On 2/03/21 5:12 pm, Zhi Li wrote: > > > On Tue, Mar 2, 2021 at 1:03 AM Adrian Hunter <adrian.hunter@xxxxxxxxx <mailto:adrian.hunter@xxxxxxxxx>> wrote: > > On 1/03/21 7:21 pm, Frank Li wrote: > > [ 6684.493350] Unable to handle kernel paging request at virtual address ffff800011c5b0f0 > > [ 6684.498531] mmc0: card 0001 removed > > [ 6684.501556] Mem abort info: > > [ 6684.509681] ESR = 0x96000047 > > [ 6684.512786] EC = 0x25: DABT (current EL), IL = 32 bits > > [ 6684.518394] SET = 0, FnV = 0 > > [ 6684.521707] EA = 0, S1PTW = 0 > > [ 6684.524998] Data abort info: > > [ 6684.528236] ISV = 0, ISS = 0x00000047 > > [ 6684.532986] CM = 0, WnR = 1 > > [ 6684.536129] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000081b22000 > > [ 6684.543923] [ffff800011c5b0f0] pgd=00000000bffff003, p4d=00000000bffff003, pud=00000000bfffe003, pmd=00000000900e1003, pte=0000000000000000 > > [ 6684.557915] Internal error: Oops: 96000047 [#1] PREEMPT SMP > > [ 6684.564240] Modules linked in: sdhci_esdhc_imx(-) sdhci_pltfm sdhci cqhci mmc_block mmc_core fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine rng_core authenc libdes crct10dif_ce flexcan can_dev caam error [last unloaded: mmc_core] > > [ 6684.587281] CPU: 0 PID: 79138 Comm: kworker/0:3H Not tainted 5.10.9-01410-g3ba33182767b-dirty #10 > > [ 6684.596160] Hardware name: Freescale i.MX8DXL EVK (DT) > > [ 6684.601320] Workqueue: kblockd blk_mq_run_work_fn > > > > [ 6684.606094] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--) > > [ 6684.612286] pc : cqhci_request+0x148/0x4e8 [cqhci] > > ^GMessage from syslogd@ at Thu Jan 1 01:51:24 1970 ...[ 6684.617085] lr : cqhci_request+0x314/0x4e8 [cqhci] > > [ 6684.626734] sp : ffff80001243b9f0 > > [ 6684.630049] x29: ffff80001243b9f0 x28: ffff00002c3dd000 > > [ 6684.635367] x27: 0000000000000001 x26: 0000000000000001 > > [ 6684.640690] x25: ffff00002c451000 x24: 000000000000000f > > [ 6684.646007] x23: ffff000017e71c80 x22: ffff00002c451000 > > [ 6684.651326] x21: ffff00002c0f3550 x20: ffff00002c0f3550 > > [ 6684.656651] x19: ffff000017d46880 x18: ffff00002cea1500 > > [ 6684.661977] x17: 0000000000000000 x16: 0000000000000000 > > [ 6684.667294] x15: 000001ee628e3ed1 x14: 0000000000000278 > > [ 6684.672610] x13: 0000000000000001 x12: 0000000000000001 > > [ 6684.677927] x11: 0000000000000000 x10: 0000000000000000 > > [ 6684.683243] x9 : 000000000000002b x8 : 0000000000001000 > > [ 6684.688560] x7 : 0000000000000010 x6 : ffff00002c0f3678 > > [ 6684.693886] x5 : 000000000000000f x4 : ffff800011c5b000 > > [ 6684.699211] x3 : 000000000002d988 x2 : 0000000000000008 > > [ 6684.704537] x1 : 00000000000000f0 x0 : 0002d9880008102f > > [ 6684.709854] Call trace: > > [ 6684.712313] cqhci_request+0x148/0x4e8 [cqhci] > > [ 6684.716803] mmc_cqe_start_req+0x58/0x68 [mmc_core] > > [ 6684.721698] mmc_blk_mq_issue_rq+0x460/0x810 [mmc_block] > > [ 6684.727018] mmc_mq_queue_rq+0x118/0x2b0 [mmc_block] > > > > cqhci_request was called after cqhci_disable. > > > > cqhci_disable cqhci_request > > { { > > dmam_free_coherent(); (1) free > > if(!cq_host->enable) > > return > > (2) pass check here > > cq_host->enable = false; > > > > task_desc= get_desc(cq_host,tag); > > ^^^^ crash here > > (3) access memory which is already free > > > > } } > > > > Signed-off-by: Frank Li <Frank.Li@xxxxxxx <mailto:Frank.Li@xxxxxxx>> > > --- > > drivers/mmc/host/cqhci-core.c | 18 ++++++++++++++---- > > 1 file changed, 14 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/mmc/host/cqhci-core.c b/drivers/mmc/host/cqhci-core.c > > index 93b0432bb601..36d292261e50 100644 > > --- a/drivers/mmc/host/cqhci-core.c > > +++ b/drivers/mmc/host/cqhci-core.c > > @@ -389,6 +389,7 @@ static void cqhci_off(struct mmc_host *mmc) > > static void cqhci_disable(struct mmc_host *mmc) > > { > > struct cqhci_host *cq_host = mmc->cqe_private; > > + unsigned long flags; > > > > if (!cq_host->enabled) > > return; > > @@ -397,6 +398,11 @@ static void cqhci_disable(struct mmc_host *mmc) > > > > __cqhci_disable(cq_host); > > > > + /* need wait for cqhci_request finish before free memory */ > > + spin_lock_irqsave(&cq_host->lock, flags); > > + cq_host->enabled = false; > > + spin_unlock_irqrestore(&cq_host->lock, flags); > > + > > dmam_free_coherent(mmc_dev(mmc), cq_host->data_size, > > cq_host->trans_desc_base, > > cq_host->trans_desc_dma_base); > > @@ -408,7 +414,6 @@ static void cqhci_disable(struct mmc_host *mmc) > > cq_host->trans_desc_base = NULL; > > cq_host->desc_base = NULL; > > > > - cq_host->enabled = false; > > } > > > > static void cqhci_prep_task_desc(struct mmc_request *mrq, > > @@ -612,6 +617,13 @@ static int cqhci_request(struct mmc_host *mmc, struct mmc_request *mrq) > > cq_host->ops->enable(mmc); > > } > > > > + spin_lock_irqsave(&cq_host->lock, flags); > > + if (!cq_host->enabled) { > > + pr_err("%s: cqhci: not enabled\n", mmc_hostname(mmc)); > > + err = -EINVAL; > > + goto out_unlock; > > + } > > + > > if (mrq->data) { > > cqhci_prep_task_desc(mrq, cq_host, tag); > > > > @@ -619,14 +631,12 @@ static int cqhci_request(struct mmc_host *mmc, struct mmc_request *mrq) > > if (err) { > > pr_err("%s: cqhci: failed to setup tx desc: %d\n", > > mmc_hostname(mmc), err); > > - return err; > > + goto out_unlock; > > } > > } else { > > cqhci_prep_dcmd_desc(mmc, mrq); > > } > > > > - spin_lock_irqsave(&cq_host->lock, flags); > > - > > if (cq_host->recovery_halt) { > > err = -EBUSY; > > goto out_unlock; > > > > Please try the following instead: > > > diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c > index c2e70b757dd1..dfc8d2877115 100644 > --- a/drivers/mmc/core/bus.c > +++ b/drivers/mmc/core/bus.c > @@ -399,11 +399,6 @@ void mmc_remove_card(struct mmc_card *card) > mmc_remove_card_debugfs(card); > #endif > > - if (host->cqe_enabled) { > - host->cqe_ops->cqe_disable(host); > - host->cqe_enabled = false; > - } > - > if (mmc_card_present(card)) { > if (mmc_host_is_spi(card->host)) { > pr_info("%s: SPI card removed\n", > @@ -416,6 +411,11 @@ void mmc_remove_card(struct mmc_card *card) > of_node_put(card->dev.of_node); > } > > + if (host->cqe_enabled) { > + host->cqe_ops->cqe_disable(host); > + host->cqe_enabled = false; > + } > + > put_device(&card->dev); > } > > > Actually this is my first solution, it can't resolve issues 100% and just reduce possibility. > > One core run The another core run > mmc_remove_card mmc_mq_queue_rq > { { > > if (mmc_card_removed(mq->card)) { > req->rq_flags |= RQF_QUIET; > return BLK_STS_IOERR; > } > //pass check here > device_del(&card->dev); Deleting the card device removes it from the block driver (i.e. mmc_blk_remove()), which cleans up the request queues, so the scenario you describe here should never happen. Can you determine if mmc_blk_remove() is called and whether it cleans up blk queues? > //free resource here > host->cqe_ops->cqe_disable(host); > > call cqhci_request > //kernel dump here to access memory that is already free. > > } } > > There is one fundamental problem that there is NOT read lock when checking mmc_card_removed, and write lock for updating md->card. > The risk conditions always exist between queue request and card remove. > > There are no issues for non-command queue host controllers, it just causes a redundant cmd sent by host, cmd will be timeout. Just an expected IO error > happened. Maybe just errors code is different. > > But Cmd queue is different, cmd queue disabled function free memory resources. if risk conditions happen, there are kernel dump. > > >
