Re: [PATCH] x86: suppress stack overrun message for init_task

From: AmÃrico Wang
Date: Sat Nov 21 2009 - 05:30:34 EST


On Fri, Nov 20, 2009 at 02:00:14PM +0000, Jan Beulich wrote:
>init_task doesn't get its stack end location set to STACK_END_MAGIC,
>and hence the message is confusing rather than helpful in this case.
>
>Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
>

How about the patch below? It is totally untested. ;)

-------------->

init process should also write STACK_END_MAGIC to the
end of its stack.

Signed-off-by: WANG Cong <xiyou.wangcong@xxxxxxxxx>

----
diff --git a/init/main.c b/init/main.c
index 5988deb..5a8f1b9 100644
--- a/init/main.c
+++ b/init/main.c
@@ -69,6 +69,7 @@
#include <linux/kmemtrace.h>
#include <linux/sfi.h>
#include <linux/shmem_fs.h>
+#include <linux/magic.h>
#include <trace/boot.h>

#include <asm/io.h>
@@ -798,7 +799,9 @@ static void __init do_pre_smp_initcalls(void)

static void run_init_process(char *init_filename)
{
+ unsigned long *stack_end = end_of_stack(&init_task);
argv_init[0] = init_filename;
+ *stack_end = STACK_END_MAGIC;
kernel_execve(init_filename, argv_init, envp_init);
}

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