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| author | Janosch Frank <frankja@linux.ibm.com> | 2021-01-12 11:40:53 +0100 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2021-07-05 12:44:23 +0200 |
| commit | 85b18d7b5e7ffefb2f076186511d39c4990aa005 (patch) | |
| tree | b725f7f8392d85e231b4f5c26c0c816ba75c87d1 /arch/s390/kernel/uv.c | |
| parent | s390/kprobes: use is_kernel() helper (diff) | |
| download | linux-85b18d7b5e7ffefb2f076186511d39c4990aa005.tar.xz linux-85b18d7b5e7ffefb2f076186511d39c4990aa005.zip | |
s390: mm: Fix secure storage access exception handling
Turns out that the bit 61 in the TEID is not always 1 and if that's
the case the address space ID and the address are
unpredictable. Without an address and its address space ID we can't
export memory and hence we can only send a SIGSEGV to the process or
panic the kernel depending on who caused the exception.
Unfortunately bit 61 is only reliable if we have the "misc" UV feature
bit.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 084ea4d611a3d ("s390/mm: add (non)secure page access exceptions handlers")
Cc: stable@vger.kernel.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/uv.c')
| -rw-r--r-- | arch/s390/kernel/uv.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index 6be2167943bb..aeb0a15bcbb7 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -358,6 +358,15 @@ static ssize_t uv_query_facilities(struct kobject *kobj, static struct kobj_attribute uv_query_facilities_attr = __ATTR(facilities, 0444, uv_query_facilities, NULL); +static ssize_t uv_query_feature_indications(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%lx\n", uv_info.uv_feature_indications); +} + +static struct kobj_attribute uv_query_feature_indications_attr = + __ATTR(feature_indications, 0444, uv_query_feature_indications, NULL); + static ssize_t uv_query_max_guest_cpus(struct kobject *kobj, struct kobj_attribute *attr, char *page) { @@ -390,6 +399,7 @@ static struct kobj_attribute uv_query_max_guest_addr_attr = static struct attribute *uv_query_attrs[] = { &uv_query_facilities_attr.attr, + &uv_query_feature_indications_attr.attr, &uv_query_max_guest_cpus_attr.attr, &uv_query_max_guest_vms_attr.attr, &uv_query_max_guest_addr_attr.attr, |