From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx> commit 04b74b27c2941e5d62120f6fee3a0a9388a30613 upstream. To avoid include hell, the per_cpu variable printk_func was declared in percpu.h. But it is only defined if printk is defined. As users of printk may also use the printk_func variable, it needs to be defined even if CONFIG_PRINTK is not. Also add a printk.h include in percpu.h just to be safe. Link: http://lkml.kernel.org/r/20141121183215.01ba539c@xxxxxxxxxxxxxxxx Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> [wanglong: backport to 3.10 stable - adjust context ] Signed-off-by: Wang Long <long.wanglong@xxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- include/linux/percpu.h | 1 + include/linux/printk.h | 4 ++-- kernel/printk.c | 3 +++ 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/include/linux/percpu.h b/include/linux/percpu.h index bb1d29c..60e425e 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -4,6 +4,7 @@ #include <linux/preempt.h> #include <linux/smp.h> #include <linux/cpumask.h> +#include <linux/printk.h> #include <linux/pfn.h> #include <linux/init.h> diff --git a/include/linux/printk.h b/include/linux/printk.h index ebc7f3e..14b4098 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -106,6 +106,8 @@ static inline __printf(1, 2) __cold void early_printk(const char *s, ...) { } #endif +typedef int(*printk_func_t)(const char *fmt, va_list args); + #ifdef CONFIG_PRINTK asmlinkage __printf(5, 0) int vprintk_emit(int facility, int level, @@ -144,8 +146,6 @@ extern int kptr_restrict; extern void wake_up_klogd(void); -typedef int(*printk_func_t)(const char *fmt, va_list args); - void log_buf_kexec_setup(void); void __init setup_log_buf(int early); void dump_stack_set_arch_desc(const char *fmt, ...); diff --git a/kernel/printk.c b/kernel/printk.c index d3d929d..7109b38 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1746,6 +1746,9 @@ static size_t msg_print_text(const struct log *msg, enum log_flags prev, bool syslog, char *buf, size_t size) { return 0; } static size_t cont_print_text(char *text, size_t size) { return 0; } +/* Still needs to be defined for users */ +DEFINE_PER_CPU(printk_func_t, printk_func); + #endif /* CONFIG_PRINTK */ #ifdef CONFIG_EARLY_PRINTK -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html