# git rev-parse -q --verify ab6f762f0f53162d41497708b33c9a3236d3609e^{commit} ab6f762f0f53162d41497708b33c9a3236d3609e already have revision, skipping fetch # git checkout -q -f -B kisskb ab6f762f0f53162d41497708b33c9a3236d3609e # git clean -qxdf # < git log -1 # commit ab6f762f0f53162d41497708b33c9a3236d3609e # Author: Sergey Senozhatsky # Date: Tue Mar 3 20:30:02 2020 +0900 # # printk: queue wake_up_klogd irq_work only if per-CPU areas are ready # # printk_deferred(), similarly to printk_safe/printk_nmi, does not # immediately attempt to print a new message on the consoles, avoiding # calls into non-reentrant kernel paths, e.g. scheduler or timekeeping, # which potentially can deadlock the system. # # Those printk() flavors, instead, rely on per-CPU flush irq_work to print # messages from safer contexts. For same reasons (recursive scheduler or # timekeeping calls) printk() uses per-CPU irq_work in order to wake up # user space syslog/kmsg readers. # # However, only printk_safe/printk_nmi do make sure that per-CPU areas # have been initialised and that it's safe to modify per-CPU irq_work. # This means that, for instance, should printk_deferred() be invoked "too # early", that is before per-CPU areas are initialised, printk_deferred() # will perform illegal per-CPU access. # # Lech Perczak [0] reports that after commit 1b710b1b10ef ("char/random: # silence a lockdep splat with printk()") user-space syslog/kmsg readers # are not able to read new kernel messages. # # The reason is printk_deferred() being called too early (as was pointed # out by Petr and John). # # Fix printk_deferred() and do not queue per-CPU irq_work before per-CPU # areas are initialized. # # Link: https://lore.kernel.org/lkml/aa0732c6-5c4e-8a8b-a1c1-75ebe3dca05b@camlintechnologies.com/ # Reported-by: Lech Perczak # Signed-off-by: Sergey Senozhatsky # Tested-by: Jann Horn # Reviewed-by: Petr Mladek # Cc: Greg Kroah-Hartman # Cc: Theodore Ts'o # Cc: John Ogness # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-gcc --version # < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-ld --version # < git log --format=%s --max-count=1 ab6f762f0f53162d41497708b33c9a3236d3609e # < make -s -j 48 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- allmodconfig # < make -s -j 48 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- help # make -s -j 48 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- olddefconfig # make -s -j 48 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- arch/arm64/Makefile:27: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum arch/arm64/Makefile:35: LSE atomics not supported by binutils /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #address-cells (1) differs from / (2) /kisskb/src/arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #size-cells (1) differs from / (2) /kisskb/src/scripts/dtc/include-prefixes/arm/bcm2835-rpi.dtsi:18.4-15: Warning (dma_ranges_format): /soc/firmware:dma-ranges: empty "dma-ranges" property but its #address-cells (2) differs from /soc (1) /kisskb/src/arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #address-cells (1) differs from / (2) /kisskb/src/arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #size-cells (1) differs from / (2) /kisskb/src/scripts/dtc/include-prefixes/arm/bcm2835-rpi.dtsi:18.4-15: Warning (dma_ranges_format): /soc/firmware:dma-ranges: empty "dma-ranges" property but its #address-cells (2) differs from /soc (1) /kisskb/src/scripts/dtc/include-prefixes/arm/bcm2835-rpi.dtsi:18.4-15: Warning (dma_ranges_format): /soc/firmware:dma-ranges: empty "dma-ranges" property but its #address-cells (2) differs from /soc (1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #address-cells (1) differs from / (2) /kisskb/src/arch/arm64/boot/dts/broadcom/stingray/stingray-usb.dtsi:7.3-14: Warning (dma_ranges_format): /usb:dma-ranges: empty "dma-ranges" property but its #size-cells (1) differs from / (2) /kisskb/src/scripts/dtc/include-prefixes/arm/bcm2835-rpi.dtsi:18.4-15: Warning (dma_ranges_format): /soc/firmware:dma-ranges: empty "dma-ranges" property but its #address-cells (2) differs from /soc (1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/scripts/dtc/include-prefixes/arm/bcm2835-rpi.dtsi:18.4-15: Warning (dma_ranges_format): /soc/firmware:dma-ranges: empty "dma-ranges" property but its #address-cells (2) differs from /soc (1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/arch/arm64/boot/dts/qcom/ipq6018.dtsi:127.3-14: Warning (dma_ranges_format): /soc:dma-ranges: empty "dma-ranges" property but its #address-cells (1) differs from / (2) /kisskb/src/arch/arm64/boot/dts/qcom/ipq6018.dtsi:127.3-14: Warning (dma_ranges_format): /soc:dma-ranges: empty "dma-ranges" property but its #size-cells (1) differs from / (2) /kisskb/src/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:1086.4-52: Warning (dma_ranges_format): /soc/dram-controller@1c62000:dma-ranges: "dma-ranges" property has invalid length (12 bytes) (parent #address-cells == 1, child #address-cells == 2, #size-cells == 1) /kisskb/src/net/mptcp/protocol.c: In function 'mptcp_sendmsg_frag': /kisskb/src/net/mptcp/protocol.c:611:6: warning: 'dfrag_collapsed' may be used uninitialized in this function [-Wmaybe-uninitialized] if (!dfrag_collapsed) { ^ /kisskb/src/kernel/futex.c: In function 'do_futex': /kisskb/src/kernel/futex.c:1676:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized] return oldval == cmparg; ^ /kisskb/src/kernel/futex.c:1652:6: note: 'oldval' was declared here int oldval, ret; ^ In file included from /kisskb/src/include/linux/rwsem.h:16:0, from /kisskb/src/include/linux/notifier.h:15, from /kisskb/src/include/linux/clk.h:14, from /kisskb/src/drivers/tty/serial/sh-sci.c:20: /kisskb/src/drivers/tty/serial/sh-sci.c: In function 'sci_dma_rx_submit': /kisskb/src/include/linux/spinlock.h:289:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized] _raw_spin_unlock_irqrestore(lock, flags); \ ^ /kisskb/src/drivers/tty/serial/sh-sci.c:1348:16: note: 'flags' was declared here unsigned long flags; ^ /kisskb/src/drivers/gpu/drm/bridge/tc358768.c: In function 'tc358768_bridge_pre_enable': /kisskb/src/drivers/gpu/drm/bridge/tc358768.c:840:1: warning: the frame size of 2224 bytes is larger than 2048 bytes [-Wframe-larger-than=] } ^ /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr': /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:396:26: warning: 'data' may be used uninitialized in this function [-Wmaybe-uninitialized] pd->msg->buf[real_pos] = data; ^ /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:369:16: note: 'data' was declared here unsigned char data; ^ Completed OK # rm -rf /kisskb/build/linus_arm64-allmodconfig_arm64-gcc5.4 # Build took: 0:19:33.823233