diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2013-04-27 13:07:17 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-05-02 15:50:23 +0200 |
| commit | 0a694067111e8fcd3eda430f8fa2d0277edd231f (patch) | |
| tree | 7b2a142b30bc2cfd3ce9181e28eb35b20c6caf89 /arch/s390 | |
| parent | d009f4d8860defaea65ea7573818b96f3c4b171e (diff) | |
s390/mem_detect: add DAT sanity check
Add sanity check: verify if the passed in array resides in vmalloc space.
If so print a warning and return to caller.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/mm/mem_detect.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/s390/mm/mem_detect.c b/arch/s390/mm/mem_detect.c index fb216e11c25d..854c08448de1 100644 --- a/arch/s390/mm/mem_detect.c +++ b/arch/s390/mm/mem_detect.c @@ -50,16 +50,28 @@ void detect_memory_layout(struct mem_chunk chunk[]) unsigned long flags, flags_dat, cr0; memset(chunk, 0, MEMORY_CHUNKS * sizeof(struct mem_chunk)); - /* Disable IRQs, DAT and low address protection so tprot does the + /* + * Disable IRQs, DAT and low address protection so tprot does the * right thing and we don't get scheduled away with low address * protection disabled. */ local_irq_save(flags); flags_dat = __arch_local_irq_stnsm(0xfb); + /* + * In case DAT was enabled, make sure chunk doesn't reside in vmalloc + * space. We have disabled DAT and any access to vmalloc area will + * cause an exception. + * If DAT was disabled we are called from early ipl code. + */ + if (test_bit(5, &flags_dat)) { + if (WARN_ON_ONCE(is_vmalloc_or_module_addr(chunk))) + goto out; + } __ctl_store(cr0, 0, 0); __ctl_clear_bit(0, 28); find_memory_chunks(chunk); __ctl_load(cr0, 0, 0); +out: __arch_local_irq_ssm(flags_dat); local_irq_restore(flags); } |