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authorHeiko Carstens <heiko.carstens@de.ibm.com>2009-10-29 15:04:09 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2009-10-29 15:05:12 +0100
commit4f8048ee734dab7c463574797b820c0c68c80791 (patch)
tree650554ccd94393eda80969c42dd52c3ef13aa2db /arch/s390/kernel
parent8ca45667f966968132c772ddbb6468b41a817c19 (diff)
downloadblackbird-op-linux-4f8048ee734dab7c463574797b820c0c68c80791.tar.gz
blackbird-op-linux-4f8048ee734dab7c463574797b820c0c68c80791.zip
[S390] smp: fix prefix handling of offlined cpus
Offlined cpus still have valid prefix register contents. Dumpers will store the register contents of a cpu to the location where its prefix register points to. For offlined cpus the area (lowcore) has been freed and the dumper would write the uninteresting contents of the offline cpu to a memory location which might be in use by some other component and destroy valueable information. To fix this set the prefix register of offline cpus to absolute address zero again. This prevents the current dumpers to write to random memory locations. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
-rw-r--r--arch/s390/kernel/smp.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index c932caa5e850..c699ac538c49 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -638,6 +638,8 @@ void __cpu_die(unsigned int cpu)
/* Wait until target cpu is down */
while (!cpu_stopped(cpu))
cpu_relax();
+ while (signal_processor_p(0, cpu, sigp_set_prefix) == sigp_busy)
+ udelay(10);
smp_free_lowcore(cpu);
pr_info("Processor %d stopped\n", cpu);
}
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