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2019-05-08powerpc/mm/hash: Handle mmap_min_addr correctly in get_unmapped_area topdown ↵Aneesh Kumar K.V
search commit 3b4d07d2674f6b4a9281031f99d1f7efd325b16d upstream. When doing top-down search the low_limit is not PAGE_SIZE but rather max(PAGE_SIZE, mmap_min_addr). This handle cases in which mmap_min_addr > PAGE_SIZE. Fixes: fba2369e6ceb ("mm: use vm_unmapped_area() on powerpc architecture") Reviewed-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-08kmemleak: powerpc: skip scanning holes in the .bss sectionCatalin Marinas
[ Upstream commit 298a32b132087550d3fa80641ca58323c5dfd4d9 ] Commit 2d4f567103ff ("KVM: PPC: Introduce kvm_tmp framework") adds kvm_tmp[] into the .bss section and then free the rest of unused spaces back to the page allocator. kernel_init kvm_guest_init kvm_free_tmp free_reserved_area free_unref_page free_unref_page_prepare With DEBUG_PAGEALLOC=y, it will unmap those pages from kernel. As the result, kmemleak scan will trigger a panic when it scans the .bss section with unmapped pages. This patch creates dedicated kmemleak objects for the .data, .bss and potentially .data..ro_after_init sections to allow partial freeing via the kmemleak_free_part() in the powerpc kvm_free_tmp() function. Link: http://lkml.kernel.org/r/20190321171917.62049-1-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Qian Cai <cai@lca.pw> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Qian Cai <cai@lca.pw> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Avi Kivity <avi@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-20powerpc/pseries: Remove prrn_work workqueueNathan Fontenot
[ Upstream commit cd24e457fd8b2d087d9236700c8d2957054598bf ] When a PRRN event is received we are already running in a worker thread. Instead of spawning off another worker thread on the prrn_work workqueue to handle the PRRN event we can just call the PRRN handler routine directly. With this update we can also pass the scope variable for the PRRN event directly to the handler instead of it being a global variable. This patch fixes the following oops mnessage we are seeing in PRRN testing: Oops: Bad kernel stack pointer, sig: 6 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache binfmt_misc reiserfs vfat fat rpadlpar_io(X) rpaphp(X) tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag af_packet xfs libcrc32c dm_service_time ibmveth(X) ses enclosure scsi_transport_sas rtc_generic btrfs xor raid6_pq sd_mod ibmvscsi(X) scsi_transport_srp ipr(X) libata sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4 Supported: Yes, External 54 CPU: 7 PID: 18967 Comm: kworker/u96:0 Tainted: G X 4.4.126-94.22-default #1 Workqueue: pseries hotplug workque pseries_hp_work_fn task: c000000775367790 ti: c00000001ebd4000 task.ti: c00000070d140000 NIP: 0000000000000000 LR: 000000001fb3d050 CTR: 0000000000000000 REGS: c00000001ebd7d40 TRAP: 0700 Tainted: G X (4.4.126-94.22-default) MSR: 8000000102081000 <41,VEC,ME5 CR: 28000002 XER: 20040018 4 CFAR: 000000001fb3d084 40 419 1 3 GPR00: 000000000000000040000000000010007 000000001ffff400 000000041fffe200 GPR04: 000000000000008050000000000000000 000000001fb15fa8 0000000500000500 GPR08: 000000000001f40040000000000000001 0000000000000000 000005:5200040002 GPR12: 00000000000000005c000000007a05400 c0000000000e89f8 000000001ed9f668 GPR16: 000000001fbeff944000000001fbeff94 000000001fb545e4 0000006000000060 GPR20: ffffffffffffffff4ffffffffffffffff 0000000000000000 0000000000000000 GPR24: 00000000000000005400000001fb3c000 0000000000000000 000000001fb1b040 GPR28: 000000001fb240004000000001fb440d8 0000000000000008 0000000000000000 NIP [0000000000000000] 5 (null) LR [000000001fb3d050] 031fb3d050 Call Trace: 4 Instruction dump: 4 5:47 12 2 XXXXXXXX XXXXXXXX XXXXX4XX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXX5XX XXXXXXXX 60000000 60000000 60000000 60000000 ---[ end trace aa5627b04a7d9d6b ]--- 3NMI watchdog: BUG: soft lockup - CPU#27 stuck for 23s! [kworker/27:0:13903] Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache binfmt_misc reiserfs vfat fat rpadlpar_io(X) rpaphp(X) tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag af_packet xfs libcrc32c dm_service_time ibmveth(X) ses enclosure scsi_transport_sas rtc_generic btrfs xor raid6_pq sd_mod ibmvscsi(X) scsi_transport_srp ipr(X) libata sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4 Supported: Yes, External CPU: 27 PID: 13903 Comm: kworker/27:0 Tainted: G D X 4.4.126-94.22-default #1 Workqueue: events prrn_work_fn task: c000000747cfa390 ti: c00000074712c000 task.ti: c00000074712c000 NIP: c0000000008002a8 LR: c000000000090770 CTR: 000000000032e088 REGS: c00000074712f7b0 TRAP: 0901 Tainted: G D X (4.4.126-94.22-default) MSR: 8000000100009033 <SF,EE,ME,IR,DR,RI,LE> CR: 22482044 XER: 20040000 CFAR: c0000000008002c4 SOFTE: 1 GPR00: c000000000090770 c00000074712fa30 c000000000f09800 c000000000fa1928 6:02 GPR04: c000000775f5e000 fffffffffffffffe 0000000000000001 c000000000f42db8 GPR08: 0000000000000001 0000000080000007 0000000000000000 0000000000000000 GPR12: 8006210083180000 c000000007a14400 NIP [c0000000008002a8] _raw_spin_lock+0x68/0xd0 LR [c000000000090770] mobility_rtas_call+0x50/0x100 Call Trace: 59 5 [c00000074712fa60] [c000000000090770] mobility_rtas_call+0x50/0x100 [c00000074712faf0] [c000000000090b08] pseries_devicetree_update+0xf8/0x530 [c00000074712fc20] [c000000000031ba4] prrn_work_fn+0x34/0x50 [c00000074712fc40] [c0000000000e0390] process_one_work+0x1a0/0x4e0 [c00000074712fcd0] [c0000000000e0870] worker_thread+0x1a0/0x6105:57 2 [c00000074712fd80] [c0000000000e8b18] kthread+0x128/0x150 [c00000074712fe30] [c0000000000096f8] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 2c090000 40c20010 7d40192d 40c2fff0 7c2004ac 2fa90000 40de0018 5:540030 3 e8010010 ebe1fff8 7c0803a6 4e800020 <7c210b78> e92d0000 89290009 792affe3 Signed-off-by: John Allen <jallen@linux.ibm.com> Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-17powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEMBreno Leitao
[ Upstream commit 897bc3df8c5aebb54c32d831f917592e873d0559 ] Commit e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint") moved a code block around and this block uses a 'msr' variable outside of the CONFIG_PPC_TRANSACTIONAL_MEM, however the 'msr' variable is declared inside a CONFIG_PPC_TRANSACTIONAL_MEM block, causing a possible error when CONFIG_PPC_TRANSACTION_MEM is not defined. error: 'msr' undeclared (first use in this function) This is not causing a compilation error in the mainline kernel, because 'msr' is being used as an argument of MSR_TM_ACTIVE(), which is defined as the following when CONFIG_PPC_TRANSACTIONAL_MEM is *not* set: #define MSR_TM_ACTIVE(x) 0 This patch just fixes this issue avoiding the 'msr' variable usage outside the CONFIG_PPC_TRANSACTIONAL_MEM block, avoiding trusting in the MSR_TM_ACTIVE() definition. Cc: stable@vger.kernel.org Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Fixes: e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint") Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05powerpc/pseries: Perform full re-add of CPU for topology update post-migrationNathan Fontenot
[ Upstream commit 81b61324922c67f73813d8a9c175f3c153f6a1c6 ] On pseries systems, performing a partition migration can result in altering the nodes a CPU is assigned to on the destination system. For exampl, pre-migration on the source system CPUs are in node 1 and 3, post-migration on the destination system CPUs are in nodes 2 and 3. Handling the node change for a CPU can cause corruption in the slab cache if we hit a timing where a CPUs node is changed while cache_reap() is invoked. The corruption occurs because the slab cache code appears to rely on the CPU and slab cache pages being on the same node. The current dynamic updating of a CPUs node done in arch/powerpc/mm/numa.c does not prevent us from hitting this scenario. Changing the device tree property update notification handler that recognizes an affinity change for a CPU to do a full DLPAR remove and add of the CPU instead of dynamically changing its node resolves this issue. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com> Tested-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05powerpc/hugetlb: Handle mmap_min_addr correctly in get_unmapped_area callbackAneesh Kumar K.V
[ Upstream commit 5330367fa300742a97e20e953b1f77f48392faae ] After we ALIGN up the address we need to make sure we didn't overflow and resulted in zero address. In that case, we need to make sure that the returned address is greater than mmap_min_addr. This fixes selftest va_128TBswitch --run-hugetlb reporting failures when run as non root user for mmap(-1, MAP_HUGETLB) The bug is that a non-root user requesting address -1 will be given address 0 which will then fail, whereas they should have been given something else that would have succeeded. We also avoid the first mmap(-1, MAP_HUGETLB) returning NULL address as mmap address with this change. So we think this is not a security issue, because it only affects whether we choose an address below mmap_min_addr, not whether we actually allow that address to be mapped. ie. there are existing capability checks to prevent a user mapping below mmap_min_addr and those will still be honoured even without this fix. Fixes: 484837601d4d ("powerpc/mm: Add radix support for hugetlb") Reviewed-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpcNathan Chancellor
[ Upstream commit e7140639b1de65bba435a6bd772d134901141f86 ] When building with -Wsometimes-uninitialized, Clang warns: arch/powerpc/xmon/ppc-dis.c:157:7: warning: variable 'opcode' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (cpu_has_feature(CPU_FTRS_POWER9)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/xmon/ppc-dis.c:167:7: note: uninitialized use occurs here if (opcode == NULL) ^~~~~~ arch/powerpc/xmon/ppc-dis.c:157:3: note: remove the 'if' if its condition is always true if (cpu_has_feature(CPU_FTRS_POWER9)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/xmon/ppc-dis.c:132:38: note: initialize the variable 'opcode' to silence this warning const struct powerpc_opcode *opcode; ^ = NULL 1 warning generated. This warning seems to make no sense on the surface because opcode is set to NULL right below this statement. However, there is a comma instead of semicolon to end the dialect assignment, meaning that the opcode assignment only happens in the if statement. Properly terminate that line so that Clang no longer warns. Fixes: 5b102782c7f4 ("powerpc/xmon: Enable disassembly files (compilation changes)") Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-03powerpc: bpf: Fix generation of load/store DW instructionsNaveen N. Rao
commit 86be36f6502c52ddb4b85938145324fd07332da1 upstream. Yauheni Kaliuta pointed out that PTR_TO_STACK store/load verifier test was failing on powerpc64 BE, and rightfully indicated that the PPC_LD() macro is not masking away the last two bits of the offset per the ISA, resulting in the generation of 'lwa' instruction instead of the intended 'ld' instruction. Segher also pointed out that we can't simply mask away the last two bits as that will result in loading/storing from/to a memory location that was not intended. This patch addresses this by using ldx/stdx if the offset is not word-aligned. We load the offset into a temporary register (TMP_REG_2) and use that as the index register in a subsequent ldx/stdx. We fix PPC_LD() macro to mask off the last two bits, but enhance PPC_BPF_LL() and PPC_BPF_STL() to factor in the offset value and generate the proper instruction sequence. We also convert all existing users of PPC_LD() and PPC_STD() to use these macros. All existing uses of these macros have been audited to ensure that TMP_REG_2 can be clobbered. Fixes: 156d0e290e96 ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Cc: stable@vger.kernel.org # v4.9+ Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/security: Fix spectre_v2 reportingMichael Ellerman
commit 92edf8df0ff2ae86cc632eeca0e651fd8431d40d upstream. When I updated the spectre_v2 reporting to handle software count cache flush I got the logic wrong when there's no software count cache enabled at all. The result is that on systems with the software count cache flush disabled we print: Mitigation: Indirect branch cache disabled, Software count cache flush Which correctly indicates that the count cache is disabled, but incorrectly says the software count cache flush is enabled. The root of the problem is that we are trying to handle all combinations of options. But we know now that we only expect to see the software count cache flush enabled if the other options are false. So split the two cases, which simplifies the logic and fixes the bug. We were also missing a space before "(hardware accelerated)". The result is we see one of: Mitigation: Indirect branch serialisation (kernel only) Mitigation: Indirect branch cache disabled Mitigation: Software count cache flush Mitigation: Software count cache flush (hardware accelerated) Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Fix the flush of branch predictor.Christophe Leroy
commit 27da80719ef132cf8c80eb406d5aeb37dddf78cc upstream. The commit identified below adds MC_BTB_FLUSH macro only when CONFIG_PPC_FSL_BOOK3E is defined. This results in the following error on some configs (seen several times with kisskb randconfig_defconfig) arch/powerpc/kernel/exceptions-64e.S:576: Error: Unrecognized opcode: `mc_btb_flush' make[3]: *** [scripts/Makefile.build:367: arch/powerpc/kernel/exceptions-64e.o] Error 1 make[2]: *** [scripts/Makefile.build:492: arch/powerpc/kernel] Error 2 make[1]: *** [Makefile:1043: arch/powerpc] Error 2 make: *** [Makefile:152: sub-make] Error 2 This patch adds a blank definition of MC_BTB_FLUSH for other cases. Fixes: 10c5e83afd4a ("powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)") Cc: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Fixed warning: orphan section `__btb_flush_fixup'Diana Craciun
commit 039daac5526932ec731e4499613018d263af8b3e upstream. Fixed the following build warning: powerpc-linux-gnu-ld: warning: orphan section `__btb_flush_fixup' from `arch/powerpc/kernel/head_44x.o' being placed in section `__btb_flush_fixup'. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Update Spectre v2 reportingDiana Craciun
commit dfa88658fb0583abb92e062c7a9cd5a5b94f2a46 upstream. Report branch predictor state flush as a mitigation for Spectre variant 2. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Enable runtime patching if nospectre_v2 boot arg is usedDiana Craciun
commit 3bc8ea8603ae4c1e09aca8de229ad38b8091fcb3 upstream. If the user choses not to use the mitigations, replace the code sequence with nops. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Flush branch predictor when entering KVMDiana Craciun
commit e7aa61f47b23afbec41031bc47ca8d6cb6516abc upstream. Switching from the guest to host is another place where the speculative accesses can be exploited. Flush the branch predictor when entering KVM. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Flush the branch predictor at each kernel entry (32 bit)Diana Craciun
commit 7fef436295bf6c05effe682c8797dfcb0deb112a upstream. In order to protect against speculation attacks on indirect branches, the branch predictor is flushed at kernel entry to protect for the following situations: - userspace process attacking another userspace process - userspace process attacking the kernel Basically when the privillege level change (i.e.the kernel is entered), the branch predictor state is flushed. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)Diana Craciun
commit 10c5e83afd4a3f01712d97d3bb1ae34d5b74a185 upstream. In order to protect against speculation attacks on indirect branches, the branch predictor is flushed at kernel entry to protect for the following situations: - userspace process attacking another userspace process - userspace process attacking the kernel Basically when the privillege level change (i.e. the kernel is entered), the branch predictor state is flushed. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Add nospectre_v2 command line argumentDiana Craciun
commit f633a8ad636efb5d4bba1a047d4a0f1ef719aa06 upstream. When the command line argument is present, the Spectre variant 2 mitigations are disabled. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Emulate SPRN_BUCSR registerDiana Craciun
commit 98518c4d8728656db349f875fcbbc7c126d4c973 upstream. In order to flush the branch predictor the guest kernel performs writes to the BUCSR register which is hypervisor privilleged. However, the branch predictor is flushed at each KVM entry, so the branch predictor has been already flushed, so just return as soon as possible to guest. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Tweak comment formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Fix spectre_v2 mitigations reportingDiana Craciun
commit 7d8bad99ba5a22892f0cad6881289fdc3875a930 upstream. Currently for CONFIG_PPC_FSL_BOOK3E the spectre_v2 file is incorrect: $ cat /sys/devices/system/cpu/vulnerabilities/spectre_v2 "Mitigation: Software count cache flush" Which is wrong. Fix it to report vulnerable for now. Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Add macro to flush the branch predictorDiana Craciun
commit 1cbf8990d79ff69da8ad09e8a3df014e1494462b upstream. The BUCSR register can be used to invalidate the entries in the branch prediction mechanisms. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Add infrastructure to fixup branch predictor flushDiana Craciun
commit 76a5eaa38b15dda92cd6964248c39b5a6f3a4e9d upstream. In order to protect against speculation attacks (Spectre variant 2) on NXP PowerPC platforms, the branch predictor should be flushed when the privillege level is changed. This patch is adding the infrastructure to fixup at runtime the code sections that are performing the branch predictor flush depending on a boot arg parameter which is added later in a separate patch. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/powernv: Query firmware for count cache flush settingsMichael Ellerman
commit 99d54754d3d5f896a8f616b0b6520662bc99d66b upstream. Look for fw-features properties to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/pseries: Query hypervisor for count cache flush settingsMichael Ellerman
commit ba72dc171954b782a79d25e0f4b3ed91090c3b1e upstream. Use the existing hypercall to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64s: Add support for software count cache flushMichael Ellerman
commit ee13cb249fabdff8b90aaff61add347749280087 upstream. Some CPU revisions support a mode where the count cache needs to be flushed by software on context switch. Additionally some revisions may have a hardware accelerated flush, in which case the software flush sequence can be shortened. If we detect the appropriate flag from firmware we patch a branch into _switch() which takes us to a count cache flush sequence. That sequence in turn may be patched to return early if we detect that the CPU supports accelerating the flush sequence in hardware. Add debugfs support for reporting the state of the flush, as well as runtime disabling it. And modify the spectre_v2 sysfs file to report the state of the software flush. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64s: Add new security feature flags for count cache flushMichael Ellerman
commit dc8c6cce9a26a51fc19961accb978217a3ba8c75 upstream. Add security feature flags to indicate the need for software to flush the count cache on context switch, and for the presence of a hardware assisted count cache flush. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/asm: Add a patch_site macro & helpers for patching instructionsMichael Ellerman
commit 06d0bbc6d0f56dacac3a79900e9a9a0d5972d818 upstream. Add a macro and some helper C functions for patching single asm instructions. The gas macro means we can do something like: 1: nop patch_site 1b, patch__foo Which is less visually distracting than defining a GLOBAL symbol at 1, and also doesn't pollute the symbol table which can confuse eg. perf. These are obviously similar to our existing feature sections, but are not automatically patched based on CPU/MMU features, rather they are designed to be manually patched by C code at some arbitrary point. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit platformsDiana Craciun
commit c28218d4abbf4f2035495334d8bfcba64bda4787 upstream. Used barrier_nospec to sanitize the syscall table. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/fsl: Add barrier_nospec implementation for NXP PowerPC Book3EDiana Craciun
commit ebcd1bfc33c7a90df941df68a6e5d4018c022fba upstream. Implement the barrier_nospec as a isync;sync instruction sequence. The implementation uses the infrastructure built for BOOK3S 64. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64: Make meltdown reporting Book3S 64 specificDiana Craciun
commit 406d2b6ae3420f5bb2b3db6986dc6f0b6dbb637b upstream. In a subsequent patch we will enable building security.c for Book3E. However the NXP platforms are not vulnerable to Meltdown, so make the Meltdown vulnerability reporting PPC_BOOK3S_64 specific. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64: Call setup_barrier_nospec() from setup_arch()Michael Ellerman
commit af375eefbfb27cbb5b831984e66d724a40d26b5c upstream. Currently we require platform code to call setup_barrier_nospec(). But if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case then we can call it in setup_arch(). Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64: Add CONFIG_PPC_BARRIER_NOSPECMichael Ellerman
commit 179ab1cbf883575c3a585bcfc0f2160f1d22a149 upstream. Add a config symbol to encode which platforms support the barrier_nospec speculation barrier. Currently this is just Book3S 64 but we will add Book3E in a future patch. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64: Make stf barrier PPC_BOOK3S_64 specific.Diana Craciun
commit 6453b532f2c8856a80381e6b9a1f5ea2f12294df upstream. NXP Book3E platforms are not vulnerable to speculative store bypass, so make the mitigations PPC_BOOK3S_64 specific. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64: Disable the speculation barrier from the command lineDiana Craciun
commit cf175dc315f90185128fb061dc05b6fbb211aa2f upstream. The speculation barrier can be disabled from the command line with the parameter: "nospectre_v1". Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc64s: Show ori31 availability in spectre_v1 sysfs file not v2Michael Ellerman
commit 6d44acae1937b81cf8115ada8958e04f601f3f2e upstream. When I added the spectre_v2 information in sysfs, I included the availability of the ori31 speculation barrier. Although the ori31 barrier can be used to mitigate v2, it's primarily intended as a spectre v1 mitigation. Spectre v2 is mitigated by hardware changes. So rework the sysfs files to show the ori31 information in the spectre_v1 file, rather than v2. Currently we display eg: $ grep . spectre_v* spectre_v1:Mitigation: __user pointer sanitization spectre_v2:Mitigation: Indirect branch cache disabled, ori31 speculation barrier enabled After: $ grep . spectre_v* spectre_v1:Mitigation: __user pointer sanitization, ori31 speculation barrier enabled spectre_v2:Mitigation: Indirect branch cache disabled Fixes: d6fbe1c55c55 ("powerpc/64s: Wire up cpu_show_spectre_v2()") Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64s: Enhance the information in cpu_show_spectre_v1()Michal Suchanek
commit a377514519b9a20fa1ea9adddbb4129573129cef upstream. We now have barrier_nospec as mitigation so print it in cpu_show_spectre_v1() when enabled. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64: Use barrier_nospec in syscall entryMichael Ellerman
commit 51973a815c6b46d7b23b68d6af371ad1c9d503ca upstream. Our syscall entry is done in assembly so patch in an explicit barrier_nospec. Based on a patch by Michal Suchanek. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc: Use barrier_nospec in copy_from_user()Michael Ellerman
commit ddf35cf3764b5a182b178105f57515b42e2634f8 upstream. Based on the x86 commit doing the same. See commit 304ec1b05031 ("x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec") and b3bbfb3fb5d2 ("x86: Introduce __uaccess_begin_nospec() and uaccess_try_nospec") for more detail. In all cases we are ordering the load from the potentially user-controlled pointer vs a previous branch based on an access_ok() check or similar. Base on a patch from Michal Suchanek. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64s: Enable barrier_nospec based on firmware settingsMichal Suchanek
commit cb3d6759a93c6d0aea1c10deb6d00e111c29c19c upstream. Check what firmware told us and enable/disable the barrier_nospec as appropriate. We err on the side of enabling the barrier, as it's no-op on older systems, see the comment for more detail. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64s: Patch barrier_nospec in modulesMichal Suchanek
commit 815069ca57c142eb71d27439bc27f41a433a67b3 upstream. Note that unlike RFI which is patched only in kernel the nospec state reflects settings at the time the module was loaded. Iterating all modules and re-patching every time the settings change is not implemented. Based on lwsync patching. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03powerpc/64s: Add support for ori barrier_nospec patchingMichal Suchanek
commit 2eea7f067f495e33b8b116b35b5988ab2b8aec55 upstream. Based on the RFI patching. This is required to be able to disable the speculation barrier. Only one barrier type is supported and it does nothing when the firmware does not enable it. Also re-patching modules is not supported So the only meaningful thing that can be done is patching out the speculation barrier at boot when the user says it is not wanted. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23KVM: Call kvm_arch_memslots_updated() before updating memslotsSean Christopherson
commit 152482580a1b0accb60676063a1ac57b2d12daf6 upstream. kvm_arch_memslots_updated() is at this point in time an x86-specific hook for handling MMIO generation wraparound. x86 stashes 19 bits of the memslots generation number in its MMIO sptes in order to avoid full page fault walks for repeat faults on emulated MMIO addresses. Because only 19 bits are used, wrapping the MMIO generation number is possible, if unlikely. kvm_arch_memslots_updated() alerts x86 that the generation has changed so that it can invalidate all MMIO sptes in case the effective MMIO generation has wrapped so as to avoid using a stale spte, e.g. a (very) old spte that was created with generation==0. Given that the purpose of kvm_arch_memslots_updated() is to prevent consuming stale entries, it needs to be called before the new generation is propagated to memslots. Invalidating the MMIO sptes after updating memslots means that there is a window where a vCPU could dereference the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO spte that was created with (pre-wrap) generation==0. Fixes: e59dbe09f8e6 ("KVM: Introduce kvm_arch_memslots_updated()") Cc: <stable@vger.kernel.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc/traps: Fix the message printed when stack overflowsChristophe Leroy
commit 9bf3d3c4e4fd82c7174f4856df372ab2a71005b9 upstream. Today's message is useless: [ 42.253267] Kernel stack overflow in process (ptrval), r1=c65500b0 This patch fixes it: [ 66.905235] Kernel stack overflow in process sh[356], r1=c65560b0 Fixes: ad67b74d2469 ("printk: hash addresses printed with %p") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Use task_pid_nr()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc/traps: fix recoverability of machine check handling on book3s/32Christophe Leroy
commit 0bbea75c476b77fa7d7811d6be911cc7583e640f upstream. Looks like book3s/32 doesn't set RI on machine check, so checking RI before calling die() will always be fatal allthought this is not an issue in most cases. Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc/hugetlb: Don't do runtime allocation of 16G pages in LPAR configurationAneesh Kumar K.V
commit 35f2806b481f5b9207f25e1886cba5d1c4d12cc7 upstream. We added runtime allocation of 16G pages in commit 4ae279c2c96a ("powerpc/mm/hugetlb: Allow runtime allocation of 16G.") That was done to enable 16G allocation on PowerNV and KVM config. In case of KVM config, we mostly would have the entire guest RAM backed by 16G hugetlb pages for this to work. PAPR do support partial backing of guest RAM with hugepages via ibm,expected#pages node of memory node in the device tree. This means rest of the guest RAM won't be backed by 16G contiguous pages in the host and hence a hash page table insertion can fail in such case. An example error message will look like hash-mmu: mm: Hashing failure ! EA=0x7efc00000000 access=0x8000000000000006 current=readback hash-mmu: trap=0x300 vsid=0x67af789 ssize=1 base psize=14 psize 14 pte=0xc000000400000386 readback[12260]: unhandled signal 7 at 00007efc00000000 nip 00000000100012d0 lr 000000001000127c code 2 This patch address that by preventing runtime allocation of 16G hugepages in LPAR config. To allocate 16G hugetlb one need to kernel command line hugepagesz=16G hugepages=<number of 16G pages> With radix translation mode we don't run into this issue. This change will prevent runtime allocation of 16G hugetlb pages on kvm with hash translation mode. However, with the current upstream it was observed that 16G hugetlbfs backed guest doesn't boot at all. We observe boot failure with the below message: [131354.647546] KVM: map_vrma at 0 failed, ret=-4 That means this patch is not resulting in an observable regression. Once we fix the boot issue with 16G hugetlb backed memory, we need to use ibm,expected#pages memory node attribute to indicate 16G page reservation to the guest. This will also enable partial backing of guest RAM with 16G pages. Fixes: 4ae279c2c96a ("powerpc/mm/hugetlb: Allow runtime allocation of 16G.") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc/ptrace: Simplify vr_get/set() to avoid GCC warningMichael Ellerman
commit ca6d5149d2ad0a8d2f9c28cbe379802260a0a5e0 upstream. GCC 8 warns about the logic in vr_get/set(), which with -Werror breaks the build: In function ‘user_regset_copyin’, inlined from ‘vr_set’ at arch/powerpc/kernel/ptrace.c:628:9: include/linux/regset.h:295:4: error: ‘memcpy’ offset [-527, -529] is out of the bounds [0, 16] of object ‘vrsave’ with type ‘union <anonymous>’ [-Werror=array-bounds] arch/powerpc/kernel/ptrace.c: In function ‘vr_set’: arch/powerpc/kernel/ptrace.c:623:5: note: ‘vrsave’ declared here } vrsave; This has been identified as a regression in GCC, see GCC bug 88273. However we can avoid the warning and also simplify the logic and make it more robust. Currently we pass -1 as end_pos to user_regset_copyout(). This says "copy up to the end of the regset". The definition of the regset is: [REGSET_VMX] = { .core_note_type = NT_PPC_VMX, .n = 34, .size = sizeof(vector128), .align = sizeof(vector128), .active = vr_active, .get = vr_get, .set = vr_set }, The end is calculated as (n * size), ie. 34 * sizeof(vector128). In vr_get/set() we pass start_pos as 33 * sizeof(vector128), meaning we can copy up to sizeof(vector128) into/out-of vrsave. The on-stack vrsave is defined as: union { elf_vrreg_t reg; u32 word; } vrsave; And elf_vrreg_t is: typedef __vector128 elf_vrreg_t; So there is no bug, but we rely on all those sizes lining up, otherwise we would have a kernel stack exposure/overwrite on our hands. Rather than relying on that we can pass an explict end_pos based on the sizeof(vrsave). The result should be exactly the same but it's more obviously not over-reading/writing the stack and it avoids the compiler warning. Reported-by: Meelis Roos <mroos@linux.ee> Reported-by: Mathieu Malaterre <malat@debian.org> Cc: stable@vger.kernel.org Tested-by: Mathieu Malaterre <malat@debian.org> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc: Fix 32-bit KVM-PR lockup and host crash with MacOS guestMark Cave-Ayland
commit fe1ef6bcdb4fca33434256a802a3ed6aacf0bd2f upstream. Commit 8792468da5e1 "powerpc: Add the ability to save FPU without giving it up" unexpectedly removed the MSR_FE0 and MSR_FE1 bits from the bitmask used to update the MSR of the previous thread in __giveup_fpu() causing a KVM-PR MacOS guest to lockup and panic the host kernel. Leaving FE0/1 enabled means unrelated processes might receive FPEs when they're not expecting them and crash. In particular if this happens to init the host will then panic. eg (transcribed): qemu-system-ppc[837]: unhandled signal 8 at 12cc9ce4 nip 12cc9ce4 lr 12cc9ca4 code 0 systemd[1]: unhandled signal 8 at 202f02e0 nip 202f02e0 lr 001003d4 code 0 Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Reinstate these bits to the MSR bitmask to enable MacOS guests to run under 32-bit KVM-PR once again without issue. Fixes: 8792468da5e1 ("powerpc: Add the ability to save FPU without giving it up") Cc: stable@vger.kernel.org # v4.6+ Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc/83xx: Also save/restore SPRG4-7 during suspendChristophe Leroy
commit 36da5ff0bea2dc67298150ead8d8471575c54c7d upstream. The 83xx has 8 SPRG registers and uses at least SPRG4 for DTLB handling LRU. Fixes: 2319f1239592 ("powerpc/mm: e300c2/c3/c4 TLB errata workaround") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc/powernv: Make opal log only readable by rootJordan Niethe
commit 7b62f9bd2246b7d3d086e571397c14ba52645ef1 upstream. Currently the opal log is globally readable. It is kernel policy to limit the visibility of physical addresses / kernel pointers to root. Given this and the fact the opal log may contain this information it would be better to limit the readability to root. Fixes: bfc36894a48b ("powerpc/powernv: Add OPAL message log interface") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Stewart Smith <stewart@linux.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc/wii: properly disable use of BATs when requested.Christophe Leroy
commit 6d183ca8baec983dc4208ca45ece3c36763df912 upstream. 'nobats' kernel parameter or some options like CONFIG_DEBUG_PAGEALLOC deny the use of BATS for mapping memory. This patch makes sure that the specific wii RAM mapping function takes it into account as well. Fixes: de32400dd26e ("wii: use both mem1 and mem2 as ram") Cc: stable@vger.kernel.org Reviewed-by: Jonathan Neuschafer <j.neuschaefer@gmx.net> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23powerpc/32: Clear on-stack exception marker upon exception returnChristophe Leroy
commit 9580b71b5a7863c24a9bd18bcd2ad759b86b1eff upstream. Clear the on-stack STACK_FRAME_REGS_MARKER on exception exit in order to avoid confusing stacktrace like the one below. Call Trace: [c0e9dca0] [c01c42a0] print_address_description+0x64/0x2bc (unreliable) [c0e9dcd0] [c01c4684] kasan_report+0xfc/0x180 [c0e9dd10] [c0895130] memchr+0x24/0x74 [c0e9dd30] [c00a9e38] msg_print_text+0x124/0x574 [c0e9dde0] [c00ab710] console_unlock+0x114/0x4f8 [c0e9de40] [c00adc60] vprintk_emit+0x188/0x1c4 --- interrupt: c0e9df00 at 0x400f330 LR = init_stack+0x1f00/0x2000 [c0e9de80] [c00ae3c4] printk+0xa8/0xcc (unreliable) [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108 [c0e9df50] [c0c15434] start_kernel+0x310/0x488 [c0e9dff0] [00003484] 0x3484 With this patch the trace becomes: Call Trace: [c0e9dca0] [c01c42c0] print_address_description+0x64/0x2bc (unreliable) [c0e9dcd0] [c01c46a4] kasan_report+0xfc/0x180 [c0e9dd10] [c0895150] memchr+0x24/0x74 [c0e9dd30] [c00a9e58] msg_print_text+0x124/0x574 [c0e9dde0] [c00ab730] console_unlock+0x114/0x4f8 [c0e9de40] [c00adc80] vprintk_emit+0x188/0x1c4 [c0e9de80] [c00ae3e4] printk+0xa8/0xcc [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108 [c0e9df50] [c0c15434] start_kernel+0x310/0x488 [c0e9dff0] [00003484] 0x3484 Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>