On 03/18/2014 04:37 PM, Christoph Lameter wrote:
On Tue, 18 Mar 2014, Grygorii Strashko wrote:
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index a270dce..73a2004 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -58,9 +58,6 @@ EXPORT_SYMBOL(debug_smp_processor_id);
notrace void __this_cpu_preempt_check(const char *op)
{
- char text[40];
-
- snprintf(text, sizeof(text), "__this_cpu_%s()", op);
- check_preemption_disabled(text);
+ check_preemption_disabled(op);
}
EXPORT_SYMBOL(__this_cpu_preempt_check);
So it looks like there is an early this cpu operation in a context that
cannot handle snprintf. But the checks in check_preemption_disabled()
avoid processing there so that works.
Just to be sure that I've described time point of issue correctly:
[ 2.161746] dwc3 2690000.dwc3: failed to initialize core
[ 2.167255] dwc3: probe of 2690000.dwc3 failed with error -38
[ 2.259687] Freeing unused kernel memory: 280K (c0678000 - c06be000)
Please press Enter to activate this console.
^^^ system stall here
Any way, I can boot and console works fine with your change :)
Thanks.
Tested-by: Grygorii Strashko <grygorii.stras...@ti.com>
We could fix this by moving the string concatenation operation into
the check function.
Index: linux/lib/smp_processor_id.c
===================================================================
--- linux.orig/lib/smp_processor_id.c 2014-03-18 09:36:31.330450525 -0500
+++ linux/lib/smp_processor_id.c 2014-03-18 09:36:37.822315534 -0500
@@ -7,7 +7,8 @@
#include <linux/kallsyms.h>
#include <linux/sched.h>
-notrace static unsigned int check_preemption_disabled(char *what)
+notrace static unsigned int check_preemption_disabled(const char *what1,
+ const char *what2)
{
int this_cpu = raw_smp_processor_id();
@@ -38,8 +39,8 @@
if (!printk_ratelimit())
goto out_enable;
- printk(KERN_ERR "BUG: using %s in preemptible [%08x] code: %s/%d\n",
- what, preempt_count() - 1, current->comm, current->pid);
+ printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",
+ what1, what2, preempt_count() - 1, current->comm, current->pid);
print_symbol("caller is %s\n", (long)__builtin_return_address(0));
dump_stack();
@@ -52,15 +53,12 @@
notrace unsigned int debug_smp_processor_id(void)
{
- return check_preemption_disabled("smp_processor_id()");
+ return check_preemption_disabled("smp_processor_id","");
}
EXPORT_SYMBOL(debug_smp_processor_id);
notrace void __this_cpu_preempt_check(const char *op)
{
- char text[40];
-
- snprintf(text, sizeof(text), "__this_cpu_%s()", op);
- check_preemption_disabled(text);
+ check_preemption_disabled("__this_cpu_", op);
}
EXPORT_SYMBOL(__this_cpu_preempt_check);
--
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