From: Collin Walling <walling@linux.ibm.com>
To: David Hildenbrand <david@redhat.com>,
qemu-devel@nongnu.org, qemu-s390x@nongnu.org
Cc: thuth@redhat.com, frankja@linux.ibm.com, mst@redhat.com,
cohuck@redhat.com, pasic@linux.ibm.com, borntraeger@de.ibm.com,
svens@linux.ibm.com, pbonzini@redhat.com, mihajlov@linux.ibm.com,
rth@twiddle.net
Subject: Re: [PATCH v4 4/8] s390/sclp: read sccb from mem based on sccb length
Date: Mon, 20 Jul 2020 16:06:18 -0400 [thread overview]
Message-ID: <1b552e26-3bce-0aba-0cc4-900e6b31839a@linux.ibm.com> (raw)
In-Reply-To: <cf1c33ea-2a2a-8400-a56b-384de356cf05@redhat.com>
On 7/20/20 4:19 AM, David Hildenbrand wrote:
> On 24.06.20 22:23, Collin Walling wrote:
>> The header of the SCCB contains the actual length of the SCCB. Instead
>> of using a static 4K size, let's allow for a variable size determined
>> by the value set in the header. The proper checks are already in place
>> to ensure the SCCB length is sufficent to store a full response, and
>> that the length does not cross any explicitly-set boundaries.
>>
>> Signed-off-by: Collin Walling <walling@linux.ibm.com>
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>> hw/s390x/sclp.c | 13 ++++++++-----
>> 1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
>> index 5899c1e3b8..1feba6f692 100644
>> --- a/hw/s390x/sclp.c
>> +++ b/hw/s390x/sclp.c
>> @@ -251,9 +251,8 @@ int sclp_service_call_protected(CPUS390XState *env, uint64_t sccb,
>> SCLPDevice *sclp = get_sclp_device();
>> SCLPDeviceClass *sclp_c = SCLP_GET_CLASS(sclp);
>> SCCB work_sccb;
>> - hwaddr sccb_len = sizeof(SCCB);
>>
>> - s390_cpu_pv_mem_read(env_archcpu(env), 0, &work_sccb, sccb_len);
>> + s390_cpu_pv_mem_read(env_archcpu(env), 0, &work_sccb, sizeof(SCCBHeader));
>>
>> if (!sclp_command_code_valid(code)) {
>> work_sccb.h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
>> @@ -264,6 +263,9 @@ int sclp_service_call_protected(CPUS390XState *env, uint64_t sccb,
>> goto out_write;
>> }
>>
>> + s390_cpu_pv_mem_read(env_archcpu(env), 0, &work_sccb,
>> + be16_to_cpu(work_sccb.h.length));
>> +
>> sclp_c->execute(sclp, &work_sccb, code);
>> out_write:
>> s390_cpu_pv_mem_write(env_archcpu(env), 0, &work_sccb,
>> @@ -278,8 +280,6 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code)
>> SCLPDeviceClass *sclp_c = SCLP_GET_CLASS(sclp);
>> SCCB work_sccb;
>>
>> - hwaddr sccb_len = sizeof(SCCB);
>> -
>> /* first some basic checks on program checks */
>> if (env->psw.mask & PSW_MASK_PSTATE) {
>> return -PGM_PRIVILEGED;
>> @@ -297,7 +297,7 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code)
>> * from playing dirty tricks by modifying the memory content after
>> * the host has checked the values
>> */
>> - cpu_physical_memory_read(sccb, &work_sccb, sccb_len);
>> + cpu_physical_memory_read(sccb, &work_sccb, sizeof(SCCBHeader));
>>
>> /* Valid sccb sizes */
>> if (be16_to_cpu(work_sccb.h.length) < sizeof(SCCBHeader)) {
>> @@ -313,6 +313,9 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code)
>> goto out_write;
>> }
>>
>> + /* the header contains the actual length of the sccb */
>> + cpu_physical_memory_read(sccb, &work_sccb, be16_to_cpu(work_sccb.h.length));
>> +
>> sclp_c->execute(sclp, &work_sccb, code);
>> out_write:
>> cpu_physical_memory_write(sccb, &work_sccb,
>>
>
> Reviewed-by: David Hildenbrand <david@redhat.com>
>
Thanks!
--
Regards,
Collin
Stay safe and stay healthy
next prev parent reply other threads:[~2020-07-20 20:07 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-24 20:23 [PATCH v4 0/8] s390: Extended-Length SCCB & DIAGNOSE 0x318 Collin Walling
2020-06-24 20:23 ` [PATCH v4 1/8] s390/sclp: get machine once during read scp/cpu info Collin Walling
2020-06-24 20:23 ` [PATCH v4 2/8] s390/sclp: check sccb len before filling in data Collin Walling
2020-06-24 20:23 ` [PATCH v4 3/8] s390/sclp: rework sclp boundary and length checks Collin Walling
2020-06-25 6:29 ` Thomas Huth
2020-07-20 8:17 ` David Hildenbrand
2020-07-20 20:06 ` Collin Walling
2020-07-21 8:41 ` David Hildenbrand
2020-07-21 18:40 ` Collin Walling
2020-07-23 6:26 ` Cornelia Huck
2020-07-24 15:06 ` Collin Walling
2020-06-24 20:23 ` [PATCH v4 4/8] s390/sclp: read sccb from mem based on sccb length Collin Walling
2020-07-20 8:19 ` David Hildenbrand
2020-07-20 20:06 ` Collin Walling [this message]
2020-06-24 20:23 ` [PATCH v4 5/8] s390/sclp: use cpu offset to locate cpu entries Collin Walling
2020-06-24 20:23 ` [PATCH v4 6/8] s390/sclp: add extended-length sccb support for kvm guest Collin Walling
2020-06-26 10:01 ` Cornelia Huck
2020-07-15 15:35 ` Collin Walling
2020-07-15 16:05 ` Cornelia Huck
2020-06-24 20:23 ` [PATCH v4 7/8] s390/kvm: header sync for diag318 Collin Walling
2020-06-24 20:23 ` [PATCH v4 8/8] s390: guest support for diagnose 0x318 Collin Walling
2020-06-26 10:03 ` Cornelia Huck
2020-07-15 15:36 ` [PATCH v4 0/8] s390: Extended-Length SCCB & DIAGNOSE 0x318 Collin Walling
2020-07-15 16:04 ` Cornelia Huck
2020-07-15 16:26 ` Collin Walling
2020-07-16 12:02 ` Cornelia Huck
2020-09-09 7:54 ` Christian Borntraeger
2020-09-09 8:46 ` Cornelia Huck
2020-09-09 9:43 ` Cornelia Huck
2020-09-09 18:13 ` Collin Walling
2020-09-10 6:38 ` Cornelia Huck
2020-09-10 6:49 ` Collin Walling
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