# git rev-parse -q --verify ad910e36da4ca3a1bd436989f632d062dda0c921^{commit} ad910e36da4ca3a1bd436989f632d062dda0c921 already have revision, skipping fetch # git checkout -q -f -B kisskb ad910e36da4ca3a1bd436989f632d062dda0c921 # git clean -qxdf # < git log -1 # commit ad910e36da4ca3a1bd436989f632d062dda0c921 # Author: Linus Torvalds # Date: Sat Dec 7 10:41:17 2019 -0800 # # pipe: fix poll/select race introduced by the pipe rework # # The kernel wait queues have a basic rule to them: you add yourself to # the wait-queue first, and then you check the things that you're going to # wait on. That avoids the races with the event you're waiting for. # # The same goes for poll/select logic: the "poll_wait()" goes first, and # then you check the things you're polling for. # # Of course, if you use locking, the ordering doesn't matter since the # lock will serialize with anything that changes the state you're looking # at. That's not the case here, though. # # So move the poll_wait() first in pipe_poll(), before you start looking # at the pipe state. # # Fixes: 8cefc107ca54 ("pipe: Use head and tail pointers for the ring, not cursor and length") # Cc: David Howells # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 ad910e36da4ca3a1bd436989f632d062dda0c921 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/linus_ppc64_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- ppc64_defconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/linus_ppc64_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/fs/ext4/extents.c: In function 'ext4_convert_unwritten_io_end_vec': /kisskb/src/fs/ext4/extents.c:5054:23: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2591:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1852:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/bridge/br_netlink.c: In function 'br_afspec.isra.30': /kisskb/src/net/bridge/br_netlink.c:648:7: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:204:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc': /kisskb/src/fs/nfsd/nfs4xdr.c:2076:9: warning: 'str' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:338:21: note: 'pdeo' was declared here /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1377:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/core/devlink.c: In function 'devlink_fmsg_prepare_skb': /kisskb/src/net/core/devlink.c:4613:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:248:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:228:19: note: 'i' was declared here /kisskb/src/drivers/net/tun.c: In function 'tun_get_user': /kisskb/src/drivers/net/tun.c:1836:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1749:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/usb/core/devio.c: In function 'async_completed': /kisskb/src/drivers/usb/core/devio.c:625:23: warning: 'errno' may be used uninitialized in this function [-Wuninitialized] WARNING: 2 bad relocations c0000000018c4458 R_PPC64_ADDR64 _binary__btf_vmlinux_bin_start c0000000018c4460 R_PPC64_ADDR64 _binary__btf_vmlinux_bin_end Completed OK # rm -rf /kisskb/build/linus_ppc64_defconfig_powerpc-gcc4.6 # Build took: 0:02:52.056504