# git rev-parse -q --verify bddac7c1e02ba47f0570e494c9289acea3062cc1^{commit} bddac7c1e02ba47f0570e494c9289acea3062cc1 already have revision, skipping fetch # git checkout -q -f -B kisskb bddac7c1e02ba47f0570e494c9289acea3062cc1 # git clean -qxdf # < git log -1 # commit bddac7c1e02ba47f0570e494c9289acea3062cc1 # Author: Linus Torvalds # Date: Sat Mar 26 10:42:04 2022 -0700 # # Revert "swiotlb: rework "fix info leak with DMA_FROM_DEVICE"" # # This reverts commit aa6f8dcbab473f3a3c7454b74caa46d36cdc5d13. # # It turns out this breaks at least the ath9k wireless driver, and # possibly others. # # What the ath9k driver does on packet receive is to set up the DMA # transfer with: # # int ath_rx_init(..) # .. # bf->bf_buf_addr = dma_map_single(sc->dev, skb->data, # common->rx_bufsize, # DMA_FROM_DEVICE); # # and then the receive logic (through ath_rx_tasklet()) will fetch # incoming packets # # static bool ath_edma_get_buffers(..) # .. # dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr, # common->rx_bufsize, DMA_FROM_DEVICE); # # ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data); # if (ret == -EINPROGRESS) { # /*let device gain the buffer again*/ # dma_sync_single_for_device(sc->dev, bf->bf_buf_addr, # common->rx_bufsize, DMA_FROM_DEVICE); # return false; # } # # and it's worth noting how that first DMA sync: # # dma_sync_single_for_cpu(..DMA_FROM_DEVICE); # # is there to make sure the CPU can read the DMA buffer (possibly by # copying it from the bounce buffer area, or by doing some cache flush). # The iommu correctly turns that into a "copy from bounce bufer" so that # the driver can look at the state of the packets. # # In the meantime, the device may continue to write to the DMA buffer, but # we at least have a snapshot of the state due to that first DMA sync. # # But that _second_ DMA sync: # # dma_sync_single_for_device(..DMA_FROM_DEVICE); # # is telling the DMA mapping that the CPU wasn't interested in the area # because the packet wasn't there. In the case of a DMA bounce buffer, # that is a no-op. # # Note how it's not a sync for the CPU (the "for_device()" part), and it's # not a sync for data written by the CPU (the "DMA_FROM_DEVICE" part). # # Or rather, it _should_ be a no-op. That's what commit aa6f8dcbab47 # broke: it made the code bounce the buffer unconditionally, and changed # the DMA_FROM_DEVICE to just unconditionally and illogically be # DMA_TO_DEVICE. # # [ Side note: purely within the confines of the swiotlb driver it wasn't # entirely illogical: The reason it did that odd DMA_FROM_DEVICE -> # DMA_TO_DEVICE conversion thing is because inside the swiotlb driver, # it uses just a swiotlb_bounce() helper that doesn't care about the # whole distinction of who the sync is for - only which direction to # bounce. # # So it took the "sync for device" to mean that the CPU must have been # the one writing, and thought it meant DMA_TO_DEVICE. ] # # Also note how the commentary in that commit was wrong, probably due to # that whole confusion, claiming that the commit makes the swiotlb code # # "bounce unconditionally (that is, also # when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale # data from the swiotlb buffer" # # which is nonsensical for two reasons: # # - that "also when dir == DMA_TO_DEVICE" is nonsensical, as that was # exactly when it always did - and should do - the bounce. # # - since this is a sync for the device (not for the CPU), we're clearly # fundamentally not coping back stale data from the bounce buffers at # all, because we'd be copying *to* the bounce buffers. # # So that commit was just very confused. It confused the direction of the # synchronization (to the device, not the cpu) with the direction of the # DMA (from the device). # # Reported-and-bisected-by: Oleksandr Natalenko # Reported-by: Olha Cherevyk # Cc: Halil Pasic # Cc: Christoph Hellwig # Cc: Kalle Valo # Cc: Robin Murphy # Cc: Toke Høiland-Jørgensen # Cc: Maxime Bizon # Cc: Johannes Berg # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 bddac7c1e02ba47f0570e494c9289acea3062cc1 # < make -s -j 120 ARCH=powerpc O=/kisskb/build/linus_ppc64_book3e_allmodconfig_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- ppc64_book3e_allmodconfig # < make -s -j 120 ARCH=powerpc O=/kisskb/build/linus_ppc64_book3e_allmodconfig_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 120 ARCH=powerpc O=/kisskb/build/linus_ppc64_book3e_allmodconfig_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/linus_ppc64_book3e_allmodconfig_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/arch/powerpc/boot/dts/stxssa8555.dts:340.15-349.5: Warning (pci_device_reg): /pci@e0008000/i8259@19000: PCI unit address format error, expected "12,0" /kisskb/src/arch/powerpc/boot/dts/stxssa8555.dts:329.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@fffe00000/mdio@24000/ethernet-phy@0:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@fffe00000/mdio@24000/ethernet-phy@1:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@ffe00000/mdio@24000/ethernet-phy@0:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@ffe00000/mdio@24000/ethernet-phy@1:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/kmcoge4.dts:196.23-198.4: Warning (pci_bridge): /pcie@ffe201000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p2041si-post.dtsi:87.7-113.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p2041si-post.dtsi:97.9-112.4: Warning (pci_bridge): /pcie@ffe201000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/kmcoge4.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/kmcoge4.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/kmcoge4.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/ppa8548.dts:34.22-37.4: Warning (pci_bridge): /pci@fe0008000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8548si-post.dtsi:43.7-51.3 /kisskb/src/arch/powerpc/boot/dts/fsl/ppa8548.dts:39.22-42.4: Warning (pci_bridge): /pci@fe0009000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8548si-post.dtsi:54.7-62.3 /kisskb/src/arch/powerpc/boot/dts/fsl/ppa8548.dts:44.23-47.4: Warning (pci_bridge): /pcie@fe000a000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8548si-post.dtsi:65.7-90.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8548si-post.dtsi:74.9-89.4: Warning (pci_bridge): /pcie@fe000a000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/ppa8548.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/ppa8548.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/ppa8548.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/p1020rdb-pd.dts:189.11-193.6: Warning (spi_bus_reg): /soc@ffe00000/spi@7000/slic@0: SPI bus unit address format error, expected "1" /kisskb/src/arch/powerpc/boot/dts/fsl/p1020rdb-pd.dts:195.11-199.6: Warning (spi_bus_reg): /soc@ffe00000/spi@7000/slic@1: SPI bus unit address format error, expected "2" /kisskb/src/arch/powerpc/boot/dts/mpc5121.dtsi:457.13-466.5: Warning (spi_bus_bridge): /soc@80000000/psc@11900: node name for SPI buses should be 'spi' also defined at /kisskb/src/arch/powerpc/boot/dts/pdm360ng.dts:172.13-185.5 arch/powerpc/boot/dts/pdm360ng.dtb: Warning (spi_bus_reg): Failed prerequisite 'spi_bus_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8555cds.dts:341.15-350.5: Warning (pci_device_reg): /pci@e0008000/i8259@19000: PCI unit address format error, expected "12,0" /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8555cds.dts:330.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) /kisskb/src/arch/powerpc/boot/dts/mgcoge.dts:230.14-234.7: Warning (spi_bus_reg): /soc@f0000000/cpm@119c0/spi@11aa0/ds3106@1: SPI bus unit address format error, expected "0" /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@ffe00000/mdio@24000/ethernet-phy@0:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@ffe00000/mdio@24000/ethernet-phy@1:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/gef_sbc610.dts:209.22-211.4: Warning (pci_bridge): /pcie@fef09000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:119.7-144.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:129.9-143.4: Warning (pci_bridge): /pcie@fef09000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/gef_sbc610.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/gef_sbc610.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/gef_sbc610.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/bluestone.dts:272.13-277.7: Warning (i2c_bus_reg): /plb/opb/i2c@ef600700/sttm@4C: I2C bus unit address format error, expected "4c" /kisskb/src/arch/powerpc/boot/dts/fsl/gef_ppc9a.dts:211.22-213.4: Warning (pci_bridge): /pcie@fef09000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:119.7-144.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:129.9-143.4: Warning (pci_bridge): /pcie@fef09000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/gef_ppc9a.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/gef_ppc9a.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/gef_ppc9a.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/oca4080.dts:132.23-134.4: Warning (pci_bridge): /pcie@ffe200000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:58.7-84.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:68.9-83.4: Warning (pci_bridge): /pcie@ffe200000/pcie@0: missing ranges for PCI bridge (or not a bridge) /kisskb/src/arch/powerpc/boot/dts/fsl/oca4080.dts:136.23-138.4: Warning (pci_bridge): /pcie@ffe201000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:87.7-113.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:97.9-112.4: Warning (pci_bridge): /pcie@ffe201000/pcie@0: missing ranges for PCI bridge (or not a bridge) /kisskb/src/arch/powerpc/boot/dts/fsl/oca4080.dts:140.23-142.4: Warning (pci_bridge): /pcie@ffe202000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:116.7-142.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:126.9-141.4: Warning (pci_bridge): /pcie@ffe202000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/oca4080.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/oca4080.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/oca4080.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/mpc8610_hpcd.dts:420.3-21: Warning (pci_device_bus_num): /pcie@e000a000/pcie@0:bus-range: PCI bus number 0 out of range, expected (1 - 3) /kisskb/src/arch/powerpc/boot/dts/fsl/p2020rdb-pc_36b.dts:59.23-62.4: Warning (pci_bridge): /pcie@fffe08000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:100.7-126.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:109.9-125.4: Warning (pci_bridge): /pcie@fffe08000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/p2020rdb-pc_36b.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb-pc_36b.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb-pc_36b.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/p2020rdb-pc_32b.dts:59.22-62.4: Warning (pci_bridge): /pcie@ffe08000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:100.7-126.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:109.9-125.4: Warning (pci_bridge): /pcie@ffe08000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/p2020rdb-pc_32b.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb-pc_32b.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb-pc_32b.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@fffe00000/mdio@24000/ethernet-phy@0:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@fffe00000/mdio@24000/ethernet-phy@1:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/mpc5121.dtsi:397.13-406.5: Warning (spi_bus_bridge): /soc@80000000/psc@11400: node name for SPI buses should be 'spi' also defined at /kisskb/src/arch/powerpc/boot/dts/ac14xx.dts:305.19-326.5 /kisskb/src/arch/powerpc/boot/dts/mpc5121.dtsi:409.13-418.5: Warning (spi_bus_bridge): /soc@80000000/psc@11500: node name for SPI buses should be 'spi' also defined at /kisskb/src/arch/powerpc/boot/dts/ac14xx.dts:329.19-344.5 arch/powerpc/boot/dts/ac14xx.dtb: Warning (spi_bus_reg): Failed prerequisite 'spi_bus_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8541cds.dts:341.15-350.5: Warning (pci_device_reg): /pci@e0008000/i8259@19000: PCI unit address format error, expected "12,0" /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8541cds.dts:330.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:135.22-137.4: Warning (pci_bridge): /pcie@f1008000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:92.7-117.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:102.9-116.4: Warning (pci_bridge): /pcie@f1008000/pcie@0: missing ranges for PCI bridge (or not a bridge) /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:139.22-141.4: Warning (pci_bridge): /pcie@f1009000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:119.7-144.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:129.9-143.4: Warning (pci_bridge): /pcie@f1009000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/mvme7100.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/mvme7100.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/mvme7100.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:30.11-32.6: Warning (i2c_bus_reg): /soc@f1000000/i2c@3000/rtc@68: missing or empty reg property /kisskb/src/arch/powerpc/boot/dts/fsl/p2020rdb.dts:251.22-254.4: Warning (pci_bridge): /pcie@ffe08000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:43.7-68.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:52.9-67.4: Warning (pci_bridge): /pcie@ffe08000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/p2020rdb.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' Completed OK # rm -rf /kisskb/build/linus_ppc64_book3e_allmodconfig_powerpc-gcc9 # Build took: 0:07:53.804278