# git rev-parse -q --verify 9933819099c4600b41a042f27a074470a43cf6b9^{commit} 9933819099c4600b41a042f27a074470a43cf6b9 already have revision, skipping fetch # git checkout -q -f -B kisskb 9933819099c4600b41a042f27a074470a43cf6b9 # git clean -qxdf # < git log -1 # commit 9933819099c4600b41a042f27a074470a43cf6b9 # Author: Christophe Leroy # Date: Mon Jan 27 10:42:04 2020 +0000 # # powerpc/32s: Fix CPU wake-up from sleep mode # # Commit f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and # rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when # _TLF_SLEEPING is set) by delaying the tovirt(r2, r2). # # This is because r2 is not restored by fast_exception_return. It used # to work (by chance ?) because CPU wake-up interrupt never comes from # user, so r2 is expected to point to 'current' on return. # # Commit e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access # Protection") broke it even more by clobbering r0 which is not # restored by fast_exception_return either. # # Use r6 instead of r0. This is possible because r3-r6 are restored by # fast_exception_return and only r3-r5 are used for exception arguments. # # For r2 it could be converted back to virtual address, but stay on the # safe side and restore it from the stack instead. It should be live # in the cache at that moment, so loading from the stack should make # no difference compared to converting it from phys to virt. # # Fixes: f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU") # Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection") # Cc: stable@vger.kernel.org # Signed-off-by: Christophe Leroy # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/6d02c3ae6ad77af34392e98117e44c2bf6d13ba1.1580121710.git.christophe.leroy@c-s.fr # < /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 9933819099c4600b41a042f27a074470a43cf6b9 # < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_defconfig+UP_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- ppc64_defconfig # Added to kconfig CONFIG_SMP=n # yes \n | make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_defconfig+UP_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- oldconfig yes: standard output: Broken pipe # make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_defconfig+UP_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /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/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/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_write': /kisskb/src/drivers/base/regmap/regmap.c:1852:6: warning: 'ret' 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/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/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/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1426:5: warning: 'page' 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/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/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/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/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 c0000000018e8558 R_PPC64_ADDR64 _binary__btf_vmlinux_bin_start c0000000018e8560 R_PPC64_ADDR64 _binary__btf_vmlinux_bin_end Completed OK # rm -rf /kisskb/build/powerpc-next_ppc64_defconfig+UP_powerpc-gcc4.6 # Build took: 0:02:51.683452