kernel/git/stable/linux.git/arch/powerpc/mm, branch linux-5.12.y

powerpc/mm/book3s64: Fix possible build error

2021-07-20T14:02:09+00:00

[ Upstream commit 07d8ad6fd8a3d47f50595ca4826f41dbf4f3a0c6 ] Update _tlbiel_pid() such that we can avoid build errors like below when using this function in other places. arch/powerpc/mm/book3s64/radix_tlb.c: In function ‘__radix__flush_tlb_range_psize’: arch/powerpc/mm/book3s64/radix_tlb.c:114:2: warning: ‘asm’ operand 3 probably does not match constraints 114 | asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1) | ^~~ arch/powerpc/mm/book3s64/radix_tlb.c:114:2: error: impossible constraint in ‘asm’ make[4]: *** [scripts/Makefile.build:271: arch/powerpc/mm/book3s64/radix_tlb.o] Error 1 m With this fix, we can also drop the __always_inline in __radix_flush_tlb_range_psize which was added by commit e12d6d7d46a6 ("powerpc/mm/radix: mark __radix__flush_tlb_range_psize() as __always_inline") Signed-off-by: Aneesh Kumar K.V Reviewed-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210610083639.387365-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/mm: Fix lockup on kernel exec fault

2021-07-19T08:01:13+00:00

commit cd5d5e602f502895e47e18cd46804d6d7014e65c upstream. The powerpc kernel is not prepared to handle exec faults from kernel. Especially, the function is_exec_fault() will return 'false' when an exec fault is taken by kernel, because the check is based on reading current->thread.regs->trap which contains the trap from user. For instance, when provoking a LKDTM EXEC_USERSPACE test, current->thread.regs->trap is set to SYSCALL trap (0xc00), and the fault taken by the kernel is not seen as an exec fault by set_access_flags_filter(). Commit d7df2443cd5f ("powerpc/mm: Fix spurious segfaults on radix with autonuma") made it clear and handled it properly. But later on commit d3ca587404b3 ("powerpc/mm: Fix reporting of kernel execute faults") removed that handling, introducing test based on error_code. And here is the problem, because on the 603 all upper bits of SRR1 get cleared when the TLB instruction miss handler bails out to ISI. Until commit cbd7e6ca0210 ("powerpc/fault: Avoid heavy search_exception_tables() verification"), an exec fault from kernel at a userspace address was indirectly caught by the lack of entry for that address in the exception tables. But after that commit the kernel mainly relies on KUAP or on core mm handling to catch wrong user accesses. Here the access is not wrong, so mm handles it. It is a minor fault because PAGE_EXEC is not set, set_access_flags_filter() should set PAGE_EXEC and voila. But as is_exec_fault() returns false as explained in the beginning, set_access_flags_filter() bails out without setting PAGE_EXEC flag, which leads to a forever minor exec fault. As the kernel is not prepared to handle such exec faults, the thing to do is to fire in bad_kernel_fault() for any exec fault taken by the kernel, as it was prior to commit d3ca587404b3. Fixes: d3ca587404b3 ("powerpc/mm: Fix reporting of kernel execute faults") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Christophe Leroy Acked-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/024bb05105050f704743a0083fe3548702be5706.1625138205.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

powerpc/mm: Add cond_resched() while removing hpte mappings

2021-05-19T08:56:16+00:00

[ Upstream commit a5d6a3e73acbd619dd5b7b831762b755f9e2db80 ] While removing large number of mappings from hash page tables for large memory systems as soft-lockup is reported because of the time spent inside htap_remove_mapping() like one below: watchdog: BUG: soft lockup - CPU#8 stuck for 23s! NIP plpar_hcall+0x38/0x58 LR pSeries_lpar_hpte_invalidate+0x68/0xb0 Call Trace: 0x1fffffffffff000 (unreliable) pSeries_lpar_hpte_removebolted+0x9c/0x230 hash__remove_section_mapping+0xec/0x1c0 remove_section_mapping+0x28/0x3c arch_remove_memory+0xfc/0x150 devm_memremap_pages_release+0x180/0x2f0 devm_action_release+0x30/0x50 release_nodes+0x28c/0x300 device_release_driver_internal+0x16c/0x280 unbind_store+0x124/0x170 drv_attr_store+0x44/0x60 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 __vfs_write+0x3c/0x70 vfs_write+0xd4/0x270 ksys_write+0xdc/0x130 system_call+0x5c/0x70 Fix this by adding a cond_resched() to the loop in htap_remove_mapping() that issues hcall to remove hpte mapping. The call to cond_resched() is issued every HZ jiffies which should prevent the soft-lockup from being reported. Suggested-by: Aneesh Kumar K.V Signed-off-by: Vaibhav Jain Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210404163148.321346-1-vaibhav@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/64s: Use htab_convert_pte_flags() in hash__mark_rodata_ro()

2021-05-14T08:52:50+00:00

[ Upstream commit 2c02e656a29d5f64193eb93da92781bcf0517146 ] In hash__mark_rodata_ro() we pass the raw PP_RXXX value to hash__change_memory_range(). That has the effect of setting the key to zero, because PP_RXXX contains no key value. Fix it by using htab_convert_pte_flags(), which knows how to convert a pgprot into a pp value, including the key. Fixes: d94b827e89dc ("powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation") Signed-off-by: Michael Ellerman Reviewed-by: Daniel Axtens Link: https://lore.kernel.org/r/20210331003845.216246-3-mpe@ellerman.id.au Signed-off-by: Sasha Levin

powerpc/64s: Fix pte update for kernel memory on radix

2021-05-14T08:52:50+00:00

[ Upstream commit b8b2f37cf632434456182e9002d63cbc4cccc50c ] When adding a PTE a ptesync is needed to order the update of the PTE with subsequent accesses otherwise a spurious fault may be raised. radix__set_pte_at() does not do this for performance gains. For non-kernel memory this is not an issue as any faults of this kind are corrected by the page fault handler. For kernel memory these faults are not handled. The current solution is that there is a ptesync in flush_cache_vmap() which should be called when mapping from the vmalloc region. However, map_kernel_page() does not call flush_cache_vmap(). This is troublesome in particular for code patching with Strict RWX on radix. In do_patch_instruction() the page frame that contains the instruction to be patched is mapped and then immediately patched. With no ordering or synchronization between setting up the PTE and writing to the page it is possible for faults. As the code patching is done using __put_user_asm_goto() the resulting fault is obscured - but using a normal store instead it can be seen: BUG: Unable to handle kernel data access on write at 0xc008000008f24a3c Faulting instruction address: 0xc00000000008bd74 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: nop_module(PO+) [last unloaded: nop_module] CPU: 4 PID: 757 Comm: sh Tainted: P O 5.10.0-rc5-01361-ge3c1b78c8440-dirty #43 NIP: c00000000008bd74 LR: c00000000008bd50 CTR: c000000000025810 REGS: c000000016f634a0 TRAP: 0300 Tainted: P O (5.10.0-rc5-01361-ge3c1b78c8440-dirty) MSR: 9000000000009033 CR: 44002884 XER: 00000000 CFAR: c00000000007c68c DAR: c008000008f24a3c DSISR: 42000000 IRQMASK: 1 This results in the kind of issue reported here: https://lore.kernel.org/linuxppc-dev/15AC5B0E-A221-4B8C-9039-FA96B8EF7C88@lca.pw/ Chris Riedl suggested a reliable way to reproduce the issue: $ mount -t debugfs none /sys/kernel/debug $ (while true; do echo function > /sys/kernel/debug/tracing/current_tracer ; echo nop > /sys/kernel/debug/tracing/current_tracer ; done) & Turning ftrace on and off does a large amount of code patching which in usually less then 5min will crash giving a trace like: ftrace-powerpc: (____ptrval____): replaced (4b473b11) != old (60000000) ------------[ ftrace bug ]------------ ftrace failed to modify [] napi_busy_loop+0xc/0x390 actual: 11:3b:47:4b Setting ftrace call site to call ftrace function ftrace record flags: 80000001 (1) expected tramp: c00000000006c96c ------------[ cut here ]------------ WARNING: CPU: 4 PID: 809 at kernel/trace/ftrace.c:2065 ftrace_bug+0x28c/0x2e8 Modules linked in: nop_module(PO-) [last unloaded: nop_module] CPU: 4 PID: 809 Comm: sh Tainted: P O 5.10.0-rc5-01360-gf878ccaf250a #1 NIP: c00000000024f334 LR: c00000000024f330 CTR: c0000000001a5af0 REGS: c000000004c8b760 TRAP: 0700 Tainted: P O (5.10.0-rc5-01360-gf878ccaf250a) MSR: 900000000282b033 CR: 28008848 XER: 20040000 CFAR: c0000000001a9c98 IRQMASK: 0 GPR00: c00000000024f330 c000000004c8b9f0 c000000002770600 0000000000000022 GPR04: 00000000ffff7fff c000000004c8b6d0 0000000000000027 c0000007fe9bcdd8 GPR08: 0000000000000023 ffffffffffffffd8 0000000000000027 c000000002613118 GPR12: 0000000000008000 c0000007fffdca00 0000000000000000 0000000000000000 GPR16: 0000000023ec37c5 0000000000000000 0000000000000000 0000000000000008 GPR20: c000000004c8bc90 c0000000027a2d20 c000000004c8bcd0 c000000002612fe8 GPR24: 0000000000000038 0000000000000030 0000000000000028 0000000000000020 GPR28: c000000000ff1b68 c000000000bf8e5c c00000000312f700 c000000000fbb9b0 NIP ftrace_bug+0x28c/0x2e8 LR ftrace_bug+0x288/0x2e8 Call Trace: ftrace_bug+0x288/0x2e8 (unreliable) ftrace_modify_all_code+0x168/0x210 arch_ftrace_update_code+0x18/0x30 ftrace_run_update_code+0x44/0xc0 ftrace_startup+0xf8/0x1c0 register_ftrace_function+0x4c/0xc0 function_trace_init+0x80/0xb0 tracing_set_tracer+0x2a4/0x4f0 tracing_set_trace_write+0xd4/0x130 vfs_write+0xf0/0x330 ksys_write+0x84/0x140 system_call_exception+0x14c/0x230 system_call_common+0xf0/0x27c To fix this when updating kernel memory PTEs using ptesync. Fixes: f1cb8f9beba8 ("powerpc/64s/radix: avoid ptesync after set_pte and ptep_set_access_flags") Signed-off-by: Jordan Niethe Reviewed-by: Nicholas Piggin [mpe: Tidy up change log slightly] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210208032957.1232102-1-jniethe5@gmail.com Signed-off-by: Sasha Levin

powerpc/64s: Fix hash fault to use TRAP accessor

2021-05-14T08:52:47+00:00

[ Upstream commit 1479e3d3b7559133b0a107772b5841e9c2cad450 ] Hash faults use the trap vector to decide whether this is an instruction or data fault. This should use the TRAP accessor rather than open access regs->trap. This won't cause a problem at the moment because 64s only uses trap flags for system call interrupts (the norestart flag), but that could change if any other trap flags get used in future. Fixes: a4922f5442e7e ("powerpc/64s: move the hash fault handling logic to C") Suggested-by: Christophe Leroy Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210316105205.407767-1-npiggin@gmail.com Signed-off-by: Sasha Levin

powerpc/mm: Move the linear_mapping_mutex to the ifdef where it is used

2021-05-14T08:52:45+00:00

[ Upstream commit 9be77e11dade414d2fa63750aa5c754fac49d619 ] The mutex linear_mapping_mutex is defined at the of the file while its only two user are within the CONFIG_MEMORY_HOTPLUG block. A compile without CONFIG_MEMORY_HOTPLUG set fails on PREEMPT_RT because its mutex implementation is smart enough to realize that it is unused. Move the definition of linear_mapping_mutex to ifdef block where it is used. Fixes: 1f73ad3e8d755 ("powerpc/mm: print warning in arch_remove_linear_mapping()") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210219165648.2505482-1-bigeasy@linutronix.de Signed-off-by: Sasha Levin

Merge tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-02-22T22:34:00+00:00

Pull powerpc updates from Michael Ellerman: - A large series adding wrappers for our interrupt handlers, so that irq/nmi/user tracking can be isolated in the wrappers rather than spread in each handler. - Conversion of the 32-bit syscall handling into C. - A series from Nick to streamline our TLB flushing when using the Radix MMU. - Switch to using queued spinlocks by default for 64-bit server CPUs. - A rework of our PCI probing so that it happens later in boot, when more generic infrastructure is available. - Two small fixes to allow 32-bit little-endian processes to run on 64-bit kernels. - Other smaller features, fixes & cleanups. Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong, Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu, Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun. * tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits) powerpc/perf: Adds support for programming of Thresholding in P10 powerpc/pci: Remove unimplemented prototypes powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user() powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size() powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user() powerpc/64: Fix stack trace not displaying final frame powerpc/time: Remove get_tbl() powerpc/time: Avoid using get_tbl() spi: mpc52xx: Avoid using get_tbl() powerpc/syscall: Avoid storing 'current' in another pointer powerpc/32: Handle bookE debugging in C in syscall entry/exit powerpc/syscall: Do not check unsupported scv vector on PPC32 powerpc/32: Remove the counter in global_dbcr0 powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry powerpc/syscall: implement system call entry/exit logic in C for PPC32 powerpc/32: Always save non volatile GPRs at syscall entry powerpc/syscall: Change condition to check MSR_RI powerpc/syscall: Save r3 in regs->orig_r3 powerpc/syscall: Use is_compat_task() powerpc/syscall: Make interrupt.c buildable on PPC32 ...

powerpc/mm: Remove dcache flush from memory remove.

2021-02-11T12:35:07+00:00

We added dcache flush on memory add/remove in commit fb5924fddf9e ("powerpc/mm: Flush cache on memory hot(un)plug") to handle crashes on GPU hotplug. Instead of adding dcache flush in generic memory add/remove routine which is used even for regular memory, we should handle these devices specific flush in the device driver code. memtrace did handle this in the driver and that was removed by commit 7fd6641de28f ("powerpc/powernv/memtrace: Let the arch hotunplug code flush cache"). This patch reverts that commit. The dcache flush in memory add was removed by commit ea458effa88e ("powerpc: Don't flush caches when adding memory") which I don't think is correct. The reason why we require dcache flush in memtrace is to make sure we don't have a dirty cache when we remap a pfn to cache inhibited. We should do that when the memtrace module removes the memory and make the pfn available for HTM traces to map it as cache inhibited. The other device mentioned in commit fb5924fddf9e ("powerpc/mm: Flush cache on memory hot(un)plug") is nvlink device with coherent memory. The support for that was removed in commit 7eb3cf761927 ("powerpc/powernv: remove unused NPU DMA code") and commit 25b2995a35b6 ("mm: remove MEMORY_DEVICE_PUBLIC support") Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210203045812.234439-3-aneesh.kumar@linux.ibm.com

powerpc/mm: Add PG_dcache_clean to indicate dcache clean state

2021-02-11T12:35:06+00:00

This just add a better name for PG_arch_1. No functional change in this patch. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210203045812.234439-2-aneesh.kumar@linux.ibm.com