summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/exceptions-64s.S
AgeCommit message (Collapse)Author
2019-04-17powerpc/64s/radix: Fix radix segment exception handlingNicholas Piggin
commit 7100e8704b61247649c50551b965e71d168df30b upstream. Commit 48e7b76957 ("powerpc/64s/hash: Convert SLB miss handlers to C") broke the radix-mode segment exception handler. In radix mode, this is exception is not an SLB miss, rather it signals that the EA is outside the range translated by any page table. The commit lost the radix feature alternate code patch, which can cause faults to some EAs to kernel BUG at arch/powerpc/mm/slb.c:639! The original radix code would send faults to slb_miss_large_addr, which would end up faulting due to slb_addr_limit being 0. This patch sends radix directly to do_bad_slb_fault, which is a bit clearer. Fixes: 48e7b7695745 ("powerpc/64s/hash: Convert SLB miss handlers to C") Cc: stable@vger.kernel.org # v4.20+ Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-27Merge tag 'powerpc-4.21-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - Mitigations for Spectre v2 on some Freescale (NXP) CPUs. - A large series adding support for pass-through of Nvidia V100 GPUs to guests on Power9. - Another large series to enable hardware assistance for TLB table walk on MPC8xx CPUs. - Some preparatory changes to our DMA code, to make way for further cleanups from Christoph. - Several fixes for our Transactional Memory handling discovered by fuzzing the signal return path. - Support for generating our system call table(s) from a text file like other architectures. - A fix to our page fault handler so that instead of generating a WARN_ON_ONCE, user accesses of kernel addresses instead print a ratelimited and appropriately scary warning. - A cosmetic change to make our unhandled page fault messages more similar to other arches and also more compact and informative. - Freescale updates from Scott: "Highlights include elimination of legacy clock bindings use from dts files, an 83xx watchdog handler, fixes to old dts interrupt errors, and some minor cleanup." And many clean-ups, reworks and minor fixes etc. Thanks to: Alexandre Belloni, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Benjamin Herrenschmidt, Breno Leitao, Christian Lamparter, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Darren Stevens, David Gibson, Diana Craciun, Dmitry V. Levin, Firoz Khan, Geert Uytterhoeven, Greg Kurz, Gustavo Romero, Hari Bathini, Joel Stanley, Kees Cook, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Mathieu Malaterre, Michal Suchánek, Naveen N. Rao, Nick Desaulniers, Oliver O'Halloran, Paul Mackerras, Ram Pai, Ravi Bangoria, Rob Herring, Russell Currey, Sabyasachi Gupta, Sam Bobroff, Satheesh Rajendran, Scott Wood, Segher Boessenkool, Stephen Rothwell, Tang Yuantian, Thiago Jung Bauermann, Yangtao Li, Yuantian Tang, Yue Haibing" * tag 'powerpc-4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (201 commits) Revert "powerpc/fsl_pci: simplify fsl_pci_dma_set_mask" powerpc/zImage: Also check for stdout-path powerpc: Fix HMIs on big-endian with CONFIG_RELOCATABLE=y macintosh: Use of_node_name_{eq, prefix} for node name comparisons ide: Use of_node_name_eq for node name comparisons powerpc: Use of_node_name_eq for node name comparisons powerpc/pseries/pmem: Convert to %pOFn instead of device_node.name powerpc/mm: Remove very old comment in hash-4k.h powerpc/pseries: Fix node leak in update_lmb_associativity_index() powerpc/configs/85xx: Enable CONFIG_DEBUG_KERNEL powerpc/dts/fsl: Fix dtc-flagged interrupt errors clk: qoriq: add more compatibles strings powerpc/fsl: Use new clockgen binding powerpc/83xx: handle machine check caused by watchdog timer powerpc/fsl-rio: fix spelling mistake "reserverd" -> "reserved" powerpc/fsl_pci: simplify fsl_pci_dma_set_mask arch/powerpc/fsl_rmu: Use dma_zalloc_coherent vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver vfio_pci: Allow regions to add own capabilities vfio_pci: Allow mapping extra regions ...
2018-12-22powerpc: Fix HMIs on big-endian with CONFIG_RELOCATABLE=yBenjamin Herrenschmidt
HMIs will crash the kernel due to BRANCH_LINK_TO_FAR(hmi_exception_realmode) Calling into the OPD instead of the actual code. Fixes: 2337d207288f ("powerpc/64: CONFIG_RELOCATABLE support for hmi interrupts") Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Use DOTSYM() rather than #ifdef] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-17KVM: PPC: Book3S HV: Implement functions to access quadrants 1 & 2Suraj Jitindar Singh
The POWER9 radix mmu has the concept of quadrants. The quadrant number is the two high bits of the effective address and determines the fully qualified address to be used for the translation. The fully qualified address consists of the effective lpid, the effective pid and the effective address. This gives then 4 possible quadrants 0, 1, 2, and 3. When accessing these quadrants the fully qualified address is obtained as follows: Quadrant | Hypervisor | Guest -------------------------------------------------------------------------- | EA[0:1] = 0b00 | EA[0:1] = 0b00 0 | effLPID = 0 | effLPID = LPIDR | effPID = PIDR | effPID = PIDR -------------------------------------------------------------------------- | EA[0:1] = 0b01 | 1 | effLPID = LPIDR | Invalid Access | effPID = PIDR | -------------------------------------------------------------------------- | EA[0:1] = 0b10 | 2 | effLPID = LPIDR | Invalid Access | effPID = 0 | -------------------------------------------------------------------------- | EA[0:1] = 0b11 | EA[0:1] = 0b11 3 | effLPID = 0 | effLPID = LPIDR | effPID = 0 | effPID = 0 -------------------------------------------------------------------------- In the Guest; Quadrant 3 is normally used to address the operating system since this uses effPID=0 and effLPID=LPIDR, meaning the PID register doesn't need to be switched. Quadrant 0 is normally used to address user space since the effLPID and effPID are taken from the corresponding registers. In the Host; Quadrant 0 and 3 are used as above, however the effLPID is always 0 to address the host. Quadrants 1 and 2 can be used by the host to address guest memory using a guest effective address. Since the effLPID comes from the LPID register, the host loads the LPID of the guest it would like to access (and the PID of the process) and can perform accesses to a guest effective address. This means quadrant 1 can be used to address the guest user space and quadrant 2 can be used to address the guest operating system from the hypervisor, using a guest effective address. Access to the quadrants can cause a Hypervisor Data Storage Interrupt (HDSI) due to being unable to perform partition scoped translation. Previously this could only be generated from a guest and so the code path expects us to take the KVM trampoline in the interrupt handler. This is no longer the case so we modify the handler to call bad_page_fault() to check if we were expecting this fault so we can handle it gracefully and just return with an error code. In the hash mmu case we still raise an unknown exception since quadrants aren't defined for the hash mmu. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-10-14powerpc/64s/hash: Convert SLB miss handlers to CNicholas Piggin
This patch moves SLB miss handlers completely to C, using the standard exception handler macros to set up the stack and branch to C. This can be done because the segment containing the kernel stack is always bolted, so accessing it with relocation on will not cause an SLB exception. Arbitrary kernel memory must not be accessed when handling kernel space SLB misses, so care should be taken there. However user SLB misses can access any kernel memory, which can be used to move some fields out of the paca (in later patches). User SLB misses could quite easily reconcile IRQs and set up a first class kernel environment and exit via ret_from_except, however that doesn't seem to be necessary at the moment, so we only do that if a bad fault is encountered. [ Credit to Aneesh for bug fixes, error checks, and improvements to bad address handling, etc ] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Disallow tracing for all of slb.c for now.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-09Merge branch 'fixes' into nextMichael Ellerman
Merge our fixes branch. It has a few important fixes that are needed for futher testing and also some commits that will conflict with content in next.
2018-10-03Revert "convert SLB miss handlers to C" and subsequent commitsMichael Ellerman
This reverts commits: 5e46e29e6a97 ("powerpc/64s/hash: convert SLB miss handlers to C") 8fed04d0f6ae ("powerpc/64s/hash: remove user SLB data from the paca") 655deecf67b2 ("powerpc/64s/hash: SLB allocation status bitmaps") 2e1626744e8d ("powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup") 89ca4e126a3f ("powerpc/64s/hash: Add a SLB preload cache") This series had a few bugs, and the fixes are not all trivial. So revert most of it for now. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/64s/hash: convert SLB miss handlers to CNicholas Piggin
This patch moves SLB miss handlers completely to C, using the standard exception handler macros to set up the stack and branch to C. This can be done because the segment containing the kernel stack is always bolted, so accessing it with relocation on will not cause an SLB exception. Arbitrary kernel memory may not be accessed when handling kernel space SLB misses, so care should be taken there. However user SLB misses can access any kernel memory, which can be used to move some fields out of the paca (in later patches). User SLB misses could quite easily reconcile IRQs and set up a first class kernel environment and exit via ret_from_except, however that doesn't seem to be necessary at the moment, so we only do that if a bad fault is encountered. [ Credit to Aneesh for bug fixes, error checks, and improvements to bad address handling, etc ] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Since RFC: - Added MSR[RI] handling - Fixed up a register loss bug exposed by irq tracing (Aneesh) - Reject misses outside the defined kernel regions (Aneesh) - Added several more sanity checks and error handling (Aneesh), we may look at consolidating these tests and tightenig up the code but for a first pass we decided it's better to check carefully. Since v1: - Fixed SLB cache corruption (Aneesh) - Fixed untidy SLBE allocation "leak" in get_vsid error case - Now survives some stress testing on real hardware Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powernv/pseries: consolidate code for mce early handling.Mahesh Salgaonkar
Now that other platforms also implements real mode mce handler, lets consolidate the code by sharing existing powernv machine check early code. Rename machine_check_powernv_early to machine_check_common_early and reuse the code. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19powerpc/pseries: Flush SLB contents on SLB MCE errors.Mahesh Salgaonkar
On pseries, as of today system crashes if we get a machine check exceptions due to SLB errors. These are soft errors and can be fixed by flushing the SLBs so the kernel can continue to function instead of system crash. We do this in real mode before turning on MMU. Otherwise we would run into nested machine checks. This patch now fetches the rtas error log in real mode and flushes the SLBs on SLB/ERAT errors. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michal Suchanek <msuchanek@suse.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-17KVM: PPC: Book3S HV: Fix guest r11 corruption with POWER9 TM workaroundsMichael Neuling
When we come into the softpatch handler (0x1500), we use r11 to store the HSRR0 for later use by the denorm handler. We also use the softpatch handler for the TM workarounds for POWER9. Unfortunately, in kvmppc_interrupt_hv we later store r11 out to the vcpu assuming it's still what we got from userspace. This causes r11 to be corrupted in the VCPU and hence when we restore the guest, we get a corrupted r11. We've seen this when running TM tests inside guests on P9. This fixes the problem by only touching r11 in the denorm case. Fixes: 4bb3c7a020 ("KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9") Cc: <stable@vger.kernel.org> # 4.17+ Test-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64s: Make rfi_flush_fallback a little more robustMichael Ellerman
Because rfi_flush_fallback runs immediately before the return to userspace it currently runs with the user r1 (stack pointer). This means if we oops in there we will report a bad kernel stack pointer in the exception entry path, eg: Bad kernel stack pointer 7ffff7150e40 at c0000000000023b4 Oops: Bad kernel stack pointer, sig: 6 [#1] LE SMP NR_CPUS=32 NUMA PowerNV Modules linked in: CPU: 0 PID: 1246 Comm: klogd Not tainted 4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3 #7 NIP: c0000000000023b4 LR: 0000000010053e00 CTR: 0000000000000040 REGS: c0000000fffe7d40 TRAP: 4100 Not tainted (4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3) MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000 CFAR: c00000000000bac8 IRQMASK: c0000000f1e66a80 GPR00: 0000000002000000 00007ffff7150e40 00007fff93a99900 0000000000000020 ... NIP [c0000000000023b4] rfi_flush_fallback+0x34/0x80 LR [0000000010053e00] 0x10053e00 Although the NIP tells us where we were, and the TRAP number tells us what happened, it would still be nicer if we could report the actual exception rather than barfing about the stack pointer. We an do that fairly simply by loading the kernel stack pointer on entry and restoring the user value before returning. That way we see a regular oops such as: Unrecoverable exception 4100 at c00000000000239c Oops: Unrecoverable exception, sig: 6 [#1] LE SMP NR_CPUS=32 NUMA PowerNV Modules linked in: CPU: 0 PID: 1251 Comm: klogd Not tainted 4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty #40 NIP: c00000000000239c LR: 0000000010053e00 CTR: 0000000000000040 REGS: c0000000f1e17bb0 TRAP: 4100 Not tainted (4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty) MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000 CFAR: c00000000000bac8 IRQMASK: 0 ... NIP [c00000000000239c] rfi_flush_fallback+0x3c/0x80 LR [0000000010053e00] 0x10053e00 Call Trace: [c0000000f1e17e30] [c00000000000b9e4] system_call+0x5c/0x70 (unreliable) Note this shouldn't make the kernel stack pointer vulnerable to a meltdown attack, because it should be flushed from the cache before we return to userspace. The user r1 value will be in the cache, because we load it in the return path, but that is harmless. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-08-07powerpc/64s: Don't use __MASKABLE_EXCEPTION unnecessarilyMichael Ellerman
We only need to use __MASKABLE_EXCEPTION in one of the four cases for hardware interrupt, so use the helper macros in the other cases. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Remove PSERIES naming from the MASKABLE macrosMichael Ellerman
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Drop _MASKABLE_RELON_EXCEPTION_PSERIES()Michael Ellerman
_MASKABLE_RELON_EXCEPTION_PSERIES() does nothing useful, update all callers to use __MASKABLE_RELON_EXCEPTION_PSERIES() directly. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Drop _MASKABLE_EXCEPTION_PSERIES()Michael Ellerman
_MASKABLE_EXCEPTION_PSERIES() does nothing useful, update all callers to use __MASKABLE_EXCEPTION_PSERIES() directly. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Remove PSERIES from the NORI macrosMichael Ellerman
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Rename EXCEPTION_PROLOG_PSERIES_1 to EXCEPTION_PROLOG_2Michael Ellerman
As with the other patches in this series, we are removing the "PSERIES" from the name as it's no longer meaningful. In this case it's not simply a case of removing the "PSERIES" as that would result in a clash with the existing EXCEPTION_PROLOG_1. Instead we name this one EXCEPTION_PROLOG_2, as it's usually used in sequence after 0 and 1. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-30powerpc: clean inclusions of asm/feature-fixups.hChristophe Leroy
files not using feature fixup don't need asm/feature-fixups.h files using feature fixup need asm/feature-fixups.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-24powerpc/64s: make PACA_IRQ_HARD_DIS track MSR[EE] closelyNicholas Piggin
When the masked interrupt handler clears MSR[EE] for an interrupt in the PACA_IRQ_MUST_HARD_MASK set, it does not set PACA_IRQ_HARD_DIS. This makes them get out of synch. With that taken into account, it's only low level irq manipulation (and interrupt entry before reconcile) where they can be out of synch. This makes the code less surprising. It also allows the IRQ replay code to rely on the IRQ_HARD_DIS value and not have to mtmsrd again in this case (e.g., for an external interrupt that has been masked). The bigger benefit might just be that there is not such an element of surprise in these two bits of state. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-16powerpc/64s: Remove POWER9 DD1 supportNicholas Piggin
POWER9 DD1 was never a product. It is no longer supported by upstream firmware, and it is not effectively supported in Linux due to lack of testing. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [mpe: Remove arch_make_huge_pte() entirely] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-07Merge tag 'powerpc-4.18-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - Support for split PMD page table lock on 64-bit Book3S (Power8/9). - Add support for HAVE_RELIABLE_STACKTRACE, so we properly support live patching again. - Add support for patching barrier_nospec in copy_from_user() and syscall entry. - A couple of fixes for our data breakpoints on Book3S. - A series from Nick optimising TLB/mm handling with the Radix MMU. - Numerous small cleanups to squash sparse/gcc warnings from Mathieu Malaterre. - Several series optimising various parts of the 32-bit code from Christophe Leroy. - Removal of support for two old machines, "SBC834xE" and "C2K" ("GEFanuc,C2K"), which is why the diffstat has so many deletions. And many other small improvements & fixes. There's a few out-of-area changes. Some minor ftrace changes OK'ed by Steve, and a fix to our powernv cpuidle driver. Then there's a series touching mm, x86 and fs/proc/task_mmu.c, which cleans up some details around pkey support. It was ack'ed/reviewed by Ingo & Dave and has been in next for several weeks. Thanks to: Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Al Viro, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Balbir Singh, Cédric Le Goater, Christophe Leroy, Christophe Lombard, Colin Ian King, Dave Hansen, Fabio Estevam, Finn Thain, Frederic Barrat, Gautham R. Shenoy, Haren Myneni, Hari Bathini, Ingo Molnar, Jonathan Neuschäfer, Josh Poimboeuf, Kamalesh Babulal, Madhavan Srinivasan, Mahesh Salgaonkar, Mark Greer, Mathieu Malaterre, Matthew Wilcox, Michael Neuling, Michal Suchanek, Naveen N. Rao, Nicholas Piggin, Nicolai Stange, Olof Johansson, Paul Gortmaker, Paul Mackerras, Peter Rosin, Pridhiviraj Paidipeddi, Ram Pai, Rashmica Gupta, Ravi Bangoria, Russell Currey, Sam Bobroff, Samuel Mendoza-Jonas, Segher Boessenkool, Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stewart Smith, Thiago Jung Bauermann, Torsten Duwe, Vaibhav Jain, Wei Yongjun, Wolfram Sang, Yisheng Xie, YueHaibing" * tag 'powerpc-4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (251 commits) powerpc/64s/radix: Fix missing ptesync in flush_cache_vmap cpuidle: powernv: Fix promotion from snooze if next state disabled powerpc: fix build failure by disabling attribute-alias warning in pci_32 ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait() powerpc-opal: fix spelling mistake "Uniterrupted" -> "Uninterrupted" powerpc: fix spelling mistake: "Usupported" -> "Unsupported" powerpc/pkeys: Detach execute_only key on !PROT_EXEC powerpc/powernv: copy/paste - Mask SO bit in CR powerpc: Remove core support for Marvell mv64x60 hostbridges powerpc/boot: Remove core support for Marvell mv64x60 hostbridges powerpc/boot: Remove support for Marvell mv64x60 i2c controller powerpc/boot: Remove support for Marvell MPSC serial controller powerpc/embedded6xx: Remove C2K board support powerpc/lib: optimise PPC32 memcmp powerpc/lib: optimise 32 bits __clear_user() powerpc/time: inline arch_vtime_task_switch() powerpc/Makefile: set -mcpu=860 flag for the 8xx powerpc: Implement csum_ipv6_magic in assembly powerpc/32: Optimise __csum_partial() powerpc/lib: Adjust .balign inside string functions for PPC32 ...
2018-06-03powerpc/64: Save stack pointer when we hard disable interruptsMichael Ellerman
A CPU that gets stuck with interrupts hard disable can be difficult to debug, as on some platforms we have no way to interrupt the CPU to find out what it's doing. A stop-gap is to have the CPU save it's stack pointer (r1) in its paca when it hard disables interrupts. That way if we can't interrupt it, we can at least trace the stack based on where it last disabled interrupts. In some cases that will be total junk, but the stack trace code should handle that. In the simple case of a CPU that disable interrupts and then gets stuck in a loop, the stack trace should be informative. We could clear the saved stack pointer when we enable interrupts, but that loses information which could be useful if we have nothing else to go on. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-05-21powerpc/64s: Add support for a store forwarding barrier at kernel entry/exitNicholas Piggin
On some CPUs we can prevent a vulnerability related to store-to-load forwarding by preventing store forwarding between privilege domains, by inserting a barrier in kernel entry and exit paths. This is known to be the case on at least Power7, Power8 and Power9 powerpc CPUs. Barriers must be inserted generally before the first load after moving to a higher privilege, and after the last store before moving to a lower privilege, HV and PR privilege transitions must be protected. Barriers are added as patch sections, with all kernel/hypervisor entry points patched, and the exit points to lower privilge levels patched similarly to the RFI flush patching. Firmware advertisement is not implemented yet, so CPU flush types are hard coded. Thanks to Michal Suchánek for bug fixes and review. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michal Suchánek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-01powerpc/64s: Set assembler machine type to POWER4Nicholas Piggin
Rather than override the machine type in .S code (which can hide wrong or ambiguous code generation for the target), set the type to power4 for all assembly. This also means we need to be careful not to build power4-only code when we're not building for Book3S, such as the "power7" versions of copyuser/page/memcpy. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix Book3E build, don't build the "power7" variants for non-Book3S] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01powerpc/64s: return more carefully from sreset NMINicholas Piggin
System Reset, being an NMI, must return more carefully than other interrupts. It has traditionally returned via the nromal return from exception path, but that has a number of problems. - r13 does not get restored if returning to kernel. This is for interrupts which may cause a context switch, which sreset will never do. Interrupting OPAL (which uses a different r13) is one place where this causes breakage. - It may cause several other problems returning to kernel with preempt or TIF_EMULATE_STACK_STORE if it hits at the wrong time. It's safer just to have a simple restore and return, like machine check which is the other NMI. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31powerpc/mm: Add support for handling > 512TB address in SLB missAneesh Kumar K.V
For addresses above 512TB we allocate additional mmu contexts. To make it all easy, addresses above 512TB are handled with IR/DR=1 and with stack frame setup. The mmu_context_t is also updated to track the new extended_ids. To support upto 4PB we need a total 8 contexts. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Minor formatting tweaks and comment wording, switch BUG to WARN in get_ea_context().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-28Merge branch 'fixes' into nextMichael Ellerman
Merge our fixes branch from the 4.16 cycle. There were a number of important fixes merged, in particular some Power9 workarounds that we want in next for testing purposes. There's also been some conflicting changes in the CPU features code which are best merged and tested before going upstream.
2018-03-26powerpc/64s: Fix i-side SLB miss bad address handler saving nonvolatile GPRsNicholas Piggin
The SLB bad address handler's trap number fixup does not preserve the low bit that indicates nonvolatile GPRs have not been saved. This leads save_nvgprs to skip saving them, and subsequent functions and return from interrupt will think they are saved. This causes kernel branch-to-garbage debugging to not have correct registers, can also cause userspace to have its registers clobbered after a segfault. Fixes: f0f558b131db ("powerpc/mm: Preserve CFAR value on SLB miss caused by access to bogus address") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-24Merge branch 'topic/ppc-kvm' into nextMichael Ellerman
This brings in two series from Paul, one of which touches KVM code and may need to be merged into the kvm-ppc tree to resolve conflicts.
2018-03-24KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9Paul Mackerras
POWER9 has hardware bugs relating to transactional memory and thread reconfiguration (changes to hardware SMT mode). Specifically, the core does not have enough storage to store a complete checkpoint of all the architected state for all four threads. The DD2.2 version of POWER9 includes hardware modifications designed to allow hypervisor software to implement workarounds for these problems. This patch implements those workarounds in KVM code so that KVM guests see a full, working transactional memory implementation. The problems center around the use of TM suspended state, where the CPU has a checkpointed state but execution is not transactional. The workaround is to implement a "fake suspend" state, which looks to the guest like suspended state but the CPU does not store a checkpoint. In this state, any instruction that would cause a transition to transactional state (rfid, rfebb, mtmsrd, tresume) or would use the checkpointed state (treclaim) causes a "soft patch" interrupt (vector 0x1500) to the hypervisor so that it can be emulated. The trechkpt instruction also causes a soft patch interrupt. On POWER9 DD2.2, we avoid returning to the guest in any state which would require a checkpoint to be present. The trechkpt in the guest entry path which would normally create that checkpoint is replaced by either a transition to fake suspend state, if the guest is in suspend state, or a rollback to the pre-transactional state if the guest is in transactional state. Fake suspend state is indicated by a flag in the PACA plus a new bit in the PSSCR. The new PSSCR bit is write-only and reads back as 0. On exit from the guest, if the guest is in fake suspend state, we still do the treclaim instruction as we would in real suspend state, in order to get into non-transactional state, but we do not save the resulting register state since there was no checkpoint. Emulation of the instructions that cause a softpatch interrupt is handled in two paths. If the guest is in real suspend mode, we call kvmhv_p9_tm_emulation_early() to handle the cases where the guest is transitioning to transactional state. This is called before we do the treclaim in the guest exit path; because we haven't done treclaim, we can get back to the guest with the transaction still active. If the instruction is a case that kvmhv_p9_tm_emulation_early() doesn't handle, or if the guest is in fake suspend state, then we proceed to do the complete guest exit path and subsequently call kvmhv_p9_tm_emulation() in host context with the MMU on. This handles all the cases including the cases that generate program interrupts (illegal instruction or TM Bad Thing) and facility unavailable interrupts. The emulation is reasonably straightforward and is mostly concerned with checking for exception conditions and updating the state of registers such as MSR and CR0. The treclaim emulation takes care to ensure that the TEXASR register gets updated as if it were the guest treclaim instruction that had done failure recording, not the treclaim done in hypervisor state in the guest exit path. With this, the KVM_CAP_PPC_HTM capability returns true (1) even if transactional memory is not available to host userspace. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-08powerpc/64s: Fix may_hard_irq_enable() for PMI soft maskingNicholas Piggin
The soft IRQ masking code has to hard-disable interrupts in cases where the exception is not cleared by the masked handler. External interrupts used this approach for soft masking. Now recently PMU interrupts do the same thing. The soft IRQ masking code additionally allowed for interrupt handlers to hard-enable interrupts after soft-disabling them. The idea is to allow PMU interrupts through to profile interrupt handlers. So when interrupts are being replayed when there is a pending interrupt that requires hard-disabling, there is a test to prevent those handlers from hard-enabling them if there is a pending external interrupt. may_hard_irq_enable() handles this. After f442d00480 ("powerpc/64s: Add support to mask perf interrupts and replay them"), may_hard_irq_enable() could prematurely enable MSR[EE] when a PMU exception exists, which would result in the interrupt firing again while masked, and MSR[EE] being disabled again. I haven't seen that this could cause a serious problem, but it's more consistent to handle these soft-masked interrupts in the same way. So introduce a define for all types of interrupts that require MSR[EE] masking in their soft-disable handlers, and use that in may_hard_irq_enable(). Fixes: f442d004806e ("powerpc/64s: Add support to mask perf interrupts and replay them") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-23powerpc/64s: Improve RFI L1-D cache flush fallbackNicholas Piggin
The fallback RFI flush is used when firmware does not provide a way to flush the cache. It's a "displacement flush" that evicts useful data by displacing it with an uninteresting buffer. The flush has to take care to work with implementation specific cache replacment policies, so the recipe has been in flux. The initial slow but conservative approach is to touch all lines of a congruence class, with dependencies between each load. It has since been determined that a linear pattern of loads without dependencies is sufficient, and is significantly faster. Measuring the speed of a null syscall with RFI fallback flush enabled gives the relative improvement: P8 - 1.83x P9 - 1.75x The flush also becomes simpler and more adaptable to different cache geometries. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-21Merge branch 'fixes' into nextMichael Ellerman
Merge our fixes branch from the 4.15 cycle. Unusually the fixes branch saw some significant features merged, notably the RFI flush patches, so we want the code in next to be tested against that, to avoid any surprises when the two are merged. There's also some other work on the panic handling that was reverted in fixes and we now want to do properly in next, which would conflict. And we also fix a few other minor merge conflicts.
2018-01-20powerpc: Handle exceptions caused by pkey violationRam Pai
Handle Data and Instruction exceptions caused by memory protection-key. The CPU will detect the key fault if the HPTE is already programmed with the key. However if the HPTE is not hashed, a key fault will not be detected by the hardware. The software will detect pkey violation in such a case. Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19powerpc/64s: Add support to mask perf interrupts and replay themMadhavan Srinivasan
Two new bit mask field "IRQ_DISABLE_MASK_PMU" is introduced to support the masking of PMI and "IRQ_DISABLE_MASK_ALL" to aid interrupt masking checking. Couple of new irq #defs "PACA_IRQ_PMI" and "SOFTEN_VALUE_0xf0*" added to use in the exception code to check for PMI interrupts. In the masked_interrupt handler, for PMIs we reset the MSR[EE] and return. In the __check_irq_replay(), replay the PMI interrupt by calling performance_monitor_common handler. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19powerpc/64s: Add support to take additional parameter in MASKABLE_* macroMadhavan Srinivasan
To support addition of "bitmask" to MASKABLE_* macros, factor out the EXCPETION_PROLOG_1 macro. Make it explicit the interrupt masking supported by a gievn interrupt handler. Patch correspondingly extends the MASKABLE_* macros with an addition's parameter. "bitmask" parameter is passed to SOFTEN_TEST macro to decide on masking the interrupt. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc: Remove useless EXC_COMMON_HVBenjamin Herrenschmidt
The only difference between EXC_COMMON_HV and EXC_COMMON is that the former adds "2" to the trap number which is supposed to represent the fact that this is an "HV" interrupt which uses HSRR0/1. However KVM is the only one who cares and it has its own separate macros. In fact, we only have one user of EXC_COMMON_HV and it's for an unknown interrupt case. All the other ones already using EXC_COMMON. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10powerpc/64s: Add support for RFI flush of L1-D cacheMichael Ellerman
On some CPUs we can prevent the Meltdown vulnerability by flushing the L1-D cache on exit from kernel to user mode, and from hypervisor to guest. This is known to be the case on at least Power7, Power8 and Power9. At this time we do not know the status of the vulnerability on other CPUs such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale CPUs. As more information comes to light we can enable this, or other mechanisms on those CPUs. The vulnerability occurs when the load of an architecturally inaccessible memory region (eg. userspace load of kernel memory) is speculatively executed to the point where its result can influence the address of a subsequent speculatively executed load. In order for that to happen, the first load must hit in the L1, because before the load is sent to the L2 the permission check is performed. Therefore if no kernel addresses hit in the L1 the vulnerability can not occur. We can ensure that is the case by flushing the L1 whenever we return to userspace. Similarly for hypervisor vs guest. In order to flush the L1-D cache on exit, we add a section of nops at each (h)rfi location that returns to a lower privileged context, and patch that with some sequence. Newer firmwares are able to advertise to us that there is a special nop instruction that flushes the L1-D. If we do not see that advertised, we fall back to doing a displacement flush in software. For guest kernels we support migration between some CPU versions, and different CPUs may use different flush instructions. So that we are prepared to migrate to a machine with a different flush instruction activated, we may have to patch more than one flush instruction at boot if the hypervisor tells us to. In the end this patch is mostly the work of Nicholas Piggin and Michael Ellerman. However a cast of thousands contributed to analysis of the issue, earlier versions of the patch, back ports testing etc. Many thanks to all of them. Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNELNicholas Piggin
In the SLB miss handler we may be returning to user or kernel. We need to add a check early on and save the result in the cr4 register, and then we bifurcate the return path based on that. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-10powerpc/64s: Simple RFI macro conversionsNicholas Piggin
This commit does simple conversions of rfi/rfid to the new macros that include the expected destination context. By simple we mean cases where there is a single well known destination context, and it's simply a matter of substituting the instruction for the appropriate macro. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-16Merge tag 'powerpc-4.15-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "A bit of a small release, I suspect in part due to me travelling for KS. But my backlog of patches to review is smaller than usual, so I think in part folks just didn't send as much this cycle. Non-highlights: - Five fixes for the >128T address space handling, both to fix bugs in our implementation and to bring the semantics exactly into line with x86. Highlights: - Support for a new OPAL call on bare metal machines which gives us a true NMI (ie. is not masked by MSR[EE]=0) for debugging etc. - Support for Power9 DD2 in the CXL driver. - Improvements to machine check handling so that uncorrectable errors can be reported into the generic memory_failure() machinery. - Some fixes and improvements for VPHN, which is used under PowerVM to notify the Linux partition of topology changes. - Plumbing to enable TM (transactional memory) without suspend on some Power9 processors (PPC_FEATURE2_HTM_NO_SUSPEND). - Support for emulating vector loads form cache-inhibited memory, on some Power9 revisions. - Disable the fast-endian switch "syscall" by default (behind a CONFIG), we believe it has never had any users. - A major rework of the API drivers use when initiating and waiting for long running operations performed by OPAL firmware, and changes to the powernv_flash driver to use the new API. - Several fixes for the handling of FP/VMX/VSX while processes are using transactional memory. - Optimisations of TLB range flushes when using the radix MMU on Power9. - Improvements to the VAS facility used to access coprocessors on Power9, and related improvements to the way the NX crypto driver handles requests. - Implementation of PMEM_API and UACCESS_FLUSHCACHE for 64-bit. Thanks to: Alexey Kardashevskiy, Alistair Popple, Allen Pais, Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Balbir Singh, Benjamin Herrenschmidt, Breno Leitao, Christophe Leroy, Christophe Lombard, Cyril Bur, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Guilherme G. Piccoli, Gustavo Romero, Haren Myneni, Joel Stanley, Kamalesh Babulal, Kautuk Consul, Markus Elfring, Masami Hiramatsu, Michael Bringmann, Michael Neuling, Michal Suchanek, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pedro Miraglia Franco de Carvalho, Philippe Bergheaud, Sandipan Das, Seth Forshee, Shriya, Stephen Rothwell, Stewart Smith, Sukadev Bhattiprolu, Tyrel Datwyler, Vaibhav Jain, Vaidyanathan Srinivasan, and William A. Kennington III" * tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (151 commits) powerpc/64s: Fix Power9 DD2.0 workarounds by adding DD2.1 feature powerpc/64s: Fix masking of SRR1 bits on instruction fault powerpc/64s: mm_context.addr_limit is only used on hash powerpc/64s/radix: Fix 128TB-512TB virtual address boundary case allocation powerpc/64s/hash: Allow MAP_FIXED allocations to cross 128TB boundary powerpc/64s/hash: Fix fork() with 512TB process address space powerpc/64s/hash: Fix 128TB-512TB virtual address boundary case allocation powerpc/64s/hash: Fix 512T hint detection to use >= 128T powerpc: Fix DABR match on hash based systems powerpc/signal: Properly handle return value from uprobe_deny_signal() powerpc/fadump: use kstrtoint to handle sysfs store powerpc/lib: Implement UACCESS_FLUSHCACHE API powerpc/lib: Implement PMEM API powerpc/powernv/npu: Don't explicitly flush nmmu tlb powerpc/powernv/npu: Use flush_all_mm() instead of flush_tlb_mm() powerpc/powernv/idle: Round up latency and residency values powerpc/kprobes: refactor kprobe_lookup_name for safer string operations powerpc/kprobes: Blacklist emulate_update_regs() from kprobes powerpc/kprobes: Do not disable interrupts for optprobes and kprobes_on_ftrace powerpc/kprobes: Disable preemption before invoking probe handler for optprobes ...
2017-11-14powerpc/64s: Fix masking of SRR1 bits on instruction faultMichael Ellerman
On 64-bit Book3s, when we take an instruction fault the reason for the fault may be reported in SRR1. For data faults the reason is reported in DSISR (Data Storage Instruction Status Register). The reasons reported in each do not necessarily correspond, so we mask the SRR1 bits before copying them to the DSISR, which is then used by the page fault code. Prior to commit b4c001dc44f0 ("powerpc/mm: Use symbolic constants for filtering SRR1 bits on ISIs") we used a hard-coded mask of 0x58200000, which corresponds to: DSISR_NOHPTE 0x40000000 /* no translation found */ DSISR_NOEXEC_OR_G 0x10000000 /* exec of no-exec or guarded */ DSISR_PROTFAULT 0x08000000 /* protection fault */ DSISR_KEYFAULT 0x00200000 /* Storage Key fault */ That commit added a #define for the mask, DSISR_SRR1_MATCH_64S, but incorrectly used a different similarly named DSISR_BAD_FAULT_64S. This had the effect of changing the mask to 0xa43a0000, which omits everything but DSISR_KEYFAULT. Luckily this had no visible effect, because in practice we hardly use the DSISR bits. The lack of DSISR_NOHPTE means a TLB flush optimisation was missed in the native HPTE code, and DSISR_NOEXEC_OR_G and DSISR_PROTFAULT are both only used to trigger rare warnings. So we got lucky, but let's fix it. The new value only has bits between 17 and 30 set, so we can continue to use andis. Fixes: b4c001dc44f0 ("powerpc/mm: Use symbolic constants for filtering SRR1 bits on ISIs") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-13powerpc: Fix DABR match on hash based systemsBenjamin Herrenschmidt
Commit 398a719d34a1 ("powerpc/mm: Update bits used to skip hash_page") mistakenly dropped the DSISR_DABRMATCH bit from the mask of bit tested to skip trying to hash a page. As a result, the DABR matches would no longer be detected. This adds it back. We open code it in the 2 places where it matters rather than fold it into DSISR_BAD_FAULT_32S/64S because this isn't technically a bad fault and while we would never hit it with the current code, I prefer if page_fault_is_bad() didn't trigger on these. Fixes: 398a719d34a1 ("powerpc/mm: Update bits used to skip hash_page") Cc: stable@vger.kernel.org # v4.14 Tested-by: Pedro Miraglia Franco de Carvalho <pedromfc@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2017-11-06powerpc/64s: Replace CONFIG_PPC_STD_MMU_64 with CONFIG_PPC_BOOK3S_64Michael Ellerman
CONFIG_PPC_STD_MMU_64 indicates support for the "standard" powerpc MMU on 64-bit CPUs. The "standard" MMU refers to the hash page table MMU found in "server" processors, from IBM mainly. Currently CONFIG_PPC_STD_MMU_64 is == CONFIG_PPC_BOOK3S_64. While it's annoying to have two symbols that always have the same value, it's not quite annoying enough to bother removing one. However with the arrival of Power9, we now have the situation where CONFIG_PPC_STD_MMU_64 is enabled, but the kernel is running using the Radix MMU - *not* the "standard" MMU. So it is now actively confusing to use it, because it implies that code is disabled or inactive when the Radix MMU is in use, however that is not necessarily true. So s/CONFIG_PPC_STD_MMU_64/CONFIG_PPC_BOOK3S_64/, and do some minor formatting updates of some of the affected lines. This will be a pain for backports, but c'est la vie. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06KVM: PPC: Book3S HV: Handle host system reset in guest modeNicholas Piggin
If the host takes a system reset interrupt while a guest is running, the CPU must exit the guest before processing the host exception handler. After this patch, taking a sysrq+x with a CPU running in a guest gives a trace like this: cpu 0x27: Vector: 100 (System Reset) at [c000000fdf5776f0] pc: c008000010158b80: kvmppc_run_core+0x16b8/0x1ad0 [kvm_hv] lr: c008000010158b80: kvmppc_run_core+0x16b8/0x1ad0 [kvm_hv] sp: c000000fdf577850 msr: 9000000002803033 current = 0xc000000fdf4b1e00 paca = 0xc00000000fd4d680 softe: 3 irq_happened: 0x01 pid = 6608, comm = qemu-system-ppc Linux version 4.14.0-rc7-01489-g47e1893a404a-dirty #26 SMP [c000000fdf577a00] c008000010159dd4 kvmppc_vcpu_run_hv+0x3dc/0x12d0 [kvm_hv] [c000000fdf577b30] c0080000100a537c kvmppc_vcpu_run+0x44/0x60 [kvm] [c000000fdf577b60] c0080000100a1ae0 kvm_arch_vcpu_ioctl_run+0x118/0x310 [kvm] [c000000fdf577c00] c008000010093e98 kvm_vcpu_ioctl+0x530/0x7c0 [kvm] [c000000fdf577d50] c000000000357bf8 do_vfs_ioctl+0xd8/0x8c0 [c000000fdf577df0] c000000000358448 SyS_ioctl+0x68/0x100 [c000000fdf577e30] c00000000000b220 system_call+0x58/0x6c --- Exception: c01 (System Call) at 00007fff76868df0 SP (7fff7069baf0) is in userspace Fixes: e36d0a2ed5 ("powerpc/powernv: Implement NMI IPI with OPAL_SIGNAL_SYSTEM_RESET") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-22powerpc: Disable the fast-endian switch syscall by defaultMichael Ellerman
Back in 2008 we added support for "fast little-endian switch" in the syscall path. This added a special case syscall number 0x1ebe, which is caught very early in the system call exception and switches endian with as little overhead as possible. See commit 745a14cc264b ("[POWERPC] Add fast little-endian switch system call") for full details. Although it is fast, it's also completely non standard. The "syscall number" is out of the range of normal syscalls, it can't be traced or audited, and it's a bit of a wart. To the best of our knowledge it was only used by one program, now long since discontinued. So in an effort to shake out any current users, put it behind a config option, and make it default n. If anyone *is* using it they can quickly reinstate it with a rebuild, and we can flip it to default y. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-22powerpc/64s: Move the two FAST_ENDIAN macros next to each otherMichael Ellerman
So we can #ifdef them in the next patch. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-16powerpc/mce: Hookup derror (load/store) UE errorsBalbir Singh
Extract physical_address for UE errors by walking the page tables for the mm and address at the NIP, to extract the instruction. Then use the instruction to find the effective address via analyse_instr(). We might have page table walking races, but we expect them to be rare, the physical address extraction is best effort. The idea is to then hook up this infrastructure to memory failure eventually. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>