6.15-stable review patch. If anyone has any objections, please let me know.
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From: Niklas Schnelle schnelle@linux.ibm.com
commit 45537926dd2aaa9190ac0fac5a0fbeefcadfea95 upstream.
The error event information for PCI error events contains a function handle for the respective function. This handle is generally captured at the time the error event was recorded. Due to delays in processing or cascading issues, it may happen that during firmware recovery multiple events are generated. When processing these events in order Linux may already have recovered an affected function making the event information stale. Fix this by doing an unconditional CLP List PCI function retrieving the current function handle with the zdev->state_lock held and ignoring the event if its function handle is stale.
Cc: stable@vger.kernel.org Fixes: 4cdf2f4e24ff ("s390/pci: implement minimal PCI error recovery") Reviewed-by: Julian Ruess julianr@linux.ibm.com Reviewed-by: Gerd Bayer gbayer@linux.ibm.com Reviewed-by: Farhan Ali alifm@linux.ibm.com Signed-off-by: Niklas Schnelle schnelle@linux.ibm.com Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/s390/pci/pci_event.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/arch/s390/pci/pci_event.c +++ b/arch/s390/pci/pci_event.c @@ -273,6 +273,8 @@ static void __zpci_event_error(struct zp struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid); struct pci_dev *pdev = NULL; pci_ers_result_t ers_res; + u32 fh = 0; + int rc;
zpci_dbg(3, "err fid:%x, fh:%x, pec:%x\n", ccdf->fid, ccdf->fh, ccdf->pec); @@ -281,6 +283,15 @@ static void __zpci_event_error(struct zp
if (zdev) { mutex_lock(&zdev->state_lock); + rc = clp_refresh_fh(zdev->fid, &fh); + if (rc) + goto no_pdev; + if (!fh || ccdf->fh != fh) { + /* Ignore events with stale handles */ + zpci_dbg(3, "err fid:%x, fh:%x (stale %x)\n", + ccdf->fid, fh, ccdf->fh); + goto no_pdev; + } zpci_update_fh(zdev, ccdf->fh); if (zdev->zbus->bus) pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);