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2015-01-16arm64: kernel: fix __cpu_suspend mm switch on warm-bootLorenzo Pieralisi
commit f43c27188a49111b58e9611afa2f0365b0b55625 upstream. On arm64 the TTBR0_EL1 register is set to either the reserved TTBR0 page tables on boot or to the active_mm mappings belonging to user space processes, it must never be set to swapper_pg_dir page tables mappings. When a CPU is booted its active_mm is set to init_mm even though its TTBR0_EL1 points at the reserved TTBR0 page mappings. This implies that when __cpu_suspend is triggered the active_mm can point at init_mm even if the current TTBR0_EL1 register contains the reserved TTBR0_EL1 mappings. Therefore, the mm save and restore executed in __cpu_suspend might turn out to be erroneous in that, if the current->active_mm corresponds to init_mm, on resume from low power it ends up restoring in the TTBR0_EL1 the init_mm mappings that are global and can cause speculation of TLB entries which end up being propagated to user space. This patch fixes the issue by checking the active_mm pointer before restoring the TTBR0 mappings. If the current active_mm == &init_mm, the code sets the TTBR0_EL1 to the reserved TTBR0 mapping instead of switching back to the active_mm, which is the expected behaviour corresponding to the TTBR0_EL1 settings when __cpu_suspend was entered. Fixes: 95322526ef62 ("arm64: kernel: cpu_{suspend/resume} implementation") Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-16arm64: Move cpu_resume into the text sectionLaura Abbott
commit c3684fbb446501b48dec6677a6a9f61c215053de upstream. The function cpu_resume currently lives in the .data section. There's no reason for it to be there since we can use relative instructions without a problem. Move a few cpu_resume data structures out of the assembly file so the .data annotation can be dropped completely and cpu_resume ends up in the read only text section. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-16arm64: kernel: refactor the CPU suspend API for retention statesLorenzo Pieralisi
commit 714f59925595b9c2ea9c22b107b340d38e3b3bc9 upstream. CPU suspend is the standard kernel interface to be used to enter low-power states on ARM64 systems. Current cpu_suspend implementation by default assumes that all low power states are losing the CPU context, so the CPU registers must be saved and cleaned to DRAM upon state entry. Furthermore, the current cpu_suspend() implementation assumes that if the CPU suspend back-end method returns when called, this has to be considered an error regardless of the return code (which can be successful) since the CPU was not expected to return from a code path that is different from cpu_resume code path - eg returning from the reset vector. All in all this means that the current API does not cope well with low-power states that preserve the CPU context when entered (ie retention states), since first of all the context is saved for nothing on state entry for those states and a successful state entry can return as a normal function return, which is considered an error by the current CPU suspend implementation. This patch refactors the cpu_suspend() API so that it can be split in two separate functionalities. The arm64 cpu_suspend API just provides a wrapper around CPU suspend operation hook. A new function is introduced (for architecture code use only) for states that require context saving upon entry: __cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) __cpu_suspend() saves the context on function entry and calls the so called suspend finisher (ie fn) to complete the suspend operation. The finisher is not expected to return, unless it fails in which case the error is propagated back to the __cpu_suspend caller. The API refactoring results in the following pseudo code call sequence for a suspending CPU, when triggered from a kernel subsystem: /* * int cpu_suspend(unsigned long idx) * @idx: idle state index */ { -> cpu_suspend(idx) |---> CPU operations suspend hook called, if present |--> if (retention_state) |--> direct suspend back-end call (eg PSCI suspend) else |--> __cpu_suspend(idx, &back_end_finisher); } By refactoring the cpu_suspend API this way, the CPU operations back-end has a chance to detect whether idle states require state saving or not and can call the required suspend operations accordingly either through simple function call or indirectly through __cpu_suspend() which carries out state saving and suspend finisher dispatching to complete idle state entry. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-16arm64: kernel: add missing __init section marker to cpu_suspend_initLorenzo Pieralisi
commit 18ab7db6b749ac27aac08d572afbbd2f4d937934 upstream. Suspend init function must be marked as __init, since it is not needed after the kernel has booted. This patch moves the cpu_suspend_init() function to the __init section. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-08arm64: Add COMPAT_HWCAP_LPAECatalin Marinas
commit 7d57511d2dba03a8046c8b428dd9192a4bfc1e73 upstream. Commit a469abd0f868 (ARM: elf: add new hwcap for identifying atomic ldrd/strd instructions) introduces HWCAP_ELF for 32-bit ARM applications. As LPAE is always present on arm64, report the corresponding compat HWCAP to user space. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-21Correct the race condition in aarch64_insn_patch_text_sync()William Cohen
commit 899d5933b2dd2720f2b20b01eaa07871aa6ad096 upstream. When experimenting with patches to provide kprobes support for aarch64 smp machines would hang when inserting breakpoints into kernel code. The hangs were caused by a race condition in the code called by aarch64_insn_patch_text_sync(). The first processor in the aarch64_insn_patch_text_cb() function would patch the code while other processors were still entering the function and incrementing the cpu_count field. This resulted in some processors never observing the exit condition and exiting the function. Thus, processors in the system hung. The first processor to enter the patching function performs the patching and signals that the patching is complete with an increment of the cpu_count field. When all the processors have incremented the cpu_count field the cpu_count will be num_cpus_online()+1 and they will return to normal execution. Fixes: ae16480785de arm64: introduce interfaces to hotpatch kernel and module code Signed-off-by: William Cohen <wcohen@redhat.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-21arm64: __clear_user: handle exceptions on strbKyle McMartin
commit 97fc15436b36ee3956efad83e22a557991f7d19d upstream. ARM64 currently doesn't fix up faults on the single-byte (strb) case of __clear_user... which means that we can cause a nasty kernel panic as an ordinary user with any multiple PAGE_SIZE+1 read from /dev/zero. i.e.: dd if=/dev/zero of=foo ibs=1 count=1 (or ibs=65537, etc.) This is a pretty obscure bug in the general case since we'll only __do_kernel_fault (since there's no extable entry for pc) if the mmap_sem is contended. However, with CONFIG_DEBUG_VM enabled, we'll always fault. if (!down_read_trylock(&mm->mmap_sem)) { if (!user_mode(regs) && !search_exception_tables(regs->pc)) goto no_context; retry: down_read(&mm->mmap_sem); } else { /* * The above down_read_trylock() might have succeeded in * which * case, we'll have missed the might_sleep() from * down_read(). */ might_sleep(); if (!user_mode(regs) && !search_exception_tables(regs->pc)) goto no_context; } Fix that by adding an extable entry for the strb instruction, since it touches user memory, similar to the other stores in __clear_user. Signed-off-by: Kyle McMartin <kyle@redhat.com> Reported-by: Miloš Prchlík <mprchlik@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30arm64: compat: fix compat types affecting struct compat_elf_prpsinfoVictor Kamensky
commit 971a5b6fe634bb7b617d8c5f25b6a3ddbc600194 upstream. The compat_elf_prpsinfo structure does not match the arch/arm struct elf_pspsinfo definition. As result NT_PRPSINFO note in core file created by arm64 kernel for aarch32 (compat) process has wrong size. So gdb cannot display command that caused process crash. Fix is to change size of __compat_uid_t, __compat_gid_t so it would match size of similar fields in arch/arm case. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05arm64: ptrace: fix compat hardware watchpoint reportingWill Deacon
commit 27d7ff273c2aad37b28f6ff0cab2cfa35b51e648 upstream. I'm not sure what I was on when I wrote this, but when iterating over the hardware watchpoint array (hbp_watch_array), our index is off by ARM_MAX_BRP, so we walk off the end of our thread_struct... ... except, a dodgy condition in the loop means that it never executes at all (bp cannot be NULL). This patch fixes the code so that we remove the bp check and use the correct index for accessing the watchpoint structures. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05ARM/ARM64: KVM: Nuke Hyp-mode tlbs before enabling MMUPranavkumar Sawargaonkar
commit f6edbbf36da3a27b298b66c7955fc84e1dcca305 upstream. X-Gene u-boot runs in EL2 mode with MMU enabled hence we might have stale EL2 tlb enteris when we enable EL2 MMU on each host CPU. This can happen on any ARM/ARM64 board running bootloader in Hyp-mode (or EL2-mode) with MMU enabled. This patch ensures that we flush all Hyp-mode (or EL2-mode) TLBs on each host CPU before enabling Hyp-mode (or EL2-mode) MMU. Tested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Signed-off-by: Anup Patel <anup.patel@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05arm/arm64: KVM: Complete WFI/WFE instructionsChristoffer Dall
commit 05e0127f9e362b36aa35f17b1a3d52bca9322a3a upstream. The architecture specifies that when the processor wakes up from a WFE or WFI instruction, the instruction is considered complete, however we currrently return to EL1 (or EL0) at the WFI/WFE instruction itself. While most guests may not be affected by this because their local exception handler performs an exception returning setting the event bit or with an interrupt pending, some guests like UEFI will get wedged due this little mishap. Simply skip the instruction when we have completed the emulation. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05arm64: use irq_set_affinity with force=false when migrating irqsSudeep Holla
commit 3d8afe3099ebc602848aa7f09235cce3a9a023ce upstream. The arm64 interrupt migration code on cpu offline calls irqchip.irq_set_affinity() with the argument force=true. Originally this argument had no effect because it was not used by any interrupt chip driver and there was no semantics defined. This changed with commit 01f8fa4f01d8 ("genirq: Allow forcing cpu affinity of interrupts") which made the force argument useful to route interrupts to not yet online cpus without checking the target cpu against the cpu online mask. The following commit ffde1de64012 ("irqchip: gic: Support forced affinity setting") implemented this for the GIC interrupt controller. As a consequence the cpu offline irq migration fails if CPU0 is offlined, because CPU0 is still set in the affinity mask and the validation against cpu online mask is skipped to the force argument being true. The following first_cpu(mask) selection always selects CPU0 as the target. Commit 601c942176d8("arm64: use cpu_online_mask when using forced irq_set_affinity") intended to fix the above mentioned issue but introduced another issue where affinity can be migrated to a wrong CPU due to unconditional copy of cpu_online_mask. As with for arm, solve the issue by calling irq_set_affinity() with force=false from the CPU offline irq migration code so the GIC driver validates the affinity mask against CPU online mask and therefore removes CPU0 from the possible target candidates. Also revert the changes done in the commit 601c942176d8 as it's no longer needed. Tested on Juno platform. Fixes: 601c942176d8("arm64: use cpu_online_mask when using forced irq_set_affinity") Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-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.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05arm64: flush TLS registers during execWill Deacon
commit eb35bdd7bca29a13c8ecd44e6fd747a84ce675db upstream. Nathan reports that we leak TLS information from the parent context during an exec, as we don't clear the TLS registers when flushing the thread state. This patch updates the flushing code so that we: (1) Unconditionally zero the tpidr_el0 register (since this is fully context switched for native tasks and zeroed for compat tasks) (2) Zero the tp_value state in thread_info before clearing the tpidrr0_el0 register for compat tasks (since this is only writable by the set_tls compat syscall and therefore not fully switched). A missing compiler barrier is also added to the compat set_tls syscall. Acked-by: Nathan Lynch <Nathan_Lynch@mentor.com> Reported-by: Nathan Lynch <Nathan_Lynch@mentor.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-28locking/mutex: Disable optimistic spinning on some architecturesPeter Zijlstra
commit 4badad352a6bb202ec68afa7a574c0bb961e5ebc upstream. The optimistic spin code assumes regular stores and cmpxchg() play nice; this is found to not be true for at least: parisc, sparc32, tile32, metag-lock1, arc-!llsc and hexagon. There is further wreckage, but this in particular seemed easy to trigger, so blacklist this. Opt in for known good archs. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Jason Low <jason.low2@hp.com> Cc: Waiman Long <waiman.long@hp.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: John David Anglin <dave.anglin@bell.net> Cc: James Hogan <james.hogan@imgtec.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17arm64: implement TASK_SIZE_OFColin Cross
commit fa2ec3ea10bd377f9d55772b1dab65178425a1a2 upstream. include/linux/sched.h implements TASK_SIZE_OF as TASK_SIZE if it is not set by the architecture headers. TASK_SIZE uses the current task to determine the size of the virtual address space. On a 64-bit kernel this will cause reading /proc/pid/pagemap of a 64-bit process from a 32-bit process to return EOF when it reads past 0xffffffff. Implement TASK_SIZE_OF exactly the same as TASK_SIZE with test_tsk_thread_flag instead of test_thread_flag. Signed-off-by: Colin Cross <ccross@android.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09arm64: Bug fix in stack alignment exceptionChiaHao
commit 3906c2b53cd23c2ae03e6ce41432c8e7f0a3cbbb upstream. The value of ESR has been stored into x1, and should be directly pass to do_sp_pc_abort function, "MOV x1, x25" is an extra operation and do_sp_pc_abort will get the wrong value of ESR. Signed-off-by: ChiaHao <andy.jhshiu@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09arm64: mm: Make icache synchronisation logic huge page awareSteve Capper
commit 923b8f5044da753e4985ab15c1374ced2cdf616c upstream. The __sync_icache_dcache routine will only flush the dcache for the first page of a compound page, potentially leading to stale icache data residing further on in a hugetlb page. This patch addresses this issue by taking into consideration the order of the page when flushing the dcache. Reported-by: Mark Brown <broonie@linaro.org> Tested-by: Mark Brown <broonie@linaro.org> Signed-off-by: Steve Capper <steve.capper@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-30arm64/dma: Removing ARCH_HAS_DMA_GET_REQUIRED_MASK macroSuravee Suthikulpanit
commit f3a183cb422574014538017b5b291a416396f97e upstream. Arm64 does not define dma_get_required_mask() function. Therefore, it should not define the ARCH_HAS_DMA_GET_REQUIRED_MASK. This causes build errors in some device drivers (e.g. mpt2sas) Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-30arm64: ptrace: fix empty registers set in prstatus of aarch32 process coreVictor Kamensky
commit 2227901a0230d8fde81ba9c602d649839390f56b upstream. Currently core file of aarch32 process prstatus note has empty registers set. As result aarch32 core files create by V8 kernel are not very useful. It happens because compat_gpr_get and compat_gpr_set functions can copy registers values to/from either kbuf or ubuf. ELF core file collection function fill_thread_core_info calls compat_gpr_get with kbuf set and ubuf set to 0. But current compat_gpr_get and compat_gpr_set function handle copy to/from only ubuf case. Fix is to handle kbuf and ubuf as two separate cases in similar way as other functions like user_regset_copyout, user_regset_copyin do. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-30arm64: ptrace: change fs when passing kernel pointer to regset codeWill Deacon
commit c168870704bcde6bb63d05f7882b620dd3985a46 upstream. Our compat PTRACE_POKEUSR implementation simply passes the user data to regset_copy_from_user after some simple range checking. Unfortunately, the data in question has already been copied to the kernel stack by this point, so the subsequent access_ok check fails and the ptrace request returns -EFAULT. This causes problems tracing fork() with older versions of strace. This patch briefly changes the fs to KERNEL_DS, so that the access_ok check passes even with a kernel address. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-30hugetlb: restrict hugepage_migration_support() to x86_64Naoya Horiguchi
commit c177c81e09e517bbf75b67762cdab1b83aba6976 upstream. Currently hugepage migration is available for all archs which support pmd-level hugepage, but testing is done only for x86_64 and there're bugs for other archs. So to avoid breaking such archs, this patch limits the availability strictly to x86_64 until developers of other archs get interested in enabling this feature. Simply disabling hugepage migration on non-x86_64 archs is not enough to fix the reported problem where sys_move_pages() hits the BUG_ON() in follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is supported in vma_migratable(). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07arm64: use cpu_online_mask when using forced irq_set_affinitySudeep Holla
commit 601c942176d8ad8334118bddb747e3720bed24f8 upstream. Commit 01f8fa4f01d8("genirq: Allow forcing cpu affinity of interrupts") enabled the forced irq_set_affinity which previously refused to route an interrupt to an offline cpu. Commit ffde1de64012("irqchip: Gic: Support forced affinity setting") implements this force logic and disables the cpu online check for GIC interrupt controller. When __cpu_disable calls migrate_irqs, it disables the current cpu in cpu_online_mask and uses forced irq_set_affinity to migrate the IRQs away from the cpu but passes affinity mask with the cpu being offlined also included in it. When calling irq_set_affinity with force == true in a cpu hotplug path, the caller must ensure that the cpu being offlined is not present in the affinity mask or it may be selected as the target CPU, leading to the interrupt not being migrated. This patch uses cpu_online_mask when using forced irq_set_affinity so that the IRQs are properly migrated away. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07arm64: fix pud_huge() for 2-level pagetablesMark Salter
commit 4797ec2dc83a43be35bad56037d1b53db9e2b5d5 upstream. The following happens when trying to run a kvm guest on a kernel configured for 64k pages. This doesn't happen with 4k pages: BUG: failure at include/linux/mm.h:297/put_page_testzero()! Kernel panic - not syncing: BUG! CPU: 2 PID: 4228 Comm: qemu-system-aar Tainted: GF 3.13.0-0.rc7.31.sa2.k32v1.aarch64.debug #1 Call trace: [<fffffe0000096034>] dump_backtrace+0x0/0x16c [<fffffe00000961b4>] show_stack+0x14/0x1c [<fffffe000066e648>] dump_stack+0x84/0xb0 [<fffffe0000668678>] panic+0xf4/0x220 [<fffffe000018ec78>] free_reserved_area+0x0/0x110 [<fffffe000018edd8>] free_pages+0x50/0x88 [<fffffe00000a759c>] kvm_free_stage2_pgd+0x30/0x40 [<fffffe00000a5354>] kvm_arch_destroy_vm+0x18/0x44 [<fffffe00000a1854>] kvm_put_kvm+0xf0/0x184 [<fffffe00000a1938>] kvm_vm_release+0x10/0x1c [<fffffe00001edc1c>] __fput+0xb0/0x288 [<fffffe00001ede4c>] ____fput+0xc/0x14 [<fffffe00000d5a2c>] task_work_run+0xa8/0x11c [<fffffe0000095c14>] do_notify_resume+0x54/0x58 In arch/arm/kvm/mmu.c:unmap_range(), we end up doing an extra put_page() on the stage2 pgd which leads to the BUG in put_page_testzero(). This happens because a pud_huge() test in unmap_range() returns true when it should always be false with 2-level pages tables used by 64k pages. This patch removes support for huge puds if 2-level pagetables are being used. Signed-off-by: Mark Salter <msalter@redhat.com> [catalin.marinas@arm.com: removed #ifndef around PUD_SIZE check] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-06arm64: __NR_compat_syscalls fixMiklos Szeredi
commit 838977f0178334bf3d7f3e974ea3154b68979be0 upstream. This fixes commit 6290b53de025 (arm64: compat: Wire up new AArch32 syscalls) which did not update __NR_compat_syscalls accordingly. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-06arm64: Make DMA coherent and strongly ordered mappings not executableCatalin Marinas
commit de2db7432917a82b62d55bb59635586eeca6d1bd upstream. pgprot_{dmacoherent,writecombine,noncached} don't need to generate executable mappings with side-effects like __sync_icache_dcache() being called when the mapping is in user space. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Bharat Bhushan <Bharat.Bhushan@freescale.com> Tested-by: Laura Abbott <lauraa@codeaurora.org> Tested-by: Bharat Bhushan <Bharat.Bhushan@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-06arm64: Do not synchronise I and D caches for special ptesCatalin Marinas
commit 71fdb6bf61bf0692f004f9daf5650392c0cfe300 upstream. Special pte mappings are not intended to be executable and do not even have an associated struct page. This patch ensures that we do not call __sync_icache_dcache() on such ptes. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Steve Capper <Steve.Capper@arm.com> Tested-by: Laura Abbott <lauraa@codeaurora.org> Tested-by: Bharat Bhushan <Bharat.Bhushan@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "Three x86 fixes and one for ARM/ARM64. In particular, nested virtualization on Intel is broken in 3.13 and fixed by this pull request" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm, vmx: Really fix lazy FPU on nested guest kvm: x86: fix emulator buffer overflow (CVE-2014-0049) arm/arm64: KVM: detect CPU reset on CPU_PM_EXIT KVM: MMU: drop read-only large sptes when creating lower level sptes
2014-02-28arm64: Fix !CONFIG_SMP kernel buildCatalin Marinas
Commit fb4a96029c8a (arm64: kernel: fix per-cpu offset restore on resume) uses per_cpu_offset() unconditionally during CPU wakeup, however, this is only defined for the SMP case. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Dave P Martin <Dave.Martin@arm.com>
2014-02-28arm64: mm: Add double logical invert to pte accessorsSteve Capper
Page table entries on ARM64 are 64 bits, and some pte functions such as pte_dirty return a bitwise-and of a flag with the pte value. If the flag to be tested resides in the upper 32 bits of the pte, then we run into the danger of the result being dropped if downcast. For example: gather_stats(page, md, pte_dirty(*pte), 1); where pte_dirty(*pte) is downcast to an int. This patch adds a double logical invert to all the pte_ accessors to ensure predictable downcasting. Signed-off-by: Steve Capper <steve.capper@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-27arm/arm64: KVM: detect CPU reset on CPU_PM_EXITMarc Zyngier
Commit 1fcf7ce0c602 (arm: kvm: implement CPU PM notifier) added support for CPU power-management, using a cpu_notifier to re-init KVM on a CPU that entered CPU idle. The code assumed that a CPU entering idle would actually be powered off, loosing its state entierely, and would then need to be reinitialized. It turns out that this is not always the case, and some HW performs CPU PM without actually killing the core. In this case, we try to reinitialize KVM while it is still live. It ends up badly, as reported by Andre Przywara (using a Calxeda Midway): [ 3.663897] Kernel panic - not syncing: unexpected prefetch abort in Hyp mode at: 0x685760 [ 3.663897] unexpected data abort in Hyp mode at: 0xc067d150 [ 3.663897] unexpected HVC/SVC trap in Hyp mode at: 0xc0901dd0 The trick here is to detect if we've been through a full re-init or not by looking at HVBAR (VBAR_EL2 on arm64). This involves implementing the backend for __hyp_get_vectors in the main KVM HYP code (rather small), and checking the return value against the default one when the CPU notifier is called on CPU_PM_EXIT. Reported-by: Andre Przywara <osp@andrep.de> Tested-by: Andre Przywara <osp@andrep.de> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Rob Herring <rob.herring@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-17ARM64: unwind: Fix PC calculationOlof Johansson
The frame PC value in the unwind code used to just take the saved LR value and use that. That's incorrect as a stack trace, since it shows the return path stack, not the call path stack. In particular, it shows faulty information in case the bl is done as the very last instruction of one label, since the return point will be in the next label. That can easily be seen with tail calls to panic(), which is marked __noreturn and thus doesn't have anything useful after it. Easiest here is to just correct the unwind code and do a -4, to get the actual call site for the backtrace instead of the return site. Signed-off-by: Olof Johansson <olof@lixom.net> Cc: stable@vger.kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-14Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "A small error handling problem and a compile breakage for ARM64" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: arm64: KVM: Add VGIC device control for arm64 KVM: return an error code in kvm_vm_ioctl_register_coalesced_mmio()
2014-02-14arm64: KVM: Add VGIC device control for arm64Christoffer Dall
This fixes the build breakage introduced by c07a0191ef2de1f9510f12d1f88e3b0b5cd8d66f and adds support for the device control API and save/restore of the VGIC state for ARMv8. The defines were simply missing from the arm64 header files and uaccess.h must be implicitly imported from somewhere else on arm. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-02-07arm64: defconfig: Expand default enabled featuresMark Rutland
FPGA implementations of the Cortex-A57 and Cortex-A53 are now available in the form of the SMM-A57 and SMM-A53 Soft Macrocell Models (SMMs) for Versatile Express. As these attach to a Motherboard Express V2M-P1 it would be useful to have support for some V2M-P1 peripherals enabled by default. Additionally a couple of of features have been introduced since the last defconfig update (CMA, jump labels) that would be good to have enabled by default to ensure they are build and boot tested. This patch updates the arm64 defconfig to enable support for these devices and features. The arm64 Kconfig is modified to select HAVE_PATA_PLATFORM, which is required to enable support for the CompactFlash controller on the V2M-P1. A few options which don't need to appear in defconfig are trimmed: * BLK_DEV - selected by default * EXPERIMENTAL - otherwise gone from the kernel * MII - selected by drivers which require it * USB_SUPPORT - selected by default Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-07arm64: asm: remove redundant "cc" clobbersWill Deacon
cbnz/tbnz don't update the condition flags, so remove the "cc" clobbers from inline asm blocks that only use these instructions to implement conditional branches. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-07arm64: atomics: fix use of acquire + release for full barrier semanticsWill Deacon
Linux requires a number of atomic operations to provide full barrier semantics, that is no memory accesses after the operation can be observed before any accesses up to and including the operation in program order. On arm64, these operations have been incorrectly implemented as follows: // A, B, C are independent memory locations <Access [A]> // atomic_op (B) 1: ldaxr x0, [B] // Exclusive load with acquire <op(B)> stlxr w1, x0, [B] // Exclusive store with release cbnz w1, 1b <Access [C]> The assumption here being that two half barriers are equivalent to a full barrier, so the only permitted ordering would be A -> B -> C (where B is the atomic operation involving both a load and a store). Unfortunately, this is not the case by the letter of the architecture and, in fact, the accesses to A and C are permitted to pass their nearest half barrier resulting in orderings such as Bl -> A -> C -> Bs or Bl -> C -> A -> Bs (where Bl is the load-acquire on B and Bs is the store-release on B). This is a clear violation of the full barrier requirement. The simple way to fix this is to implement the same algorithm as ARMv7 using explicit barriers: <Access [A]> // atomic_op (B) dmb ish // Full barrier 1: ldxr x0, [B] // Exclusive load <op(B)> stxr w1, x0, [B] // Exclusive store cbnz w1, 1b dmb ish // Full barrier <Access [C]> but this has the undesirable effect of introducing *two* full barrier instructions. A better approach is actually the following, non-intuitive sequence: <Access [A]> // atomic_op (B) 1: ldxr x0, [B] // Exclusive load <op(B)> stlxr w1, x0, [B] // Exclusive store with release cbnz w1, 1b dmb ish // Full barrier <Access [C]> The simple observations here are: - The dmb ensures that no subsequent accesses (e.g. the access to C) can enter or pass the atomic sequence. - The dmb also ensures that no prior accesses (e.g. the access to A) can pass the atomic sequence. - Therefore, no prior access can pass a subsequent access, or vice-versa (i.e. A is strictly ordered before C). - The stlxr ensures that no prior access can pass the store component of the atomic operation. The only tricky part remaining is the ordering between the ldxr and the access to A, since the absence of the first dmb means that we're now permitting re-ordering between the ldxr and any prior accesses. From an (arbitrary) observer's point of view, there are two scenarios: 1. We have observed the ldxr. This means that if we perform a store to [B], the ldxr will still return older data. If we can observe the ldxr, then we can potentially observe the permitted re-ordering with the access to A, which is clearly an issue when compared to the dmb variant of the code. Thankfully, the exclusive monitor will save us here since it will be cleared as a result of the store and the ldxr will retry. Notice that any use of a later memory observation to imply observation of the ldxr will also imply observation of the access to A, since the stlxr/dmb ensure strict ordering. 2. We have not observed the ldxr. This means we can perform a store and influence the later ldxr. However, that doesn't actually tell us anything about the access to [A], so we've not lost anything here either when compared to the dmb variant. This patch implements this solution for our barriered atomic operations, ensuring that we satisfy the full barrier requirements where they are needed. Cc: <stable@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-06arm64: barriers: allow dsb macro to take option parameterWill Deacon
The dsb instruction takes an option specifying both the target access types and shareability domain. This patch allows such an option to be passed to the dsb macro, resulting in potentially more efficient code. Currently the option is ignored until all callers are updated (unlike ARM, the option is mandated by the assembler). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: compat: Wire up new AArch32 syscallsCatalin Marinas
This patch enables sys_compat, sys_finit_module, sys_sched_setattr and sys_sched_getattr for compat (AArch32) applications. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: vdso: update wtm fields for CLOCK_MONOTONIC_COARSENathan Lynch
Update wall-to-monotonic fields in the VDSO data page unconditionally. These are used to service CLOCK_MONOTONIC_COARSE, which is not guarded by use_syscall. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: vdso: fix coarse clock handlingNathan Lynch
When __kernel_clock_gettime is called with a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE clock id, it returns incorrectly to whatever the caller has placed in x2 ("ret x2" to return from the fast path). Fix this by saving x30/LR to x2 only in code that will call __do_get_tspec, restoring x30 afterward, and using a plain "ret" to return from the routine. Also: while the resulting tv_nsec value for CLOCK_REALTIME and CLOCK_MONOTONIC must be computed using intermediate values that are left-shifted by cs_shift (x12, set by __do_get_tspec), the results for coarse clocks should be calculated using unshifted values (xtime_coarse_nsec is in units of actual nanoseconds). The current code shifts intermediate values by x12 unconditionally, but x12 is uninitialized when servicing a coarse clock. Fix this by setting x12 to 0 once we know we are dealing with a coarse clock id. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: simplify pgd_allocMark Rutland
Currently pgd_alloc has a redundant NULL check in its return path that can be removed with no ill effects. With that removed it's also possible to return early and eliminate the new_pgd temporary variable. This patch applies said modifications, making the logic of pgd_alloc correspond 1-1 with that of pgd_free. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: fix typo: s/SERRROR/SERROR/Mark Rutland
Somehow SERROR has acquired an additional 'R' in a couple of headers. This patch removes them before they spread further. As neither instance is in use yet, no other sites need to be fixed up. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: Invalidate the TLB when replacing pmd entries during bootCatalin Marinas
With the 64K page size configuration, __create_page_tables in head.S maps enough memory to get started but using 64K pages rather than 512M sections with a single pgd/pud/pmd entry pointing to a pte table. create_mapping() may override the pgd/pud/pmd table entry with a block (section) one if the RAM size is more than 512MB and aligned correctly. For the end of this block to be accessible, the old TLB entry must be invalidated. Cc: <stable@vger.kernel.org> Reported-by: Mark Salter <msalter@redhat.com> Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: Align CMA sizes to PAGE_SIZELaura Abbott
dma_alloc_from_contiguous takes number of pages for a size. Align up the dma size passed in to page size to avoid truncation and allocation failures on sizes less than PAGE_SIZE. Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: add DSB after icache flush in __flush_icache_all()Vinayak Kale
Add DSB after icache flush to complete the cache maintenance operation. The function __flush_icache_all() is used only for user space mappings and an ISB is not required because of an exception return before executing user instructions. An exception return would behave like an ISB. Signed-off-by: Vinayak Kale <vkale@apm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-04arm64: vdso: prevent ld from aligning PT_LOAD segments to 64kWill Deacon
Whilst the text segment for our VDSO is marked as PT_LOAD in the ELF headers, it is mapped by the kernel and not actually subject to demand-paging. ld doesn't realise this, and emits a p_align field of 64k (the maximum supported page size), which conflicts with the load address picked by the kernel on 4k systems, which will be 4k aligned. This causes GDB to fail with "Failed to read a valid object file image from memory" when attempting to load the VDSO. This patch passes the -n option to ld, which prevents it from aligning PT_LOAD segments to the maximum page size. Cc: <stable@vger.kernel.org> Reported-by: Kyle McMartin <kyle@redhat.com> Acked-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-31Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pyll ARM64 patches from Catalin Marinas: - Build fix with DMA_CMA enabled - Introduction of PTE_WRITE to distinguish between writable but clean and truly read-only pages - FIQs enabling/disabling clean-up (they aren't used on arm64) - CPU resume fix for the per-cpu offset restoring - Code comment typos * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: mm: Introduce PTE_WRITE arm64: mm: Remove PTE_BIT_FUNC macro arm64: FIQs are unused arm64: mm: fix the function name in comment of cpu_do_switch_mm arm64: fix build error if DMA_CMA is enabled arm64: kernel: fix per-cpu offset restore on resume arm64: mm: fix the function name in comment of __flush_dcache_area arm64: mm: use ubfm for dcache_line_size
2014-01-31arm64: mm: Introduce PTE_WRITESteve Capper
We have the following means for encoding writable or dirty ptes: PTE_DIRTY PTE_RDONLY !pte_dirty && !pte_write 0 1 !pte_dirty && pte_write 0 1 pte_dirty && !pte_write 1 1 pte_dirty && pte_write 1 0 So we can't distinguish between writable clean ptes and read only ptes. This can cause problems with ptes being incorrectly flagged as read only when they are writable but not dirty. This patch introduces a new software bit PTE_WRITE which allows us to correctly identify writable ptes. PTE_RDONLY is now only clear for valid ptes where a page is both writable and dirty. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-31arm64: mm: Remove PTE_BIT_FUNC macroSteve Capper
Expand out the pte manipulation functions. This makes our life easier when using things like tags and cscope. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-30arm64: FIQs are unusedNicolas Pitre
So any FIQ handling is superfluous at the moment. The functions to disable/enable FIQs is kept around if ever someone needs them in the future, but existing calling sites including arch_cpu_idle_prepare() may go for now. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>