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[PATCH v5 2/8] s390/sclp: rework sclp boundary checks
From: |
Collin Walling |
Subject: |
[PATCH v5 2/8] s390/sclp: rework sclp boundary checks |
Date: |
Thu, 10 Sep 2020 05:36:49 -0400 |
Rework the SCLP boundary check to account for different SCLP commands
(eventually) allowing different boundary sizes.
Signed-off-by: Collin Walling <walling@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
---
hw/s390x/sclp.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
index 28b973de8f..69a8724dc7 100644
--- a/hw/s390x/sclp.c
+++ b/hw/s390x/sclp.c
@@ -49,6 +49,18 @@ static inline bool sclp_command_code_valid(uint32_t code)
return false;
}
+static bool sccb_verify_boundary(uint64_t sccb_addr, uint16_t len)
+{
+ uint64_t sccb_max_addr = sccb_addr + be16_to_cpu(len) - 1;
+ uint64_t sccb_boundary = (sccb_addr & PAGE_MASK) + PAGE_SIZE;
+
+ if (sccb_max_addr < sccb_boundary) {
+ return true;
+ }
+
+ return false;
+}
+
static void prepare_cpu_entries(MachineState *ms, CPUEntry *entry, int *count)
{
uint8_t features[SCCB_CPU_FEATURE_LEN] = { 0 };
@@ -229,6 +241,11 @@ int sclp_service_call_protected(CPUS390XState *env,
uint64_t sccb,
goto out_write;
}
+ if (!sccb_verify_boundary(sccb, work_sccb.h.length)) {
+ work_sccb.h.response_code =
cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
+ goto out_write;
+ }
+
sclp_c->execute(sclp, &work_sccb, code);
out_write:
s390_cpu_pv_mem_write(env_archcpu(env), 0, &work_sccb,
@@ -274,7 +291,7 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb,
uint32_t code)
goto out_write;
}
- if ((sccb + be16_to_cpu(work_sccb.h.length)) > ((sccb & PAGE_MASK) +
PAGE_SIZE)) {
+ if (!sccb_verify_boundary(sccb, work_sccb.h.length)) {
work_sccb.h.response_code =
cpu_to_be16(SCLP_RC_SCCB_BOUNDARY_VIOLATION);
goto out_write;
}
--
2.26.2
[PATCH v5 8/8] s390: guest support for diagnose 0x318, Collin Walling, 2020/09/10