path: root/init
diff options
authorSteven Rostedt (VMware) <rostedt@goodmis.org>2017-04-03 12:57:35 -0400
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2017-04-03 14:04:00 -0400
commitb80f0f6c9ed3958ff4002b6135f43a1ef312a610 (patch)
treec30589b7e985125ef81a56e84aef47cb21207378 /init
parent5bd84629a7a0e2462c28ca52e213ebe27fadfee8 (diff)
ftrace: Have init/main.c call ftrace directly to free init memory
Relying on free_reserved_area() to call ftrace to free init memory proved to not be sufficient. The issue is that on x86, when debug_pagealloc is enabled, the init memory is not freed, but simply set as not present. Since ftrace was uninformed of this, starting function tracing still tries to update pages that are not present according to the page tables, causing ftrace to bug, as well as killing the kernel itself. Instead of relying on free_reserved_area(), have init/main.c call ftrace directly just before it frees the init memory. Then it needs to use __init_begin and __init_end to know where the init memory location is. Looking at all archs (and testing what I can), it appears that this should work for each of them. Reported-by: kernel test robot <xiaolong.ye@intel.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'init')
1 files changed, 1 insertions, 0 deletions
diff --git a/init/main.c b/init/main.c
index c0137b916aa1..0e8849f74561 100644
--- a/init/main.c
+++ b/init/main.c
@@ -962,6 +962,7 @@ static int __ref kernel_init(void *unused)
/* need to finish all async __init code before freeing the memory */
+ ftrace_free_init_mem();
system_state = SYSTEM_RUNNING;