From: Ahmed S. Darwish <a.darw...@linutronix.de>

[ Upstream commit feb18e900f0048001ff375dca639eaa327ab3c1b ]

mvsas calls the non _gfp version of the libsas event notifiers API, leading
to the buggy call chains below:

  mvsas/mv_sas.c: mvs_work_queue() [process context]
  spin_lock_irqsave(mvs_info::lock, )
    -> libsas/sas_event.c: sas_notify_phy_event()
      -> sas_alloc_event()
        -> in_interrupt() = false
          -> invalid GFP_KERNEL allocation
    -> libsas/sas_event.c: sas_notify_port_event()
      -> sas_alloc_event()
        -> in_interrupt() = false
          -> invalid GFP_KERNEL allocation

Use the new event notifiers API instead, which requires callers to
explicitly pass the gfp_t memory allocation flags.

Below are context analysis for the modified functions:

=> mvs_bytes_dmaed():

Since it is invoked from both process and atomic contexts, let its callers
pass the gfp_t flags. Call chains:

  scsi_scan.c: do_scsi_scan_host() [has msleep()]
    -> shost->hostt->scan_start()
    -> [mvsas/mv_init.c: Scsi_Host::scsi_host_template .scan_start = 
mvs_scan_start()]
    -> mvsas/mv_sas.c: mvs_scan_start()
      -> mvs_bytes_dmaed(..., GFP_KERNEL)

  mvsas/mv_sas.c: mvs_work_queue()
  spin_lock_irqsave(mvs_info::lock,)
    -> mvs_bytes_dmaed(..., GFP_ATOMIC)

  mvsas/mv_64xx.c: mvs_64xx_isr() || mvsas/mv_94xx.c: mvs_94xx_isr()
    -> mvsas/mv_chips.h: mvs_int_full()
      -> mvsas/mv_sas.c: mvs_int_port()
        -> mvs_bytes_dmaed(..., GFP_ATOMIC);

=> mvs_work_queue():

Invoked from process context, but it calls all the libsas event notifier
APIs under a spin_lock_irqsave(). Pass GFP_ATOMIC.

Link: https://lore.kernel.org/r/20210118100955.1761652-5-a.darw...@linutronix.de
Fixes: 1c393b970e0f ("scsi: libsas: Use dynamic alloced work to avoid sas event 
lost")
Cc: Jason Yan <yanai...@huawei.com>
Reviewed-by: John Garry <john.ga...@huawei.com>
Signed-off-by: Ahmed S. Darwish <a.darw...@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/scsi/mvsas/mv_sas.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index e5e3e95f78b0c..484e01428da28 100644
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -216,7 +216,7 @@ void mvs_set_sas_addr(struct mvs_info *mvi, int port_id, 
u32 off_lo,
        MVS_CHIP_DISP->write_port_cfg_data(mvi, port_id, hi);
 }
 
-static void mvs_bytes_dmaed(struct mvs_info *mvi, int i)
+static void mvs_bytes_dmaed(struct mvs_info *mvi, int i, gfp_t gfp_flags)
 {
        struct mvs_phy *phy = &mvi->phy[i];
        struct asd_sas_phy *sas_phy = &phy->sas_phy;
@@ -229,7 +229,7 @@ static void mvs_bytes_dmaed(struct mvs_info *mvi, int i)
                return;
        }
 
-       sas_notify_phy_event(sas_phy, PHYE_OOB_DONE);
+       sas_notify_phy_event_gfp(sas_phy, PHYE_OOB_DONE, gfp_flags);
 
        if (sas_phy->phy) {
                struct sas_phy *sphy = sas_phy->phy;
@@ -261,7 +261,7 @@ static void mvs_bytes_dmaed(struct mvs_info *mvi, int i)
 
        sas_phy->frame_rcvd_size = phy->frame_rcvd_size;
 
-       sas_notify_port_event(sas_phy, PORTE_BYTES_DMAED);
+       sas_notify_port_event_gfp(sas_phy, PORTE_BYTES_DMAED, gfp_flags);
 }
 
 void mvs_scan_start(struct Scsi_Host *shost)
@@ -277,7 +277,7 @@ void mvs_scan_start(struct Scsi_Host *shost)
        for (j = 0; j < core_nr; j++) {
                mvi = ((struct mvs_prv_info *)sha->lldd_ha)->mvi[j];
                for (i = 0; i < mvi->chip->n_phy; ++i)
-                       mvs_bytes_dmaed(mvi, i);
+                       mvs_bytes_dmaed(mvi, i, GFP_KERNEL);
        }
        mvs_prv->scan_finished = 1;
 }
@@ -1892,20 +1892,21 @@ static void mvs_work_queue(struct work_struct *work)
                        if (!(tmp & PHY_READY_MASK)) {
                                sas_phy_disconnected(sas_phy);
                                mvs_phy_disconnected(phy);
-                               sas_notify_phy_event(sas_phy,
-                                       PHYE_LOSS_OF_SIGNAL);
+                               sas_notify_phy_event_gfp(sas_phy,
+                                       PHYE_LOSS_OF_SIGNAL, GFP_ATOMIC);
                                mv_dprintk("phy%d Removed Device\n", phy_no);
                        } else {
                                MVS_CHIP_DISP->detect_porttype(mvi, phy_no);
                                mvs_update_phyinfo(mvi, phy_no, 1);
-                               mvs_bytes_dmaed(mvi, phy_no);
+                               mvs_bytes_dmaed(mvi, phy_no, GFP_ATOMIC);
                                mvs_port_notify_formed(sas_phy, 0);
                                mv_dprintk("phy%d Attached Device\n", phy_no);
                        }
                }
        } else if (mwq->handler & EXP_BRCT_CHG) {
                phy->phy_event &= ~EXP_BRCT_CHG;
-               sas_notify_port_event(sas_phy, PORTE_BROADCAST_RCVD);
+               sas_notify_port_event_gfp(sas_phy,
+                               PORTE_BROADCAST_RCVD, GFP_ATOMIC);
                mv_dprintk("phy%d Got Broadcast Change\n", phy_no);
        }
        list_del(&mwq->entry);
@@ -2022,7 +2023,7 @@ void mvs_int_port(struct mvs_info *mvi, int phy_no, u32 
events)
                                mdelay(10);
                        }
 
-                       mvs_bytes_dmaed(mvi, phy_no);
+                       mvs_bytes_dmaed(mvi, phy_no, GFP_ATOMIC);
                        /* whether driver is going to handle hot plug */
                        if (phy->phy_event & PHY_PLUG_OUT) {
                                mvs_port_notify_formed(&phy->sas_phy, 0);
-- 
2.27.0



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