https://github.com/torvalds/linux
Revision 25fab9ebac445d57b656f5faabac5a195bed2f82 authored by Peter Oberparleiter on 12 February 2006, 01:55:59 UTC, committed by Linus Torvalds on 12 February 2006, 05:41:12 UTC
When the sclp interface takes very long to serve a request, the sclp core driver will report a failed request to the sclp tty driver even though the request is still being processed by the sclp interface. Eventually the sclp interface completes the request and updates some fields in the request buffer which leads to a corrupted tty pages list. The next time function sclp_tty_write_room is called, the corrupted list will be traversed, resulting in an oops. To avoid this remove the busy retry limit and increase retry intervals. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent e6f3601
Tip revision: 25fab9ebac445d57b656f5faabac5a195bed2f82 authored by Peter Oberparleiter on 12 February 2006, 01:55:59 UTC
[PATCH] s390: fix sclp memory corruption in tty pages list
[PATCH] s390: fix sclp memory corruption in tty pages list
Tip revision: 25fab9e
smp_processor_id.c
/*
* lib/smp_processor_id.c
*
* DEBUG_PREEMPT variant of smp_processor_id().
*/
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/sched.h>
unsigned int debug_smp_processor_id(void)
{
unsigned long preempt_count = preempt_count();
int this_cpu = raw_smp_processor_id();
cpumask_t this_mask;
if (likely(preempt_count))
goto out;
if (irqs_disabled())
goto out;
/*
* Kernel threads bound to a single CPU can safely use
* smp_processor_id():
*/
this_mask = cpumask_of_cpu(this_cpu);
if (cpus_equal(current->cpus_allowed, this_mask))
goto out;
/*
* It is valid to assume CPU-locality during early bootup:
*/
if (system_state != SYSTEM_RUNNING)
goto out;
/*
* Avoid recursion:
*/
preempt_disable();
if (!printk_ratelimit())
goto out_enable;
printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] code: %s/%d\n", preempt_count(), current->comm, current->pid);
print_symbol("caller is %s\n", (long)__builtin_return_address(0));
dump_stack();
out_enable:
preempt_enable_no_resched();
out:
return this_cpu;
}
EXPORT_SYMBOL(debug_smp_processor_id);
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