Buildresult: powerpc-next/pq2fads_defconfig/powerpc-gcc4.6 built on May 2 2019, 00:38

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Status:	OK
Date/Time:	May 2 2019, 00:38
Duration:	0:00:51.461177
Builder:	ka2
Revision:	powerpc/tm: Avoid machine crash on rt_sigreturn() (`e620d45065c7b5b8d6ae11217c09c09380103b83)`
Target:	powerpc-next/pq2fads_defconfig/powerpc-gcc4.6
Branch:	powerpc-next
Compiler:	powerpc-gcc4.6 (powerpc-linux-gcc (GCC) 4.6.3 / GNU ld (GNU Binutils) 2.22)
Config:	pq2fads_defconfig (download)
Log:	Download original Possible warnings (11) <stdin>:1478:2: warning: #warning syscall pidfd_send_signal not implemented [-Wcpp] <stdin>:1481:2: warning: #warning syscall io_uring_setup not implemented [-Wcpp] <stdin>:1484:2: warning: #warning syscall io_uring_enter not implemented [-Wcpp] <stdin>:1487:2: warning: #warning syscall io_uring_register not implemented [-Wcpp] kernel/printk/printk.c:187:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] kernel/futex.c:1658:3: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized] include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] drivers/net/tun.c:1842:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] drivers/net/tun.c:1755:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] WARNING: vmlinux.o(.text+0x10858): Section mismatch in reference from the function setup_kup() to the function .init.text:setup_kuep() WARNING: vmlinux.o(.text+0x10860): Section mismatch in reference from the function setup_kup() to the function .init.text:setup_kuap() Full Log # git rev-parse -q --verify e620d45065c7b5b8d6ae11217c09c09380103b83^{commit} e620d45065c7b5b8d6ae11217c09c09380103b83 already have revision, skipping fetch # git checkout -q -f -B kisskb e620d45065c7b5b8d6ae11217c09c09380103b83 # git clean -qxdf # < git log -1 # commit e620d45065c7b5b8d6ae11217c09c09380103b83 # Author: Breno Leitao <leitao@debian.org> # Date: Wed Jan 16 14:47:44 2019 -0200 # # powerpc/tm: Avoid machine crash on rt_sigreturn() # # There is a kernel crash that happens if rt_sigreturn() is called inside # a transactional block. # # This crash happens if the kernel hits an in-kernel page fault when # accessing userspace memory, usually through copy_ckvsx_to_user(). A # major page fault calls might_sleep() function, which can cause a task # reschedule. A task reschedule (switch_to()) reclaim and recheckpoint # the TM states, but, in the signal return path, the checkpointed memory # was already reclaimed, thus the exception stack has MSR that points to # MSR[TS]=0. # # When the code returns from might_sleep() and a task reschedule # happened, then this task is returned with the memory recheckpointed, # and CPU MSR[TS] = suspended. # # This means that there is a side effect at might_sleep() if it is # called with CPU MSR[TS] = 0 and the task has regs->msr[TS] != 0. # # This side effect can cause a TM bad thing, since at the exception # entrance, the stack saves MSR[TS]=0, and this is what will be used at # RFID, but, the processor has MSR[TS] = Suspended, and this transition # will be invalid and a TM Bad thing will be raised, causing the # following crash: # # Unexpected TM Bad Thing exception at c00000000000e9ec (msr 0x8000000302a03031) tm_scratch=800000010280b033 # cpu 0xc: Vector: 700 (Program Check) at [c00000003ff1fd70] # pc: c00000000000e9ec: fast_exception_return+0x100/0x1bc # lr: c000000000032948: handle_rt_signal64+0xb8/0xaf0 # sp: c0000004263ebc40 # msr: 8000000302a03031 # current = 0xc000000415050300 # paca = 0xc00000003ffc4080 irqmask: 0x03 irq_happened: 0x01 # pid = 25006, comm = sigfuz # Linux version 5.0.0-rc1-00001-g3bd6e94bec12 (breno@debian) (gcc version 8.2.0 (Debian 8.2.0-3)) #899 SMP Mon Jan 7 11:30:07 EST 2019 # WARNING: exception is not recoverable, can't continue # enter ? for help # [c0000004263ebc40] c000000000032948 handle_rt_signal64+0xb8/0xaf0 (unreliable) # [c0000004263ebd30] c000000000022780 do_notify_resume+0x2f0/0x430 # [c0000004263ebe20] c00000000000e844 ret_from_except_lite+0x70/0x74 # --- Exception: c00 (System Call) at 00007fffbaac400c # SP (7fffeca90f40) is in userspace # # The solution for this problem is running the sigreturn code with # regs->msr[TS] disabled, thus, avoiding hitting the side effect above. # This does not seem to be a problem since regs->msr will be replaced by # the ucontext value, so, it is being flushed already. In this case, it # is flushed earlier. # # Signed-off-by: Breno Leitao <leitao@debian.org> # Acked-by: Michael Neuling <mikey@neuling.org> # Signed-off-by: Michael Ellerman <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 e620d45065c7b5b8d6ae11217c09c09380103b83 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_pq2fads_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- pq2fads_defconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_pq2fads_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- <stdin>:1478:2: warning: #warning syscall pidfd_send_signal not implemented [-Wcpp] <stdin>:1481:2: warning: #warning syscall io_uring_setup not implemented [-Wcpp] <stdin>:1484:2: warning: #warning syscall io_uring_enter not implemented [-Wcpp] <stdin>:1487:2: warning: #warning syscall io_uring_register not implemented [-Wcpp] /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:187:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/futex.c: In function 'do_futex': /kisskb/src/kernel/futex.c:1658:3: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/futex.c:1633:6: note: 'oldval' was declared here /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:337:21: note: 'pdeo' was declared here /kisskb/src/drivers/net/tun.c: In function 'tun_get_user': /kisskb/src/drivers/net/tun.c:1842:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1755:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] WARNING: vmlinux.o(.text+0x10858): Section mismatch in reference from the function setup_kup() to the function .init.text:setup_kuep() The function setup_kup() references the function __init setup_kuep(). This is often because setup_kup lacks a __init annotation or the annotation of setup_kuep is wrong. WARNING: vmlinux.o(.text+0x10860): Section mismatch in reference from the function setup_kup() to the function .init.text:setup_kuap() The function setup_kup() references the function __init setup_kuap(). This is often because setup_kup lacks a __init annotation or the annotation of setup_kuap is wrong. INFO: Uncompressed kernel (size 0x5911d0) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x580bc4) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-5.1.0-rc3-ge620d45065c7 Created: Thu May 2 00:39:47 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2874867 Bytes = 2807.49 KiB = 2.74 MiB Load Address: 00600000 Entry Point: 00600888 Image Name: Linux-5.1.0-rc3-ge620d45065c7 Created: Thu May 2 00:39:47 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2842849 Bytes = 2776.22 KiB = 2.71 MiB Load Address: 00000000 Entry Point: 00000000 Completed OK # rm -rf /kisskb/build/powerpc-next_pq2fads_defconfig_powerpc-gcc4.6 # Build took: 0:00:51.461177

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