Buildresult: powerpc-fixes/ep88xc_defconfig/powerpc-gcc4.6 built on Feb 8 2020, 00:11

kisskb

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Status:	OK
Date/Time:	Feb 8 2020, 00:11
Duration:	0:00:44.127568
Builder:	blade4b
Revision:	powerpc/futex: Fix incorrect user access blocking (`8cb55a3daebd4b38330b706117e1c8203ffaf3f5)`
Target:	powerpc-fixes/ep88xc_defconfig/powerpc-gcc4.6
Branch:	powerpc-fixes
Compiler:	powerpc-gcc4.6 (powerpc-linux-gcc (GCC) 4.6.3 / GNU ld (GNU Binutils) 2.22)
Config:	ep88xc_defconfig (download)
Log:	Download original Possible warnings (3) include/linux/list.h:72:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] kernel/printk/printk.c:204:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] fs/io_uring.c:5713:13: warning: 'err' may be used uninitialized in this function [-Wuninitialized] Full Log # git rev-parse -q --verify 8cb55a3daebd4b38330b706117e1c8203ffaf3f5^{commit} 8cb55a3daebd4b38330b706117e1c8203ffaf3f5 already have revision, skipping fetch # git checkout -q -f -B kisskb 8cb55a3daebd4b38330b706117e1c8203ffaf3f5 # git clean -qxdf # < git log -1 # commit 8cb55a3daebd4b38330b706117e1c8203ffaf3f5 # Author: Michael Ellerman <mpe@ellerman.id.au> # Date: Fri Feb 7 22:15:46 2020 +1100 # # powerpc/futex: Fix incorrect user access blocking # # The early versions of our kernel user access prevention (KUAP) were # written by Russell and Christophe, and didn't have separate # read/write access. # # At some point I picked up the series and added the read/write access, # but I failed to update the usages in futex.h to correctly allow read # and write. # # However we didn't notice because of another bug which was causing the # low-level code to always enable read and write. That bug was fixed # recently in commit 1d8f739b07bd ("powerpc/kuap: Fix set direction in # allow/prevent_user_access()"). # # futex_atomic_cmpxchg_inatomic() is passed the user address as %3 and # does: # # 1: lwarx %1, 0, %3 # cmpw 0, %1, %4 # bne- 3f # 2: stwcx. %5, 0, %3 # # Which clearly loads and stores from/to %3. The logic in # arch_futex_atomic_op_inuser() is similar, so fix both of them to use # allow_read_write_user(). # # Without this fix, and with PPC_KUAP_DEBUG=y, we see eg: # # Bug: Read fault blocked by AMR! # WARNING: CPU: 94 PID: 149215 at arch/powerpc/include/asm/book3s/64/kup-radix.h:126 __do_page_fault+0x600/0xf30 # CPU: 94 PID: 149215 Comm: futex_requeue_p Tainted: G W 5.5.0-rc7-gcc9x-g4c25df5640ae #1 # ... # NIP [c000000000070680] __do_page_fault+0x600/0xf30 # LR [c00000000007067c] __do_page_fault+0x5fc/0xf30 # Call Trace: # [c00020138e5637e0] [c00000000007067c] __do_page_fault+0x5fc/0xf30 (unreliable) # [c00020138e5638c0] [c00000000000ada8] handle_page_fault+0x10/0x30 # --- interrupt: 301 at cmpxchg_futex_value_locked+0x68/0xd0 # LR = futex_lock_pi_atomic+0xe0/0x1f0 # [c00020138e563bc0] [c000000000217b50] futex_lock_pi_atomic+0x80/0x1f0 (unreliable) # [c00020138e563c30] [c00000000021b668] futex_requeue+0x438/0xb60 # [c00020138e563d60] [c00000000021c6cc] do_futex+0x1ec/0x2b0 # [c00020138e563d90] [c00000000021c8b8] sys_futex+0x128/0x200 # [c00020138e563e20] [c00000000000b7ac] system_call+0x5c/0x68 # # Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection") # Cc: stable@vger.kernel.org # v5.2+ # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # Link: https://lore.kernel.org/r/20200207122145.11928-1-mpe@ellerman.id.au # < /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 8cb55a3daebd4b38330b706117e1c8203ffaf3f5 # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ep88xc_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- ep88xc_defconfig # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ep88xc_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:72:12: 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/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/io_uring.c: In function '__io_sqe_files_update.isra.74': /kisskb/src/fs/io_uring.c:5713:13: warning: 'err' may be used uninitialized in this function [-Wuninitialized] Completed OK # rm -rf /kisskb/build/powerpc-fixes_ep88xc_defconfig_powerpc-gcc4.6 # Build took: 0:00:44.127568

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