BMC/Intel-BMC/linux.git/arch/powerpc/include, branch dev-5.15-intel

powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit

2022-04-13T18:59:28+00:00

commit ffa0b64e3be58519ae472ea29a1a1ad681e32f48 upstream. mpe: On 64-bit Book3E vmalloc space starts at 0x8000000000000000. Because of the way __pa() works we have: __pa(0x8000000000000000) == 0, and therefore virt_to_pfn(0x8000000000000000) == 0, and therefore virt_addr_valid(0x8000000000000000) == true Which is wrong, virt_addr_valid() should be false for vmalloc space. In fact all vmalloc addresses that alias with a valid PFN will return true from virt_addr_valid(). That can cause bugs with hardened usercopy as described below by Kefeng Wang: When running ethtool eth0 on 64-bit Book3E, a BUG occurred: usercopy: Kernel memory exposure attempt detected from SLUB object not in SLUB page?! (offset 0, size 1048)! kernel BUG at mm/usercopy.c:99 ... usercopy_abort+0x64/0xa0 (unreliable) __check_heap_object+0x168/0x190 __check_object_size+0x1a0/0x200 dev_ethtool+0x2494/0x2b20 dev_ioctl+0x5d0/0x770 sock_do_ioctl+0xf0/0x1d0 sock_ioctl+0x3ec/0x5a0 __se_sys_ioctl+0xf0/0x160 system_call_exception+0xfc/0x1f0 system_call_common+0xf8/0x200 The code shows below, data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN)); copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN)) The data is alloced by vmalloc(), virt_addr_valid(ptr) will return true on 64-bit Book3E, which leads to the panic. As commit 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va and __pa addresses") does, make sure the virt addr above PAGE_OFFSET in the virt_addr_valid() for 64-bit, also add upper limit check to make sure the virt is below high_memory. Meanwhile, for 32-bit PAGE_OFFSET is the virtual address of the start of lowmem, high_memory is the upper low virtual address, the check is suitable for 32-bit, this will fix the issue mentioned in commit 602946ec2f90 ("powerpc: Set max_mapnr correctly") too. On 32-bit there is a similar problem with high memory, that was fixed in commit 602946ec2f90 ("powerpc: Set max_mapnr correctly"), but that commit breaks highmem and needs to be reverted. We can't easily fix __pa(), we have code that relies on its current behaviour. So for now add extra checks to virt_addr_valid(). For 64-bit Book3S the extra checks are not necessary, the combination of virt_to_pfn() and pfn_valid() should yield the correct result, but they are harmless. Signed-off-by: Kefeng Wang Reviewed-by: Christophe Leroy [mpe: Add additional change log detail] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220406145802.538416-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman

powerpc/64s/hash: Make hash faults work in NMI context

2022-04-13T18:59:07+00:00

[ Upstream commit 8b91cee5eadd2021f55e6775f2d50bd56d00c217 ] Hash faults are not resoved in NMI context, instead causing the access to fail. This is done because perf interrupts can get backtraces including walking the user stack, and taking a hash fault on those could deadlock on the HPTE lock if the perf interrupt hits while the same HPTE lock is being held by the hash fault code. The user-access for the stack walking will notice the access failed and deal with that in the perf code. The reason to allow perf interrupts in is to better profile hash faults. The problem with this is any hash fault on a kernel access that happens in NMI context will crash, because kernel accesses must not fail. Hard lockups, system reset, machine checks that access vmalloc space including modules and including stack backtracing and symbol lookup in modules, per-cpu data, etc could all run into this problem. Fix this by disallowing perf interrupts in the hash fault code (the direct hash fault is covered by MSR[EE]=0 so the PMI disable just needs to extend to the preload case). This simplifies the tricky logic in hash faults and perf, at the cost of reduced profiling of hash faults. perf can still latch addresses when interrupts are disabled, it just won't get the stack trace at that point, so it would still find hot spots, just sometimes with confusing stack chains. An alternative could be to allow perf interrupts here but always do the slowpath stack walk if we are in nmi context, but that slows down all perf interrupt stack walking on hash though and it does not remove as much tricky code. Reported-by: Laurent Dufour Signed-off-by: Nicholas Piggin Tested-by: Laurent Dufour Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220204035348.545435-1-npiggin@gmail.com Signed-off-by: Sasha Levin

powerpc: Fix build errors with newer binutils

2022-04-08T12:24:04+00:00

commit 8667d0d64dd1f84fd41b5897fd87fa9113ae05e3 upstream. Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian 2.37.90.20220207) the following build error shows up: {standard input}: Assembler messages: {standard input}:1190: Error: unrecognized opcode: `stbcix' {standard input}:1433: Error: unrecognized opcode: `lwzcix' {standard input}:1453: Error: unrecognized opcode: `stbcix' {standard input}:1460: Error: unrecognized opcode: `stwcix' {standard input}:1596: Error: unrecognized opcode: `stbcix' ... Rework to add assembler directives [1] around the instruction. Going through them one by one shows that the changes should be safe. Like __get_user_atomic_128_aligned() is only called in p9_hmi_special_emu(), which according to the name is specific to power9. And __raw_rm_read*() are only called in things that are powernv or book3s_hv specific. [1] https://sourceware.org/binutils/docs/as/PowerPC_002dPseudo.html#PowerPC_002dPseudo Cc: stable@vger.kernel.org Co-developed-by: Arnd Bergmann Signed-off-by: Arnd Bergmann Signed-off-by: Anders Roxell Reviewed-by: Segher Boessenkool [mpe: Make commit subject more descriptive] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220224162215.3406642-2-anders.roxell@linaro.org Signed-off-by: Greg Kroah-Hartman

powerpc: Add set_memory_{p/np}() and remove set_memory_attr()

2022-04-08T12:24:04+00:00

commit f222ab83df92acf72691a2021e1f0d99880dcdf1 upstream. set_memory_attr() was implemented by commit 4d1755b6a762 ("powerpc/mm: implement set_memory_attr()") because the set_memory_xx() couldn't be used at that time to modify memory "on the fly" as explained it the commit. But set_memory_attr() uses set_pte_at() which leads to warnings when CONFIG_DEBUG_VM is selected, because set_pte_at() is unexpected for updating existing page table entries. The check could be bypassed by using __set_pte_at() instead, as it was the case before commit c988cfd38e48 ("powerpc/32: use set_memory_attr()") but since commit 9f7853d7609d ("powerpc/mm: Fix set_memory_*() against concurrent accesses") it is now possible to use set_memory_xx() functions to update page table entries "on the fly" because the update is now atomic. For DEBUG_PAGEALLOC we need to clear and set back _PAGE_PRESENT. Add set_memory_np() and set_memory_p() for that. Replace all uses of set_memory_attr() by the relevant set_memory_xx() and remove set_memory_attr(). Fixes: c988cfd38e48 ("powerpc/32: use set_memory_attr()") Cc: stable@vger.kernel.org Reported-by: Maxime Bizon Signed-off-by: Christophe Leroy Tested-by: Maxime Bizon Reviewed-by: Russell Currey Depends-on: 9f7853d7609d ("powerpc/mm: Fix set_memory_*() against concurrent accesses") Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/cda2b44b55c96f9ac69fa92e68c01084ec9495c5.1640344012.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

powerpc/fixmap: Fix VM debug warning on unmap

2022-02-16T11:56:12+00:00

[ Upstream commit aec982603aa8cc0a21143681feb5f60ecc69d718 ] Unmapping a fixmap entry is done by calling __set_fixmap() with FIXMAP_PAGE_CLEAR as flags. Today, powerpc __set_fixmap() calls map_kernel_page(). map_kernel_page() is not happy when called a second time for the same page. WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8 CPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682 NIP: c0017cd4 LR: c00187f0 CTR: 00000010 REGS: e1011d50 TRAP: 0700 Not tainted (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty) MSR: 00029032 CR: 42000208 XER: 00000000 GPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c GPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 GPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000 NIP [c0017cd4] set_pte_at+0xc/0x1e8 LR [c00187f0] map_kernel_page+0x9c/0x100 Call Trace: [e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable) [e1011e30] [c0165fec] __set_fixmap+0x30/0x44 [e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170 [e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0 [e1011e90] [c0c03634] do_one_initcall+0x80/0x178 [e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250 [e1011f20] [c0007e34] kernel_init+0x24/0x140 [e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010 4e800020 81250000 712a0001 41820008 <0fe00000> 9421ffe0 93e1001c 48000030 Implement unmap_kernel_page() which clears an existing pte. Reported-by: Maxime Bizon Signed-off-by: Christophe Leroy Tested-by: Maxime Bizon Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b0b752f6f6ecc60653e873f385c6f0dce4e9ab6a.1638789098.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin

powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06

2022-02-01T16:27:09+00:00

[ Upstream commit 3f5f766d5f7f95a69a630da3544a1a0cee1cdddf ] Johan reported the below crash with test_bpf on ppc64 e5500: test_bpf: #296 ALU_END_FROM_LE 64: 0x0123456789abcdef -> 0x67452301 jited:1 Oops: Exception in kernel mode, sig: 4 [#1] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 Modules linked in: test_bpf(+) CPU: 0 PID: 76 Comm: insmod Not tainted 5.14.0-03771-g98c2059e008a-dirty #1 NIP: 8000000000061c3c LR: 80000000006dea64 CTR: 8000000000061c18 REGS: c0000000032d3420 TRAP: 0700 Not tainted (5.14.0-03771-g98c2059e008a-dirty) MSR: 0000000080089000 CR: 88002822 XER: 20000000 IRQMASK: 0 <...> NIP [8000000000061c3c] 0x8000000000061c3c LR [80000000006dea64] .__run_one+0x104/0x17c [test_bpf] Call Trace: .__run_one+0x60/0x17c [test_bpf] (unreliable) .test_bpf_init+0x6a8/0xdc8 [test_bpf] .do_one_initcall+0x6c/0x28c .do_init_module+0x68/0x28c .load_module+0x2460/0x2abc .__do_sys_init_module+0x120/0x18c .system_call_exception+0x110/0x1b8 system_call_common+0xf0/0x210 --- interrupt: c00 at 0x101d0acc <...> ---[ end trace 47b2bf19090bb3d0 ]--- Illegal instruction The illegal instruction turned out to be 'ldbrx' emitted for BPF_FROM_[L|B]E, which was only introduced in ISA v2.06. Guard use of the same and implement an alternative approach for older processors. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Reported-by: Johan Almbladh Signed-off-by: Naveen N. Rao Tested-by: Johan Almbladh Acked-by: Johan Almbladh Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/d1e51c6fdf572062cf3009a751c3406bda01b832.1641468127.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Sasha Levin

powerpc/32s: Fix kasan_init_region() for KASAN

2022-02-01T16:27:06+00:00

commit d37823c3528e5e0705fc7746bcbc2afffb619259 upstream. It has been reported some configuration where the kernel doesn't boot with KASAN enabled. This is due to wrong BAT allocation for the KASAN area: ---[ Data Block Address Translation ]--- 0: 0xc0000000-0xcfffffff 0x00000000 256M Kernel rw m 1: 0xd0000000-0xdfffffff 0x10000000 256M Kernel rw m 2: 0xe0000000-0xefffffff 0x20000000 256M Kernel rw m 3: 0xf8000000-0xf9ffffff 0x2a000000 32M Kernel rw m 4: 0xfa000000-0xfdffffff 0x2c000000 64M Kernel rw m A BAT must have both virtual and physical addresses alignment matching the size of the BAT. This is not the case for BAT 4 above. Fix kasan_init_region() by using block_size() function that is in book3s32/mmu.c. To be able to reuse it here, make it non static and change its name to bat_block_size() in order to avoid name conflict with block_size() defined in Also reuse find_free_bat() to avoid an error message from setbat() when no BAT is available. And allocate memory outside of linear memory mapping to avoid wasting that precious space. With this change we get correct alignment for BATs and KASAN shadow memory is allocated outside the linear memory space. ---[ Data Block Address Translation ]--- 0: 0xc0000000-0xcfffffff 0x00000000 256M Kernel rw 1: 0xd0000000-0xdfffffff 0x10000000 256M Kernel rw 2: 0xe0000000-0xefffffff 0x20000000 256M Kernel rw 3: 0xf8000000-0xfbffffff 0x7c000000 64M Kernel rw 4: 0xfc000000-0xfdffffff 0x7a000000 32M Kernel rw Fixes: 7974c4732642 ("powerpc/32s: Implement dedicated kasan_init_region()") Cc: stable@vger.kernel.org Reported-by: Maxime Bizon Signed-off-by: Christophe Leroy Tested-by: Maxime Bizon Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/7a50ef902494d1325227d47d33dada01e52e5518.1641818726.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

KVM: PPC: Book3S HV Nested: Fix nested HFSCR being clobbered with multiple vCPUs

2022-02-01T16:27:03+00:00

commit 22f7ff0dea9491e90b6fe808ed40c30bd791e5c2 upstream. The L0 is storing HFSCR requested by the L1 for the L2 in struct kvm_nested_guest when the L1 requests a vCPU enter L2. kvm_nested_guest is not a per-vCPU structure. Hilarity ensues. Fix it by moving the nested hfscr into the vCPU structure together with the other per-vCPU nested fields. Fixes: 8b210a880b35 ("KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessible") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Nicholas Piggin Reviewed-by: Fabiano Rosas Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220122105530.3477250-1-npiggin@gmail.com Signed-off-by: Greg Kroah-Hartman

powerpc/audit: Fix syscall_get_arch()

2022-02-01T16:27:01+00:00

commit 252745240ba0ae774d2f80c5e185ed59fbc4fb41 upstream. Commit 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()") and commit 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()") replaced test_tsk_thread_flag(task, TIF_32BIT)) by is_32bit_task(). But is_32bit_task() applies on current task while be want the test done on task 'task' So add a new macro is_tsk_32bit_task() to check any task. Fixes: 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()") Fixes: 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()") Cc: stable@vger.kernel.org Reported-by: Dmitry V. Levin Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c55cddb8f65713bf5859ed675d75a50cb37d5995.1642159570.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

powerpc/perf: Fix PMU callbacks to clear pending PMI before resetting an overflown PMC

2022-01-27T10:04:07+00:00

[ Upstream commit 2c9ac51b850d84ee496b0a5d832ce66d411ae552 ] Running perf fuzzer showed below in dmesg logs: "Can't find PMC that caused IRQ" This means a PMU exception happened, but none of the PMC's (Performance Monitor Counter) were found to be overflown. There are some corner cases that clears the PMCs after PMI gets masked. In such cases, the perf interrupt handler will not find the active PMC values that had caused the overflow and thus leads to this message while replaying. Case 1: PMU Interrupt happens during replay of other interrupts and counter values gets cleared by PMU callbacks before replay: During replay of interrupts like timer, __do_irq() and doorbell exception, we conditionally enable interrupts via may_hard_irq_enable(). This could potentially create a window to generate a PMI. Since irq soft mask is set to ALL_DISABLED, the PMI will get masked here. We could get IPIs run before perf interrupt is replayed and the PMU events could be deleted or stopped. This will change the PMU SPR values and resets the counters. Snippet of ftrace log showing PMU callbacks invoked in __do_irq(): -0 [051] dns. 132025441306354: __do_irq <-call_do_irq -0 [051] dns. 132025441306430: irq_enter <-__do_irq -0 [051] dns. 132025441306503: irq_enter_rcu <-__do_irq -0 [051] dnH. 132025441306599: xive_get_irq <-__do_irq <<>> -0 [051] dnH. 132025441307770: generic_smp_call_function_single_interrupt <-smp_ipi_demux_relaxed -0 [051] dnH. 132025441307839: flush_smp_call_function_queue <-smp_ipi_demux_relaxed -0 [051] dnH. 132025441308057: _raw_spin_lock <-event_function -0 [051] dnH. 132025441308206: power_pmu_disable <-perf_pmu_disable -0 [051] dnH. 132025441308337: power_pmu_del <-event_sched_out -0 [051] dnH. 132025441308407: power_pmu_read <-power_pmu_del -0 [051] dnH. 132025441308477: read_pmc <-power_pmu_read -0 [051] dnH. 132025441308590: isa207_disable_pmc <-power_pmu_del -0 [051] dnH. 132025441308663: write_pmc <-power_pmu_del -0 [051] dnH. 132025441308787: power_pmu_event_idx <-perf_event_update_userpage -0 [051] dnH. 132025441308859: rcu_read_unlock_strict <-perf_event_update_userpage -0 [051] dnH. 132025441308975: power_pmu_enable <-perf_pmu_enable <<>> -0 [051] dnH. 132025441311108: irq_exit <-__do_irq -0 [051] dns. 132025441311319: performance_monitor_exception <-replay_soft_interrupts Case 2: PMI's masked during local_* operations, example local_add(). If the local_add() operation happens within a local_irq_save(), replay of PMI will be during local_irq_restore(). Similar to case 1, this could also create a window before replay where PMU events gets deleted or stopped. Fix it by updating the PMU callback function power_pmu_disable() to check for pending perf interrupt. If there is an overflown PMC and pending perf interrupt indicated in paca, clear the PMI bit in paca to drop that sample. Clearing of PMI bit is done in power_pmu_disable() since disable is invoked before any event gets deleted/stopped. With this fix, if there are more than one event running in the PMU, there is a chance that we clear the PMI bit for the event which is not getting deleted/stopped. The other events may still remain active. Hence to make sure we don't drop valid sample in such cases, another check is added in power_pmu_enable. This checks if there is an overflown PMC found among the active events and if so enable back the PMI bit. Two new helper functions are introduced to clear/set the PMI, ie clear_pmi_irq_pending() and set_pmi_irq_pending(). Helper function pmi_irq_pending() is introduced to give a warning if there is pending PMI bit in paca, but no PMC is overflown. Also there are corner cases which result in performance monitor interrupts being triggered during power_pmu_disable(). This happens since PMXE bit is not cleared along with disabling of other MMCR0 bits in the pmu_disable. Such PMI's could leave the PMU running and could trigger PMI again which will set MMCR0 PMAO bit. This could lead to spurious interrupts in some corner cases. Example, a timer after power_pmu_del() which will re-enable interrupts and triggers a PMI again since PMAO bit is still set. But fails to find valid overflow since PMC was cleared in power_pmu_del(). Fix that by disabling PMXE along with disabling of other MMCR0 bits in power_pmu_disable(). We can't just replay PMI any time. Hence this approach is preferred rather than replaying PMI before resetting overflown PMC. Patch also documents core-book3s on a race condition which can trigger these PMC messages during idle path in PowerNV. Fixes: f442d004806e ("powerpc/64s: Add support to mask perf interrupts and replay them") Reported-by: Nageswara R Sastry Suggested-by: Nicholas Piggin Suggested-by: Madhavan Srinivasan Signed-off-by: Athira Rajeev Tested-by: Nageswara R Sastry Reviewed-by: Nicholas Piggin [mpe: Make pmi_irq_pending() return bool, reflow/reword some comments] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1626846509-1350-2-git-send-email-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin