On Fri, Mar 16, 2018 at 11:11:54AM +0800, Li Wang wrote: > Hi, > > ltp/dynamic_debug01.sh trigger this Warning on x86_64 with > kernel-v4.16.0-rc5. > > > [ 8216.976433] ------------[ cut here ]------------ > [ 8216.981615] can't patch jump_label at dmi_sysfs_exit+0x0/0x2d > [ 8216.981625] WARNING: CPU: 0 PID: 22572 at kernel/jump_label.c:376 > __jump_label_update+0x9d/0xb0
Hi Li, Thanks for reporting it. This seems to be caused by the pr_debug() in dmi_sysfs_exit(), which is in the .exit.text section (assuming your config has CONFIG_DMI_SYSFS=y, which means the function is freed during boot.) Can you test the following fix? diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 2168cc6b8b30..b46b541c67c4 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -151,7 +151,7 @@ extern struct jump_entry __start___jump_table[]; extern struct jump_entry __stop___jump_table[]; extern void jump_label_init(void); -extern void jump_label_invalidate_init(void); +extern void jump_label_invalidate_initmem(void); extern void jump_label_lock(void); extern void jump_label_unlock(void); extern void arch_jump_label_transform(struct jump_entry *entry, @@ -199,7 +199,7 @@ static __always_inline void jump_label_init(void) static_key_initialized = true; } -static inline void jump_label_invalidate_init(void) {} +static inline void jump_label_invalidate_initmem(void) {} static __always_inline bool static_key_false(struct static_key *key) { diff --git a/init/main.c b/init/main.c index 969eaf140ef0..21efbf6ace93 100644 --- a/init/main.c +++ b/init/main.c @@ -1001,7 +1001,7 @@ static int __ref kernel_init(void *unused) /* need to finish all async __init code before freeing the memory */ async_synchronize_full(); ftrace_free_init_mem(); - jump_label_invalidate_init(); + jump_label_invalidate_initmem(); free_initmem(); mark_readonly(); system_state = SYSTEM_RUNNING; diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 52a0a7af8640..b44ab1273456 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -16,6 +16,7 @@ #include <linux/jump_label_ratelimit.h> #include <linux/bug.h> #include <linux/cpu.h> +#include <asm/sections.h> #ifdef HAVE_JUMP_LABEL @@ -420,15 +421,15 @@ void __init jump_label_init(void) cpus_read_unlock(); } -/* Disable any jump label entries in __init code */ -void __init jump_label_invalidate_init(void) +/* Disable any jump label entries in __init/__exit code */ +void __init jump_label_invalidate_initmem(void) { struct jump_entry *iter_start = __start___jump_table; struct jump_entry *iter_stop = __stop___jump_table; struct jump_entry *iter; for (iter = iter_start; iter < iter_stop; iter++) { - if (init_kernel_text(iter->code)) + if (init_section_contains((void *)(unsigned long)iter->code, 1)) iter->code = 0; } }