linux-toradex.git/drivers/mmc, branch v5.14 Linux kernel for Apalis and Colibri modules Revert "mmc: sdhci-iproc: Set SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN on BCM2711" 2021-08-27T14:30:36+00:00 Ulf Hansson ulf.hansson@linaro.org 2021-08-27T14:30:36+00:00 885814a97f5a1a2daf66bde5f2076f0bf632c174 This reverts commit 419dd626e357e89fc9c4e3863592c8b38cfe1571. It turned out that the change from the reverted commit breaks the ACPI based rpi's because it causes the 100Mhz max clock to be overridden to the return from sdhci_iproc_get_max_clock(), which is 0 because there isn't a OF/DT based clock device. Reported-by: Jeremy Linton <jeremy.linton@arm.com> Fixes: 419dd626e357 ("mmc: sdhci-iproc: Set SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN on BCM2711") Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 
This reverts commit 419dd626e357e89fc9c4e3863592c8b38cfe1571.

It turned out that the change from the reverted commit breaks the ACPI
based rpi's because it causes the 100Mhz max clock to be overridden to the
return from sdhci_iproc_get_max_clock(), which is 0 because there isn't a
OF/DT based clock device.

Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Fixes: 419dd626e357 ("mmc: sdhci-iproc: Set SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN on BCM2711")
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
mmc: sdhci-iproc: Set SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN on BCM2711 2021-08-16T10:12:05+00:00 Nicolas Saenz Julienne nsaenz@kernel.org 2021-08-07T11:06:36+00:00 419dd626e357e89fc9c4e3863592c8b38cfe1571 The controller doesn't seem to pick-up on clock changes, so set the SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN flag to query the clock frequency directly from the clock. Fixes: f84e411c85be ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711") Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1628334401-6577-6-git-send-email-stefan.wahren@i2se.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 
The controller doesn't seem to pick-up on clock changes, so set the
SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN flag to query the clock frequency
directly from the clock.

Fixes: f84e411c85be ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711")
Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1628334401-6577-6-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
mmc: sdhci-iproc: Cap min clock frequency on BCM2711 2021-08-16T10:09:11+00:00 Nicolas Saenz Julienne nsaenz@kernel.org 2021-08-07T11:06:35+00:00 c9107dd0b851777d7e134420baf13a5c5343bc16 There is a known bug on BCM2711's SDHCI core integration where the controller will hang when the difference between the core clock and the bus clock is too great. Specifically this can be reproduced under the following conditions: - No SD card plugged in, polling thread is running, probing cards at 100 kHz. - BCM2711's core clock configured at 500MHz or more. So set 200 kHz as the minimum clock frequency available for that board. For more information on the issue see this: https://lore.kernel.org/linux-mmc/20210322185816.27582-1-nsaenz@kernel.org/T/#m11f2783a09b581da6b8a15f302625b43a6ecdeca Fixes: f84e411c85be ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711") Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1628334401-6577-5-git-send-email-stefan.wahren@i2se.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 
There is a known bug on BCM2711's SDHCI core integration where the
controller will hang when the difference between the core clock and the
bus clock is too great. Specifically this can be reproduced under the
following conditions:

- No SD card plugged in, polling thread is running, probing cards at
  100 kHz.
- BCM2711's core clock configured at 500MHz or more.

So set 200 kHz as the minimum clock frequency available for that board.

For more information on the issue see this:
https://lore.kernel.org/linux-mmc/20210322185816.27582-1-nsaenz@kernel.org/T/#m11f2783a09b581da6b8a15f302625b43a6ecdeca

Fixes: f84e411c85be ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711")
Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1628334401-6577-5-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
mmc: sdhci-msm: Update the software timeout value for sdhc 2021-08-04T11:17:21+00:00 Shaik Sajida Bhanu sbhanu@codeaurora.org 2021-07-16T11:46:14+00:00 67b13f3e221ed81b46a657e2b499bf8b20162476 Whenever SDHC run at clock rate 50MHZ or below, the hardware data timeout value will be 21.47secs, which is approx. 22secs and we have a current software timeout value as 10secs. We have to set software timeout value more than the hardware data timeout value to avioid seeing the below register dumps. [ 332.953670] mmc2: Timeout waiting for hardware interrupt. [ 332.959608] mmc2: sdhci: ============ SDHCI REGISTER DUMP =========== [ 332.966450] mmc2: sdhci: Sys addr: 0x00000000 | Version: 0x00007202 [ 332.973256] mmc2: sdhci: Blk size: 0x00000200 | Blk cnt: 0x00000001 [ 332.980054] mmc2: sdhci: Argument: 0x00000000 | Trn mode: 0x00000027 [ 332.986864] mmc2: sdhci: Present: 0x01f801f6 | Host ctl: 0x0000001f [ 332.993671] mmc2: sdhci: Power: 0x00000001 | Blk gap: 0x00000000 [ 333.000583] mmc2: sdhci: Wake-up: 0x00000000 | Clock: 0x00000007 [ 333.007386] mmc2: sdhci: Timeout: 0x0000000e | Int stat: 0x00000000 [ 333.014182] mmc2: sdhci: Int enab: 0x03ff100b | Sig enab: 0x03ff100b [ 333.020976] mmc2: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000 [ 333.027771] mmc2: sdhci: Caps: 0x322dc8b2 | Caps_1: 0x0000808f [ 333.034561] mmc2: sdhci: Cmd: 0x0000183a | Max curr: 0x00000000 [ 333.041359] mmc2: sdhci: Resp[0]: 0x00000900 | Resp[1]: 0x00000000 [ 333.048157] mmc2: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000 [ 333.054945] mmc2: sdhci: Host ctl2: 0x00000000 [ 333.059657] mmc2: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x0000000ffffff218 [ 333.067178] mmc2: sdhci_msm: ----------- VENDOR REGISTER DUMP ----------- [ 333.074343] mmc2: sdhci_msm: DLL sts: 0x00000000 | DLL cfg: 0x6000642c | DLL cfg2: 0x0020a000 [ 333.083417] mmc2: sdhci_msm: DLL cfg3: 0x00000000 | DLL usr ctl: 0x00000000 | DDR cfg: 0x80040873 [ 333.092850] mmc2: sdhci_msm: Vndr func: 0x00008a9c | Vndr func2 : 0xf88218a8 Vndr func3: 0x02626040 [ 333.102371] mmc2: sdhci: ============================================ So, set software timeout value more than hardware timeout value. Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1626435974-14462-1-git-send-email-sbhanu@codeaurora.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 
Whenever SDHC run at clock rate 50MHZ or below, the hardware data
timeout value will be 21.47secs, which is approx. 22secs and we have
a current software timeout value as 10secs. We have to set software
timeout value more than the hardware data timeout value to avioid seeing
the below register dumps.

[  332.953670] mmc2: Timeout waiting for hardware interrupt.
[  332.959608] mmc2: sdhci: ============ SDHCI REGISTER DUMP ===========
[  332.966450] mmc2: sdhci: Sys addr:  0x00000000 | Version:  0x00007202
[  332.973256] mmc2: sdhci: Blk size:  0x00000200 | Blk cnt:  0x00000001
[  332.980054] mmc2: sdhci: Argument:  0x00000000 | Trn mode: 0x00000027
[  332.986864] mmc2: sdhci: Present:   0x01f801f6 | Host ctl: 0x0000001f
[  332.993671] mmc2: sdhci: Power:     0x00000001 | Blk gap:  0x00000000
[  333.000583] mmc2: sdhci: Wake-up:   0x00000000 | Clock:    0x00000007
[  333.007386] mmc2: sdhci: Timeout:   0x0000000e | Int stat: 0x00000000
[  333.014182] mmc2: sdhci: Int enab:  0x03ff100b | Sig enab: 0x03ff100b
[  333.020976] mmc2: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
[  333.027771] mmc2: sdhci: Caps:      0x322dc8b2 | Caps_1:   0x0000808f
[  333.034561] mmc2: sdhci: Cmd:       0x0000183a | Max curr: 0x00000000
[  333.041359] mmc2: sdhci: Resp[0]:   0x00000900 | Resp[1]:  0x00000000
[  333.048157] mmc2: sdhci: Resp[2]:   0x00000000 | Resp[3]:  0x00000000
[  333.054945] mmc2: sdhci: Host ctl2: 0x00000000
[  333.059657] mmc2: sdhci: ADMA Err:  0x00000000 | ADMA Ptr:
0x0000000ffffff218
[  333.067178] mmc2: sdhci_msm: ----------- VENDOR REGISTER DUMP
-----------
[  333.074343] mmc2: sdhci_msm: DLL sts: 0x00000000 | DLL cfg:
0x6000642c | DLL cfg2: 0x0020a000
[  333.083417] mmc2: sdhci_msm: DLL cfg3: 0x00000000 | DLL usr ctl:
0x00000000 | DDR cfg: 0x80040873
[  333.092850] mmc2: sdhci_msm: Vndr func: 0x00008a9c | Vndr func2 :
0xf88218a8 Vndr func3: 0x02626040
[  333.102371] mmc2: sdhci: ============================================

So, set software timeout value more than hardware timeout value.

Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1626435974-14462-1-git-send-email-sbhanu@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
mmc: mmci: stm32: Check when the voltage switch procedure should be done 2021-08-04T10:46:02+00:00 Christophe Kerello christophe.kerello@foss.st.com 2021-07-01T14:33:53+00:00 d8e193f13b07e6c0ffaa1a999386f1989f2b4c5e If the card has not been power cycled, it may still be using 1.8V signaling. This situation is detected in mmc_sd_init_card function and should be handled in mmci stm32 variant. The host->pwr_reg variable is also correctly protected with spin locks. Fixes: 94b94a93e355 ("mmc: mmci_sdmmc: Implement signal voltage callbacks") Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com> Signed-off-by: Yann Gautier <yann.gautier@foss.st.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210701143353.13188-1-yann.gautier@foss.st.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 
If the card has not been power cycled, it may still be using 1.8V
signaling. This situation is detected in mmc_sd_init_card function and
should be handled in mmci stm32 variant.  The host->pwr_reg variable is
also correctly protected with spin locks.

Fixes: 94b94a93e355 ("mmc: mmci_sdmmc: Implement signal voltage callbacks")
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210701143353.13188-1-yann.gautier@foss.st.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
mmc: dw_mmc: Fix hang on data CRC error 2021-08-04T10:41:20+00:00 Vincent Whitchurch vincent.whitchurch@axis.com 2021-06-30T10:22:32+00:00 25f8203b4be1937c4939bb98623e67dcfd7da4d1 When a Data CRC interrupt is received, the driver disables the DMA, then sends the stop/abort command and then waits for Data Transfer Over. However, sometimes, when a data CRC error is received in the middle of a multi-block write transfer, the Data Transfer Over interrupt is never received, and the driver hangs and never completes the request. The driver sets the BMOD.SWR bit (SDMMC_IDMAC_SWRESET) when stopping the DMA, but according to the manual CMD.STOP_ABORT_CMD should be programmed "before assertion of SWR". Do these operations in the recommended order. With this change the Data Transfer Over is always received correctly in my tests. Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210630102232.16011-1-vincent.whitchurch@axis.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 
When a Data CRC interrupt is received, the driver disables the DMA, then
sends the stop/abort command and then waits for Data Transfer Over.

However, sometimes, when a data CRC error is received in the middle of a
multi-block write transfer, the Data Transfer Over interrupt is never
received, and the driver hangs and never completes the request.

The driver sets the BMOD.SWR bit (SDMMC_IDMAC_SWRESET) when stopping the
DMA, but according to the manual CMD.STOP_ABORT_CMD should be programmed
"before assertion of SWR".  Do these operations in the recommended
order.  With this change the Data Transfer Over is always received
correctly in my tests.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210630102232.16011-1-vincent.whitchurch@axis.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Merge tag 'mmc-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc 2021-07-22T16:51:38+00:00 Linus Torvalds torvalds@linux-foundation.org 2021-07-22T16:51:38+00:00 5e09e197a85a98d59d9089ffb2fae1d0b1ba6cd2 Pull MMC fixes from Ulf Hansson: - Use kref to fix KASAN splats triggered during card removal - Don't allocate IDA for OF aliases * tag 'mmc-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: mmc: core: Don't allocate IDA for OF aliases mmc: core: Use kref in place of struct mmc_blk_data::usage 
Pull MMC fixes from Ulf Hansson:

 - Use kref to fix KASAN splats triggered during card removal

 - Don't allocate IDA for OF aliases

* tag 'mmc-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: core: Don't allocate IDA for OF aliases
  mmc: core: Use kref in place of struct mmc_blk_data::usage
mmc: core: Don't allocate IDA for OF aliases 2021-07-14T16:55:28+00:00 Stephen Boyd swboyd@chromium.org 2021-06-23T07:50:02+00:00 10252bae863d09b9648bed2e035572d207200ca1 There's a chance that the IDA allocated in mmc_alloc_host() is not freed for some time because it's freed as part of a class' release function (see mmc_host_classdev_release() where the IDA is freed). If another thread is holding a reference to the class, then only once all balancing device_put() calls (in turn calling kobject_put()) have been made will the IDA be released and usable again. Normally this isn't a problem because the kobject is released before anything else that may want to use the same number tries to again, but with CONFIG_DEBUG_KOBJECT_RELEASE=y and OF aliases it becomes pretty easy to try to allocate an alias from the IDA twice while the first time it was allocated is still pending a call to ida_simple_remove(). It's also possible to trigger it by using CONFIG_DEBUG_KOBJECT_RELEASE and probe defering a driver at boot that calls mmc_alloc_host() before trying to get resources that may defer likes clks or regulators. Instead of allocating from the IDA in this scenario, let's just skip it if we know this is an OF alias. The number is already "claimed" and devices that aren't using OF aliases won't try to use the claimed numbers anyway (see mmc_first_nonreserved_index()). This should avoid any issues with mmc_alloc_host() returning failures from the ida_simple_get() in the case that we're using an OF alias. Cc: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Cc: Sujit Kautkar <sujitka@chromium.org> Reported-by: Zubin Mithra <zsm@chromium.org> Fixes: fa2d0aa96941 ("mmc: core: Allow setting slot index via device tree alias") Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20210623075002.1746924-3-swboyd@chromium.org Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 
There's a chance that the IDA allocated in mmc_alloc_host() is not freed
for some time because it's freed as part of a class' release function
(see mmc_host_classdev_release() where the IDA is freed). If another
thread is holding a reference to the class, then only once all balancing
device_put() calls (in turn calling kobject_put()) have been made will
the IDA be released and usable again.

Normally this isn't a problem because the kobject is released before
anything else that may want to use the same number tries to again, but
with CONFIG_DEBUG_KOBJECT_RELEASE=y and OF aliases it becomes pretty
easy to try to allocate an alias from the IDA twice while the first time
it was allocated is still pending a call to ida_simple_remove(). It's
also possible to trigger it by using CONFIG_DEBUG_KOBJECT_RELEASE and
probe defering a driver at boot that calls mmc_alloc_host() before
trying to get resources that may defer likes clks or regulators.

Instead of allocating from the IDA in this scenario, let's just skip it
if we know this is an OF alias. The number is already "claimed" and
devices that aren't using OF aliases won't try to use the claimed
numbers anyway (see mmc_first_nonreserved_index()). This should avoid
any issues with mmc_alloc_host() returning failures from the
ida_simple_get() in the case that we're using an OF alias.

Cc: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Cc: Sujit Kautkar <sujitka@chromium.org>
Reported-by: Zubin Mithra <zsm@chromium.org>
Fixes: fa2d0aa96941 ("mmc: core: Allow setting slot index via device tree alias")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20210623075002.1746924-3-swboyd@chromium.org
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
mmc: core: Use kref in place of struct mmc_blk_data::usage 2021-07-14T16:55:24+00:00 Stephen Boyd swboyd@chromium.org 2021-06-23T07:50:01+00:00 edb25572fc7058db5a98223e11d2d50497178553 Ulf reported the following KASAN splat after adding some manual hacks into mmc-utils[1]. DEBUG: mmc_blk_open: Let's sleep for 10s.. mmc1: card 0007 removed BUG: KASAN: use-after-free in mmc_blk_get+0x58/0xb8 Read of size 4 at addr ffff00000a394a28 by task mmc/180 CPU: 2 PID: 180 Comm: mmc Not tainted 5.10.0-rc4-00069-gcc758c8c7127-dirty #5 Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) Call trace: dump_backtrace+0x0/0x2b4 show_stack+0x18/0x6c dump_stack+0xfc/0x168 print_address_description.constprop.0+0x6c/0x488 kasan_report+0x118/0x210 __asan_load4+0x94/0xd0 mmc_blk_get+0x58/0xb8 mmc_blk_open+0x7c/0xdc __blkdev_get+0x3b4/0x964 blkdev_get+0x64/0x100 blkdev_open+0xe8/0x104 do_dentry_open+0x234/0x61c vfs_open+0x54/0x64 path_openat+0xe04/0x1584 do_filp_open+0xe8/0x1e4 do_sys_openat2+0x120/0x230 __arm64_sys_openat+0xf0/0x15c el0_svc_common.constprop.0+0xac/0x234 do_el0_svc+0x84/0xa0 el0_sync_handler+0x264/0x270 el0_sync+0x174/0x180 Allocated by task 33: stack_trace_save+0x9c/0xdc kasan_save_stack+0x28/0x60 __kasan_kmalloc.constprop.0+0xc8/0xf0 kasan_kmalloc+0x10/0x20 mmc_blk_alloc_req+0x94/0x4b0 mmc_blk_probe+0x2d4/0xaa4 mmc_bus_probe+0x34/0x4c really_probe+0x148/0x6e0 driver_probe_device+0x78/0xec __device_attach_driver+0x108/0x16c bus_for_each_drv+0xf4/0x15c __device_attach+0x168/0x240 device_initial_probe+0x14/0x20 bus_probe_device+0xec/0x100 device_add+0x55c/0xaf0 mmc_add_card+0x288/0x380 mmc_attach_sd+0x18c/0x22c mmc_rescan+0x444/0x4f0 process_one_work+0x3b8/0x650 worker_thread+0xa0/0x724 kthread+0x218/0x220 ret_from_fork+0x10/0x38 Freed by task 33: stack_trace_save+0x9c/0xdc kasan_save_stack+0x28/0x60 kasan_set_track+0x28/0x40 kasan_set_free_info+0x24/0x4c __kasan_slab_free+0x100/0x180 kasan_slab_free+0x14/0x20 kfree+0xb8/0x46c mmc_blk_put+0xe4/0x11c mmc_blk_remove_req.part.0+0x6c/0xe4 mmc_blk_remove+0x368/0x370 mmc_bus_remove+0x34/0x50 __device_release_driver+0x228/0x31c device_release_driver+0x2c/0x44 bus_remove_device+0x1e4/0x200 device_del+0x2b0/0x770 mmc_remove_card+0xf0/0x150 mmc_sd_detect+0x9c/0x150 mmc_rescan+0x110/0x4f0 process_one_work+0x3b8/0x650 worker_thread+0xa0/0x724 kthread+0x218/0x220 ret_from_fork+0x10/0x38 The buggy address belongs to the object at ffff00000a394800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 552 bytes inside of 1024-byte region [ffff00000a394800, ffff00000a394c00) The buggy address belongs to the page: page:00000000ff84ed53 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8a390 head:00000000ff84ed53 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x3fffc0000010200(slab|head) raw: 03fffc0000010200 dead000000000100 dead000000000122 ffff000009f03800 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff00000a394900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff00000a394980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff00000a394a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff00000a394a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff00000a394b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Looking closer at the problem, it looks like a classic dangling pointer bug. The 'struct mmc_blk_data' that is used after being freed in mmc_blk_put() is stashed away in 'md->disk->private_data' via mmc_blk_alloc_req() but used in mmc_blk_get() because the 'usage' count isn't properly aligned with the lifetime of the pointer. You'd expect the 'usage' member to be in sync with the kfree(), and it mostly is, except that mmc_blk_get() needs to dereference the potentially freed memory storage for the 'struct mmc_blk_data' stashed away in the private_data member to look at 'usage' before it actually figures out if it wants to consider it a valid pointer or not. That's not going to work if the freed memory has been overwritten by something else after the free, and KASAN rightly complains here. To fix the immediate problem, let's set the private_data member to NULL in mmc_blk_put() so that mmc_blk_get() can consider the object "on the way out" if the pointer is NULL and not even try to look at 'usage' if the object isn't going to be around much longer. With that set to NULL on the last mmc_blk_put(), optimize the get path further and use a kref underneath the 'open_lock' mutex to only up the reference count if it's non-zero, i.e. alive, and otherwise make mmc_blk_get() return NULL, without actually testing the reference count if we're in the process of removing the object from the system. Finally, tighten the locking region on the put side to only be around the parts that are removing the 'mmc_blk_data' from the system and publishing that fact to the gendisk and then drop the lock as soon as we can to avoid holding the lock around code that doesn't need it. This fixes the KASAN issue. Cc: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Cc: Sujit Kautkar <sujitka@chromium.org> Cc: Zubin Mithra <zsm@chromium.org> Reported-by: Ulf Hansson <ulf.hansson@linaro.org> Link: https://lore.kernel.org/linux-mmc/CAPDyKFryT63Jc7+DXWSpAC19qpZRqFr1orxwYGMuSqx247O8cQ@mail.gmail.com/ [1] Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20210623075002.1746924-2-swboyd@chromium.org Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> 
Ulf reported the following KASAN splat after adding some manual hacks
into mmc-utils[1].

 DEBUG: mmc_blk_open: Let's sleep for 10s..
 mmc1: card 0007 removed
 BUG: KASAN: use-after-free in mmc_blk_get+0x58/0xb8
 Read of size 4 at addr ffff00000a394a28 by task mmc/180

 CPU: 2 PID: 180 Comm: mmc Not tainted 5.10.0-rc4-00069-gcc758c8c7127-dirty #5
 Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
 Call trace:
  dump_backtrace+0x0/0x2b4
  show_stack+0x18/0x6c
  dump_stack+0xfc/0x168
  print_address_description.constprop.0+0x6c/0x488
  kasan_report+0x118/0x210
  __asan_load4+0x94/0xd0
  mmc_blk_get+0x58/0xb8
  mmc_blk_open+0x7c/0xdc
  __blkdev_get+0x3b4/0x964
  blkdev_get+0x64/0x100
  blkdev_open+0xe8/0x104
  do_dentry_open+0x234/0x61c
  vfs_open+0x54/0x64
  path_openat+0xe04/0x1584
  do_filp_open+0xe8/0x1e4
  do_sys_openat2+0x120/0x230
  __arm64_sys_openat+0xf0/0x15c
  el0_svc_common.constprop.0+0xac/0x234
  do_el0_svc+0x84/0xa0
  el0_sync_handler+0x264/0x270
  el0_sync+0x174/0x180

 Allocated by task 33:
  stack_trace_save+0x9c/0xdc
  kasan_save_stack+0x28/0x60
  __kasan_kmalloc.constprop.0+0xc8/0xf0
  kasan_kmalloc+0x10/0x20
  mmc_blk_alloc_req+0x94/0x4b0
  mmc_blk_probe+0x2d4/0xaa4
  mmc_bus_probe+0x34/0x4c
  really_probe+0x148/0x6e0
  driver_probe_device+0x78/0xec
  __device_attach_driver+0x108/0x16c
  bus_for_each_drv+0xf4/0x15c
  __device_attach+0x168/0x240
  device_initial_probe+0x14/0x20
  bus_probe_device+0xec/0x100
  device_add+0x55c/0xaf0
  mmc_add_card+0x288/0x380
  mmc_attach_sd+0x18c/0x22c
  mmc_rescan+0x444/0x4f0
  process_one_work+0x3b8/0x650
  worker_thread+0xa0/0x724
  kthread+0x218/0x220
  ret_from_fork+0x10/0x38

 Freed by task 33:
  stack_trace_save+0x9c/0xdc
  kasan_save_stack+0x28/0x60
  kasan_set_track+0x28/0x40
  kasan_set_free_info+0x24/0x4c
  __kasan_slab_free+0x100/0x180
  kasan_slab_free+0x14/0x20
  kfree+0xb8/0x46c
  mmc_blk_put+0xe4/0x11c
  mmc_blk_remove_req.part.0+0x6c/0xe4
  mmc_blk_remove+0x368/0x370
  mmc_bus_remove+0x34/0x50
  __device_release_driver+0x228/0x31c
  device_release_driver+0x2c/0x44
  bus_remove_device+0x1e4/0x200
  device_del+0x2b0/0x770
  mmc_remove_card+0xf0/0x150
  mmc_sd_detect+0x9c/0x150
  mmc_rescan+0x110/0x4f0
  process_one_work+0x3b8/0x650
  worker_thread+0xa0/0x724
  kthread+0x218/0x220
  ret_from_fork+0x10/0x38

 The buggy address belongs to the object at ffff00000a394800
  which belongs to the cache kmalloc-1k of size 1024
 The buggy address is located 552 bytes inside of
  1024-byte region [ffff00000a394800, ffff00000a394c00)
 The buggy address belongs to the page:
 page:00000000ff84ed53 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8a390
 head:00000000ff84ed53 order:3 compound_mapcount:0 compound_pincount:0
 flags: 0x3fffc0000010200(slab|head)
 raw: 03fffc0000010200 dead000000000100 dead000000000122 ffff000009f03800
 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff00000a394900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff00000a394980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 >ffff00000a394a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                   ^
  ffff00000a394a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff00000a394b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Looking closer at the problem, it looks like a classic dangling pointer
bug. The 'struct mmc_blk_data' that is used after being freed in
mmc_blk_put() is stashed away in 'md->disk->private_data' via
mmc_blk_alloc_req() but used in mmc_blk_get() because the 'usage' count
isn't properly aligned with the lifetime of the pointer. You'd expect
the 'usage' member to be in sync with the kfree(), and it mostly is,
except that mmc_blk_get() needs to dereference the potentially freed
memory storage for the 'struct mmc_blk_data' stashed away in the
private_data member to look at 'usage' before it actually figures out if
it wants to consider it a valid pointer or not. That's not going to work
if the freed memory has been overwritten by something else after the
free, and KASAN rightly complains here.

To fix the immediate problem, let's set the private_data member to NULL
in mmc_blk_put() so that mmc_blk_get() can consider the object "on the
way out" if the pointer is NULL and not even try to look at 'usage' if
the object isn't going to be around much longer. With that set to NULL
on the last mmc_blk_put(), optimize the get path further and use a kref
underneath the 'open_lock' mutex to only up the reference count if it's
non-zero, i.e.  alive, and otherwise make mmc_blk_get() return NULL,
without actually testing the reference count if we're in the process of
removing the object from the system.

Finally, tighten the locking region on the put side to only be around
the parts that are removing the 'mmc_blk_data' from the system and
publishing that fact to the gendisk and then drop the lock as soon as we
can to avoid holding the lock around code that doesn't need it. This
fixes the KASAN issue.

Cc: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Cc: Sujit Kautkar <sujitka@chromium.org>
Cc: Zubin Mithra <zsm@chromium.org>
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/linux-mmc/CAPDyKFryT63Jc7+DXWSpAC19qpZRqFr1orxwYGMuSqx247O8cQ@mail.gmail.com/ [1]
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20210623075002.1746924-2-swboyd@chromium.org
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
mmc: jz4740: Fix fall-through warning for Clang 2021-07-13T18:59:22+00:00 Gustavo A. R. Silva gustavoars@kernel.org 2021-07-13T18:23:21+00:00 f95deaeca8e106af891061e5f9c745dc7dc172c0 Fix the following fallthrough warning (mips-randconfig with Clang): drivers/mmc/host/jz4740_mmc.c:792:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough] Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/60edca25.k00ut905IFBjPyt5%25lkp@intel.com/ Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> 
Fix the following fallthrough warning (mips-randconfig with Clang):

drivers/mmc/host/jz4740_mmc.c:792:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/60edca25.k00ut905IFBjPyt5%25lkp@intel.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>