summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorChristian Borntraeger <borntraeger@de.ibm.com>2017-05-18 13:04:16 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-06-12 16:25:58 +0200
commit9cf8edb7a33b7689d4c3429b1d339d29e7c3db86 (patch)
tree58e7a42f25ae6d136e47e87dee86d339d2e3313b
parentac994e80f94f440138774830f2edf148d6ece1f3 (diff)
s390/smp: fix false positive kmemleak of mcesa data structure
I get number of CPUs - 1 kmemleak hits like unreferenced object 0x37ec6f000 (size 1024): comm "swapper/0", pid 1, jiffies 4294937330 (age 889.690s) hex dump (first 32 bytes): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk backtrace: [<000000000034a848>] kmem_cache_alloc+0x2b8/0x3d0 [<00000000001164de>] __cpu_up+0x456/0x488 [<000000000016f60c>] bringup_cpu+0x4c/0xd0 [<000000000016d5d2>] cpuhp_invoke_callback+0xe2/0x9e8 [<000000000016f3c6>] cpuhp_up_callbacks+0x5e/0x110 [<000000000016f988>] _cpu_up+0xe0/0x158 [<000000000016faf0>] do_cpu_up+0xf0/0x110 [<0000000000dae1ee>] smp_init+0x126/0x130 [<0000000000d9bd04>] kernel_init_freeable+0x174/0x2e0 [<000000000089fc62>] kernel_init+0x2a/0x148 [<00000000008adce2>] kernel_thread_starter+0x6/0xc [<00000000008adcdc>] kernel_thread_starter+0x0/0xc [<ffffffffffffffff>] 0xffffffffffffffff The pointer of this data structure is stored in the prefix page of that CPU together with some extra bits ORed into the the low bits. Mark the data structure as non-leak. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/kernel/smp.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 363000a77ffc..1020a11a24e5 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -26,6 +26,7 @@
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
+#include <linux/kmemleak.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irqflags.h>
@@ -207,6 +208,8 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
kmem_cache_alloc(pcpu_mcesa_cache, GFP_KERNEL);
if (!mcesa_origin)
goto out;
+ /* The pointer is stored with mcesa_bits ORed in */
+ kmemleak_not_leak((void *) mcesa_origin);
mcesa_bits = MACHINE_HAS_GS ? 11 : 0;
}
} else {