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2019-01-26powerpc/xmon: Fix invocation inside lock regionBreno Leitao
[ Upstream commit 8d4a862276a9c30a269d368d324fb56529e6d5fd ] Currently xmon needs to get devtree_lock (through rtas_token()) during its invocation (at crash time). If there is a crash while devtree_lock is being held, then xmon tries to get the lock but spins forever and never get into the interactive debugger, as in the following case: int *ptr = NULL; raw_spin_lock_irqsave(&devtree_lock, flags); *ptr = 0xdeadbeef; This patch avoids calling rtas_token(), thus trying to get the same lock, at crash time. This new mechanism proposes getting the token at initialization time (xmon_init()) and just consuming it at crash time. This would allow xmon to be possible invoked independent of devtree_lock being held or not. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-13powerpc/tm: Set MSR[TS] just prior to recheckpointBreno Leitao
commit e1c3743e1a20647c53b719dbf28b48f45d23f2cd upstream. On a signal handler return, the user could set a context with MSR[TS] bits set, and these bits would be copied to task regs->msr. At restore_tm_sigcontexts(), after current task regs->msr[TS] bits are set, several __get_user() are called and then a recheckpoint is executed. This is a problem since a page fault (in kernel space) could happen when calling __get_user(). If it happens, the process MSR[TS] bits were already set, but recheckpoint was not executed, and SPRs are still invalid. The page fault can cause the current process to be de-scheduled, with MSR[TS] active and without tm_recheckpoint() being called. More importantly, without TEXASR[FS] bit set also. Since TEXASR might not have the FS bit set, and when the process is scheduled back, it will try to reclaim, which will be aborted because of the CPU is not in the suspended state, and, then, recheckpoint. This recheckpoint will restore thread->texasr into TEXASR SPR, which might be zero, hitting a BUG_ON(). kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434! cpu 0xb: Vector: 700 (Program Check) at [c00000041f1576d0] pc: c000000000054550: restore_gprs+0xb0/0x180 lr: 0000000000000000 sp: c00000041f157950 msr: 8000000100021033 current = 0xc00000041f143000 paca = 0xc00000000fb86300 softe: 0 irq_happened: 0x01 pid = 1021, comm = kworker/11:1 kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434! Linux version 4.9.0-3-powerpc64le (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2+deb9u2 (2017-06-26) enter ? for help [c00000041f157b30] c00000000001bc3c tm_recheckpoint.part.11+0x6c/0xa0 [c00000041f157b70] c00000000001d184 __switch_to+0x1e4/0x4c0 [c00000041f157bd0] c00000000082eeb8 __schedule+0x2f8/0x990 [c00000041f157cb0] c00000000082f598 schedule+0x48/0xc0 [c00000041f157ce0] c0000000000f0d28 worker_thread+0x148/0x610 [c00000041f157d80] c0000000000f96b0 kthread+0x120/0x140 [c00000041f157e30] c00000000000c0e0 ret_from_kernel_thread+0x5c/0x7c This patch simply delays the MSR[TS] set, so, if there is any page fault in the __get_user() section, it does not have regs->msr[TS] set, since the TM structures are still invalid, thus avoiding doing TM operations for in-kernel exceptions and possible process reschedule. With this patch, the MSR[TS] will only be set just before recheckpointing and setting TEXASR[FS] = 1, thus avoiding an interrupt with TM registers in invalid state. Other than that, if CONFIG_PREEMPT is set, there might be a preemption just after setting MSR[TS] and before tm_recheckpoint(), thus, this block must be atomic from a preemption perspective, thus, calling preempt_disable/enable() on this code. It is not possible to move tm_recheckpoint to happen earlier, because it is required to get the checkpointed registers from userspace, with __get_user(), thus, the only way to avoid this undesired behavior is delaying the MSR[TS] set. The 32-bits signal handler seems to be safe this current issue, but, it might be exposed to the preemption issue, thus, disabling preemption in this chunk of code. Changes from v2: * Run the critical section with preempt_disable. Fixes: 87b4e5393af7 ("powerpc/tm: Fix return of active 64bit signals") Cc: stable@vger.kernel.org (v3.9+) Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13Revert "powerpc/tm: Unset MSR[TS] if not recheckpointing"Greg Kroah-Hartman
This reverts commit a9935a12768851762089fda8e5a9daaf0231808e which is commit 6f5b9f018f4c7686fd944d920209d1382d320e4e upstream. It breaks the powerpc build, so drop it from the tree until a fix goes upstream. Reported-by: Guenter Roeck <linux@roeck-us.net> Cc: Breno Leitao <leitao@debian.org> Cc: Michal Suchánek <msuchanek@suse.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13powerpc/boot: Set target when cross-compiling for clangJoel Stanley
commit 813af51f5d30a2da6a2523c08465f9726e51772e upstream. Clang needs to be told which target it is building for when cross compiling. Link: https://github.com/ClangBuiltLinux/linux/issues/259 Signed-off-by: Joel Stanley <joel@jms.id.au> Tested-by: Daniel Axtens <dja@axtens.net> # powerpc 64-bit BE Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13powerpc: Disable -Wbuiltin-requires-header when setjmp is usedJoel Stanley
commit aea447141c7e7824b81b49acd1bc785506fba46e upstream. The powerpc kernel uses setjmp which causes a warning when building with clang: In file included from arch/powerpc/xmon/xmon.c:51: ./arch/powerpc/include/asm/setjmp.h:15:13: error: declaration of built-in function 'setjmp' requires inclusion of the header <setjmp.h> [-Werror,-Wbuiltin-requires-header] extern long setjmp(long *); ^ ./arch/powerpc/include/asm/setjmp.h:16:13: error: declaration of built-in function 'longjmp' requires inclusion of the header <setjmp.h> [-Werror,-Wbuiltin-requires-header] extern void longjmp(long *, long); ^ This *is* the header and we're not using the built-in setjump but rather the one in arch/powerpc/kernel/misc.S. As the compiler warning does not make sense, it for the files where setjmp is used. Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> [mpe: Move subdir-ccflags in xmon/Makefile to not clobber -Werror] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13powerpc: avoid -mno-sched-epilog on GCC 4.9 and newerNicholas Piggin
commit 6977f95e63b9b3fb4a5973481a800dd9f48a1338 upstream. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13powerpc: consolidate -mno-sched-epilog into FTRACE flagsNicholas Piggin
commit 2a056f58fd33ccc6a0261b552b0f17e7fa4a12f3 upstream. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13powerpc: remove old GCC version checksNicholas Piggin
commit f2910f0e6835339e6ce82cef22fa15718b7e3bfa upstream. GCC 4.6 is the minimum supported now. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> [nc: Applied to minimize unnecessary conflicts] Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13powerpc/mm: Fallback to RAM if the altmap is unusableOliver O'Halloran
[ Upstream commit 9ef34630a4614ee1cd478f9859ebea55d55f10ec ] The "altmap" is used to provide a pool of memory that is reserved for the vmemmap backing of hot-plugged memory. This is useful when adding large amount of ZONE_DEVICE memory to a system with a limited amount of normal memory. On ppc64 we use huge pages to map the vmemmap which requires the backing storage to be contigious and aligned to the hugepage size. The altmap implementation allows for the altmap provider to reserve a few PFNs at the start of the range for it's own uses and when this occurs the first chunk of the altmap is not usable for hugepage mappings. On hash there is no sane way to fall back to a normal sized page mapping so we fail the allocation. This results in memory hotplug failing with ENOMEM when the new range doesn't fall into an existing vmemmap block. This patch handles this case by falling back to using system memory rather than failing if we cannot allocate from the altmap. This fallback should only ever be used for the first vmemmap block so it should not cause excess memory consumption. Fixes: 7b73d978a5d0 ("mm: pass the vmem_altmap to vmemmap_populate") Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-13powerpc/mm: Fix linux page tables build with some configsMichael Ellerman
[ Upstream commit 462951cd32e1496dc64b00051dfb777efc8ae5d8 ] For some configs the build fails with: arch/powerpc/mm/dump_linuxpagetables.c: In function 'populate_markers': arch/powerpc/mm/dump_linuxpagetables.c:306:39: error: 'PKMAP_BASE' undeclared (first use in this function) arch/powerpc/mm/dump_linuxpagetables.c:314:50: error: 'LAST_PKMAP' undeclared (first use in this function) These come from highmem.h, including that fixes the build. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-13powerpc: Fix COFF zImage booting on old powermacsPaul Mackerras
[ Upstream commit 5564597d51c8ff5b88d95c76255e18b13b760879 ] Commit 6975a783d7b4 ("powerpc/boot: Allow building the zImage wrapper as a relocatable ET_DYN", 2011-04-12) changed the procedure descriptor at the start of crt0.S to have a hard-coded start address of 0x500000 rather than a reference to _zimage_start, presumably because having a reference to a symbol introduced a relocation which is awkward to handle in a position-independent executable. Unfortunately, what is at 0x500000 in the COFF image is not the first instruction, but the procedure descriptor itself, that is, a word containing 0x500000, which is not a valid instruction. Hence, booting a COFF zImage results in a "DEFAULT CATCH!, code=FFF00700" message from Open Firmware. This fixes the problem by (a) putting the procedure descriptor in the data section and (b) adding a branch to _zimage_start as the first instruction in the program. Fixes: 6975a783d7b4 ("powerpc/boot: Allow building the zImage wrapper as a relocatable ET_DYN") Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-09powerpc/tm: Unset MSR[TS] if not recheckpointingBreno Leitao
commit 6f5b9f018f4c7686fd944d920209d1382d320e4e upstream. There is a TM Bad Thing bug that can be caused when you return from a signal context in a suspended transaction but with ucontext MSR[TS] unset. This forces regs->msr[TS] to be set at syscall entrance (since the CPU state is transactional). It also calls treclaim() to flush the transaction state, which is done based on the live (mfmsr) MSR state. Since user context MSR[TS] is not set, then restore_tm_sigcontexts() is not called, thus, not executing recheckpoint, keeping the CPU state as not transactional. When calling rfid, SRR1 will have MSR[TS] set, but the CPU state is non transactional, causing the TM Bad Thing with the following stack: [ 33.862316] Bad kernel stack pointer 3fffd9dce3e0 at c00000000000c47c cpu 0x8: Vector: 700 (Program Check) at [c00000003ff7fd40] pc: c00000000000c47c: fast_exception_return+0xac/0xb4 lr: 00003fff865f442c sp: 3fffd9dce3e0 msr: 8000000102a03031 current = 0xc00000041f68b700 paca = 0xc00000000fb84800 softe: 0 irq_happened: 0x01 pid = 1721, comm = tm-signal-sigre Linux version 4.9.0-3-powerpc64le (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2+deb9u2 (2017-06-26) WARNING: exception is not recoverable, can't continue The same problem happens on 32-bits signal handler, and the fix is very similar, if tm_recheckpoint() is not executed, then regs->msr[TS] should be zeroed. This patch also fixes a sparse warning related to lack of indentation when CONFIG_PPC_TRANSACTIONAL_MEM is set. Fixes: 2b0a576d15e0e ("powerpc: Add new transactional memory state to the signal context") CC: Stable <stable@vger.kernel.org> # 3.10+ Signed-off-by: Breno Leitao <leitao@debian.org> Tested-by: Michal Suchánek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09powerpc/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>
2018-12-19powerpc: Look for "stdout-path" when setting up legacy consolesBenjamin Herrenschmidt
commit bf3d6afbb234156749b640b6c50f714967a85964 upstream. Commit 78e5dfea84dc ("powerpc: dts: replace 'linux,stdout-path' with 'stdout-path'") broke the default console on a number of embedded PowerPC systems, because it failed to also update the code in arch/powerpc/kernel/legacy_serial.c to look for that property in addition to the old one. This fixes it. Fixes: 78e5dfea84dc ("powerpc: dts: replace 'linux,stdout-path' with 'stdout-path'") Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19powerpc/msi: Fix NULL pointer access in teardown codeRadu Rendec
commit 78e7b15e17ac175e7eed9e21c6f92d03d3b0a6fa upstream. The arch_teardown_msi_irqs() function assumes that controller ops pointers were already checked in arch_setup_msi_irqs(), but this assumption is wrong: arch_teardown_msi_irqs() can be called even when arch_setup_msi_irqs() returns an error (-ENOSYS). This can happen in the following scenario: - msi_capability_init() calls pci_msi_setup_msi_irqs() - pci_msi_setup_msi_irqs() returns -ENOSYS - msi_capability_init() notices the error and calls free_msi_irqs() - free_msi_irqs() calls pci_msi_teardown_msi_irqs() This is easier to see when CONFIG_PCI_MSI_IRQ_DOMAIN is not set and pci_msi_setup_msi_irqs() and pci_msi_teardown_msi_irqs() are just aliases to arch_setup_msi_irqs() and arch_teardown_msi_irqs(). The call to free_msi_irqs() upon pci_msi_setup_msi_irqs() failure seems legit, as it does additional cleanup; e.g. list_del(&entry->list) and kfree(entry) inside free_msi_irqs() do happen (MSI descriptors are allocated before pci_msi_setup_msi_irqs() is called and need to be cleaned up if that fails). Fixes: 6b2fd7efeb88 ("PCI/MSI/PPC: Remove arch_msi_check_device()") Cc: stable@vger.kernel.org # v3.18+ Signed-off-by: Radu Rendec <radu.rendec@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05powerpc/function_graph: Simplify with function_graph_enter()Steven Rostedt (VMware)
commit fe60522ec60082a1dd735691b82c64f65d4ad15e upstream. The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return(). Have powerpc use the new code, and remove the shadow stack management as well as having to set up the trace structure. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-01powerpc/numa: Suppress "VPHN is not supported" messagesSatheesh Rajendran
[ Upstream commit 437ccdc8ce629470babdda1a7086e2f477048cbd ] When VPHN function is not supported and during cpu hotplug event, kernel prints message 'VPHN function not supported. Disabling polling...'. Currently it prints on every hotplug event, it floods dmesg when a KVM guest tries to hotplug huge number of vcpus, let's just print once and suppress further kernel prints. Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-01powerpc/io: Fix the IO workarounds code to work with RadixMichael Ellerman
[ Upstream commit 43c6494fa1499912c8177e71450c0279041152a6 ] Back in 2006 Ben added some workarounds for a misbehaviour in the Spider IO bridge used on early Cell machines, see commit 014da7ff47b5 ("[POWERPC] Cell "Spider" MMIO workarounds"). Later these were made to be generic, ie. not tied specifically to Spider. The code stashes a token in the high bits (59-48) of virtual addresses used for IO (eg. returned from ioremap()). This works fine when using the Hash MMU, but when we're using the Radix MMU the bits used for the token overlap with some of the bits of the virtual address. This is because the maximum virtual address is larger with Radix, up to c00fffffffffffff, and in fact we use that high part of the address range for ioremap(), see RADIX_KERN_IO_START. As it happens the bits that are used overlap with the bits that differentiate an IO address vs a linear map address. If the resulting address lies outside the linear mapping we will crash (see below), if not we just corrupt memory. virtio-pci 0000:00:00.0: Using 64-bit direct DMA at offset 800000000000000 Unable to handle kernel paging request for data at address 0xc000000080000014 ... CFAR: c000000000626b98 DAR: c000000080000014 DSISR: 42000000 IRQMASK: 0 GPR00: c0000000006c54fc c00000003e523378 c0000000016de600 0000000000000000 GPR04: c00c000080000014 0000000000000007 0fffffff000affff 0000000000000030 ^^^^ ... NIP [c000000000626c5c] .iowrite8+0xec/0x100 LR [c0000000006c992c] .vp_reset+0x2c/0x90 Call Trace: .pci_bus_read_config_dword+0xc4/0x120 (unreliable) .register_virtio_device+0x13c/0x1c0 .virtio_pci_probe+0x148/0x1f0 .local_pci_probe+0x68/0x140 .pci_device_probe+0x164/0x220 .really_probe+0x274/0x3b0 .driver_probe_device+0x80/0x170 .__driver_attach+0x14c/0x150 .bus_for_each_dev+0xb8/0x130 .driver_attach+0x34/0x50 .bus_add_driver+0x178/0x2f0 .driver_register+0x90/0x1a0 .__pci_register_driver+0x6c/0x90 .virtio_pci_driver_init+0x2c/0x40 .do_one_initcall+0x64/0x280 .kernel_init_freeable+0x36c/0x474 .kernel_init+0x24/0x160 .ret_from_kernel_thread+0x58/0x7c This hasn't been a problem because CONFIG_PPC_IO_WORKAROUNDS which enables this code is usually not enabled. It is only enabled when it's selected by PPC_CELL_NATIVE which is only selected by PPC_IBM_CELL_BLADE and that in turn depends on BIG_ENDIAN. So in order to hit the bug you need to build a big endian kernel, with IBM Cell Blade support enabled, as well as Radix MMU support, and then boot that on Power9 using Radix MMU. Still we can fix the bug, so let's do that. We simply use fewer bits for the token, taking the union of the restrictions on the address from both Hash and Radix, we end up with 8 bits we can use for the token. The only user of the token is iowa_mem_find_bus() which only supports 8 token values, so 8 bits is plenty for that. Fixes: 566ca99af026 ("powerpc/mm/radix: Add dummy radix_enabled()") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-01KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILEScott Wood
[ Upstream commit 28c5bcf74fa07c25d5bd118d1271920f51ce2a98 ] TRACE_INCLUDE_PATH and TRACE_INCLUDE_FILE are used by <trace/define_trace.h>, so like that #include, they should be outside #ifdef protection. They also need to be #undefed before defining, in case multiple trace headers are included by the same C file. This became the case on book3e after commit cf4a6085151a ("powerpc/mm: Add missing tracepoint for tlbie"), leading to the following build error: CC arch/powerpc/kvm/powerpc.o In file included from arch/powerpc/kvm/powerpc.c:51:0: arch/powerpc/kvm/trace.h:9:0: error: "TRACE_INCLUDE_PATH" redefined [-Werror] #define TRACE_INCLUDE_PATH . ^ In file included from arch/powerpc/kvm/../mm/mmu_decl.h:25:0, from arch/powerpc/kvm/powerpc.c:48: ./arch/powerpc/include/asm/trace.h:224:0: note: this is the location of the previous definition #define TRACE_INCLUDE_PATH asm ^ cc1: all warnings being treated as errors Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-21Revert "powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP"Christophe Leroy
commit cc4ebf5c0a3440ed0a32d25c55ebdb6ce5f3c0bc upstream. This reverts commit 4f94b2c7462d9720b2afa7e8e8d4c19446bb31ce. That commit was buggy, as it used rlwinm instead of rlwimi. Instead of fixing that bug, we revert the previous commit in order to reduce the dependency between L1 entries and L2 entries Fixes: 4f94b2c7462d9 ("powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP") 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>
2018-11-21powerpc/memtrace: Remove memory in chunksRashmica Gupta
[ Upstream commit 3f7daf3d7582dc6628ac40a9045dd1bbd80c5f35 ] When hot-removing memory release_mem_region_adjustable() splits iomem resources if they are not the exact size of the memory being hot-deleted. Adding this memory back to the kernel adds a new resource. Eg a node has memory 0x0 - 0xfffffffff. Hot-removing 1GB from 0xf40000000 results in the single resource 0x0-0xfffffffff being split into two resources: 0x0-0xf3fffffff and 0xf80000000-0xfffffffff. When we hot-add the memory back we now have three resources: 0x0-0xf3fffffff, 0xf40000000-0xf7fffffff, and 0xf80000000-0xfffffffff. This is an issue if we try to remove some memory that overlaps resources. Eg when trying to remove 2GB at address 0xf40000000, release_mem_region_adjustable() fails as it expects the chunk of memory to be within the boundaries of a single resource. We then get the warning: "Unable to release resource" and attempting to use memtrace again gives us this error: "bash: echo: write error: Resource temporarily unavailable" This patch makes memtrace remove memory in chunks that are always the same size from an address that is always equal to end_of_memory - n*size, for some n. So hotremoving and hotadding memory of different sizes will now not attempt to remove memory that spans multiple resources. Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/boot: Ensure _zimage_start is a weak symbolJoel Stanley
[ Upstream commit ee9d21b3b3583712029a0db65a4b7c081d08d3b3 ] When building with clang crt0's _zimage_start is not marked weak, which breaks the build when linking the kernel image: $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ 0000000000000058 g .text 0000000000000000 _zimage_start ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start': (.text+0x58): multiple definition of '_zimage_start'; arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here Clang requires the .weak directive to appear after the symbol is declared. The binutils manual says: This directive sets the weak attribute on the comma separated list of symbol names. If the symbols do not already exist, they will be created. So it appears this is different with clang. The only reference I could see for this was an OpenBSD mailing list post[1]. Changing it to be after the declaration fixes building with Clang, and still works with GCC. $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$ 0000000000000058 w .text 0000000000000000 _zimage_start Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921 [1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/mm: Don't report hugepage tables as memory leaks when using kmemleakChristophe Leroy
[ Upstream commit 803d690e68f0c5230183f1a42c7d50a41d16e380 ] When a process allocates a hugepage, the following leak is reported by kmemleak. This is a false positive which is due to the pointer to the table being stored in the PGD as physical memory address and not virtual memory pointer. unreferenced object 0xc30f8200 (size 512): comm "mmap", pid 374, jiffies 4872494 (age 627.630s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<e32b68da>] huge_pte_alloc+0xdc/0x1f8 [<9e0df1e1>] hugetlb_fault+0x560/0x8f8 [<7938ec6c>] follow_hugetlb_page+0x14c/0x44c [<afbdb405>] __get_user_pages+0x1c4/0x3dc [<b8fd7cd9>] __mm_populate+0xac/0x140 [<3215421e>] vm_mmap_pgoff+0xb4/0xb8 [<c148db69>] ksys_mmap_pgoff+0xcc/0x1fc [<4fcd760f>] ret_from_syscall+0x0/0x38 See commit a984506c542e2 ("powerpc/mm: Don't report PUDs as memory leaks when using kmemleak") for detailed explanation. To fix that, this patch tells kmemleak to ignore the allocated hugepage table. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/nohash: fix undefined behaviour when testing page size supportDaniel Axtens
[ Upstream commit f5e284803a7206d43e26f9ffcae5de9626d95e37 ] When enumerating page size definitions to check hardware support, we construct a constant which is (1U << (def->shift - 10)). However, the array of page size definitions is only initalised for various MMU_PAGE_* constants, so it contains a number of 0-initialised elements with def->shift == 0. This means we end up shifting by a very large number, which gives the following UBSan splat: ================================================================================ UBSAN: Undefined behaviour in /home/dja/dev/linux/linux/arch/powerpc/mm/tlb_nohash.c:506:21 shift exponent 4294967286 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-00045-ga604f927b012-dirty #6 Call Trace: [c00000000101bc20] [c000000000a13d54] .dump_stack+0xa8/0xec (unreliable) [c00000000101bcb0] [c0000000004f20a8] .ubsan_epilogue+0x18/0x64 [c00000000101bd30] [c0000000004f2b10] .__ubsan_handle_shift_out_of_bounds+0x110/0x1a4 [c00000000101be20] [c000000000d21760] .early_init_mmu+0x1b4/0x5a0 [c00000000101bf10] [c000000000d1ba28] .early_setup+0x100/0x130 [c00000000101bf90] [c000000000000528] start_here_multiplatform+0x68/0x80 ================================================================================ Fix this by first checking if the element exists (shift != 0) before constructing the constant. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/eeh: Fix possible null deref in eeh_dump_dev_log()Sam Bobroff
[ Upstream commit f9bc28aedfb5bbd572d2d365f3095c1becd7209b ] If an error occurs during an unplug operation, it's possible for eeh_dump_dev_log() to be called when edev->pdn is null, which currently leads to dereferencing a null pointer. Handle this by skipping the error log for those devices. Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/Makefile: Fix PPC_BOOK3S_64 ASFLAGSJoel Stanley
[ Upstream commit 960e30029863db95ec79a71009272d4661db5991 ] Ever since commit 15a3204d24a3 ("powerpc/64s: Set assembler machine type to POWER4") we force -mpower4 to be passed to the assembler irrespective of the CFLAGS used (for Book3s 64). When building a powerpc64 kernel with clang, clang will not add -many to the assembler flags, so any instructions that the compiler has generated that are not available on power4 will cause an error: /usr/bin/as -a64 -mppc64 -mlittle-endian -mpower8 \ -I ./arch/powerpc/include -I ./arch/powerpc/include/generated \ -I ./include -I ./arch/powerpc/include/uapi \ -I ./arch/powerpc/include/generated/uapi -I ./include/uapi \ -I ./include/generated/uapi -I arch/powerpc -I arch/powerpc \ -maltivec -mpower4 -o init/do_mounts.o /tmp/do_mounts-3b0a3d.s /tmp/do_mounts-51ce54.s:748: Error: unrecognized opcode: `isel' GCC does include -many, so the GCC driven gas call will succeed: as -v -I ./arch/powerpc/include -I ./arch/powerpc/include/generated -I ./include -I ./arch/powerpc/include/uapi -I ./arch/powerpc/include/generated/uapi -I ./include/uapi -I ./include/generated/uapi -I arch/powerpc -I arch/powerpc -a64 -mpower8 -many -mlittle -maltivec -mpower4 -o init/do_mounts.o Note that isel is power7 and above for IBM CPUs. GCC only generates it for Power9 and above, but the above test was run against the clang generated assembly. Peter Bergner explains: When using -many -mpower4, gas will first try and find a matching power4 mnemonic and failing that, it will then allow any valid mnemonic that gas knows about. GCC's use of -many predates me though. IIRC, Alan looked at trying to remove it, but I forget why he didn't. Could be either a gcc or gas issue at the time. I'm not sure whether issue still exists or not. He and I have modified how gas works internally a fair amount since he tried removing gcc use of -many. I will also note that when using -many, gas will choose the first mnemonic that matches in the mnemonic table and we have (mostly) sorted the table so that server mnemonics show up earlier in the table than other mnemonics, so they'll be seen/chosen first. By explicitly setting -many we can build with Clang and GCC while retaining the -mpower4 option. Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/mm: fix always true/false warning in slice.cChristophe Leroy
[ Upstream commit 37e9c674e7e6f445e12cb1151017bd4bacdd1e2d ] This patch fixes the following warnings (obtained with make W=1). arch/powerpc/mm/slice.c: In function 'slice_range_to_mask': arch/powerpc/mm/slice.c:73:12: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (start < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c:81:20: error: comparison is always false due to limited range of data type [-Werror=type-limits] if ((start + len) > SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c: In function 'slice_mask_for_free': arch/powerpc/mm/slice.c:136:17: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (high_limit <= SLICE_LOW_TOP) ^ arch/powerpc/mm/slice.c: In function 'slice_check_range_fits': arch/powerpc/mm/slice.c:185:12: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (start < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c:195:39: error: comparison is always false due to limited range of data type [-Werror=type-limits] if (SLICE_NUM_HIGH && ((start + len) > SLICE_LOW_TOP)) { ^ arch/powerpc/mm/slice.c: In function 'slice_scan_available': arch/powerpc/mm/slice.c:306:11: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (addr < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c: In function 'get_slice_psize': arch/powerpc/mm/slice.c:709:11: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (addr < SLICE_LOW_TOP) { ^ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/mm: Fix page table dump to work on RadixMichael Ellerman
[ Upstream commit 0d923962ab69c27cca664a2d535e90ef655110ca ] When we're running on Book3S with the Radix MMU enabled the page table dump currently prints the wrong addresses because it uses the wrong start address. Fix it to use PAGE_OFFSET rather than KERN_VIRT_START. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/64/module: REL32 relocation range checkNicholas Piggin
[ Upstream commit b851ba02a6f3075f0f99c60c4bc30a4af80cf428 ] The recent module relocation overflow crash demonstrated that we have no range checking on REL32 relative relocations. This patch implements a basic check, the same kernel that previously oopsed and rebooted now continues with some of these errors when loading the module: module_64: x_tables: REL32 527703503449812 out of range! Possibly other relocations (ADDR32, REL16, TOC16, etc.) should also have overflow checks. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21powerpc/traps: restore recoverability of machine_check interruptsChristophe Leroy
[ Upstream commit daf00ae71dad8aa05965713c62558aeebf2df48e ] commit b96672dd840f ("powerpc: Machine check interrupt is a non- maskable interrupt") added a call to nmi_enter() at the beginning of machine check restart exception handler. Due to that, in_interrupt() always returns true regardless of the state before entering the exception, and die() panics even when the system was not already in interrupt. This patch calls nmi_exit() before calling die() in order to restore the interrupt state we had before calling nmi_enter() Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13powerpc/64s/hash: Do not use PPC_INVALIDATE_ERAT on CPUs before POWER9Nicholas Piggin
commit bc276ecba132caccb1fda5863a652c15def2b8c6 upstream. PPC_INVALIDATE_ERAT is slbia IH=7 which is a new variant introduced with POWER9, and the result is undefined on earlier CPUs. Commits 7b9f71f974 ("powerpc/64s: POWER9 machine check handler") and d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9") caused POWER7/8 code to use this instruction. Remove it. An ERAT flush can be made by invalidatig the SLB, but before POWER9 that requires a flush and rebolt. Fixes: 7b9f71f974 ("powerpc/64s: POWER9 machine check handler") Fixes: d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13powerpc/tm: Fix HFSCR bit for no suspend caseMichael Neuling
commit dd9a8c5a87395b6f05552c3b44e42fdc95760552 upstream. Currently on P9N DD2.1 we end up taking infinite TM facility unavailable exceptions on the first TM usage by userspace. In the special case of TM no suspend (P9N DD2.1), Linux is told TM is off via CPU dt-ftrs but told to (partially) use it via OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED. So HFSCR[TM] will be off from dt-ftrs but we need to turn it on for the no suspend case. This patch fixes this by enabling HFSCR TM in this case. Cc: stable@vger.kernel.org # 4.15+ Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13powerpc/msi: Fix compile error on mpc83xxChristophe Leroy
commit 0f99153def98134403c9149128e59d3e1786cf04 upstream. mpic_get_primary_version() is not defined when not using MPIC. The compile error log like: arch/powerpc/sysdev/built-in.o: In function `fsl_of_msi_probe': fsl_msi.c:(.text+0x150c): undefined reference to `fsl_mpic_primary_get_version' Signed-off-by: Jia Hongtao <hongtao.jia@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com> Reported-by: Radu Rendec <radu.rendec@gmail.com> Fixes: 807d38b73b6 ("powerpc/mpic: Add get_version API both for internal and external use") 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>
2018-11-13powerpc64/module elfv1: Set opd addresses after module relocationNaveen N. Rao
commit 59fe7eaf3598a89cbcd72e645b1d08afd76f7b29 upstream. module_frob_arch_sections() is called before the module is moved to its final location. The function descriptor section addresses we are setting here are thus invalid. Fix this by processing opd section during module_finalize() Fixes: 5633e85b2c313 ("powerpc64: Add .opd based function descriptor dereference") Cc: stable@vger.kernel.org # v4.16 Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-14Merge tag 'libnvdimm-fixes-4.19-rc8' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Dan writes: "libnvdimm/dax 4.19-rc8 * Fix a livelock in dax_layout_busy_page() present since v4.18. The lockup triggers when truncating an actively mapped huge page out of a mapping pinned for direct-I/O. * Fix mprotect() clobbers of _PAGE_DEVMAP. Broken since v4.5 mprotect() clears this flag that is needed to communicate the liveness of device pages to the get_user_pages() path." * tag 'libnvdimm-fixes-4.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: mm: Preserve _PAGE_DEVMAP across mprotect() calls filesystem-dax: Fix dax_layout_busy_page() livelock
2018-10-09mm: Preserve _PAGE_DEVMAP across mprotect() callsJan Kara
Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a result we will see warnings such as: BUG: Bad page map in process JobWrk0013 pte:800001803875ea25 pmd:7624381067 addr:00007f0930720000 vm_flags:280000f9 anon_vma: (null) mapping:ffff97f2384056f0 index:0 file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage: (null) CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G W 4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased) Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018 Call Trace: dump_stack+0x5a/0x75 print_bad_pte+0x217/0x2c0 ? enqueue_task_fair+0x76/0x9f0 _vm_normal_page+0xe5/0x100 zap_pte_range+0x148/0x740 unmap_page_range+0x39a/0x4b0 unmap_vmas+0x42/0x90 unmap_region+0x99/0xf0 ? vma_gap_callbacks_rotate+0x1a/0x20 do_munmap+0x255/0x3a0 vm_munmap+0x54/0x80 SyS_munmap+0x1d/0x30 do_syscall_64+0x74/0x150 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 ... when mprotect(2) gets used on DAX mappings. Also there is a wide variety of other failures that can result from the missing _PAGE_DEVMAP flag when the area gets used by get_user_pages() later. Fix the problem by including _PAGE_DEVMAP in a set of flags that get preserved by mprotect(2). Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP") Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") Cc: <stable@vger.kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-10-07Merge tag 'powerpc-4.19-4' of ↵Greg Kroah-Hartman
https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Michael writes: "powerpc fixes for 4.19 #4 Four regression fixes. A fix for a change to lib/xz which broke our zImage loader when building with XZ compression. OK'ed by Herbert who merged the original patch. The recent fix we did to avoid patching __init text broke some 32-bit machines, fix that. Our show_user_instructions() could be tricked into printing kernel memory, add a check to avoid that. And a fix for a change to our NUMA initialisation logic, which causes crashes in some kdump configurations. Thanks to: Christophe Leroy, Hari Bathini, Jann Horn, Joel Stanley, Meelis Roos, Murilo Opsfelder Araujo, Srikar Dronamraju." * tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/numa: Skip onlining a offline node in kdump path powerpc: Don't print kernel instructions in show_user_instructions() powerpc/lib: fix book3s/32 boot failure due to code patching lib/xz: Put CRC32_POLY_LE in xz_private.h
2018-10-05Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmGreg Kroah-Hartman
Paolo writes: "KVM changes for 4.19-rc7 x86 and PPC bugfixes, mostly introduced in 4.19-rc1." * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: nVMX: fix entry with pending interrupt if APICv is enabled KVM: VMX: hide flexpriority from guest when disabled at the module level KVM: VMX: check for existence of secondary exec controls before accessing KVM: PPC: Book3S HV: Avoid crash from THP collapse during radix page fault KVM: x86: fix L1TF's MMIO GFN calculation tools/kvm_stat: cut down decimal places in update interval dialog KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGS KVM: x86: Do not use kvm_x86_ops->mpx_supported() directly KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabled KVM: x86: never trap MSR_KERNEL_GS_BASE
2018-10-05powerpc/numa: Skip onlining a offline node in kdump pathSrikar Dronamraju
With commit 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot"), kdump kernel on shared LPAR may crash. The necessary conditions are - Shared LPAR with at least 2 nodes having memory and CPUs. - Memory requirement for kdump kernel must be met by the first N-1 nodes where there are at least N nodes with memory and CPUs. Example numactl of such a machine. $ numactl -H available: 5 nodes (0,2,5-7) node 0 cpus: node 0 size: 0 MB node 0 free: 0 MB node 2 cpus: node 2 size: 255 MB node 2 free: 189 MB node 5 cpus: 24 25 26 27 28 29 30 31 node 5 size: 4095 MB node 5 free: 4024 MB node 6 cpus: 0 1 2 3 4 5 6 7 16 17 18 19 20 21 22 23 node 6 size: 6353 MB node 6 free: 5998 MB node 7 cpus: 8 9 10 11 12 13 14 15 32 33 34 35 36 37 38 39 node 7 size: 7640 MB node 7 free: 7164 MB node distances: node 0 2 5 6 7 0: 10 40 40 40 40 2: 40 10 40 40 40 5: 40 40 10 40 40 6: 40 40 40 10 20 7: 40 40 40 20 10 Steps to reproduce. 1. Load / start kdump service. 2. Trigger a kdump (for example : echo c > /proc/sysrq-trigger) When booting a kdump kernel with 2048M: kexec: Starting switchover sequence. I'm in purgatory Using 1TB segments hash-mmu: Initializing hash mmu with SLB Linux version 4.19.0-rc5-master+ (srikar@linux-xxu6) (gcc version 4.8.5 (SUSE Linux)) #1 SMP Thu Sep 27 19:45:00 IST 2018 Found initrd at 0xc000000009e70000:0xc00000000ae554b4 Using pSeries machine description ----------------------------------------------------- ppc64_pft_size = 0x1e phys_mem_size = 0x88000000 dcache_bsize = 0x80 icache_bsize = 0x80 cpu_features = 0x000000ff8f5d91a7 possible = 0x0000fbffcf5fb1a7 always = 0x0000006f8b5c91a1 cpu_user_features = 0xdc0065c2 0xef000000 mmu_features = 0x7c006001 firmware_features = 0x00000007c45bfc57 htab_hash_mask = 0x7fffff physical_start = 0x8000000 ----------------------------------------------------- numa: NODE_DATA [mem 0x87d5e300-0x87d67fff] numa: NODE_DATA(0) on node 6 numa: NODE_DATA [mem 0x87d54600-0x87d5e2ff] Top of RAM: 0x88000000, Total RAM: 0x88000000 Memory hole size: 0MB Zone ranges: DMA [mem 0x0000000000000000-0x0000000087ffffff] DMA32 empty Normal empty Movable zone start for each node Early memory node ranges node 6: [mem 0x0000000000000000-0x0000000087ffffff] Could not find start_pfn for node 0 Initmem setup node 0 [mem 0x0000000000000000-0x0000000000000000] On node 0 totalpages: 0 Initmem setup node 6 [mem 0x0000000000000000-0x0000000087ffffff] On node 6 totalpages: 34816 Unable to handle kernel paging request for data at address 0x00000060 Faulting instruction address: 0xc000000008703a54 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 11 PID: 1 Comm: swapper/11 Not tainted 4.19.0-rc5-master+ #1 NIP: c000000008703a54 LR: c000000008703a38 CTR: 0000000000000000 REGS: c00000000b673440 TRAP: 0380 Not tainted (4.19.0-rc5-master+) MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 24022022 XER: 20000002 CFAR: c0000000086fc238 IRQMASK: 0 GPR00: c000000008703a38 c00000000b6736c0 c000000009281900 0000000000000000 GPR04: 0000000000000000 0000000000000000 fffffffffffff001 c00000000b660080 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000220 GPR12: 0000000000002200 c000000009e51400 0000000000000000 0000000000000008 GPR16: 0000000000000000 c000000008c152e8 c000000008c152a8 0000000000000000 GPR20: c000000009422fd8 c000000009412fd8 c000000009426040 0000000000000008 GPR24: 0000000000000000 0000000000000000 c000000009168bc8 c000000009168c78 GPR28: c00000000b126410 0000000000000000 c00000000916a0b8 c00000000b126400 NIP [c000000008703a54] bus_add_device+0x84/0x1e0 LR [c000000008703a38] bus_add_device+0x68/0x1e0 Call Trace: [c00000000b6736c0] [c000000008703a38] bus_add_device+0x68/0x1e0 (unreliable) [c00000000b673740] [c000000008700194] device_add+0x454/0x7c0 [c00000000b673800] [c00000000872e660] __register_one_node+0xb0/0x240 [c00000000b673860] [c00000000839a6bc] __try_online_node+0x12c/0x180 [c00000000b673900] [c00000000839b978] try_online_node+0x58/0x90 [c00000000b673930] [c0000000080846d8] find_and_online_cpu_nid+0x158/0x190 [c00000000b673a10] [c0000000080848a0] numa_update_cpu_topology+0x190/0x580 [c00000000b673c00] [c000000008d3f2e4] smp_cpus_done+0x94/0x108 [c00000000b673c70] [c000000008d5c00c] smp_init+0x174/0x19c [c00000000b673d00] [c000000008d346b8] kernel_init_freeable+0x1e0/0x450 [c00000000b673dc0] [c0000000080102e8] kernel_init+0x28/0x160 [c00000000b673e30] [c00000000800b65c] ret_from_kernel_thread+0x5c/0x80 Instruction dump: 60000000 60000000 e89e0020 7fe3fb78 4bff87d5 60000000 7c7d1b79 4082008c e8bf0050 e93e0098 3b9f0010 2fa50000 <e8690060> 38630018 419e0114 7f84e378 ---[ end trace 593577668c2daa65 ]--- However a regular kernel with 4096M (2048 gets reserved for crash kernel) boots properly. Unlike regular kernels, which mark all available nodes as online, kdump kernel only marks just enough nodes as online and marks the rest as offline at boot. However kdump kernel boots with all available CPUs. With Commit 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot"), all CPUs are onlined on their respective nodes at boot time. try_online_node() tries to online the offline nodes but fails as all needed subsystems are not yet initialized. As part of fix, detect and skip early onlining of a offline node. Fixes: 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot") Reported-by: Pavithra Prakash <pavrampu@in.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-05powerpc: Don't print kernel instructions in show_user_instructions()Michael Ellerman
Recently we implemented show_user_instructions() which dumps the code around the NIP when a user space process dies with an unhandled signal. This was modelled on the x86 code, and we even went so far as to implement the exact same bug, namely that if the user process crashed with its NIP pointing into the kernel we will dump kernel text to dmesg. eg: bad-bctr[2996]: segfault (11) at c000000000010000 nip c000000000010000 lr 12d0b0894 code 1 bad-bctr[2996]: code: fbe10068 7cbe2b78 7c7f1b78 fb610048 38a10028 38810020 fb810050 7f8802a6 bad-bctr[2996]: code: 3860001c f8010080 48242371 60000000 <7c7b1b79> 4082002c e8010080 eb610048 This was discovered on x86 by Jann Horn and fixed in commit 342db04ae712 ("x86/dumpstack: Don't dump kernel memory based on usermode RIP"). Fix it by checking the adjusted NIP value (pc) and number of instructions against USER_DS, and bail if we fail the check, eg: bad-bctr[2969]: segfault (11) at c000000000010000 nip c000000000010000 lr 107930894 code 1 bad-bctr[2969]: Bad NIP, not dumping instructions. Fixes: 88b0fe175735 ("powerpc: Add show_user_instructions()") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-04KVM: PPC: Book3S HV: Avoid crash from THP collapse during radix page faultPaul Mackerras
Commit 71d29f43b633 ("KVM: PPC: Book3S HV: Don't use compound_order to determine host mapping size", 2018-09-11) added a call to __find_linux_pte() and a dereference of the returned PTE pointer to the radix page fault path in the common case where the page is normal system memory. Previously, __find_linux_pte() was only called for mappings to physical addresses which don't have a page struct (e.g. memory-mapped I/O) or where the page struct is marked as reserved memory. This exposes us to the possibility that the returned PTE pointer could be NULL, for example in the case of a concurrent THP collapse operation. Dereferencing the returned NULL pointer causes a host crash. To fix this, we check for NULL, and if it is NULL, we retry the operation by returning to the guest, with the expectation that it will generate the same page fault again (unless of course it has been fixed up by another CPU in the meantime). Fixes: 71d29f43b633 ("KVM: PPC: Book3S HV: Don't use compound_order to determine host mapping size") Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-10-02powerpc/lib: fix book3s/32 boot failure due to code patchingChristophe Leroy
Commit 51c3c62b58b3 ("powerpc: Avoid code patching freed init sections") accesses 'init_mem_is_free' flag too early, before the kernel is relocated. This provokes early boot failure (before the console is active). As it is not necessary to do this verification that early, this patch moves the test into patch_instruction() instead of __patch_instruction(). This modification also has the advantage of avoiding unnecessary remappings. Fixes: 51c3c62b58b3 ("powerpc: Avoid code patching freed init sections") Cc: stable@vger.kernel.org # 4.13+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-28Merge tag 'powerpc-4.19-3' of ↵Greg Kroah-Hartman
https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Michael writes: "powerpc fixes for 4.19 #3 A reasonably big batch of fixes due to me being away for a few weeks. A fix for the TM emulation support on Power9, which could result in corrupting the guest r11 when running under KVM. Two fixes to the TM code which could lead to userspace GPR corruption if we take an SLB miss at exactly the wrong time. Our dynamic patching code had a bug that meant we could patch freed __init text, which could lead to corrupting userspace memory. csum_ipv6_magic() didn't work on little endian platforms since we optimised it recently. A fix for an endian bug when reading a device tree property telling us how many storage keys the machine has available. Fix a crash seen on some configurations of PowerVM when migrating the partition from one machine to another. A fix for a regression in the setup of our CPU to NUMA node mapping in KVM guests. A fix to our selftest Makefiles to make them work since a recent change to the shared Makefile logic." * tag 'powerpc-4.19-3' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: selftests/powerpc: Fix Makefiles for headers_install change powerpc/numa: Use associativity if VPHN hcall is successful powerpc/tm: Avoid possible userspace r1 corruption on reclaim powerpc/tm: Fix userspace r13 corruption powerpc/pseries: Fix unitialized timer reset on migration powerpc/pkeys: Fix reading of ibm, processor-storage-keys property powerpc: fix csum_ipv6_magic() on little endian platforms powerpc/powernv/ioda2: Reduce upper limit for DMA window size (again) powerpc: Avoid code patching freed init sections KVM: PPC: Book3S HV: Fix guest r11 corruption with POWER9 TM workarounds
2018-09-25powerpc/numa: Use associativity if VPHN hcall is successfulSrikar Dronamraju
Currently associativity is used to lookup node-id even if the preceding VPHN hcall failed. However this can cause CPU to be made part of the wrong node, (most likely to be node 0). This is because VPHN is not enabled on KVM guests. With 2ea6263 ("powerpc/topology: Get topology for shared processors at boot"), associativity is used to set to the wrong node. Hence KVM guest topology is broken. For example : A 4 node KVM guest before would have reported. [root@localhost ~]# numactl -H available: 4 nodes (0-3) node 0 cpus: 0 1 2 3 node 0 size: 1746 MB node 0 free: 1604 MB node 1 cpus: 4 5 6 7 node 1 size: 2044 MB node 1 free: 1765 MB node 2 cpus: 8 9 10 11 node 2 size: 2044 MB node 2 free: 1837 MB node 3 cpus: 12 13 14 15 node 3 size: 2044 MB node 3 free: 1903 MB node distances: node 0 1 2 3 0: 10 40 40 40 1: 40 10 40 40 2: 40 40 10 40 3: 40 40 40 10 Would now report: [root@localhost ~]# numactl -H available: 4 nodes (0-3) node 0 cpus: 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 node 0 size: 1746 MB node 0 free: 1244 MB node 1 cpus: node 1 size: 2044 MB node 1 free: 2032 MB node 2 cpus: 1 node 2 size: 2044 MB node 2 free: 2028 MB node 3 cpus: node 3 size: 2044 MB node 3 free: 2032 MB node distances: node 0 1 2 3 0: 10 40 40 40 1: 40 10 40 40 2: 40 40 10 40 3: 40 40 40 10 Fix this by skipping associativity lookup if the VPHN hcall failed. Fixes: 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot") Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-25powerpc/tm: Avoid possible userspace r1 corruption on reclaimMichael Neuling
Current we store the userspace r1 to PACATMSCRATCH before finally saving it to the thread struct. In theory an exception could be taken here (like a machine check or SLB miss) that could write PACATMSCRATCH and hence corrupt the userspace r1. The SLB fault currently doesn't touch PACATMSCRATCH, but others do. We've never actually seen this happen but it's theoretically possible. Either way, the code is fragile as it is. This patch saves r1 to the kernel stack (which can't fault) before we turn MSR[RI] back on. PACATMSCRATCH is still used but only with MSR[RI] off. We then copy r1 from the kernel stack to the thread struct once we have MSR[RI] back on. Suggested-by: Breno Leitao <leitao@debian.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-25powerpc/tm: Fix userspace r13 corruptionMichael Neuling
When we treclaim we store the userspace checkpointed r13 to a scratch SPR and then later save the scratch SPR to the user thread struct. Unfortunately, this doesn't work as accessing the user thread struct can take an SLB fault and the SLB fault handler will write the same scratch SPRG that now contains the userspace r13. To fix this, we store r13 to the kernel stack (which can't fault) before we access the user thread struct. Found by running P8 guest + powervm + disable_1tb_segments + TM. Seen as a random userspace segfault with r13 looking like a kernel address. Signed-off-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-24powerpc/pseries: Fix unitialized timer reset on migrationMichael Bringmann
After migration of a powerpc LPAR, the kernel executes code to update the system state to reflect new platform characteristics. Such changes include modifications to device tree properties provided to the system by PHYP. Property notifications received by the post_mobility_fixup() code are passed along to the kernel in general through a call to of_update_property() which in turn passes such events back to all modules through entries like the '.notifier_call' function within the NUMA module. When the NUMA module updates its state, it resets its event timer. If this occurs after a previous call to stop_topology_update() or on a system without VPHN enabled, the code runs into an unitialized timer structure and crashes. This patch adds a safety check along this path toward the problem code. An example crash log is as follows. ibmvscsi 30000081: Re-enabling adapter! ------------[ cut here ]------------ kernel BUG at kernel/time/timer.c:958! Oops: Exception in kernel mode, sig: 5 [#1] LE SMP NR_CPUS=2048 NUMA pSeries Modules linked in: nfsv3 nfs_acl nfs tcp_diag udp_diag inet_diag lockd unix_diag af_packet_diag netlink_diag grace fscache sunrpc xts vmx_crypto pseries_rng sg binfmt_misc ip_tables xfs libcrc32c sd_mod ibmvscsi ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod CPU: 11 PID: 3067 Comm: drmgr Not tainted 4.17.0+ #179 ... NIP mod_timer+0x4c/0x400 LR reset_topology_timer+0x40/0x60 Call Trace: 0xc0000003f9407830 (unreliable) reset_topology_timer+0x40/0x60 dt_update_callback+0x100/0x120 notifier_call_chain+0x90/0x100 __blocking_notifier_call_chain+0x60/0x90 of_property_notify+0x90/0xd0 of_update_property+0x104/0x150 update_dt_property+0xdc/0x1f0 pseries_devicetree_update+0x2d0/0x510 post_mobility_fixup+0x7c/0xf0 migration_store+0xa4/0xc0 kobj_attr_store+0x30/0x60 sysfs_kf_write+0x64/0xa0 kernfs_fop_write+0x16c/0x240 __vfs_write+0x40/0x200 vfs_write+0xc8/0x240 ksys_write+0x5c/0x100 system_call+0x58/0x6c Fixes: 5d88aa85c00b ("powerpc/pseries: Update CPU maps when device tree is updated") Cc: stable@vger.kernel.org # v3.10+ Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-20powerpc/pkeys: Fix reading of ibm, processor-storage-keys propertyThiago Jung Bauermann
scan_pkey_feature() uses of_property_read_u32_array() to read the ibm,processor-storage-keys property and calls be32_to_cpu() on the value it gets. The problem is that of_property_read_u32_array() already returns the value converted to the CPU byte order. The value of pkeys_total ends up more or less sane because there's a min() call in pkey_initialize() which reduces pkeys_total to 32. So in practice the kernel ignores the fact that the hypervisor reserved one key for itself (the device tree advertises 31 keys in my test VM). This is wrong, but the effect in practice is that when a process tries to allocate the 32nd key, it gets an -EINVAL error instead of -ENOSPC which would indicate that there aren't any keys available Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-20powerpc: fix csum_ipv6_magic() on little endian platformsChristophe Leroy
On little endian platforms, csum_ipv6_magic() keeps len and proto in CPU byte order. This generates a bad results leading to ICMPv6 packets from other hosts being dropped by powerpc64le platforms. In order to fix this, len and proto should be converted to network byte order ie bigendian byte order. However checksumming 0x12345678 and 0x56341278 provide the exact same result so it is enough to rotate the sum of len and proto by 1 byte. PPC32 only support bigendian so the fix is needed for PPC64 only Fixes: e9c4943a107b ("powerpc: Implement csum_ipv6_magic in assembly") Reported-by: Jianlin Shi <jishi@redhat.com> Reported-by: Xin Long <lucien.xin@gmail.com> Cc: <stable@vger.kernel.org> # 4.18+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Tested-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-20powerpc/powernv/ioda2: Reduce upper limit for DMA window size (again)Alexey Kardashevskiy
mpe: This was fixed originally in commit d3d4ffaae439 ("powerpc/powernv/ioda2: Reduce upper limit for DMA window size"), but contrary to what the merge commit says was inadvertently lost by me in commit ce57c6610cc2 ("Merge branch 'topic/ppc-kvm' into next") which brought in changes that moved the code to a new file. So reapply it to the new file. Original commit message follows: We use PHB in mode1 which uses bit 59 to select a correct DMA window. However there is mode2 which uses bits 59:55 and allows up to 32 DMA windows per a PE. Even though documentation does not clearly specify that, it seems that the actual hardware does not support bits 59:55 even in mode1, in other words we can create a window as big as 1<<58 but DMA simply won't work. This reduces the upper limit from 59 to 55 bits to let the userspace know about the hardware limits. Fixes: ce57c6610cc2 ("Merge branch 'topic/ppc-kvm' into next") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>