pm24.git/arch/powerpc/kernel/process.c, branch v5.6

powerpc: use probe_user_read() and probe_user_write()

2020-01-25T13:11:35Z

Instead of opencoding, use probe_user_read() to failessly read a user location and probe_user_write() for writing to user. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/e041f5eedb23f09ab553be8a91c3de2087147320.1579800517.git.christophe.leroy@c-s.fr

powerpc/hw_breakpoints: Rewrite 8xx breakpoints to allow any address range size.

2020-01-23T10:31:14Z

Unlike standard powerpc, Powerpc 8xx doesn't have SPRN_DABR, but it has a breakpoint support based on a set of comparators which allow more flexibility. Commit 4ad8622dc548 ("powerpc/8xx: Implement hw_breakpoint") implemented breakpoints by emulating the DABR behaviour. It did this by setting one comparator the match 4 bytes at breakpoint address and the other comparator to match 4 bytes at breakpoint address + 4. Rewrite 8xx hw_breakpoint to make breakpoints match all addresses defined by the breakpoint address and length by making full use of comparators. Now, comparator E is set to match any address greater than breakpoint address minus one. Comparator F is set to match any address lower than breakpoint address plus breakpoint length. Addresses are aligned to 32 bits. When the breakpoint range starts at address 0, the breakpoint is set to match comparator F only. When the breakpoint range end at address 0xffffffff, the breakpoint is set to match comparator E only. Otherwise the breakpoint is set to match comparator E and F. At the same time, use registers bit names instead of hardcoded values. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/05105deeaf63bc02151aea2cdeaf525534e0e9d4.1574790198.git.christophe.leroy@c-s.fr

powerpc/watchpoint: Fix length calculation for unaligned target

2019-11-13T05:58:03Z

Watchpoint match range is always doubleword(8 bytes) aligned on powerpc. If the given range is crossing doubleword boundary, we need to increase the length such that next doubleword also get covered. Ex, address len = 6 bytes |=========. |------------v--|------v--------| | | | | | | | | | | | | | | | | | |---------------|---------------| <---8 bytes---> In such case, current code configures hw as: start_addr = address & ~HW_BREAKPOINT_ALIGN len = 8 bytes And thus read/write in last 4 bytes of the given range is ignored. Fix this by including next doubleword in the length. Signed-off-by: Ravi Bangoria Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191017093204.7511-3-ravi.bangoria@linux.ibm.com

Merge tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2019-09-20T18:48:06Z

Pull powerpc updates from Michael Ellerman: "This is a bit late, partly due to me travelling, and partly due to a power outage knocking out some of my test systems *while* I was travelling. - Initial support for running on a system with an Ultravisor, which is software that runs below the hypervisor and protects guests against some attacks by the hypervisor. - Support for building the kernel to run as a "Secure Virtual Machine", ie. as a guest capable of running on a system with an Ultravisor. - Some changes to our DMA code on bare metal, to allow devices with medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of DMA space. - Support for firmware assisted crash dumps on bare metal (powernv). - Two series fixing bugs in and refactoring our PCI EEH code. - A large series refactoring our exception entry code to use gas macros, both to make it more readable and also enable some future optimisations. As well as many cleanups and other minor features & fixups. Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual, Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand, Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar, Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm, Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu, Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom Lendacky, Vasant Hegde" * tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits) powerpc/mm/mce: Keep irqs disabled during lockless page table walk powerpc: Use ftrace_graph_ret_addr() when unwinding powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR ftrace: Look up the address of return_to_handler() using helpers powerpc: dump kernel log before carrying out fadump or kdump docs: powerpc: Add missing documentation reference powerpc/xmon: Fix output of XIVE IPI powerpc/xmon: Improve output of XIVE interrupts powerpc/mm/radix: remove useless kernel messages powerpc/fadump: support holes in kernel boot memory area powerpc/fadump: remove RMA_START and RMA_END macros powerpc/fadump: update documentation about option to release opalcore powerpc/fadump: consider f/w load area powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel powerpc/fadump: improve how crashed kernel's memory is reserved powerpc/fadump: consider reserved ranges while releasing memory powerpc/fadump: make crash memory ranges array allocation generic ...

powerpc: Use ftrace_graph_ret_addr() when unwinding

2019-09-18T02:24:55Z

With support for HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, ftrace_graph_ret_addr() provides more robust unwinding when function graph is in use. Update show_stack() to use the same. With dump_stack() added to sysrq_sysctl_handler(), before this patch: root@(none):/sys/kernel/debug/tracing# cat /proc/sys/kernel/sysrq CPU: 0 PID: 218 Comm: cat Not tainted 5.3.0-rc7-00868-g8453ad4a078c-dirty #20 Call Trace: [c0000000d1e13c30] [c00000000006ab98] return_to_handler+0x0/0x40 (dump_stack+0xe8/0x164) (unreliable) [c0000000d1e13c80] [c000000000145680] sysrq_sysctl_handler+0x48/0xb8 [c0000000d1e13cd0] [c00000000006ab98] return_to_handler+0x0/0x40 (proc_sys_call_handler+0x274/0x2a0) [c0000000d1e13d60] [c00000000006ab98] return_to_handler+0x0/0x40 (return_to_handler+0x0/0x40) [c0000000d1e13d80] [c00000000006ab98] return_to_handler+0x0/0x40 (__vfs_read+0x3c/0x70) [c0000000d1e13dd0] [c00000000006ab98] return_to_handler+0x0/0x40 (vfs_read+0xb8/0x1b0) [c0000000d1e13e20] [c00000000006ab98] return_to_handler+0x0/0x40 (ksys_read+0x7c/0x140) After this patch: Call Trace: [c0000000d1e33c30] [c00000000006ab58] return_to_handler+0x0/0x40 (dump_stack+0xe8/0x164) (unreliable) [c0000000d1e33c80] [c000000000145680] sysrq_sysctl_handler+0x48/0xb8 [c0000000d1e33cd0] [c00000000006ab58] return_to_handler+0x0/0x40 (proc_sys_call_handler+0x274/0x2a0) [c0000000d1e33d60] [c00000000006ab58] return_to_handler+0x0/0x40 (__vfs_read+0x3c/0x70) [c0000000d1e33d80] [c00000000006ab58] return_to_handler+0x0/0x40 (vfs_read+0xb8/0x1b0) [c0000000d1e33dd0] [c00000000006ab58] return_to_handler+0x0/0x40 (ksys_read+0x7c/0x140) [c0000000d1e33e20] [c00000000006ab58] return_to_handler+0x0/0x40 (system_call+0x5c/0x68) Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/dc89c9a887121342d9c7819482c3dabdece2a323.1567707399.git.naveen.n.rao@linux.vnet.ibm.com

powerpc/tm: Fix restoring FP/VMX facility incorrectly on interrupts

2019-09-04T12:31:13Z

When in userspace and MSR FP=0 the hardware FP state is unrelated to the current process. This is extended for transactions where if tbegin is run with FP=0, the hardware checkpoint FP state will also be unrelated to the current process. Due to this, we need to ensure this hardware checkpoint is updated with the correct state before we enable FP for this process. Unfortunately we get this wrong when returning to a process from a hardware interrupt. A process that starts a transaction with FP=0 can take an interrupt. When the kernel returns back to that process, we change to FP=1 but with hardware checkpoint FP state not updated. If this transaction is then rolled back, the FP registers now contain the wrong state. The process looks like this: Userspace: Kernel Start userspace with MSR FP=0 TM=1 < ----- ... tbegin bne Hardware interrupt ---- > .... ret_from_except restore_math() /* sees FP=0 */ restore_fp() tm_active_with_fp() /* sees FP=1 (Incorrect) */ load_fp_state() FP = 0 -> 1 < ----- Return to userspace with MSR TM=1 FP=1 with junk in the FP TM checkpoint TM rollback reads FP junk When returning from the hardware exception, tm_active_with_fp() is incorrectly making restore_fp() call load_fp_state() which is setting FP=1. The fix is to remove tm_active_with_fp(). tm_active_with_fp() is attempting to handle the case where FP state has been changed inside a transaction. In this case the checkpointed and transactional FP state is different and hence we must restore the FP state (ie. we can't do lazy FP restore inside a transaction that's used FP). It's safe to remove tm_active_with_fp() as this case is handled by restore_tm_state(). restore_tm_state() detects if FP has been using inside a transaction and will set load_fp and call restore_math() to ensure the FP state (checkpoint and transaction) is restored. This is a data integrity problem for the current process as the FP registers are corrupted. It's also a security problem as the FP registers from one process may be leaked to another. Similarly for VMX. A simple testcase to replicate this will be posted to tools/testing/selftests/powerpc/tm/tm-poison.c This fixes CVE-2019-15031. Fixes: a7771176b439 ("powerpc: Don't enable FP/Altivec if not checkpointed") Cc: stable@vger.kernel.org # 4.15+ Signed-off-by: Gustavo Romero Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190904045529.23002-2-gromero@linux.vnet.ibm.com

powerpc/tm: Fix FP/VMX unavailable exceptions inside a transaction

2019-09-04T12:31:13Z

When we take an FP unavailable exception in a transaction we have to account for the hardware FP TM checkpointed registers being incorrect. In this case for this process we know the current and checkpointed FP registers must be the same (since FP wasn't used inside the transaction) hence in the thread_struct we copy the current FP registers to the checkpointed ones. This copy is done in tm_reclaim_thread(). We use thread->ckpt_regs.msr to determine if FP was on when in userspace. thread->ckpt_regs.msr represents the state of the MSR when exiting userspace. This is setup by check_if_tm_restore_required(). Unfortunatley there is an optimisation in giveup_all() which returns early if tsk->thread.regs->msr (via local variable `usermsr`) has FP=VEC=VSX=SPE=0. This optimisation means that check_if_tm_restore_required() is not called and hence thread->ckpt_regs.msr is not updated and will contain an old value. This can happen if due to load_fp=255 we start a userspace process with MSR FP=1 and then we are context switched out. In this case thread->ckpt_regs.msr will contain FP=1. If that same process is then context switched in and load_fp overflows, MSR will have FP=0. If that process now enters a transaction and does an FP instruction, the FP unavailable will not update thread->ckpt_regs.msr (the bug) and MSR FP=1 will be retained in thread->ckpt_regs.msr. tm_reclaim_thread() will then not perform the required memcpy and the checkpointed FP regs in the thread struct will contain the wrong values. The code path for this happening is: Userspace: Kernel Start userspace with MSR FP/VEC/VSX/SPE=0 TM=1 < ----- ... tbegin bne fp instruction FP unavailable ---- > fp_unavailable_tm() tm_reclaim_current() tm_reclaim_thread() giveup_all() return early since FP/VMX/VSX=0 /* ckpt MSR not updated (Incorrect) */ tm_reclaim() /* thread_struct ckpt FP regs contain junk (OK) */ /* Sees ckpt MSR FP=1 (Incorrect) */ no memcpy() performed /* thread_struct ckpt FP regs not fixed (Incorrect) */ tm_recheckpoint() /* Put junk in hardware checkpoint FP regs */ .... < ----- Return to userspace with MSR TM=1 FP=1 with junk in the FP TM checkpoint TM rollback reads FP junk This is a data integrity problem for the current process as the FP registers are corrupted. It's also a security problem as the FP registers from one process may be leaked to another. This patch moves up check_if_tm_restore_required() in giveup_all() to ensure thread->ckpt_regs.msr is updated correctly. A simple testcase to replicate this will be posted to tools/testing/selftests/powerpc/tm/tm-poison.c Similarly for VMX. This fixes CVE-2019-15030. Fixes: f48e91e87e67 ("powerpc/tm: Fix FP and VMX register corruption") Cc: stable@vger.kernel.org # 4.12+ Signed-off-by: Gustavo Romero Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190904045529.23002-1-gromero@linux.vnet.ibm.com

powerpc: convert to copy_thread_tls

2019-08-28T13:19:34Z

Commit 3033f14ab78c3 ("clone: support passing tls argument via C rather than pt_regs magic") introduced the HAVE_COPY_THREAD_TLS option. Use it to avoid a subtle assumption about the argument ordering of clone type syscalls. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190827033010.28090-2-npiggin@gmail.com

Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2019-07-13T23:08:36Z

Pull powerpc updates from Michael Ellerman: "Notable changes: - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well as some other functions only used by drivers that haven't (yet?) made it upstream. - A fix for a bug in our handling of hardware watchpoints (eg. perf record -e mem: ...) which could lead to register corruption and kernel crashes. - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc when using the Radix MMU. - A large but incremental rewrite of our exception handling code to use gas macros rather than multiple levels of nested CPP macros. And the usual small fixes, cleanups and improvements. Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung Bauermann, YueHaibing" * tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits) powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state. powerpc/eeh: Handle hugepages in ioremap space ocxl: Update for AFU descriptor template version 1.1 powerpc/boot: pass CONFIG options in a simpler and more robust way powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h powerpc/irq: Don't WARN continuously in arch_local_irq_restore() powerpc/module64: Use symbolic instructions names. powerpc/module32: Use symbolic instructions names. powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h powerpc/module64: Fix comment in R_PPC64_ENTRY handling powerpc/boot: Add lzo support for uImage powerpc/boot: Add lzma support for uImage powerpc/boot: don't force gzipped uImage powerpc/8xx: Add microcode patch to move SMC parameter RAM. powerpc/8xx: Use IO accessors in microcode programming. powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c powerpc/8xx: refactor programming of microcode CPM params. powerpc/8xx: refactor printing of microcode patch name. powerpc/8xx: Refactor microcode write powerpc/8xx: refactor writing of CPM microcode arrays ...

Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2019-07-09T04:48:15Z

Pull force_sig() argument change from Eric Biederman: "A source of error over the years has been that force_sig has taken a task parameter when it is only safe to use force_sig with the current task. The force_sig function is built for delivering synchronous signals such as SIGSEGV where the userspace application caused a synchronous fault (such as a page fault) and the kernel responded with a signal. Because the name force_sig does not make this clear, and because the force_sig takes a task parameter the function force_sig has been abused for sending other kinds of signals over the years. Slowly those have been fixed when the oopses have been tracked down. This set of changes fixes the remaining abusers of force_sig and carefully rips out the task parameter from force_sig and friends making this kind of error almost impossible in the future" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits) signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus signal: Remove the signal number and task parameters from force_sig_info signal: Factor force_sig_info_to_task out of force_sig_info signal: Generate the siginfo in force_sig signal: Move the computation of force into send_signal and correct it. signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal signal: Remove the task parameter from force_sig_fault signal: Use force_sig_fault_to_task for the two calls that don't deliver to current signal: Explicitly call force_sig_fault on current signal/unicore32: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from ptrace_break signal/nds32: Remove tsk parameter from send_sigtrap signal/riscv: Remove tsk parameter from do_trap signal/sh: Remove tsk parameter from force_sig_info_fault signal/um: Remove task parameter from send_sigtrap signal/x86: Remove task parameter from send_sigtrap signal: Remove task parameter from force_sig_mceerr signal: Remove task parameter from force_sig signal: Remove task parameter from force_sigsegv ...