Buildresult: powerpc-next/arm64-defconfig/arm64-gcc5 built on Jun 19 2019, 01:11

kisskb

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Status:	OK
Date/Time:	Jun 19 2019, 01:11
Duration:	0:02:27.599346
Builder:	ka4
Revision:	powerpc/watchpoint: Restore NV GPRs while returning from exception (`4ea6e7299deb821cd410d8efb8ad86de9f867251)`
Target:	powerpc-next/arm64-defconfig/arm64-gcc5
Branch:	powerpc-next
Compiler:	arm64-gcc5 (aarch64-linux-gcc.br_real (Buildroot 2016.11-git-00613-ge98b4dd) 5.4.0 / GNU ld (GNU Binutils) 2.25.1)
Config:	defconfig (download)
Log:	Download original Possible warnings (3) net/ipv4/fib_semantics.c:1027:12: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized] drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wmaybe-uninitialized] include/linux/spinlock.h:288:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized] Full Log # git rev-parse -q --verify 4ea6e7299deb821cd410d8efb8ad86de9f867251^{commit} 4ea6e7299deb821cd410d8efb8ad86de9f867251 already have revision, skipping fetch # git checkout -q -f -B kisskb 4ea6e7299deb821cd410d8efb8ad86de9f867251 # git clean -qxdf # < git log -1 # commit 4ea6e7299deb821cd410d8efb8ad86de9f867251 # Author: Ravi Bangoria <ravi.bangoria@linux.ibm.com> # Date: Thu Jun 13 09:00:14 2019 +0530 # # powerpc/watchpoint: Restore NV GPRs while returning from exception # # powerpc hardware triggers watchpoint before executing the instruction. # To make trigger-after-execute behavior, kernel emulates the # instruction. If the instruction is 'load something into non-volatile # register', exception handler should restore emulated register state # while returning back, otherwise there will be register state # corruption. eg, adding a watchpoint on a list can corrput the list: # # # cat /proc/kallsyms \| grep kthread_create_list # c00000000121c8b8 d kthread_create_list # # Add watchpoint on kthread_create_list->prev: # # # perf record -e mem:0xc00000000121c8c0 # # Run some workload such that new kthread gets invoked. eg, I just # logged out from console: # # list_add corruption. next->prev should be prev (c000000001214e00), \ # but was c00000000121c8b8. (next=c00000000121c8b8). # WARNING: CPU: 59 PID: 309 at lib/list_debug.c:25 __list_add_valid+0xb4/0xc0 # CPU: 59 PID: 309 Comm: kworker/59:0 Kdump: loaded Not tainted 5.1.0-rc7+ #69 # ... # NIP __list_add_valid+0xb4/0xc0 # LR __list_add_valid+0xb0/0xc0 # Call Trace: # __list_add_valid+0xb0/0xc0 (unreliable) # __kthread_create_on_node+0xe0/0x260 # kthread_create_on_node+0x34/0x50 # create_worker+0xe8/0x260 # worker_thread+0x444/0x560 # kthread+0x160/0x1a0 # ret_from_kernel_thread+0x5c/0x70 # # List corruption happened because it uses 'load into non-volatile # register' instruction: # # Snippet from __kthread_create_on_node: # # c000000000136be8: addis r29,r2,-19 # c000000000136bec: ld r29,31424(r29) # if (!__list_add_valid(new, prev, next)) # c000000000136bf0: mr r3,r30 # c000000000136bf4: mr r5,r28 # c000000000136bf8: mr r4,r29 # c000000000136bfc: bl c00000000059a2f8 <__list_add_valid+0x8> # # Register state from WARN_ON(): # # GPR00: c00000000059a3a0 c000007ff23afb50 c000000001344e00 0000000000000075 # GPR04: 0000000000000000 0000000000000000 0000001852af8bc1 0000000000000000 # GPR08: 0000000000000001 0000000000000007 0000000000000006 00000000000004aa # GPR12: 0000000000000000 c000007ffffeb080 c000000000137038 c000005ff62aaa00 # GPR16: 0000000000000000 0000000000000000 c000007fffbe7600 c000007fffbe7370 # GPR20: c000007fffbe7320 c000007fffbe7300 c000000001373a00 0000000000000000 # GPR24: fffffffffffffef7 c00000000012e320 c000007ff23afcb0 c000000000cb8628 # GPR28: c00000000121c8b8 c000000001214e00 c000007fef5b17e8 c000007fef5b17c0 # # Watchpoint hit at 0xc000000000136bec. # # addis r29,r2,-19 # => r29 = 0xc000000001344e00 + (-19 << 16) # => r29 = 0xc000000001214e00 # # ld r29,31424(r29) # => r29 = (0xc000000001214e00 + 31424) # => r29 = (0xc00000000121c8c0) # # 0xc00000000121c8c0 is where we placed a watchpoint and thus this # instruction was emulated by emulate_step. But because handle_dabr_fault # did not restore emulated register state, r29 still contains stale # value in above register state. # # Fixes: 5aae8a5370802 ("powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors") # Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> # Cc: stable@vger.kernel.org # 2.6.36+ # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # < /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 4ea6e7299deb821cd410d8efb8ad86de9f867251 # < make -s -j 120 ARCH=arm64 O=/kisskb/build/powerpc-next_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux- defconfig # make -s -j 120 ARCH=arm64 O=/kisskb/build/powerpc-next_arm64-defconfig_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:40: LSE atomics not supported by binutils /kisskb/src/net/ipv4/fib_semantics.c: In function 'fib_check_nh_v4_gw': /kisskb/src/net/ipv4/fib_semantics.c:1027:12: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized] if (!tbl \|\| err) { ^ /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr': /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:399:26: 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:372:16: note: 'data' was declared here unsigned char data; ^ 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:17, from /kisskb/src/drivers/tty/serial/sh-sci.c:24: /kisskb/src/drivers/tty/serial/sh-sci.c: In function 'sci_dma_rx_submit': /kisskb/src/include/linux/spinlock.h:288:3: 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:1353:16: note: 'flags' was declared here unsigned long flags; ^ Completed OK # rm -rf /kisskb/build/powerpc-next_arm64-defconfig_arm64-gcc5.4 # Build took: 0:02:27.599346

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