Take 2, hopefully with Stewart's correct email address this time.
~Andrew
On 28/02/2024 12:17 pm, Andrew Cooper wrote:
> Not sure how well this is going to be formatted, but there's one new and
> potentially interesting issue found by Coverity.
>
> ~Andrew
>
> ----8<----
>
> New defect(s) Reported-by: Coverity Scan
> Showing 1 of 1 defect(s)
>
>
> ** CID 1592633: (LOCK_EVASION)
> /xen/drivers/vpci/header.c: 229 in vpci_process_pending()
> /xen/drivers/vpci/header.c: 189 in vpci_process_pending()
> /xen/drivers/vpci/header.c: 239 in vpci_process_pending()
>
>
> ________________________________________________________________________________________________________
> *** CID 1592633: (LOCK_EVASION)
> /xen/drivers/vpci/header.c: 229 in vpci_process_pending()
> 223 224 /* Clean all the rangesets */
> 225 for ( i = 0; i < ARRAY_SIZE(header->bars); i++ )
> 226 if ( !rangeset_is_empty(header->bars[i].mem) )
> 227 rangeset_purge(header->bars[i].mem);
> 228
>>>> CID 1592633: (LOCK_EVASION)
>>>> Thread1 sets "pdev" to a new value. Now the two threads have an
>>>> inconsistent view of "pdev" and updates to fields of "pdev" or
>>>> fields correlated with "pdev" may be lost.
> 229 v->vpci.pdev = NULL;
> 230 231 read_unlock(&v->domain->pci_lock);
> 232 233 if ( !is_hardware_domain(v->domain) )
> 234 domain_crash(v->domain);
> /xen/drivers/vpci/header.c: 189 in vpci_process_pending()
> 183 return false;
> 184 185 read_lock(&v->domain->pci_lock);
> 186 187 if ( !pdev->vpci || (v->domain != pdev->domain) )
> 188 {
>>>> CID 1592633: (LOCK_EVASION)
>>>> Thread1 sets "pdev" to a new value. Now the two threads have an
>>>> inconsistent view of "pdev" and updates to fields of "pdev" or
>>>> fields correlated with "pdev" may be lost.
> 189 v->vpci.pdev = NULL;
> 190 read_unlock(&v->domain->pci_lock);
> 191 return false;
> 192 }
> 193 194 header = &pdev->vpci->header;
> /xen/drivers/vpci/header.c: 239 in vpci_process_pending()
> 233 if ( !is_hardware_domain(v->domain) )
> 234 domain_crash(v->domain);
> 235 236 return false;
> 237 }
> 238 }
>>>> CID 1592633: (LOCK_EVASION)
>>>> Thread1 sets "pdev" to a new value. Now the two threads have an
>>>> inconsistent view of "pdev" and updates to fields of "pdev" or
>>>> fields correlated with "pdev" may be lost.
> 239 v->vpci.pdev = NULL;
> 240 241 spin_lock(&pdev->vpci->lock);
> 242 modify_decoding(pdev, v->vpci.cmd, v->vpci.rom_only);
> 243 spin_unlock(&pdev->vpci->lock);
> 244
>
