Message ID | 5f036d83.1c69fb81.10199.06d0@mx.google.com (mailing list archive) |
---|---|
State | Not Applicable |
Headers | show |
Series | next/master bisection: baseline.login on qemu_arm64-virt-gicv3 | expand |
On 7/6/2020 11:29 AM, kernelci.org bot wrote: > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > * This automated bisection report was sent to you on the basis * > * that you may be involved with the breaking commit it has * > * found. No manual investigation has been done to verify it, * > * and the root cause of the problem may be somewhere else. * > * * > * If you do send a fix, please include this trailer: * > * Reported-by: "kernelci.org bot" <bot@kernelci.org> * > * * > * Hope this helps! * > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > > next/master bisection: baseline.login on qemu_arm64-virt-gicv3 > > Summary: > Start: 5680d14d59bd Add linux-next specific files for 20200706 > Plain log: https://storage.kernelci.org/next/master/next-20200706/arm64/defconfig+CONFIG_RANDOMIZE_BASE=y/gcc-8/lab-collabora/baseline-qemu_arm64-virt-gicv3.txt > HTML log: https://storage.kernelci.org/next/master/next-20200706/arm64/defconfig+CONFIG_RANDOMIZE_BASE=y/gcc-8/lab-collabora/baseline-qemu_arm64-virt-gicv3.html > Result: deb9541f5052 dmaengine: check device and channel list for empty > > Checks: > revert: PASS > verify: PASS > > Parameters: > Tree: next > URL: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git > Branch: master > Target: qemu_arm64-virt-gicv3 > CPU arch: arm64 > Lab: lab-collabora > Compiler: gcc-8 > Config: defconfig+CONFIG_RANDOMIZE_BASE=y > Test case: baseline.login This should be already fixed. Same issue that Naresh reported and Arnd bisected. https://www.spinics.net/lists/dmaengine/msg22787.html > > Breaking commit found: > > ------------------------------------------------------------------------------- > commit deb9541f5052b2f93bd51cb263d9035bfd89fa96 > Author: Dave Jiang <dave.jiang@intel.com> > Date: Fri Jun 26 11:09:41 2020 -0700 > > dmaengine: check device and channel list for empty > > Check dma device list and channel list for empty before iterate as the > iteration function assume the list to be not empty. With devices and > channels now being hot pluggable this is a condition that needs to be > checked. Otherwise it can cause the iterator to spin forever. > > Fixes: e81274cd6b52 ("dmaengine: add support to dynamic register/unregister of channels") > Reported-by: Swathi Kovvuri <swathi.kovvuri@intel.com> > Signed-off-by: Dave Jiang <dave.jiang@intel.com> > Tested-by: Swathi Kovvuri <swathi.kovvuri@intel.com> > Link: https://lore.kernel.org/r/159319496403.69045.16298280729899651363.stgit@djiang5-desk3.ch.intel.com > Signed-off-by: Vinod Koul <vkoul@kernel.org> > > diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c > index 2b06a7a8629d..0d6529eff66f 100644 > --- a/drivers/dma/dmaengine.c > +++ b/drivers/dma/dmaengine.c > @@ -85,6 +85,9 @@ static void dmaengine_dbg_summary_show(struct seq_file *s, > { > struct dma_chan *chan; > > + if (list_empty(&dma_dev->channels)) > + return; > + > list_for_each_entry(chan, &dma_dev->channels, device_node) { > if (chan->client_count) { > seq_printf(s, " %-13s| %s", dma_chan_name(chan), > @@ -104,6 +107,11 @@ static int dmaengine_summary_show(struct seq_file *s, void *data) > struct dma_device *dma_dev = NULL; > > mutex_lock(&dma_list_mutex); > + if (list_empty(&dma_device_list)) { > + mutex_unlock(&dma_list_mutex); > + return 0; > + } > + > list_for_each_entry(dma_dev, &dma_device_list, global_node) { > seq_printf(s, "dma%d (%s): number of channels: %u\n", > dma_dev->dev_id, dev_name(dma_dev->dev), > @@ -324,10 +332,15 @@ static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu) > struct dma_chan *min = NULL; > struct dma_chan *localmin = NULL; > > + if (list_empty(&dma_device_list)) > + return NULL; > + > list_for_each_entry(device, &dma_device_list, global_node) { > if (!dma_has_cap(cap, device->cap_mask) || > dma_has_cap(DMA_PRIVATE, device->cap_mask)) > continue; > + if (list_empty(&device->channels)) > + continue; > list_for_each_entry(chan, &device->channels, device_node) { > if (!chan->client_count) > continue; > @@ -365,6 +378,9 @@ static void dma_channel_rebalance(void) > int cpu; > int cap; > > + if (list_empty(&dma_device_list)) > + return; > + > /* undo the last distribution */ > for_each_dma_cap_mask(cap, dma_cap_mask_all) > for_each_possible_cpu(cpu) > @@ -373,6 +389,8 @@ static void dma_channel_rebalance(void) > list_for_each_entry(device, &dma_device_list, global_node) { > if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) > continue; > + if (list_empty(&device->channels)) > + continue; > list_for_each_entry(chan, &device->channels, device_node) > chan->table_count = 0; > } > @@ -556,6 +574,10 @@ void dma_issue_pending_all(void) > struct dma_chan *chan; > > rcu_read_lock(); > + if (list_empty(&dma_device_list)) { > + rcu_read_unlock(); > + return; > + } > list_for_each_entry_rcu(device, &dma_device_list, global_node) { > if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) > continue; > @@ -613,6 +635,10 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask, > dev_dbg(dev->dev, "%s: wrong capabilities\n", __func__); > return NULL; > } > + > + if (list_empty(&dev->channels)) > + return NULL; > + > /* devices with multiple channels need special handling as we need to > * ensure that all channels are either private or public. > */ > @@ -749,6 +775,11 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, > > /* Find a channel */ > mutex_lock(&dma_list_mutex); > + if (list_empty(&dma_device_list)) { > + mutex_unlock(&dma_list_mutex); > + return NULL; > + } > + > list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { > /* Finds a DMA controller with matching device node */ > if (np && device->dev->of_node && np != device->dev->of_node) > @@ -819,6 +850,11 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name) > > /* Try to find the channel via the DMA filter map(s) */ > mutex_lock(&dma_list_mutex); > + if (list_empty(&dma_device_list)) { > + mutex_unlock(&dma_list_mutex); > + return NULL; > + } > + > list_for_each_entry_safe(d, _d, &dma_device_list, global_node) { > dma_cap_mask_t mask; > const struct dma_slave_map *map = dma_filter_match(d, name, dev); > @@ -942,10 +978,17 @@ void dmaengine_get(void) > mutex_lock(&dma_list_mutex); > dmaengine_ref_count++; > > + if (list_empty(&dma_device_list)) { > + mutex_unlock(&dma_list_mutex); > + return; > + } > + > /* try to grab channels */ > list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { > if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) > continue; > + if (list_empty(&device->channels)) > + continue; > list_for_each_entry(chan, &device->channels, device_node) { > err = dma_chan_get(chan); > if (err == -ENODEV) { > @@ -980,10 +1023,17 @@ void dmaengine_put(void) > mutex_lock(&dma_list_mutex); > dmaengine_ref_count--; > BUG_ON(dmaengine_ref_count < 0); > + if (list_empty(&dma_device_list)) { > + mutex_unlock(&dma_list_mutex); > + return; > + } > + > /* drop channel references */ > list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { > if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) > continue; > + if (list_empty(&device->channels)) > + continue; > list_for_each_entry(chan, &device->channels, device_node) > dma_chan_put(chan); > } > @@ -1132,6 +1182,39 @@ void dma_async_device_channel_unregister(struct dma_device *device, > } > EXPORT_SYMBOL_GPL(dma_async_device_channel_unregister); > > +static int dma_channel_enumeration(struct dma_device *device) > +{ > + struct dma_chan *chan; > + int rc; > + > + if (list_empty(&device->channels)) > + return 0; > + > + /* represent channels in sysfs. Probably want devs too */ > + list_for_each_entry(chan, &device->channels, device_node) { > + rc = __dma_async_device_channel_register(device, chan); > + if (rc < 0) > + return rc; > + } > + > + /* take references on public channels */ > + if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask)) > + list_for_each_entry(chan, &device->channels, device_node) { > + /* if clients are already waiting for channels we need > + * to take references on their behalf > + */ > + if (dma_chan_get(chan) == -ENODEV) { > + /* note we can only get here for the first > + * channel as the remaining channels are > + * guaranteed to get a reference > + */ > + return -ENODEV; > + } > + } > + > + return 0; > +} > + > /** > * dma_async_device_register - registers DMA devices found > * @device: pointer to &struct dma_device > @@ -1247,33 +1330,15 @@ int dma_async_device_register(struct dma_device *device) > if (rc != 0) > return rc; > > + mutex_lock(&dma_list_mutex); > mutex_init(&device->chan_mutex); > ida_init(&device->chan_ida); > - > - /* represent channels in sysfs. Probably want devs too */ > - list_for_each_entry(chan, &device->channels, device_node) { > - rc = __dma_async_device_channel_register(device, chan); > - if (rc < 0) > - goto err_out; > + rc = dma_channel_enumeration(device); > + if (rc < 0) { > + mutex_unlock(&dma_list_mutex); > + goto err_out; > } > > - mutex_lock(&dma_list_mutex); > - /* take references on public channels */ > - if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask)) > - list_for_each_entry(chan, &device->channels, device_node) { > - /* if clients are already waiting for channels we need > - * to take references on their behalf > - */ > - if (dma_chan_get(chan) == -ENODEV) { > - /* note we can only get here for the first > - * channel as the remaining channels are > - * guaranteed to get a reference > - */ > - rc = -ENODEV; > - mutex_unlock(&dma_list_mutex); > - goto err_out; > - } > - } > list_add_tail_rcu(&device->global_node, &dma_device_list); > if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) > device->privatecnt++; /* Always private */ > @@ -1291,6 +1356,9 @@ int dma_async_device_register(struct dma_device *device) > return rc; > } > > + if (list_empty(&device->channels)) > + return rc; > + > list_for_each_entry(chan, &device->channels, device_node) { > if (chan->local == NULL) > continue; > @@ -1317,8 +1385,9 @@ void dma_async_device_unregister(struct dma_device *device) > > dmaengine_debug_unregister(device); > > - list_for_each_entry_safe(chan, n, &device->channels, device_node) > - __dma_async_device_channel_unregister(device, chan); > + if (!list_empty(&device->channels)) > + list_for_each_entry_safe(chan, n, &device->channels, device_node) > + __dma_async_device_channel_unregister(device, chan); > > mutex_lock(&dma_list_mutex); > /* > ------------------------------------------------------------------------------- > > > Git bisection log: > > ------------------------------------------------------------------------------- > git bisect start > # good: [bb5a93aaf25261321db0c499cde7da6ee9d8b164] x86/ldt: use "pr_info_once()" instead of open-coding it badly > git bisect good bb5a93aaf25261321db0c499cde7da6ee9d8b164 > # bad: [5680d14d59bddc8bcbc5badf00dbbd4374858497] Add linux-next specific files for 20200706 > git bisect bad 5680d14d59bddc8bcbc5badf00dbbd4374858497 > # good: [2549a884c8373a109a93521bf806cc523c92340b] Merge remote-tracking branch 'crypto/master' > git bisect good 2549a884c8373a109a93521bf806cc523c92340b > # good: [f94ee8e6645aadfc1e80c2a5fe5fb07841526610] Merge remote-tracking branch 'selinux/next' > git bisect good f94ee8e6645aadfc1e80c2a5fe5fb07841526610 > # good: [16d4f454c697a796cfac0af2b5ab39bedf71f4fe] Merge remote-tracking branch 'thunderbolt/next' > git bisect good 16d4f454c697a796cfac0af2b5ab39bedf71f4fe > # bad: [2c43abadd30bab02d2a94b5aa72a7eb6edbe6b96] Merge remote-tracking branch 'nvdimm/libnvdimm-for-next' > git bisect bad 2c43abadd30bab02d2a94b5aa72a7eb6edbe6b96 > # bad: [d5a942e3894462eb44f6bb51dde5b5b481ba355a] Merge remote-tracking branch 'scsi/for-next' > git bisect bad d5a942e3894462eb44f6bb51dde5b5b481ba355a > # good: [bd7a168a024dcfbc4db7fb79a51c8b574f55b527] staging: rtl8712: use common ieee80211 constants > git bisect good bd7a168a024dcfbc4db7fb79a51c8b574f55b527 > # good: [28ed7374401b20915bf980fdf2d3ac80f8c2945d] scsi: lpfc: Fix language in 0373 message to reflect non-error message > git bisect good 28ed7374401b20915bf980fdf2d3ac80f8c2945d > # good: [198d6cb9263bb25156132d87babfe6e6506a4c88] Merge remote-tracking branch 'icc/icc-next' > git bisect good 198d6cb9263bb25156132d87babfe6e6506a4c88 > # good: [7244068998c8266300c48f1a3af7b237446de885] Merge branch 'misc' into for-next > git bisect good 7244068998c8266300c48f1a3af7b237446de885 > # good: [999a32efed09d724c426568731c5691233d3a680] dmaengine: hisilicon: Use struct_size() in devm_kzalloc() > git bisect good 999a32efed09d724c426568731c5691233d3a680 > # good: [d12ea5591eddf625b7707c018b72e46e8674c3c2] dmaengine: pl330: Make sure the debug is idle before doing DMAGO > git bisect good d12ea5591eddf625b7707c018b72e46e8674c3c2 > # bad: [f50b150e315ed133b74a75e3c71864fb2cd4cece] dmaengine: idxd: add work queue drain support > git bisect bad f50b150e315ed133b74a75e3c71864fb2cd4cece > # bad: [deb9541f5052b2f93bd51cb263d9035bfd89fa96] dmaengine: check device and channel list for empty > git bisect bad deb9541f5052b2f93bd51cb263d9035bfd89fa96 > # first bad commit: [deb9541f5052b2f93bd51cb263d9035bfd89fa96] dmaengine: check device and channel list for empty > ------------------------------------------------------------------------------- >
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 2b06a7a8629d..0d6529eff66f 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -85,6 +85,9 @@ static void dmaengine_dbg_summary_show(struct seq_file *s, { struct dma_chan *chan; + if (list_empty(&dma_dev->channels)) + return; + list_for_each_entry(chan, &dma_dev->channels, device_node) { if (chan->client_count) { seq_printf(s, " %-13s| %s", dma_chan_name(chan), @@ -104,6 +107,11 @@ static int dmaengine_summary_show(struct seq_file *s, void *data) struct dma_device *dma_dev = NULL; mutex_lock(&dma_list_mutex); + if (list_empty(&dma_device_list)) { + mutex_unlock(&dma_list_mutex); + return 0; + } + list_for_each_entry(dma_dev, &dma_device_list, global_node) { seq_printf(s, "dma%d (%s): number of channels: %u\n", dma_dev->dev_id, dev_name(dma_dev->dev), @@ -324,10 +332,15 @@ static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu) struct dma_chan *min = NULL; struct dma_chan *localmin = NULL; + if (list_empty(&dma_device_list)) + return NULL; + list_for_each_entry(device, &dma_device_list, global_node) { if (!dma_has_cap(cap, device->cap_mask) || dma_has_cap(DMA_PRIVATE, device->cap_mask)) continue; + if (list_empty(&device->channels)) + continue; list_for_each_entry(chan, &device->channels, device_node) { if (!chan->client_count) continue; @@ -365,6 +378,9 @@ static void dma_channel_rebalance(void) int cpu; int cap; + if (list_empty(&dma_device_list)) + return; + /* undo the last distribution */ for_each_dma_cap_mask(cap, dma_cap_mask_all) for_each_possible_cpu(cpu) @@ -373,6 +389,8 @@ static void dma_channel_rebalance(void) list_for_each_entry(device, &dma_device_list, global_node) { if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) continue; + if (list_empty(&device->channels)) + continue; list_for_each_entry(chan, &device->channels, device_node) chan->table_count = 0; } @@ -556,6 +574,10 @@ void dma_issue_pending_all(void) struct dma_chan *chan; rcu_read_lock(); + if (list_empty(&dma_device_list)) { + rcu_read_unlock(); + return; + } list_for_each_entry_rcu(device, &dma_device_list, global_node) { if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) continue; @@ -613,6 +635,10 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask, dev_dbg(dev->dev, "%s: wrong capabilities\n", __func__); return NULL; } + + if (list_empty(&dev->channels)) + return NULL; + /* devices with multiple channels need special handling as we need to * ensure that all channels are either private or public. */ @@ -749,6 +775,11 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, /* Find a channel */ mutex_lock(&dma_list_mutex); + if (list_empty(&dma_device_list)) { + mutex_unlock(&dma_list_mutex); + return NULL; + } + list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { /* Finds a DMA controller with matching device node */ if (np && device->dev->of_node && np != device->dev->of_node) @@ -819,6 +850,11 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name) /* Try to find the channel via the DMA filter map(s) */ mutex_lock(&dma_list_mutex); + if (list_empty(&dma_device_list)) { + mutex_unlock(&dma_list_mutex); + return NULL; + } + list_for_each_entry_safe(d, _d, &dma_device_list, global_node) { dma_cap_mask_t mask; const struct dma_slave_map *map = dma_filter_match(d, name, dev); @@ -942,10 +978,17 @@ void dmaengine_get(void) mutex_lock(&dma_list_mutex); dmaengine_ref_count++; + if (list_empty(&dma_device_list)) { + mutex_unlock(&dma_list_mutex); + return; + } + /* try to grab channels */ list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) continue; + if (list_empty(&device->channels)) + continue; list_for_each_entry(chan, &device->channels, device_node) { err = dma_chan_get(chan); if (err == -ENODEV) { @@ -980,10 +1023,17 @@ void dmaengine_put(void) mutex_lock(&dma_list_mutex); dmaengine_ref_count--; BUG_ON(dmaengine_ref_count < 0); + if (list_empty(&dma_device_list)) { + mutex_unlock(&dma_list_mutex); + return; + } + /* drop channel references */ list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) continue; + if (list_empty(&device->channels)) + continue; list_for_each_entry(chan, &device->channels, device_node) dma_chan_put(chan); } @@ -1132,6 +1182,39 @@ void dma_async_device_channel_unregister(struct dma_device *device, } EXPORT_SYMBOL_GPL(dma_async_device_channel_unregister); +static int dma_channel_enumeration(struct dma_device *device) +{ + struct dma_chan *chan; + int rc; + + if (list_empty(&device->channels)) + return 0; + + /* represent channels in sysfs. Probably want devs too */ + list_for_each_entry(chan, &device->channels, device_node) { + rc = __dma_async_device_channel_register(device, chan); + if (rc < 0) + return rc; + } + + /* take references on public channels */ + if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask)) + list_for_each_entry(chan, &device->channels, device_node) { + /* if clients are already waiting for channels we need + * to take references on their behalf + */ + if (dma_chan_get(chan) == -ENODEV) { + /* note we can only get here for the first + * channel as the remaining channels are + * guaranteed to get a reference + */ + return -ENODEV; + } + } + + return 0; +} + /** * dma_async_device_register - registers DMA devices found * @device: pointer to &struct dma_device @@ -1247,33 +1330,15 @@ int dma_async_device_register(struct dma_device *device) if (rc != 0) return rc; + mutex_lock(&dma_list_mutex); mutex_init(&device->chan_mutex); ida_init(&device->chan_ida); - - /* represent channels in sysfs. Probably want devs too */ - list_for_each_entry(chan, &device->channels, device_node) { - rc = __dma_async_device_channel_register(device, chan); - if (rc < 0) - goto err_out; + rc = dma_channel_enumeration(device); + if (rc < 0) { + mutex_unlock(&dma_list_mutex); + goto err_out; } - mutex_lock(&dma_list_mutex); - /* take references on public channels */ - if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask)) - list_for_each_entry(chan, &device->channels, device_node) { - /* if clients are already waiting for channels we need - * to take references on their behalf - */ - if (dma_chan_get(chan) == -ENODEV) { - /* note we can only get here for the first - * channel as the remaining channels are - * guaranteed to get a reference - */ - rc = -ENODEV; - mutex_unlock(&dma_list_mutex); - goto err_out; - } - } list_add_tail_rcu(&device->global_node, &dma_device_list); if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) device->privatecnt++; /* Always private */ @@ -1291,6 +1356,9 @@ int dma_async_device_register(struct dma_device *device) return rc; } + if (list_empty(&device->channels)) + return rc; + list_for_each_entry(chan, &device->channels, device_node) { if (chan->local == NULL) continue; @@ -1317,8 +1385,9 @@ void dma_async_device_unregister(struct dma_device *device) dmaengine_debug_unregister(device); - list_for_each_entry_safe(chan, n, &device->channels, device_node) - __dma_async_device_channel_unregister(device, chan); + if (!list_empty(&device->channels)) + list_for_each_entry_safe(chan, n, &device->channels, device_node) + __dma_async_device_channel_unregister(device, chan); mutex_lock(&dma_list_mutex); /*