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2019-09-17arm64: fix unreachable code issue with cmpxchgArnd Bergmann
On arm64 build with clang, sometimes the __cmpxchg_mb is not inlined when CONFIG_OPTIMIZE_INLINING is set. Clang then fails a compile-time assertion, because it cannot tell at compile time what the size of the argument is: mm/memcontrol.o: In function `__cmpxchg_mb': memcontrol.c:(.text+0x1a4c): undefined reference to `__compiletime_assert_175' memcontrol.c:(.text+0x1a4c): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `__compiletime_assert_175' Mark all of the cmpxchg() style functions as __always_inline to ensure that the compiler can see the result. Acked-by: Nick Desaulniers <ndesaulniers@google.com> Reported-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/648 Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Andrew Murray <andrew.murray@arm.com> Tested-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Will Deacon <will@kernel.org>
2019-09-04arm64: remove __iounmapChristoph Hellwig
No need to indirect iounmap for arm64. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-30Merge branch 'for-next/atomics' into for-next/coreWill Deacon
* for-next/atomics: (10 commits) Rework LSE instruction selection to use static keys instead of alternatives
2019-08-30Merge branches 'for-next/52-bit-kva', 'for-next/cpu-topology', ↵Will Deacon
'for-next/error-injection', 'for-next/perf', 'for-next/psci-cpuidle', 'for-next/rng', 'for-next/smpboot', 'for-next/tbi' and 'for-next/tlbi' into for-next/core * for-next/52-bit-kva: (25 commits) Support for 52-bit virtual addressing in kernel space * for-next/cpu-topology: (9 commits) Move CPU topology parsing into core code and add support for ACPI 6.3 * for-next/error-injection: (2 commits) Support for function error injection via kprobes * for-next/perf: (8 commits) Support for i.MX8 DDR PMU and proper SMMUv3 group validation * for-next/psci-cpuidle: (7 commits) Move PSCI idle code into a new CPUidle driver * for-next/rng: (4 commits) Support for 'rng-seed' property being passed in the devicetree * for-next/smpboot: (3 commits) Reduce fragility of secondary CPU bringup in debug configurations * for-next/tbi: (10 commits) Introduce new syscall ABI with relaxed requirements for pointer tags * for-next/tlbi: (6 commits) Handle spurious page faults arising from kernel space
2019-08-30arm64: atomics: Use K constraint when toolchain appears to support itWill Deacon
The 'K' constraint is a documented AArch64 machine constraint supported by GCC for matching integer constants that can be used with a 32-bit logical instruction. Unfortunately, some released compilers erroneously accept the immediate '4294967295' for this constraint, which is later refused by GAS at assembly time. This had led us to avoid the use of the 'K' constraint altogether. Instead, detect whether the compiler is up to the job when building the kernel and pass the 'K' constraint to our 32-bit atomic macros when it appears to be supported. Signed-off-by: Will Deacon <will@kernel.org>
2019-08-30arm64: atomics: Undefine internal macros after useWill Deacon
We use a bunch of internal macros when constructing our atomic and cmpxchg routines in order to save on boilerplate. Avoid exposing these directly to users of the header files. Reviewed-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-30arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABELWill Deacon
Support for LSE atomic instructions (CONFIG_ARM64_LSE_ATOMICS) relies on a static key to select between the legacy LL/SC implementation which is available on all arm64 CPUs and the super-duper LSE implementation which is available on CPUs implementing v8.1 and later. Unfortunately, when building a kernel with CONFIG_JUMP_LABEL disabled (e.g. because the toolchain doesn't support 'asm goto'), the static key inside the atomics code tries to use atomics itself. This results in a mess of circular includes and a build failure: In file included from ./arch/arm64/include/asm/lse.h:11, from ./arch/arm64/include/asm/atomic.h:16, from ./include/linux/atomic.h:7, from ./include/asm-generic/bitops/atomic.h:5, from ./arch/arm64/include/asm/bitops.h:26, from ./include/linux/bitops.h:19, from ./include/linux/kernel.h:12, from ./include/asm-generic/bug.h:18, from ./arch/arm64/include/asm/bug.h:26, from ./include/linux/bug.h:5, from ./include/linux/page-flags.h:10, from kernel/bounds.c:10: ./include/linux/jump_label.h: In function ‘static_key_count’: ./include/linux/jump_label.h:254:9: error: implicit declaration of function ‘atomic_read’ [-Werror=implicit-function-declaration] return atomic_read(&key->enabled); ^~~~~~~~~~~ [ ... more of the same ... ] Since LSE atomic instructions are not critical to the operation of the kernel, make them depend on JUMP_LABEL at compile time. Reviewed-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-30arm64: asm: Kill 'asm/atomic_arch.h'Will Deacon
The contents of 'asm/atomic_arch.h' can be split across some of our other 'asm/' headers. Remove it. Reviewed-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-30arm64: lse: Remove unused 'alt_lse' assembly macroWill Deacon
The 'alt_lse' assembly macro has been unused since 7c8fc35dfc32 ("locking/atomics/arm64: Replace our atomic/lock bitop implementations with asm-generic"). Remove it. Reviewed-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-29arm64: atomics: Remove atomic_ll_sc compilation unitAndrew Murray
We no longer fall back to out-of-line atomics on systems with CONFIG_ARM64_LSE_ATOMICS where ARM64_HAS_LSE_ATOMICS is not set. Remove the unused compilation unit which provided these symbols. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-29arm64: avoid using hard-coded registers for LSE atomicsAndrew Murray
Now that we have removed the out-of-line ll/sc atomics we can give the compiler the freedom to choose its own register allocation. Remove the hard-coded use of x30. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-29arm64: atomics: avoid out-of-line ll/sc atomicsAndrew Murray
When building for LSE atomics (CONFIG_ARM64_LSE_ATOMICS), if the hardware or toolchain doesn't support it the existing code will fallback to ll/sc atomics. It achieves this by branching from inline assembly to a function that is built with special compile flags. Further this results in the clobbering of registers even when the fallback isn't used increasing register pressure. Improve this by providing inline implementations of both LSE and ll/sc and use a static key to select between them, which allows for the compiler to generate better atomics code. Put the LL/SC fallback atomics in their own subsection to improve icache performance. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-29arm64: Use correct ll/sc atomic constraintsAndrew Murray
The A64 ISA accepts distinct (but overlapping) ranges of immediates for: * add arithmetic instructions ('I' machine constraint) * sub arithmetic instructions ('J' machine constraint) * 32-bit logical instructions ('K' machine constraint) * 64-bit logical instructions ('L' machine constraint) ... but we currently use the 'I' constraint for many atomic operations using sub or logical instructions, which is not always valid. When CONFIG_ARM64_LSE_ATOMICS is not set, this allows invalid immediates to be passed to instructions, potentially resulting in a build failure. When CONFIG_ARM64_LSE_ATOMICS is selected the out-of-line ll/sc atomics always use a register as they have no visibility of the value passed by the caller. This patch adds a constraint parameter to the ATOMIC_xx and __CMPXCHG_CASE macros so that we can pass appropriate constraints for each case, with uses updated accordingly. Unfortunately prior to GCC 8.1.0 the 'K' constraint erroneously accepted '4294967295', so we must instead force the use of a register. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-28arm64: kpti: ensure patched kernel text is fetched from PoUMark Rutland
While the MMUs is disabled, I-cache speculation can result in instructions being fetched from the PoC. During boot we may patch instructions (e.g. for alternatives and jump labels), and these may be dirty at the PoU (and stale at the PoC). Thus, while the MMU is disabled in the KPTI pagetable fixup code we may load stale instructions into the I-cache, potentially leading to subsequent crashes when executing regions of code which have been modified at runtime. Similarly to commit: 8ec41987436d566f ("arm64: mm: ensure patched kernel text is fetched from PoU") ... we can invalidate the I-cache after enabling the MMU to prevent such issues. The KPTI pagetable fixup code itself should be clean to the PoC per the boot protocol, so no maintenance is required for this code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-28arm64: fix fixmap copy for 16K pages and 48-bit VAMark Rutland
With 16K pages and 48-bit VAs, the PGD level of table has two entries, and so the fixmap shares a PGD with the kernel image. Since commit: f9040773b7bbbd9e ("arm64: move kernel image to base of vmalloc area") ... we copy the existing fixmap to the new fine-grained page tables at the PUD level in this case. When walking to the new PUD, we forgot to offset the PGD entry and always used the PGD entry at index 0, but this worked as the kernel image and fixmap were in the low half of the TTBR1 address space. As of commit: 14c127c957c1c607 ("arm64: mm: Flip kernel VA space") ... the kernel image and fixmap are in the high half of the TTBR1 address space, and hence use the PGD at index 1, but we didn't update the fixmap copying code to account for this. Thus, we'll erroneously try to copy the fixmap slots into a PUD under the PGD entry at index 0. At the point we do so this PGD entry has not been initialised, and thus we'll try to write a value to a small offset from physical address 0, causing a number of potential problems. Fix this be correctly offsetting the PGD. This is split over a few steps for legibility. Fixes: 14c127c957c1c607 ("arm64: mm: Flip kernel VA space") Reported-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Acked-by: Steve Capper <Steve.Capper@arm.com> Tested-by: Steve Capper <Steve.Capper@arm.com> Tested-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_FWill Deacon
Now that we have a definition for the 'F' field of PAR_EL1, use that instead of coding the immediate directly. Acked-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27arm64: mm: Ignore spurious translation faults taken from the kernelWill Deacon
Thanks to address translation being performed out of order with respect to loads and stores, it is possible for a CPU to take a translation fault when accessing a page that was mapped by a different CPU. For example, in the case that one CPU maps a page and then sets a flag to tell another CPU: CPU 0 ----- MOV X0, <valid pte> STR X0, [Xptep] // Store new PTE to page table DSB ISHST ISB MOV X1, #1 STR X1, [Xflag] // Set the flag CPU 1 ----- loop: LDAR X0, [Xflag] // Poll flag with Acquire semantics CBZ X0, loop LDR X1, [X2] // Translates using the new PTE then the final load on CPU 1 can raise a translation fault because the translation can be performed speculatively before the read of the flag and marked as "faulting" by the CPU. This isn't quite as bad as it sounds since, in reality, code such as: CPU 0 CPU 1 ----- ----- spin_lock(&lock); spin_lock(&lock); *ptr = vmalloc(size); if (*ptr) spin_unlock(&lock); foo = **ptr; spin_unlock(&lock); will not trigger the fault because there is an address dependency on CPU 1 which prevents the speculative translation. However, more exotic code where the virtual address is known ahead of time, such as: CPU 0 CPU 1 ----- ----- spin_lock(&lock); spin_lock(&lock); set_fixmap(0, paddr, prot); if (mapped) mapped = true; foo = *fix_to_virt(0); spin_unlock(&lock); spin_unlock(&lock); could fault. This can be avoided by any of: * Introducing broadcast TLB maintenance on the map path * Adding a DSB;ISB sequence after checking a flag which indicates that a virtual address is now mapped * Handling the spurious fault Given that we have never observed a problem due to this under Linux and future revisions of the architecture are being tightened so that translation table walks are effectively ordered in the same way as explicit memory accesses, we no longer treat spurious kernel faults as fatal if an AT instruction indicates that the access does not trigger a translation fault. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27arm64: sysreg: Add some field definitions for PAR_EL1Will Deacon
PAR_EL1 is a mysterious creature, but sometimes it's necessary to read it when translating addresses in situations where we cannot walk the page table directly. Add a couple of system register definitions for the fault indication field ('F') and the fault status code ('FST'). Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27arm64: mm: Add ISB instruction to set_pgd()Will Deacon
Commit 6a4cbd63c25a ("Revert "arm64: Remove unnecessary ISBs from set_{pte,pmd,pud}"") reintroduced ISB instructions to some of our page table setter functions in light of a recent clarification to the Armv8 architecture. Although 'set_pgd()' isn't currently used to update a live page table, add the ISB instruction there too for consistency with the other macros and to provide some future-proofing if we use it on live tables in the future. Reported-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27arm64: tlb: Ensure we execute an ISB following walk cache invalidationWill Deacon
05f2d2f83b5a ("arm64: tlbflush: Introduce __flush_tlb_kernel_pgtable") added a new TLB invalidation helper which is used when freeing intermediate levels of page table used for kernel mappings, but is missing the required ISB instruction after completion of the TLBI instruction. Add the missing barrier. Cc: <stable@vger.kernel.org> Fixes: 05f2d2f83b5a ("arm64: tlbflush: Introduce __flush_tlb_kernel_pgtable") Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27Revert "arm64: Remove unnecessary ISBs from set_{pte,pmd,pud}"Will Deacon
This reverts commit 24fe1b0efad4fcdd32ce46cffeab297f22581707. Commit 24fe1b0efad4fcdd ("arm64: Remove unnecessary ISBs from set_{pte,pmd,pud}") removed ISB instructions immediately following updates to the page table, on the grounds that they are not required by the architecture and a DSB alone is sufficient to ensure that subsequent data accesses use the new translation: DDI0487E_a, B2-128: | ... no instruction that appears in program order after the DSB | instruction can alter any state of the system or perform any part of | its functionality until the DSB completes other than: | | * Being fetched from memory and decoded | * Reading the general-purpose, SIMD and floating-point, | Special-purpose, or System registers that are directly or indirectly | read without causing side-effects. However, the same document also states the following: DDI0487E_a, B2-125: | DMB and DSB instructions affect reads and writes to the memory system | generated by Load/Store instructions and data or unified cache | maintenance instructions being executed by the PE. Instruction fetches | or accesses caused by a hardware translation table access are not | explicit accesses. which appears to claim that the DSB alone is insufficient. Unfortunately, some CPU designers have followed the second clause above, whereas in Linux we've been relying on the first. This means that our mapping sequence: MOV X0, <valid pte> STR X0, [Xptep] // Store new PTE to page table DSB ISHST LDR X1, [X2] // Translates using the new PTE can actually raise a translation fault on the load instruction because the translation can be performed speculatively before the page table update and then marked as "faulting" by the CPU. For user PTEs, this is ok because we can handle the spurious fault, but for kernel PTEs and intermediate table entries this results in a panic(). Revert the offending commit to reintroduce the missing barriers. Cc: <stable@vger.kernel.org> Fixes: 24fe1b0efad4fcdd ("arm64: Remove unnecessary ISBs from set_{pte,pmd,pud}") Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27arm64: smp: Treat unknown boot failures as being 'stuck in kernel'Will Deacon
When we fail to bring a secondary CPU online and it fails in an unknown state, we should assume the worst and increment 'cpus_stuck_in_kernel' so that things like kexec() are disabled. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27arm64: smp: Don't enter kernel with NULL stack pointer or task structWill Deacon
Although SMP bringup is inherently racy, we can significantly reduce the window during which secondary CPUs can unexpectedly enter the kernel by sanity checking the 'stack' and 'task' fields of the 'secondary_data' structure. If the booting CPU gave up waiting for us, then they will have been cleared to NULL and we should spin in a WFE; WFI loop instead. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27arm64: smp: Increase secondary CPU boot timeout valueWill Deacon
When many debug options are enabled simultaneously (e.g. PROVE_LOCKING, KMEMLEAK, DEBUG_PAGE_ALLOC, KASAN etc), it is possible for us to timeout when attempting to boot a secondary CPU and give up. Unfortunately, the CPU will /eventually/ appear, and sit in the background happily stuck in a recursive exception due to a NULL stack pointer. Increase the timeout to 5s, which will of course be enough for anybody. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-23arm64: kexec_file: add rng-seed supportHsin-Yi Wang
Adding "rng-seed" to dtb. It's fine to add this property if original fdt doesn't contain it. Since original seed will be wiped after read, so use a default size 128 bytes here. Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-23arm64: map FDT as RW for early_init_dt_scan()Hsin-Yi Wang
Currently in arm64, FDT is mapped to RO before it's passed to early_init_dt_scan(). However, there might be some codes (eg. commit "fdt: add support for rng-seed") that need to modify FDT during init. Map FDT to RO after early fixups are done. Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-21arm64: add arch/arm64/KbuildMasahiro Yamada
Use the standard obj-y form to specify the sub-directories under arch/arm64/. No functional change intended. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-21arm64: entry: Move ct_user_exit before any other exceptionJames Morse
When taking an SError or Debug exception from EL0, we run the C handler for these exceptions before updating the context tracking code and unmasking lower priority interrupts. When booting with nohz_full lockdep tells us we got this wrong: | ============================= | WARNING: suspicious RCU usage | 5.3.0-rc2-00010-gb4b5e9dcb11b-dirty #11271 Not tainted | ----------------------------- | include/linux/rcupdate.h:643 rcu_read_unlock() used illegally wh! | | other info that might help us debug this: | | | RCU used illegally from idle CPU! | rcu_scheduler_active = 2, debug_locks = 1 | RCU used illegally from extended quiescent state! | 1 lock held by a.out/432: | #0: 00000000c7a79515 (rcu_read_lock){....}, at: brk_handler+0x00 | | stack backtrace: | CPU: 1 PID: 432 Comm: a.out Not tainted 5.3.0-rc2-00010-gb4b5e9d1 | Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno De8 | Call trace: | dump_backtrace+0x0/0x140 | show_stack+0x14/0x20 | dump_stack+0xbc/0x104 | lockdep_rcu_suspicious+0xf8/0x108 | brk_handler+0x164/0x1b0 | do_debug_exception+0x11c/0x278 | el0_dbg+0x14/0x20 Moving the ct_user_exit calls to be before do_debug_exception() means they are also before trace_hardirqs_off() has been updated. Add a new ct_user_exit_irqoff macro to avoid the context-tracking code using irqsave/restore before we've updated trace_hardirqs_off(). To be consistent, do this everywhere. The C helper is called enter_from_user_mode() to match x86 in the hope we can merge them into kernel/context_tracking.c later. Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 6c81fe7925cc4c42 ("arm64: enable context tracking") Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20arm64: Change the tagged_addr sysctl control semantics to only prevent the ↵Catalin Marinas
opt-in First rename the sysctl control to abi.tagged_addr_disabled and make it default off (zero). When abi.tagged_addr_disabled == 1, only block the enabling of the TBI ABI via prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE). Getting the status of the ABI or disabling it is still allowed. Acked-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20arm64: perf_event: Add missing header needed for smp_processor_id()Raphael Gault
In perf_event.c we use smp_processor_id(), but we haven't included <linux/smp.h> where it is defined, and rely on this being pulled in via a transitive include. Let's make this more robust by including <linux.smp.h> explicitly. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Raphael Gault <raphael.gault@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-20powerpc/Makefile: Always pass --synthetic to nm if supportedMichael Ellerman
Back in 2004 we added logic to arch/ppc64/Makefile to pass the --synthetic option to nm, if it was supported by nm. Then in 2005 when arch/ppc64 and arch/ppc were merged, the logic to add --synthetic was moved inside an #ifdef CONFIG_PPC64 block within arch/powerpc/Makefile, and has remained there since. That was fine, though crufty, until recently when a change to init/Kconfig added a config time check that uses $(NM). On powerpc that leads to an infinite loop because Kconfig uses $(NM) to calculate some values, then the powerpc Makefile changes $(NM), which Kconfig notices and restarts. The original commit that added --synthetic simply said: On new toolchains we need to use nm --synthetic or we miss code symbols. And the nm man page says that the --synthetic option causes nm to: Include synthetic symbols in the output. These are special symbols created by the linker for various purposes. So it seems safe to always pass --synthetic if nm supports it, ie. on 32-bit and 64-bit, it just means 32-bit kernels might have more symbols reported (and in practice I see no extra symbols). Making it unconditional avoids the #ifdef CONFIG_PPC64, which in turn avoids the infinite loop. Debugged-by: Peter Collingbourne <pcc@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-15arm64: unexport set_memory_x and set_memory_nxChristoph Hellwig
No module currently messed with clearing or setting the execute permission of kernel memory, and none really should. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-15arm64: smp: disable hotplug on trusted OS resident CPUSudeep Holla
The trusted OS may reject CPU_OFF calls to its resident CPU, so we must avoid issuing those. We never migrate a Trusted OS and we already take care to prevent CPU_OFF PSCI call. However, this is not reflected explicitly to the userspace. Any user can attempt to hotplug trusted OS resident CPU. The entire motion of going through the various state transitions in the CPU hotplug state machine gets executed and the PSCI layer finally refuses to make CPU_OFF call. This results is unnecessary unwinding of CPU hotplug state machine in the kernel. Instead we can mark the trusted OS resident CPU as not available for hotplug, so that the user attempt or request to do the same will get immediately rejected. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64/efi: Move variable assignments after SECTIONSKees Cook
It seems that LLVM's linker does not correctly handle variable assignments involving section positions that are updated during the SECTIONS parsing. Commit aa69fb62bea1 ("arm64/efi: Mark __efistub_stext_offset as an absolute symbol explicitly") ran into this too, but found a different workaround. However, this was not enough, as other variables were also miscalculated which manifested as boot failures under UEFI where __efistub__end was not taking the correct _end value (they should be the same): $ ld.lld -EL -maarch64elf --no-undefined -X -shared \ -Bsymbolic -z notext -z norelro --no-apply-dynamic-relocs \ -o vmlinux.lld -T poc.lds --whole-archive vmlinux.o && \ readelf -Ws vmlinux.lld | egrep '\b(__efistub_|)_end\b' 368272: ffff000002218000 0 NOTYPE LOCAL HIDDEN 38 __efistub__end 368322: ffff000012318000 0 NOTYPE GLOBAL DEFAULT 38 _end $ aarch64-linux-gnu-ld.bfd -EL -maarch64elf --no-undefined -X -shared \ -Bsymbolic -z notext -z norelro --no-apply-dynamic-relocs \ -o vmlinux.bfd -T poc.lds --whole-archive vmlinux.o && \ readelf -Ws vmlinux.bfd | egrep '\b(__efistub_|)_end\b' 338124: ffff000012318000 0 NOTYPE LOCAL DEFAULT ABS __efistub__end 383812: ffff000012318000 0 NOTYPE GLOBAL DEFAULT 15325 _end To work around this, all of the __efistub_-prefixed variable assignments need to be moved after the linker script's SECTIONS entry. As it turns out, this also solves the problem fixed in commit aa69fb62bea1, so those changes are reverted here. Link: https://github.com/ClangBuiltLinux/linux/issues/634 Link: https://bugs.llvm.org/show_bug.cgi?id=42990 Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: Clarify when cpu_enable() is calledMark Brown
Strengthen the wording in the documentation for cpu_enable() to make it more obvious to readers not already familiar with the code when the core will call this callback and that this is intentional. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> [will: minor tweak to emphasis in the comment] Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: rename VA_START to PAGE_ENDMark Rutland
Prior to commit: 14c127c957c1c607 ("arm64: mm: Flip kernel VA space") ... VA_START described the start of the TTBR1 address space for a given VA size described by VA_BITS, where all kernel mappings began. Since that commit, VA_START described a portion midway through the address space, where the linear map ends and other kernel mappings begin. To avoid confusion, let's rename VA_START to PAGE_END, making it clear that it's not the start of the TTBR1 address space and implying that it's related to PAGE_OFFSET. Comments and other mnemonics are updated accordingly, along with a typo fix in the decription of VMEMMAP_SIZE. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: fix flipped VA space falloutMark Rutland
VA_START used to be the start of the TTBR1 address space, but now it's a point midway though. In a couple of places we still use VA_START to get the start of the TTBR1 address space, so let's fix these up to use PAGE_OFFSET instead. Fixes: 14c127c957c1c607 ("arm64: mm: Flip kernel VA space") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Cosmetic cleanupsWill Deacon
Cleanup memory.h so that the indentation is consistent, remove pointless line-wrapping and use consistent parameter names for different versions of the same macro. Reviewed-by: Steve Capper <steve.capper@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Add comments to end of non-trivial #ifdef blocksWill Deacon
Commenting the #endif of a multi-statement #ifdef block with the condition which guards it is useful and can save having to scroll back through the file to figure out which set of Kconfig options apply to a particular piece of code. Reviewed-by: Steve Capper <steve.capper@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Implement __tag_set() as common functionWill Deacon
There's no need for __tag_set() to be a complicated macro when CONFIG_KASAN_SW_TAGS=y and a simple static inline otherwise. Rewrite the thing as a common static inline function. Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Simplify _VA_START and _PAGE_OFFSET definitionsWill Deacon
Rather than subtracting from -1 and then adding 1, we can simply subtract from 0. Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Simplify virt_to_page() implementationWill Deacon
Build virt_to_page() on top of virt_to_pfn() so we can avoid the need for explicit shifting. Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Rewrite default page_to_virt()/virt_to_page()Will Deacon
The default implementations of page_to_virt() and virt_to_page() are fairly confusing to read and the former evaluates its 'page' parameter twice in the macro Rewrite them so that the computation is expressed as 'base + index' in both cases and the parameter is always evaluated exactly once. Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Ensure address tag is masked in conversion macrosWill Deacon
When converting a linear virtual address to a physical address, pfn or struct page *, we must make sure that the tag bits are masked before the calculation otherwise we end up with corrupt pointers when running with CONFIG_KASAN_SW_TAGS=y: | Unable to handle kernel paging request at virtual address 0037fe0007580d08 | [0037fe0007580d08] address between user and kernel address ranges Mask out the tag in __virt_to_phys_nodebug() and virt_to_page(). Reported-by: Qian Cai <cai@lca.pw> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Fixes: 9cb1c5ddd2c4 ("arm64: mm: Remove bit-masking optimisations for PAGE_OFFSET and VMEMMAP_START") Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Fix virt_addr_valid() using __is_lm_address()Will Deacon
virt_addr_valid() is intended to test whether or not the passed address is a valid linear map address. Unfortunately, it relies on _virt_addr_is_linear() which is broken because it assumes the linear map is at the top of the address space, which it no longer is. Reimplement virt_addr_valid() using __is_lm_address() and remove _virt_addr_is_linear() entirely. At the same time, ensure we evaluate the macro parameter only once and move it within the __ASSEMBLY__ block. Reported-by: Qian Cai <cai@lca.pw> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Fixes: 14c127c957c1 ("arm64: mm: Flip kernel VA space") Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14Merge tag 'common/for-v5.4-rc1/cpu-topology' of ↵Will Deacon
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux into for-next/cpu-topology Pull in generic CPU topology changes from Paul Walmsley (RISC-V). * tag 'common/for-v5.4-rc1/cpu-topology' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: MAINTAINERS: Add an entry for generic architecture topology base: arch_topology: update Kconfig help description RISC-V: Parse cpu topology during boot. arm: Use common cpu_topology structure and functions. cpu-topology: Move cpu topology code to common code. dt-binding: cpu-topology: Move cpu-map to a common binding. Documentation: DT: arm: add support for sockets defining package boundaries
2019-08-13arm64: constify sys64_hook instancesMark Rutland
All instances of struct sys64_hook contain compile-time constant data, and are never inentionally modified, so let's make them all const. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13arm64: constify aarch64_insn_encoding_class[]Mark Rutland
The aarch64_insn_encoding_class[] array contains compile-time constant data, and is never intentionally modified, so let's mark it as const. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13arm64: constify icache_policy_str[]Mark Rutland
The icache_policy_str[] array contains compile-time constant data, and is never intentionally modified, so let's mark it as const. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13arm64: prefer __section from compiler_attributes.hNick Desaulniers
GCC unescapes escaped string section names while Clang does not. Because __section uses the `#` stringification operator for the section name, it doesn't need to be escaped. This antipattern was found with: $ grep -e __section\(\" -e __section__\(\" -r Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>