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2021-03-30powerpc/4xx: Fix build errors from mfdcr()Michael Ellerman
[ Upstream commit eead089311f4d935ab5d1d8fbb0c42ad44699ada ] lkp reported a build error in fsp2.o: CC arch/powerpc/platforms/44x/fsp2.o {standard input}:577: Error: unsupported relocation against base Which comes from: pr_err("GESR0: 0x%08x\n", mfdcr(base + PLB4OPB_GESR0)); Where our mfdcr() macro is stringifying "base + PLB4OPB_GESR0", and passing that to the assembler, which obviously doesn't work. The mfdcr() macro already checks that the argument is constant using __builtin_constant_p(), and if not calls the out-of-line version of mfdcr(). But in this case GCC is smart enough to notice that "base + PLB4OPB_GESR0" will be constant, even though it's not something we can immediately stringify into a register number. Segher pointed out that passing the register number to the inline asm as a constant would be better, and in fact it fixes the build error, presumably because it gives GCC a chance to resolve the value. While we're at it, change mtdcr() similarly. Reported-by: kernel test robot <lkp@intel.com> Suggested-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Feng Tang <feng.tang@intel.com> Link: https://lore.kernel.org/r/20210218123058.748882-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-24powerpc: Force inlining of cpu_has_feature() to avoid build failureChristophe Leroy
commit eed5fae00593ab9d261a0c1ffc1bdb786a87a55a upstream. The code relies on constant folding of cpu_has_feature() based on possible and always true values as defined per CPU_FTRS_ALWAYS and CPU_FTRS_POSSIBLE. Build failure is encountered with for instance book3e_all_defconfig on kisskb in the AMDGPU driver which uses cpu_has_feature(CPU_FTR_VSX_COMP) to decide whether calling kernel_enable_vsx() or not. The failure is due to cpu_has_feature() not being inlined with that configuration with gcc 4.9. In the same way as commit acdad8fb4a15 ("powerpc: Force inlining of mmu_has_feature to fix build failure"), for inlining of cpu_has_feature(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b231dfa040ce4cc37f702f5c3a595fdeabfe0462.1615378209.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-24vmlinux.lds.h: Create section for protection against instrumentationNicolas Boichat
From: Thomas Gleixner <tglx@linutronix.de> commit 6553896666433e7efec589838b400a2a652b3ffa upstream. Some code pathes, especially the low level entry code, must be protected against instrumentation for various reasons: - Low level entry code can be a fragile beast, especially on x86. - With NO_HZ_FULL RCU state needs to be established before using it. Having a dedicated section for such code allows to validate with tooling that no unsafe functions are invoked. Add the .noinstr.text section and the noinstr attribute to mark functions. noinstr implies notrace. Kprobes will gain a section check later. Provide also a set of markers: instrumentation_begin()/end() These are used to mark code inside a noinstr function which calls into regular instrumentable text section as safe. The instrumentation markers are only active when CONFIG_DEBUG_ENTRY is enabled as the end marker emits a NOP to prevent the compiler from merging the annotation points. This means the objtool verification requires a kernel compiled with this option. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134100.075416272@linutronix.de [Nicolas: Guard noinstr macro in include/linux/compiler_types.h in __KERNEL__ && !__ASSEMBLY__, otherwise noinstr is expanded in the linker script construct. Upstream does not have this problem as many macros were moved by commit 71391bdd2e9a ("include/linux/compiler_types.h: don't pollute userspace with macro definitions"). We take the minimal approach here and just guard the new macro. Minor context conflicts in: arch/powerpc/kernel/vmlinux.lds.S include/asm-generic/vmlinux.lds.h include/linux/compiler.h] Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17powerpc/64s: Fix instruction encoding for lis in ppc_function_entry()Naveen N. Rao
commit cea15316ceee2d4a51dfdecd79e08a438135416c upstream. 'lis r2,N' is 'addis r2,0,N' and the instruction encoding in the macro LIS_R2 is incorrect (it currently maps to 'addis r0,r2,N'). Fix the same. Fixes: c71b7eff426f ("powerpc: Add ABIv2 support to ppc_function_entry") Cc: stable@vger.kernel.org # v3.16+ Reported-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210304020411.16796-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17powerpc/perf: Record counter overflow always if SAMPLE_IP is unsetAthira Rajeev
[ Upstream commit d137845c973147a22622cc76c7b0bc16f6206323 ] While sampling for marked events, currently we record the sample only if the SIAR valid bit of Sampled Instruction Event Register (SIER) is set. SIAR_VALID bit is used for fetching the instruction address from Sampled Instruction Address Register(SIAR). But there are some usecases, where the user is interested only in the PMU stats at each counter overflow and the exact IP of the overflow event is not required. Dropping SIAR invalid samples will fail to record some of the counter overflows in such cases. Example of such usecase is dumping the PMU stats (event counts) after some regular amount of instructions/events from the userspace (ex: via ptrace). Here counter overflow is indicated to userspace via signal handler, and captured by monitoring and enabling I/O signaling on the event file descriptor. In these cases, we expect to get sample/overflow indication after each specified sample_period. Perf event attribute will not have PERF_SAMPLE_IP set in the sample_type if exact IP of the overflow event is not requested. So while profiling if SAMPLE_IP is not set, just record the counter overflow irrespective of SIAR_VALID check. Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> [mpe: Reflow comment and if formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1612516492-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17powerpc: improve handling of unrecoverable system resetNicholas Piggin
[ Upstream commit 11cb0a25f71818ca7ab4856548ecfd83c169aa4d ] If an unrecoverable system reset hits in process context, the system does not have to panic. Similar to machine check, call nmi_exit() before die(). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-26-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17powerpc/pci: Add ppc_md.discover_phbs()Oliver O'Halloran
[ Upstream commit 5537fcb319d016ce387f818dd774179bc03217f5 ] On many powerpc platforms the discovery and initalisation of pci_controllers (PHBs) happens inside of setup_arch(). This is very early in boot (pre-initcalls) and means that we're initialising the PHB long before many basic kernel services (slab allocator, debugfs, a real ioremap) are available. On PowerNV this causes an additional problem since we map the PHB registers with ioremap(). As of commit d538aadc2718 ("powerpc/ioremap: warn on early use of ioremap()") a warning is printed because we're using the "incorrect" API to setup and MMIO mapping in searly boot. The kernel does provide early_ioremap(), but that is not intended to create long-lived MMIO mappings and a seperate warning is printed by generic code if early_ioremap() mappings are "leaked." This is all fixable with dumb hacks like using early_ioremap() to setup the initial mapping then replacing it with a real ioremap later on in boot, but it does raise the question: Why the hell are we setting up the PHB's this early in boot? The old and wise claim it's due to "hysterical rasins." Aside from amused grapes there doesn't appear to be any real reason to maintain the current behaviour. Already most of the newer embedded platforms perform PHB discovery in an arch_initcall and between the end of setup_arch() and the start of initcalls none of the generic kernel code does anything PCI related. On powerpc scanning PHBs occurs in a subsys_initcall so it should be possible to move the PHB discovery to a core, postcore or arch initcall. This patch adds the ppc_md.discover_phbs hook and a core_initcall stub that calls it. The core_initcalls are the earliest to be called so this will any possibly issues with dependency between initcalls. This isn't just an academic issue either since on pseries and PowerNV EEH init occurs in an arch_initcall and depends on the pci_controllers being available, similarly the creation of pci_dns occurs at core_initcall_sync (i.e. between core and postcore initcalls). These problems need to be addressed seperately. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> [mpe: Make discover_phbs() static] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201103043523.916109-1-oohall@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04powerpc/8xx: Fix software emulation interruptChristophe Leroy
[ Upstream commit 903178d0ce6bb30ef80a3604ab9ee2b57869fbc9 ] For unimplemented instructions or unimplemented SPRs, the 8xx triggers a "Software Emulation Exception" (0x1000). That interrupt doesn't set reason bits in SRR1 as the "Program Check Exception" does. Go through emulation_assist_interrupt() to set REASON_ILLEGAL. Fixes: fbbcc3bb139e ("powerpc/8xx: Remove SoftwareEmulation()") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ad782af87a222efc79cfb06079b0fd23d4224eaf.1612515180.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04powerpc/pseries/dlpar: handle ibm, configure-connector delay statusNathan Lynch
[ Upstream commit 768d70e19ba525debd571b36e6d0ab19956c63d7 ] dlpar_configure_connector() has two problems in its handling of ibm,configure-connector's return status: 1. When the status is -2 (busy, call again), we call ibm,configure-connector again immediately without checking whether to schedule, which can result in monopolizing the CPU. 2. Extended delay status (9900..9905) goes completely unhandled, causing the configuration to unnecessarily terminate. Fix both of these issues by using rtas_busy_delay(). Fixes: ab519a011caa ("powerpc/pseries: Kernel DLPAR Infrastructure") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210107025900.410369-1-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04powerpc/47x: Disable 256k page sizeChristophe Leroy
[ Upstream commit 910a0cb6d259736a0c86e795d4c2f42af8d0d775 ] PPC47x_TLBE_SIZE isn't defined for 256k pages, leading to a build break if 256k pages is selected. So change the kconfig so that 256k pages can't be selected for 47x. Fixes: e7f75ad01d59 ("powerpc/47x: Base ppc476 support") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Expand change log to mention build break] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2fed79b1154c872194f98bac4422c23918325e61.1611128938.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04KVM: PPC: Make the VMX instruction emulation routines staticCédric Le Goater
[ Upstream commit 9236f57a9e51c72ce426ccd2e53e123de7196a0f ] These are only used locally. It fixes these W=1 compile errors : ../arch/powerpc/kvm/powerpc.c:1521:5: error: no previous prototype for ‘kvmppc_get_vmx_dword’ [-Werror=missing-prototypes] 1521 | int kvmppc_get_vmx_dword(struct kvm_vcpu *vcpu, int index, u64 *val) | ^~~~~~~~~~~~~~~~~~~~ ../arch/powerpc/kvm/powerpc.c:1539:5: error: no previous prototype for ‘kvmppc_get_vmx_word’ [-Werror=missing-prototypes] 1539 | int kvmppc_get_vmx_word(struct kvm_vcpu *vcpu, int index, u64 *val) | ^~~~~~~~~~~~~~~~~~~ ../arch/powerpc/kvm/powerpc.c:1557:5: error: no previous prototype for ‘kvmppc_get_vmx_hword’ [-Werror=missing-prototypes] 1557 | int kvmppc_get_vmx_hword(struct kvm_vcpu *vcpu, int index, u64 *val) | ^~~~~~~~~~~~~~~~~~~~ ../arch/powerpc/kvm/powerpc.c:1575:5: error: no previous prototype for ‘kvmppc_get_vmx_byte’ [-Werror=missing-prototypes] 1575 | int kvmppc_get_vmx_byte(struct kvm_vcpu *vcpu, int index, u64 *val) | ^~~~~~~~~~~~~~~~~~~ Fixes: acc9eb9305fe ("KVM: PPC: Reimplement LOAD_VMX/STORE_VMX instruction mmio emulation with analyse_instr() input") Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210104143206.695198-19-clg@kaod.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06powerpc: sysdev: add missing iounmap() on error in mpic_msgr_probe()Qinglang Miao
[ Upstream commit ffa1797040c5da391859a9556be7b735acbe1242 ] I noticed that iounmap() of msgr_block_addr before return from mpic_msgr_probe() in the error handling case is missing. So use devm_ioremap() instead of just ioremap() when remapping the message register block, so the mapping will be automatically released on probe failure. Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201028091551.136400-1-miaoqinglang@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06powerpc/bitops: Fix possible undefined behaviour with fls() and fls64()Christophe Leroy
[ Upstream commit 1891ef21d92c4801ea082ee8ed478e304ddc6749 ] fls() and fls64() are using __builtin_ctz() and _builtin_ctzll(). On powerpc, those builtins trivially use ctlzw and ctlzd power instructions. Allthough those instructions provide the expected result with input argument 0, __builtin_ctz() and __builtin_ctzll() are documented as undefined for value 0. The easiest fix would be to use fls() and fls64() functions defined in include/asm-generic/bitops/builtin-fls.h and include/asm-generic/bitops/fls64.h, but GCC output is not optimal: 00000388 <testfls>: 388: 2c 03 00 00 cmpwi r3,0 38c: 41 82 00 10 beq 39c <testfls+0x14> 390: 7c 63 00 34 cntlzw r3,r3 394: 20 63 00 20 subfic r3,r3,32 398: 4e 80 00 20 blr 39c: 38 60 00 00 li r3,0 3a0: 4e 80 00 20 blr 000003b0 <testfls64>: 3b0: 2c 03 00 00 cmpwi r3,0 3b4: 40 82 00 1c bne 3d0 <testfls64+0x20> 3b8: 2f 84 00 00 cmpwi cr7,r4,0 3bc: 38 60 00 00 li r3,0 3c0: 4d 9e 00 20 beqlr cr7 3c4: 7c 83 00 34 cntlzw r3,r4 3c8: 20 63 00 20 subfic r3,r3,32 3cc: 4e 80 00 20 blr 3d0: 7c 63 00 34 cntlzw r3,r3 3d4: 20 63 00 40 subfic r3,r3,64 3d8: 4e 80 00 20 blr When the input of fls(x) is a constant, just check x for nullity and return either 0 or __builtin_clz(x). Otherwise, use cntlzw instruction directly. For fls64() on PPC64, do the same but with __builtin_clzll() and cntlzd instruction. On PPC32, lets take the generic fls64() which will use our fls(). The result is as expected: 00000388 <testfls>: 388: 7c 63 00 34 cntlzw r3,r3 38c: 20 63 00 20 subfic r3,r3,32 390: 4e 80 00 20 blr 000003a0 <testfls64>: 3a0: 2c 03 00 00 cmpwi r3,0 3a4: 40 82 00 10 bne 3b4 <testfls64+0x14> 3a8: 7c 83 00 34 cntlzw r3,r4 3ac: 20 63 00 20 subfic r3,r3,32 3b0: 4e 80 00 20 blr 3b4: 7c 63 00 34 cntlzw r3,r3 3b8: 20 63 00 40 subfic r3,r3,64 3bc: 4e 80 00 20 blr Fixes: 2fcff790dcb4 ("powerpc: Use builtin functions for fls()/__fls()/fls64()") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/348c2d3f19ffcff8abe50d52513f989c4581d000.1603375524.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30powerpc/powernv/memtrace: Fix crashing the kernel when enabling concurrentlyDavid Hildenbrand
commit d6718941a2767fb383e105d257d2105fe4f15f0e upstream. It's very easy to crash the kernel right now by simply trying to enable memtrace concurrently, hammering on the "enable" interface loop.sh: #!/bin/bash dmesg --console-off while true; do echo 0x40000000 > /sys/kernel/debug/powerpc/memtrace/enable done [root@localhost ~]# loop.sh & [root@localhost ~]# loop.sh & Resulting quickly in a kernel crash. Let's properly protect using a mutex. Fixes: 9d5171a8f248 ("powerpc/powernv: Enable removal of memory for in memory tracing") Cc: stable@vger.kernel.org# v4.14+ Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201111145322.15793-3-david@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30powerpc/powernv/memtrace: Don't leak kernel memory to user spaceDavid Hildenbrand
commit c74cf7a3d59a21b290fe0468f5b470d0b8ee37df upstream. We currently leak kernel memory to user space, because memory offlining doesn't do any implicit clearing of memory and we are missing explicit clearing of memory. Let's keep it simple and clear pages before removing the linear mapping. Reproduced in QEMU/TCG with 10 GiB of main memory: [root@localhost ~]# dd obs=9G if=/dev/urandom of=/dev/null [... wait until "free -m" used counter no longer changes and cancel] 19665802+0 records in 1+0 records out 9663676416 bytes (9.7 GB, 9.0 GiB) copied, 135.548 s, 71.3 MB/s [root@localhost ~]# cat /sys/devices/system/memory/block_size_bytes 40000000 [root@localhost ~]# echo 0x40000000 > /sys/kernel/debug/powerpc/memtrace/enable [ 402.978663][ T1086] page:000000001bc4bc74 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24900 [ 402.980063][ T1086] flags: 0x7ffff000001000(reserved) [ 402.980415][ T1086] raw: 007ffff000001000 c00c000000924008 c00c000000924008 0000000000000000 [ 402.980627][ T1086] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 [ 402.980845][ T1086] page dumped because: unmovable page [ 402.989608][ T1086] Offlined Pages 16384 [ 403.324155][ T1086] memtrace: Allocated trace memory on node 0 at 0x0000000200000000 Before this patch: [root@localhost ~]# hexdump -C /sys/kernel/debug/powerpc/memtrace/00000000/trace | head 00000000 c8 25 72 51 4d 26 36 c5 5c c2 56 15 d5 1a cd 10 |.%rQM&6.\.V.....| 00000010 19 b9 50 b2 cb e3 60 b8 ec 0a f3 ec 4b 3c 39 f0 |..P...`.....K<9.|$ 00000020 4e 5a 4c cf bd 26 19 ff 37 79 13 67 24 b7 b8 57 |NZL..&..7y.g$..W|$ 00000030 98 3e f5 be 6f 14 6a bd a4 52 bc 6e e9 e0 c1 5d |.>..o.j..R.n...]|$ 00000040 76 b3 ae b5 88 d7 da e3 64 23 85 2c 10 88 07 b6 |v.......d#.,....|$ 00000050 9a d8 91 de f7 50 27 69 2e 64 9c 6f d3 19 45 79 |.....P'i.d.o..Ey|$ 00000060 6a 6f 8a 61 71 19 1f c7 f1 df 28 26 ca 0f 84 55 |jo.aq.....(&...U|$ 00000070 01 3f be e4 e2 e1 da ff 7b 8c 8e 32 37 b4 24 53 |.?......{..27.$S|$ 00000080 1b 70 30 45 56 e6 8c c4 0e b5 4c fb 9f dd 88 06 |.p0EV.....L.....|$ 00000090 ef c4 18 79 f1 60 b1 5c 79 59 4d f4 36 d7 4a 5c |...y.`.\yYM.6.J\|$ After this patch: [root@localhost ~]# hexdump -C /sys/kernel/debug/powerpc/memtrace/00000000/trace | head 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 40000000 Fixes: 9d5171a8f248 ("powerpc/powernv: Enable removal of memory for in memory tracing") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201111145322.15793-2-david@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30powerpc/xmon: Change printk() to pr_cont()Christophe Leroy
commit 7c6c86b36a36dd4a13d30bba07718e767aa2e7a1 upstream. Since some time now, printk() adds carriage return, leading to unusable xmon output if there is no udbg backend available: [ 54.288722] sysrq: Entering xmon [ 54.292209] Vector: 0 at [cace3d2c] [ 54.292274] pc: [ 54.292331] c0023650 [ 54.292468] : xmon+0x28/0x58 [ 54.292519] [ 54.292574] lr: [ 54.292630] c0023724 [ 54.292749] : sysrq_handle_xmon+0xa4/0xfc [ 54.292801] [ 54.292867] sp: cace3de8 [ 54.292931] msr: 9032 [ 54.292999] current = 0xc28d0000 [ 54.293072] pid = 377, comm = sh [ 54.293157] Linux version 5.10.0-rc6-s3k-dev-01364-gedf13f0ccd76-dirty (root@po17688vm.idsi0.si.c-s.fr) (powerpc64-linux-gcc (GCC) 10.1.0, GNU ld (GNU Binutils) 2.34) #4211 PREEMPT Fri Dec 4 09:32:11 UTC 2020 [ 54.293287] enter ? for help [ 54.293470] [cace3de8] [ 54.293532] c0023724 [ 54.293654] sysrq_handle_xmon+0xa4/0xfc [ 54.293711] (unreliable) ... [ 54.296002] [ 54.296159] --- Exception: c01 (System Call) at [ 54.296217] 0fd4e784 [ 54.296303] [ 54.296375] SP (7fca6ff0) is in userspace [ 54.296431] mon> [ 54.296484] <no input ...> Use pr_cont() instead. Fixes: 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Mention that it only happens when udbg is not available] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c8a6ec704416ecd5ff2bd26213c9bc026bdd19de.1607077340.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30powerpc/rtas: Fix typo of ibm,open-errinjct in RTAS filterTyrel Datwyler
commit f10881a46f8914428110d110140a455c66bdf27b upstream. Commit bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") introduced the following error when invoking the errinjct userspace tool: [root@ltcalpine2-lp5 librtas]# errinjct open [327884.071171] sys_rtas: RTAS call blocked - exploit attempt? [327884.071186] sys_rtas: token=0x26, nargs=0 (called by errinjct) errinjct: Could not open RTAS error injection facility errinjct: librtas: open: Unexpected I/O error The entry for ibm,open-errinjct in rtas_filter array has a typo where the "j" is omitted in the rtas call name. After fixing this typo the errinjct tool functions again as expected. [root@ltcalpine2-lp5 linux]# errinjct open RTAS error injection facility open, token = 1 Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace") Cc: stable@vger.kernel.org Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201208195434.8289-1-tyreld@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30powerpc: Fix incorrect stw{, ux, u, x} instructions in __set_pte_atMathieu Desnoyers
commit d85be8a49e733dcd23674aa6202870d54bf5600d upstream. The placeholder for instruction selection should use the second argument's operand, which is %1, not %0. This could generate incorrect assembly code if the memory addressing of operand %0 is a different form from that of operand %1. Also remove the %Un placeholder because having %Un placeholders for two operands which are based on the same local var (ptep) doesn't make much sense. By the way, it doesn't change the current behaviour because "<>" constraint is missing for the associated "=m". [chleroy: revised commit log iaw segher's comments and removed %U0] Fixes: 9bf2b5cdc5fe ("powerpc: Fixes for CONFIG_PTE_64BIT for SMP support") Cc: <stable@vger.kernel.org> # v2.6.28+ Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/96354bd77977a6a933fe9020da57629007fdb920.1603358942.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30powerpc/perf: Exclude kernel samples while counting events in user space.Athira Rajeev
commit aa8e21c053d72b6639ea5a7f1d3a1d0209534c94 upstream. Perf event attritube supports exclude_kernel flag to avoid sampling/profiling in supervisor state (kernel). Based on this event attr flag, Monitor Mode Control Register bit is set to freeze on supervisor state. But sometimes (due to hardware limitation), Sampled Instruction Address Register (SIAR) locks on to kernel address even when freeze on supervisor is set. Patch here adds a check to drop those samples. Cc: stable@vger.kernel.org Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1606289215-1433-1-git-send-email-atrajeev@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30powerpc/pseries/hibernation: remove redundant cacheinfo updateNathan Lynch
[ Upstream commit b866459489fe8ef0e92cde3cbd6bbb1af6c4e99b ] Partitions with cache nodes in the device tree can encounter the following warning on resume: CPU 0 already accounted in PowerPC,POWER9@0(Data) WARNING: CPU: 0 PID: 3177 at arch/powerpc/kernel/cacheinfo.c:197 cacheinfo_cpu_online+0x640/0x820 These calls to cacheinfo_cpu_offline/online have been redundant since commit e610a466d16a ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration"). Fixes: e610a466d16a ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-25-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30powerpc/pseries/hibernation: drop pseries_suspend_begin() from suspend opsNathan Lynch
[ Upstream commit 52719fce3f4c7a8ac9eaa191e8d75a697f9fbcbc ] There are three ways pseries_suspend_begin() can be reached: 1. When "mem" is written to /sys/power/state: kobj_attr_store() -> state_store() -> pm_suspend() -> suspend_devices_and_enter() -> pseries_suspend_begin() This never works because there is no way to supply a valid stream id using this interface, and H_VASI_STATE is called with a stream id of zero. So this call path is useless at best. 2. When a stream id is written to /sys/devices/system/power/hibernate. pseries_suspend_begin() is polled directly from store_hibernate() until the stream is in the "Suspending" state (i.e. the platform is ready for the OS to suspend execution): dev_attr_store() -> store_hibernate() -> pseries_suspend_begin() 3. When a stream id is written to /sys/devices/system/power/hibernate (continued). After #2, pseries_suspend_begin() is called once again from the pm core: dev_attr_store() -> store_hibernate() -> pm_suspend() -> suspend_devices_and_enter() -> pseries_suspend_begin() This is redundant because the VASI suspend state is already known to be Suspending. The begin() callback of platform_suspend_ops is optional, so we can simply remove that assignment with no loss of function. Fixes: 32d8ad4e621d ("powerpc/pseries: Partition hibernation support") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-18-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30powerpc/feature: Fix CPU_FTRS_ALWAYS by removing CPU_FTRS_GENERIC_32Christophe Leroy
[ Upstream commit 78665179e569c7e1fe102fb6c21d0f5b6951f084 ] On 8xx, we get the following features: [ 0.000000] cpu_features = 0x0000000000000100 [ 0.000000] possible = 0x0000000000000120 [ 0.000000] always = 0x0000000000000000 This is not correct. As CONFIG_PPC_8xx is mutually exclusive with all other configurations, the three lines should be equal. The problem is due to CPU_FTRS_GENERIC_32 which is taken when CONFIG_BOOK3S_32 is NOT selected. This CPU_FTRS_GENERIC_32 is pointless because there is no generic configuration supporting all 32 bits but book3s/32. Remove this pointless generic features definition to unbreak the calculation of 'possible' features and 'always' features. Fixes: 76bc080ef5a3 ("[POWERPC] Make default cputable entries reflect selected CPU family") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/76a85f30bf981d1aeaae00df99321235494da254.1604426550.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30powerpc/64: Set up a kernel stack for secondaries before cpu_restore()Jordan Niethe
[ Upstream commit 3c0b976bf20d236c57adcefa80f86a0a1d737727 ] Currently in generic_secondary_smp_init(), cur_cpu_spec->cpu_restore() is called before a stack has been set up in r1. This was previously fine as the cpu_restore() functions were implemented in assembly and did not use a stack. However commit 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features") used __restore_cpu_cpufeatures() as the cpu_restore() function for a device-tree features based cputable entry. This is a C function and hence uses a stack in r1. generic_secondary_smp_init() is entered on the secondary cpus via the primary cpu using the OPAL call opal_start_cpu(). In OPAL, each hardware thread has its own stack. The OPAL call is ran in the primary's hardware thread. During the call, a job is scheduled on a secondary cpu that will start executing at the address of generic_secondary_smp_init(). Hence the value that will be left in r1 when the secondary cpu enters the kernel is part of that secondary cpu's individual OPAL stack. This means that __restore_cpu_cpufeatures() will write to that OPAL stack. This is not horribly bad as each hardware thread has its own stack and the call that enters the kernel from OPAL never returns, but it is still wrong and should be corrected. Create the temp kernel stack before calling cpu_restore(). As noted by mpe, for a kexec boot, the secondary CPUs are released from the spin loop at address 0x60 by smp_release_cpus() and then jump to generic_secondary_smp_init(). The call to smp_release_cpus() is in setup_arch(), and it comes before the call to emergency_stack_init(). emergency_stack_init() allocates an emergency stack in the PACA for each CPU. This address in the PACA is what is used to set up the temp kernel stack in generic_secondary_smp_init(). Move releasing the secondary CPUs to after the PACAs have been allocated an emergency stack, otherwise the PACA stack pointer will contain garbage and hence the temp kernel stack created from it will be broken. Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features") Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201014072837.24539-1-jniethe5@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30powerpc: Drop -me200 addition to build flagsMichael Ellerman
[ Upstream commit e02152ba2810f7c88cb54e71cda096268dfa9241 ] Currently a build with CONFIG_E200=y will fail with: Error: invalid switch -me200 Error: unrecognized option -me200 Upstream binutils has never supported an -me200 option. Presumably it was supported at some point by either a fork or Freescale internal binutils. We can't support code that we can't even build test, so drop the addition of -me200 to the build flags, so we can at least build with CONFIG_E200=y. Reported-by: Németh Márton <nm127@freemail.hu> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Scott Wood <oss@buserror.net> Link: https://lore.kernel.org/r/20201116120913.165317-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-22powerpc/8xx: Always fault when _PAGE_ACCESSED is not setChristophe Leroy
commit 29daf869cbab69088fe1755d9dd224e99ba78b56 upstream. The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. This adds at least 3 instructions to the TLB miss exception handlers fast path. Following patch will reduce this overhead. Also update the rotation instruction to the correct number of bits to reflect all changes done to _PAGE_ACCESSED over time. Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.") Fixes: 5f356497c384 ("powerpc/8xx: remove unused _PAGE_WRITETHRU") Fixes: e0a8e0d90a9f ("powerpc/8xx: Handle PAGE_USER via APG bits") Fixes: 5b2753fc3e8a ("powerpc/8xx: Implementation of PAGE_EXEC") Fixes: a891c43b97d3 ("powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc/64s: flush L1D after user accessesNicholas Piggin
commit 9a32a7e78bd0cd9a9b6332cbdc345ee5ffd0c5de upstream. IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache after user accesses. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc/uaccess: Evaluate macro arguments once, before user access is allowedNicholas Piggin
commit d02f6b7dab8228487268298ea1f21081c0b4b3eb upstream. get/put_user() can be called with nontrivial arguments. fs/proc/page.c has a good example: if (put_user(stable_page_flags(ppage), out)) { stable_page_flags() is quite a lot of code, including spin locks in the page allocator. Ensure these arguments are evaluated before user access is allowed. This improves security by reducing code with access to userspace, but it also fixes a PREEMPT bug with KUAP on powerpc/64s: stable_page_flags() is currently called with AMR set to allow writes, it ends up calling spin_unlock(), which can call preempt_schedule. But the task switch code can not be called with AMR set (it relies on interrupts saving the register), so this blows up. It's fine if the code inside allow_user_access() is preemptible, because a timer or IPI will save the AMR, but it's not okay to explicitly cause a reschedule. Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200407041245.600651-1-npiggin@gmail.com Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc: Fix __clear_user() with KUAP enabledAndrew Donnellan
commit 61e3acd8c693a14fc69b824cb5b08d02cb90a6e7 upstream. The KUAP implementation adds calls in clear_user() to enable and disable access to userspace memory. However, it doesn't add these to __clear_user(), which is used in the ptrace regset code. As there's only one direct user of __clear_user() (the regset code), and the time taken to set the AMR for KUAP purposes is going to dominate the cost of a quick access_ok(), there's not much point having a separate path. Rename __clear_user() to __arch_clear_user(), and make __clear_user() just call clear_user(). Reported-by: syzbot+f25ecf4b2982d8c7a640@syzkaller-ppc64.appspotmail.com Reported-by: Daniel Axtens <dja@axtens.net> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection") Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> [mpe: Use __arch_clear_user() for the asm version like arm64 & nds32] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191209132221.15328-1-ajd@linux.ibm.com Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc: Implement user_access_begin and friendsChristophe Leroy
commit 5cd623333e7cf4e3a334c70529268b65f2a6c2c7 upstream. Today, when a function like strncpy_from_user() is called, the userspace access protection is de-activated and re-activated for every word read. By implementing user_access_begin and friends, the protection is de-activated at the beginning of the copy and re-activated at the end. Implement user_access_begin(), user_access_end() and unsafe_get_user(), unsafe_put_user() and unsafe_copy_to_user() For the time being, we keep user_access_save() and user_access_restore() as nops. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/36d4fbf9e56a75994aca4ee2214c77b26a5a8d35.1579866752.git.christophe.leroy@c-s.fr Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc: Add a framework for user access trackingChristophe Leroy
Backported from commit de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection"). Here we don't try to add the KUAP framework, we just want the helper functions because we want to put uaccess flush helpers in them. In terms of fixes, we don't need commit 1d8f739b07bd ("powerpc/kuap: Fix set direction in allow/prevent_user_access()") as we don't have real KUAP. Likewise as all our allows are noops and all our prevents are just flushes, we don't need commit 9dc086f1e9ef ("powerpc/futex: Fix incorrect user access blocking") The other 2 fixes we do need. The original description is: This patch implements a framework for Kernel Userspace Access Protection. Then subarches will have the possibility to provide their own implementation by providing setup_kuap() and allow/prevent_user_access(). Some platforms will need to know the area accessed and whether it is accessed from read, write or both. Therefore source, destination and size and handed over to the two functions. mpe: Rename to allow/prevent rather than unlock/lock, and add read/write wrappers. Drop the 32-bit code for now until we have an implementation for it. Add kuap to pt_regs for 64-bit as well as 32-bit. Don't split strings, use pr_crit_ratelimited(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc/64s: flush L1D on kernel entryNicholas Piggin
commit f79643787e0a0762d2409b7b8334e83f22d85695 upstream. IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache on kernel entry. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc/64s: move some exception handlers out of lineDaniel Axtens
(backport only) We're about to grow the exception handlers, which will make a bunch of them no longer fit within the space available. We move them out of line. This is a fiddly and error-prone business, so in the interests of reviewability I haven't merged this in with the addition of the entry flush. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulationMichael Neuling
commit 1da4a0272c5469169f78cd76cf175ff984f52f06 upstream. __get_user_atomic_128_aligned() stores to kaddr using stvx which is a VMX store instruction, hence kaddr must be 16 byte aligned otherwise the store won't occur as expected. Unfortunately when we call __get_user_atomic_128_aligned() in p9_hmi_special_emu(), the buffer we pass as kaddr (ie. vbuf) isn't guaranteed to be 16B aligned. This means that the write to vbuf in __get_user_atomic_128_aligned() has the bottom bits of the address truncated. This results in other local variables being overwritten. Also vbuf will not contain the correct data which results in the userspace emulation being wrong and hence undetected user data corruption. In the past we've been mostly lucky as vbuf has ended up aligned but this is fragile and isn't always true. CONFIG_STACKPROTECTOR in particular can change the stack arrangement enough that our luck runs out. This issue only occurs on POWER9 Nimbus <= DD2.1 bare metal. The fix is to align vbuf to a 16 byte boundary. Fixes: 5080332c2c89 ("powerpc/64s: Add workaround for P9 vector CI load issue") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201013043741.743413-1-mikey@neuling.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05powerpc/powernv/elog: Fix race while processing OPAL error log event.Mahesh Salgaonkar
commit aea948bb80b478ddc2448f7359d574387521a52d upstream. Every error log reported by OPAL is exported to userspace through a sysfs interface and notified using kobject_uevent(). The userspace daemon (opal_errd) then reads the error log and acknowledges the error log is saved safely to disk. Once acknowledged the kernel removes the respective sysfs file entry causing respective resources to be released including kobject. However it's possible the userspace daemon may already be scanning elog entries when a new sysfs elog entry is created by the kernel. User daemon may read this new entry and ack it even before kernel can notify userspace about it through kobject_uevent() call. If that happens then we have a potential race between elog_ack_store->kobject_put() and kobject_uevent which can lead to use-after-free of a kernfs object resulting in a kernel crash. eg: BUG: Unable to handle kernel data access on read at 0x6b6b6b6b6b6b6bfb Faulting instruction address: 0xc0000000008ff2a0 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV CPU: 27 PID: 805 Comm: irq/29-opal-elo Not tainted 5.9.0-rc2-gcc-8.2.0-00214-g6f56a67bcbb5-dirty #363 ... NIP kobject_uevent_env+0xa0/0x910 LR elog_event+0x1f4/0x2d0 Call Trace: 0x5deadbeef0000122 (unreliable) elog_event+0x1f4/0x2d0 irq_thread_fn+0x4c/0xc0 irq_thread+0x1c0/0x2b0 kthread+0x1c4/0x1d0 ret_from_kernel_thread+0x5c/0x6c This patch fixes this race by protecting the sysfs file creation/notification by holding a reference count on kobject until we safely send kobject_uevent(). The function create_elog_obj() returns the elog object which if used by caller function will end up in use-after-free problem again. However, the return value of create_elog_obj() function isn't being used today and there is no need as well. Hence change it to return void to make this fix complete. Fixes: 774fea1a38c6 ("powerpc/powernv: Read OPAL error log and export it through sysfs") Cc: stable@vger.kernel.org # v3.15+ Reported-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> [mpe: Rework the logic to use a single return, reword comments, add oops] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201006122051.190176-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05powerpc: Warn about use of smt_snooze_delayJoel Stanley
commit a02f6d42357acf6e5de6ffc728e6e77faf3ad217 upstream. It's not done anything for a long time. Save the percpu variable, and emit a warning to remind users to not expect it to do anything. This uses pr_warn_once instead of pr_warn_ratelimit as testing 'ppc64_cpu --smt=off' on a 24 core / 4 SMT system showed the warning to be noisy, as the online/offline loop is slow. Fixes: 3fa8cad82b94 ("powerpc/pseries/cpuidle: smt-snooze-delay cleanup.") Cc: stable@vger.kernel.org # v3.14 Signed-off-by: Joel Stanley <joel@jms.id.au> Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200902000012.3440389-1-joel@jms.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05powerpc/rtas: Restrict RTAS requests from userspaceAndrew Donnellan
commit bd59380c5ba4147dcbaad3e582b55ccfd120b764 upstream. A number of userspace utilities depend on making calls to RTAS to retrieve information and update various things. The existing API through which we expose RTAS to userspace exposes more RTAS functionality than we actually need, through the sys_rtas syscall, which allows root (or anyone with CAP_SYS_ADMIN) to make any RTAS call they want with arbitrary arguments. Many RTAS calls take the address of a buffer as an argument, and it's up to the caller to specify the physical address of the buffer as an argument. We allocate a buffer (the "RMO buffer") in the Real Memory Area that RTAS can access, and then expose the physical address and size of this buffer in /proc/powerpc/rtas/rmo_buffer. Userspace is expected to read this address, poke at the buffer using /dev/mem, and pass an address in the RMO buffer to the RTAS call. However, there's nothing stopping the caller from specifying whatever address they want in the RTAS call, and it's easy to construct a series of RTAS calls that can overwrite arbitrary bytes (even without /dev/mem access). Additionally, there are some RTAS calls that do potentially dangerous things and for which there are no legitimate userspace use cases. In the past, this would not have been a particularly big deal as it was assumed that root could modify all system state freely, but with Secure Boot and lockdown we need to care about this. We can't fundamentally change the ABI at this point, however we can address this by implementing a filter that checks RTAS calls against a list of permitted calls and forces the caller to use addresses within the RMO buffer. The list is based off the list of calls that are used by the librtas userspace library, and has been tested with a number of existing userspace RTAS utilities. For compatibility with any applications we are not aware of that require other calls, the filter can be turned off at build time. Cc: stable@vger.kernel.org Reported-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200820044512.7543-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05powerpc/drmem: Make lmb_size 64 bitAneesh Kumar K.V
commit ec72024e35dddb88a81e40071c87ceb18b5ee835 upstream. Similar to commit 89c140bbaeee ("pseries: Fix 64 bit logical memory block panic") make sure different variables tracking lmb_size are updated to be 64 bit. This was found by code audit. Cc: stable@vger.kernel.org Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Acked-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201007114836.282468-2-aneesh.kumar@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05powerpc: select ARCH_WANT_IRQS_OFF_ACTIVATE_MMNicholas Piggin
[ Upstream commit 66acd46080bd9e5ad2be4b0eb1d498d5145d058e ] powerpc uses IPIs in some situations to switch a kernel thread away from a lazy tlb mm, which is subject to the TLB flushing race described in the changelog introducing ARCH_WANT_IRQS_OFF_ACTIVATE_MM. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200914045219.3736466-3-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-05powerpc/powernv/smp: Fix spurious DBG() warningOliver O'Halloran
[ Upstream commit f6bac19cf65c5be21d14a0c9684c8f560f2096dd ] When building with W=1 we get the following warning: arch/powerpc/platforms/powernv/smp.c: In function ‘pnv_smp_cpu_kill_self’: arch/powerpc/platforms/powernv/smp.c:276:16: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body] 276 | cpu, srr1); | ^ cc1: all warnings being treated as errors The full context is this block: if (srr1 && !generic_check_cpu_restart(cpu)) DBG("CPU%d Unexpected exit while offline srr1=%lx!\n", cpu, srr1); When building with DEBUG undefined DBG() expands to nothing and GCC emits the warning due to the lack of braces around an empty statement. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200804005410.146094-2-oohall@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-30powerpc/powernv/dump: Fix race while processing OPAL dumpVasant Hegde
[ Upstream commit 0a43ae3e2beb77e3481d812834d33abe270768ab ] Every dump reported by OPAL is exported to userspace through a sysfs interface and notified using kobject_uevent(). The userspace daemon (opal_errd) then reads the dump and acknowledges that the dump is saved safely to disk. Once acknowledged the kernel removes the respective sysfs file entry causing respective resources to be released including kobject. However it's possible the userspace daemon may already be scanning dump entries when a new sysfs dump entry is created by the kernel. User daemon may read this new entry and ack it even before kernel can notify userspace about it through kobject_uevent() call. If that happens then we have a potential race between dump_ack_store->kobject_put() and kobject_uevent which can lead to use-after-free of a kernfs object resulting in a kernel crash. This patch fixes this race by protecting the sysfs file creation/notification by holding a reference count on kobject until we safely send kobject_uevent(). The function create_dump_obj() returns the dump object which if used by caller function will end up in use-after-free problem again. However, the return value of create_dump_obj() function isn't being used today and there is no need as well. Hence change it to return void to make this fix complete. Fixes: c7e64b9ce04a ("powerpc/powernv Platform dump interface") Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201017164210.264619-1-hegdevasant@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-30powerpc/perf/hv-gpci: Fix starting index valueKajol Jain
[ Upstream commit 0f9866f7e85765bbda86666df56c92f377c3bc10 ] Commit 9e9f60108423f ("powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated") adds a framework for defining gpci counters. In this patch, they adds starting_index value as '0xffffffffffffffff'. which is wrong as starting_index is of size 32 bits. Because of this, incase we try to run hv-gpci event we get error. In power9 machine: command#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ -C 0 -I 1000 event syntax error: '..bie_count_and_time_tlbie_instructions_issued/' \___ value too big for format, maximum is 4294967295 This patch fix this issue and changes starting_index value to '0xffffffff' After this patch: command#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ -C 0 -I 1000 1.000085786 1,024 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 2.000287818 1,024 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ 2.439113909 17,408 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ Fixes: 9e9f60108423 ("powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated") Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201003074943.338618-1-kjain@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-30powerpc/perf: Exclude pmc5/6 from the irrelevant PMU group constraintsAthira Rajeev
[ Upstream commit 3b6c3adbb2fa42749c3d38cfc4d4d0b7e096bb7b ] PMU counter support functions enforces event constraints for group of events to check if all events in a group can be monitored. Incase of event codes using PMC5 and PMC6 ( 500fa and 600f4 respectively ), not all constraints are applicable, say the threshold or sample bits. But current code includes pmc5 and pmc6 in some group constraints (like IC_DC Qualifier bits) which is actually not applicable and hence results in those events not getting counted when scheduled along with group of other events. Patch fixes this by excluding PMC5/6 from constraints which are not relevant for it. Fixes: 7ffd948 ("powerpc/perf: factor out power8 pmu functions") Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1600672204-1610-1-git-send-email-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-30powerpc/64s/radix: Fix mm_cpumask trimming race vs kthread_use_mmNicholas Piggin
[ Upstream commit a665eec0a22e11cdde708c1c256a465ebe768047 ] Commit 0cef77c7798a7 ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask") added a mechanism to trim the mm_cpumask of a process under certain conditions. One of the assumptions is that mm_users would not be incremented via a reference outside the process context with mmget_not_zero() then go on to kthread_use_mm() via that reference. That invariant was broken by io_uring code (see previous sparc64 fix), but I'll point Fixes: to the original powerpc commit because we are changing that assumption going forward, so this will make backports match up. Fix this by no longer relying on that assumption, but by having each CPU check the mm is not being used, and clearing their own bit from the mask only if it hasn't been switched-to by the time the IPI is processed. This relies on commit 38cf307c1f20 ("mm: fix kthread_use_mm() vs TLB invalidate") and ARCH_WANT_IRQS_OFF_ACTIVATE_MM to disable irqs over mm switch sequences. Fixes: 0cef77c7798a7 ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> Depends-on: 38cf307c1f20 ("mm: fix kthread_use_mm() vs TLB invalidate") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200914045219.3736466-5-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-30powerpc/tau: Disable TAU between measurementsFinn Thain
[ Upstream commit e63d6fb5637e92725cf143559672a34b706bca4f ] Enabling CONFIG_TAU_INT causes random crashes: Unrecoverable exception 1700 at c0009414 (msr=1000) Oops: Unrecoverable exception, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-pmac-00043-gd5f545e1a8593 #5 NIP: c0009414 LR: c0009414 CTR: c00116fc REGS: c0799eb8 TRAP: 1700 Not tainted (5.7.0-pmac-00043-gd5f545e1a8593) MSR: 00001000 <ME> CR: 22000228 XER: 00000100 GPR00: 00000000 c0799f70 c076e300 00800000 0291c0ac 00e00000 c076e300 00049032 GPR08: 00000001 c00116fc 00000000 dfbd3200 ffffffff 007f80a8 00000000 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 c075ce04 GPR24: c075ce04 dfff8880 c07b0000 c075ce04 00080000 00000001 c079ef98 c079ef5c NIP [c0009414] arch_cpu_idle+0x24/0x6c LR [c0009414] arch_cpu_idle+0x24/0x6c Call Trace: [c0799f70] [00000001] 0x1 (unreliable) [c0799f80] [c0060990] do_idle+0xd8/0x17c [c0799fa0] [c0060ba4] cpu_startup_entry+0x20/0x28 [c0799fb0] [c072d220] start_kernel+0x434/0x44c [c0799ff0] [00003860] 0x3860 Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX 3d20c07b XXXXXXXX XXXXXXXX XXXXXXXX 7c0802a6 XXXXXXXX XXXXXXXX XXXXXXXX 4e800421 XXXXXXXX XXXXXXXX XXXXXXXX 7d2000a6 ---[ end trace 3a0c9b5cb216db6b ]--- Resolve this problem by disabling each THRMn comparator when handling the associated THRMn interrupt and by disabling the TAU entirely when updating THRMn thresholds. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5a0ba3dc5612c7aac596727331284a3676c08472.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-30powerpc/tau: Check processor type before enabling TAU interruptFinn Thain
[ Upstream commit 5e3119e15fed5b9a9a7e528665ff098a4a8dbdbc ] According to Freescale's documentation, MPC74XX processors have an erratum that prevents the TAU interrupt from working, so don't try to use it when running on those processors. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c281611544768e758bd58fe812cf702a5bd2d042.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29powerpc/tau: Remove duplicated set_thresholds() callFinn Thain
[ Upstream commit 420ab2bc7544d978a5d0762ee736412fe9c796ab ] The commentary at the call site seems to disagree with the code. The conditional prevents calling set_thresholds() via the exception handler, which appears to crash. Perhaps that's because it immediately triggers another TAU exception. Anyway, calling set_thresholds() from TAUupdate() is redundant because tau_timeout() does so. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d7c7ee33232cf72a6a6bbb6ef05838b2e2b113c0.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29powerpc/tau: Convert from timer to workqueueFinn Thain
[ Upstream commit b1c6a0a10bfaf36ec82fde6f621da72407fa60a1 ] Since commit 19dbdcb8039cf ("smp: Warn on function calls from softirq context") the Thermal Assist Unit driver causes a warning like the following when CONFIG_SMP is enabled. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/smp.c:428 smp_call_function_many_cond+0xf4/0x38c Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-pmac #3 NIP: c00b37a8 LR: c00b3abc CTR: c001218c REGS: c0799c60 TRAP: 0700 Not tainted (5.7.0-pmac) MSR: 00029032 <EE,ME,IR,DR,RI> CR: 42000224 XER: 00000000 GPR00: c00b3abc c0799d18 c076e300 c079ef5c c0011fec 00000000 00000000 00000000 GPR08: 00000100 00000100 00008000 ffffffff 42000224 00000000 c079d040 c079d044 GPR16: 00000001 00000000 00000004 c0799da0 c079f054 c07a0000 c07a0000 00000000 GPR24: c0011fec 00000000 c079ef5c c079ef5c 00000000 00000000 00000000 00000000 NIP [c00b37a8] smp_call_function_many_cond+0xf4/0x38c LR [c00b3abc] on_each_cpu+0x38/0x68 Call Trace: [c0799d18] [ffffffff] 0xffffffff (unreliable) [c0799d68] [c00b3abc] on_each_cpu+0x38/0x68 [c0799d88] [c0096704] call_timer_fn.isra.26+0x20/0x7c [c0799d98] [c0096b40] run_timer_softirq+0x1d4/0x3fc [c0799df8] [c05b4368] __do_softirq+0x118/0x240 [c0799e58] [c0039c44] irq_exit+0xc4/0xcc [c0799e68] [c000ade8] timer_interrupt+0x1b0/0x230 [c0799ea8] [c0013520] ret_from_except+0x0/0x14 --- interrupt: 901 at arch_cpu_idle+0x24/0x6c LR = arch_cpu_idle+0x24/0x6c [c0799f70] [00000001] 0x1 (unreliable) [c0799f80] [c0060990] do_idle+0xd8/0x17c [c0799fa0] [c0060ba8] cpu_startup_entry+0x24/0x28 [c0799fb0] [c072d220] start_kernel+0x434/0x44c [c0799ff0] [00003860] 0x3860 Instruction dump: 8129f204 2f890000 40beff98 3d20c07a 8929eec4 2f890000 40beff88 0fe00000 81220000 552805de 550802ef 4182ff84 <0fe00000> 3860ffff 7f65db78 7f44d378 ---[ end trace 34a886e47819c2eb ]--- Don't call on_each_cpu() from a timer callback, call it from a worker thread instead. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bb61650bea4f4c91fb8e24b9a6f130a1438651a7.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29powerpc/tau: Use appropriate temperature sample intervalFinn Thain
[ Upstream commit 66943005cc41f48e4d05614e8f76c0ca1812f0fd ] According to the MPC750 Users Manual, the SITV value in Thermal Management Register 3 is 13 bits long. The present code calculates the SITV value as 60 * 500 cycles. This would overflow to give 10 us on a 500 MHz CPU rather than the intended 60 us. (But according to the Microprocessor Datasheet, there is also a factor of 266 that has to be applied to this value on certain parts i.e. speed sort above 266 MHz.) Always use the maximum cycle count, as recommended by the Datasheet. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/896f542e5f0f1d6cf8218524c2b67d79f3d69b3c.1599260540.git.fthain@telegraphics.com.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29powerpc/pseries: explicitly reschedule during drmem_lmb list traversalNathan Lynch
[ Upstream commit 9d6792ffe140240ae54c881cc4183f9acc24b4df ] The drmem lmb list can have hundreds of thousands of entries, and unfortunately lookups take the form of linear searches. As long as this is the case, traversals have the potential to monopolize the CPU and provoke lockup reports, workqueue stalls, and the like unless they explicitly yield. Rather than placing cond_resched() calls within various for_each_drmem_lmb() loop blocks in the code, put it in the iteration expression of the loop macro itself so users can't omit it. Introduce a drmem_lmb_next() iteration helper function which calls cond_resched() at a regular interval during array traversal. Each iteration of the loop in DLPAR code paths can involve around ten RTAS calls which can each take up to 250us, so this ensures the check is performed at worst every few milliseconds. Fixes: 6c6ea53725b3 ("powerpc/mm: Separate ibm, dynamic-memory data from DT format") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200813151131.2070161-1-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29powerpc/icp-hv: Fix missing of_node_put() in success pathNicholas Mc Guire
[ Upstream commit d3e669f31ec35856f5e85df9224ede5bdbf1bc7b ] Both of_find_compatible_node() and of_find_node_by_type() will return a refcounted node on success - thus for the success path the node must be explicitly released with a of_node_put(). Fixes: 0b05ac6e2480 ("powerpc/xics: Rewrite XICS driver") Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1530691407-3991-1-git-send-email-hofrat@osadl.org Signed-off-by: Sasha Levin <sashal@kernel.org>