b522deabc6f18e4f938d93a84f345f2cbf3347d1 printk/nmi: warn when some message has been lost in NMI context :::::: TO: Petr Mladek :::::: CC: Linus Torvalds --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation