Buildresult: powerpc-next/44x/currituck_defconfig/powerpc-gcc4.6 built on May 9 2019, 00:56

kisskb

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Status:	OK
Date/Time:	May 9 2019, 00:56
Duration:	0:00:50.894957
Builder:	ka1
Revision:	powerpc/64s: Use early_mmu_has_feature() in set_kuap() (`a5a1fb260210893015872209514f73b55ab2138e)`
Target:	powerpc-next/44x/currituck_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:	44x/currituck_defconfig (download)
Log:	Download original Possible warnings (15) <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/rcu/srcutree.c:140:32: warning: 'levelspread[<Ud640>]' 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/base/regmap/regmap.c:2594:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] drivers/base/regmap/regmap.c:1855:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] arch/powerpc/boot/dts/currituck.dts:125.28-161.5: Warning (pci_bridge): /plb/pciex@10100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/currituck.dts:163.28-198.5: Warning (pci_bridge): /plb/pciex@30100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/currituck.dts:200.28-235.5: Warning (pci_bridge): /plb/pciex@38100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/currituck.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' Full Log # git rev-parse -q --verify a5a1fb260210893015872209514f73b55ab2138e^{commit} a5a1fb260210893015872209514f73b55ab2138e already have revision, skipping fetch # git checkout -q -f -B kisskb a5a1fb260210893015872209514f73b55ab2138e # git clean -qxdf # < git log -1 # commit a5a1fb260210893015872209514f73b55ab2138e # Author: Michael Ellerman <mpe@ellerman.id.au> # Date: Wed May 8 13:06:42 2019 +1000 # # powerpc/64s: Use early_mmu_has_feature() in set_kuap() # # When implementing the KUAP support on Radix we fixed one case where # mmu_has_feature() was being called too early in boot via # __put_user_size(). # # However since then some new code in linux-next has created a new path # via which we can end up calling mmu_has_feature() too early. # # On P9 this leads to crashes early in boot if we have both PPC_KUAP and # CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG enabled. Our early boot code # calls printk() which calls probe_kernel_read(), that does a # __copy_from_user_inatomic() which calls into set_kuap() and that uses # mmu_has_feature(). # # At that point in boot we haven't patched MMU features yet so the debug # code in mmu_has_feature() complains, and calls printk(). At that point # we recurse, eg: # # ... # dump_stack+0xdc # probe_kernel_read+0x1a4 # check_pointer+0x58 # ... # printk+0x40 # dump_stack_print_info+0xbc # dump_stack+0x8 # probe_kernel_read+0x1a4 # probe_kernel_read+0x19c # check_pointer+0x58 # ... # printk+0x40 # cpufeatures_process_feature+0xc8 # scan_cpufeatures_subnodes+0x380 # of_scan_flat_dt_subnodes+0xb4 # dt_cpu_ftrs_scan_callback+0x158 # of_scan_flat_dt+0xf0 # dt_cpu_ftrs_scan+0x3c # early_init_devtree+0x360 # early_setup+0x9c # # And so on for infinity, symptom is a dead system. # # Even more fun is what happens when using the hash MMU (ie. p8 or p9 # with Radix disabled), and when we don't have # CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG enabled. With the debug disabled # we don't check if static keys have been initialised, we just rely on # the jump label. But the jump label defaults to true so we just whack # the AMR even though Radix is not enabled. # # Clearing the AMR is fine, but after we've done the user copy we write # (0b11 << 62) into AMR. When using hash that makes all pages with key # zero no longer readable or writable. All kernel pages implicitly have # key zero, and so all of a sudden the kernel can't read or write any of # its memory. Again dead system. # # In the medium term we have several options for fixing this. # probe_kernel_read() doesn't need to touch AMR at all, it's not doing a # user access after all, but it uses __copy_from_user_inatomic() just # because it's easy, we could fix that. # # It would also be safe to default to not writing to the AMR during # early boot, until we've detected features. But it's not clear that # flipping all the MMU features to static_key_false won't introduce # other bugs. # # But for now just switch to early_mmu_has_feature() in set_kuap(), that # avoids all the problems with jump labels. It adds the overhead of a # global lookup and test, but that's probably trivial compared to the # writes to the AMR anyway. # # Fixes: 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU") # 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 a5a1fb260210893015872209514f73b55ab2138e # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_44x_currituck_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- 44x/currituck_defconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_44x_currituck_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/rcu/srcutree.c: In function 'init_srcu_struct_fields': /kisskb/src/kernel/rcu/srcutree.c:140:32: warning: 'levelspread[<Ud640>]' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/rcu/srcutree.c:88:6: note: 'levelspread[<Ud640>]' 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/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2594:6: 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:1855:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' 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:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:227:19: note: 'i' was declared here /kisskb/src/arch/powerpc/boot/dts/currituck.dts:125.28-161.5: Warning (pci_bridge): /plb/pciex@10100000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/currituck.dts:163.28-198.5: Warning (pci_bridge): /plb/pciex@30100000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/currituck.dts:200.28-235.5: Warning (pci_bridge): /plb/pciex@38100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/currituck.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' Completed OK # rm -rf /kisskb/build/powerpc-next_44x_currituck_defconfig_powerpc-gcc4.6 # Build took: 0:00:50.894957

© Michael Ellerman 2006-2018.