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2015-03-06arm64: compat Fix siginfo_t -> compat_siginfo_t conversion on big endianCatalin Marinas
commit 9d42d48a342aee208c1154696196497fdc556bbf upstream. The native (64-bit) sigval_t union contains sival_int (32-bit) and sival_ptr (64-bit). When a compat application invokes a syscall that takes a sigval_t value (as part of a larger structure, e.g. compat_sys_mq_notify, compat_sys_timer_create), the compat_sigval_t union is converted to the native sigval_t with sival_int overlapping with either the least or the most significant half of sival_ptr, depending on endianness. When the corresponding signal is delivered to a compat application, on big endian the current (compat_uptr_t)sival_ptr cast always returns 0 since sival_int corresponds to the top part of sival_ptr. This patch fixes copy_siginfo_to_user32() so that sival_int is copied to the compat_siginfo_t structure. Reported-by: Bamvor Jian Zhang <bamvor.zhangjian@huawei.com> Tested-by: Bamvor Jian Zhang <bamvor.zhangjian@huawei.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-11arm64: Fix up /proc/cpuinfoMark Rutland
commit 44b82b7700d05a52cd983799d3ecde1a976b3bed upstream. Commit d7a49086f263164a (arm64: cpuinfo: print info for all CPUs) attempted to clean up /proc/cpuinfo, but due to concerns regarding further changes was reverted in commit 5e39977edf6500fd (Revert "arm64: cpuinfo: print info for all CPUs"). There are two major issues with the arm64 /proc/cpuinfo format currently: * The "Features" line describes (only) the 64-bit hwcaps, which is problematic for some 32-bit applications which attempt to parse it. As the same names are used for analogous ISA features (e.g. aes) despite these generally being architecturally unrelated, it is not possible to simply append the 64-bit and 32-bit hwcaps in a manner that might not be misleading to some applications. Various potential solutions have appeared in vendor kernels. Typically the format of the Features line varies depending on whether the task is 32-bit. * Information is only printed regarding a single CPU. This does not match the ARM format, and does not provide sufficient information in big.LITTLE systems where CPUs are heterogeneous. The CPU information printed is queried from the current CPU's registers, which is racy w.r.t. cross-cpu migration. This patch attempts to solve these issues. The following changes are made: * When a task with a LINUX32 personality attempts to read /proc/cpuinfo, the "Features" line contains the decoded 32-bit hwcaps, as with the arm port. Otherwise, the decoded 64-bit hwcaps are shown. This aligns with the behaviour of COMPAT_UTS_MACHINE and COMPAT_ELF_PLATFORM. In the absense of compat support, the Features line is empty. The set of hwcaps injected into a task's auxval are unaffected. * Properties are printed per-cpu, as with the ARM port. The per-cpu information is queried from pre-recorded cpu information (as used by the sanity checks). * As with the previous attempt at fixing up /proc/cpuinfo, the hardware field is removed. The only users so far are 32-bit applications tied to particular boards, so no portable applications should be affected, and this should prevent future tying to particular boards. The following differences remain: * No model_name is printed, as this cannot be queried from the hardware and cannot be provided in a stable fashion. Use of the CPU {implementor,variant,part,revision} fields is sufficient to identify a CPU and is portable across arm and arm64. * The following system-wide properties are not provided, as they are not possible to provide generally. Programs relying on these are already tied to particular (32-bit only) boards: - Hardware - Revision - Serial No software has yet been identified for which these remaining differences are problematic. Cc: Greg Hackmann <ghackmann@google.com> Cc: Ian Campbell <ijc@hellion.org.uk> Cc: Serban Constantinescu <serban.constantinescu@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: cross-distro@lists.linaro.org Cc: linux-api@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
2014-10-05arm64: 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>
2014-10-05arm64: 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>
2014-07-09arm64: 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>
2014-06-30arm64: 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>
2014-06-07arm64: 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>
2014-02-17ARM64: 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>
2014-02-07arm64: 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>
2014-02-05arm64: 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>
2014-02-04arm64: 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
2014-01-30arm64: 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>
2014-01-24arm64: kernel: fix per-cpu offset restore on resumeLorenzo Pieralisi
The introduction of percpu offset optimisation through tpidr_el1 in: Commit id :7158627686f02319c50c8d9d78f75d4c8 "arm64: percpu: implement optimised pcpu access using tpidr_el1" requires cpu_{suspend/resume} to restore the tpidr_el1 register upon resume so that percpu variables can be addressed correctly when a CPU comes out of reset from warm-boot. This patch fixes cpu_{suspend}/{resume} tpidr_el1 restoration on resume, by calling the set_my_cpu_offset C API, as it is done on primary and secondary CPUs on cold boot, so that, even if the register used to store the percpu offset is changed, the save and restore of general purpose registers does not have to be updated. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-20Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull ARM64 updates from Catalin Marinas: - CPU suspend support on top of PSCI (firmware Power State Coordination Interface) - jump label support - CMA can now be enabled on arm64 - HWCAP bits for crypto and CRC32 extensions - optimised percpu using tpidr_el1 register - code cleanup * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits) arm64: fix typo in entry.S arm64: kernel: restore HW breakpoint registers in cpu_suspend jump_label: use defined macros instead of hard-coding for better readability arm64, jump label: optimize jump label implementation arm64, jump label: detect %c support for ARM64 arm64: introduce aarch64_insn_gen_{nop|branch_imm}() helper functions arm64: move encode_insn_immediate() from module.c to insn.c arm64: introduce interfaces to hotpatch kernel and module code arm64: introduce basic aarch64 instruction decoding helpers arm64: dts: Reduce size of virtio block device for foundation model arm64: Remove unused __data_loc variable arm64: Enable CMA arm64: Warn on NULL device structure for dma APIs arm64: Add hwcaps for crypto and CRC32 extensions. arm64: drop redundant macros from read_cpuid() arm64: Remove outdated comment arm64: cmpxchg: update macros to prevent warnings arm64: support single-step and breakpoint handler hooks ARM64: fix framepointer check in unwind_frame ARM64: check stack pointer in get_wchan ...
2014-01-13arm64: fix typo in entry.SNeil Zhang
Commit 64681787 (arm64: let the core code deal with preempt_count) changed the code, but left the comments unchanged, fix it. Signed-off-by: Neil Zhang <zhangwm@marvell.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-10arm64: kernel: restore HW breakpoint registers in cpu_suspendLorenzo Pieralisi
When a CPU resumes from low-power, it restores HW breakpoint and watchpoint slots through a CPU PM notifier. Since we want to enable debugging as early as possible in the resume path, the mdscr content is restored along the general purpose registers in the cpu_suspend API and debug exceptions are reenabled when cpu_suspend returns. Since the CPU PM notifier is run after a CPU has been resumed, we cannot expect HW breakpoint registers to contain sane values till the notifier is run, since the HW breakpoints registers content is unknown at reset; this means that the CPU might run with debug exceptions enabled, mdscr restored but HW breakpoint registers containing junk values that can trigger spurious debug exceptions. This patch fixes current HW breakpoints restore by moving the HW breakpoints registers restoration to the cpu_suspend API, before the debug exceptions are enabled. This way, as soon as the cpu_suspend function returns the kernel can resume debugging with sane values in HW breakpoint registers. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64, jump label: optimize jump label implementationJiang Liu
Optimize jump label implementation for ARM64 by dynamically patching kernel text. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64: introduce aarch64_insn_gen_{nop|branch_imm}() helper functionsJiang Liu
Introduce aarch64_insn_gen_{nop|branch_imm}() helper functions, which will be used to implement jump label on ARM64. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64: move encode_insn_immediate() from module.c to insn.cJiang Liu
Function encode_insn_immediate() will be used by other instruction manipulate related functions, so move it into insn.c and rename it as aarch64_insn_encode_immediate(). Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64: introduce interfaces to hotpatch kernel and module codeJiang Liu
Introduce three interfaces to patch kernel and module code: aarch64_insn_patch_text_nosync(): patch code without synchronization, it's caller's responsibility to synchronize all CPUs if needed. aarch64_insn_patch_text_sync(): patch code and always synchronize with stop_machine() aarch64_insn_patch_text(): patch code and synchronize with stop_machine() if needed Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64: introduce basic aarch64 instruction decoding helpersJiang Liu
Introduce basic aarch64 instruction decoding helper aarch64_get_insn_class() and aarch64_insn_hotpatch_safe(). Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-20arm64: Remove unused __data_loc variableGeoff Levand
The __data_loc variable is an unused left over from the 32 bit arm implementation. Remove that variable and adjust the __mmap_switched startup routine accordingly. Signed-off-by: Geoff Levand <geoff@infradead.org> for Huawei, Linaro Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19Merge tag 'arm64-suspend' of git://linux-arm.org/linux-2.6-lp into upstreamCatalin Marinas
* tag 'arm64-suspend' of git://linux-arm.org/linux-2.6-lp: arm64: add CPU power management menu/entries arm64: kernel: add PM build infrastructure arm64: kernel: add CPU idle call arm64: enable generic clockevent broadcast arm64: kernel: implement HW breakpoints CPU PM notifier arm64: kernel: refactor code to install/uninstall breakpoints arm: kvm: implement CPU PM notifier arm64: kernel: implement fpsimd CPU PM notifier arm64: kernel: cpu_{suspend/resume} implementation arm64: kernel: suspend/resume registers save/restore arm64: kernel: build MPIDR_EL1 hash function data structure arm64: kernel: add MPIDR_EL1 accessors macros Conflicts: arch/arm64/Kconfig
2013-12-19arm64: Add hwcaps for crypto and CRC32 extensions.Steve Capper
Advertise the optional cryptographic and CRC32 instructions to user space where present. Several hwcap bits [3-7] are allocated. Signed-off-by: Steve Capper <steve.capper@linaro.org> [bit 2 is taken now so use bits 3-7 instead] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: Remove outdated commentLiviu Dudau
Code referenced in the comment has moved to arch/arm64/kernel/cputable.c Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: support single-step and breakpoint handler hooksSandeepa Prabhu
AArch64 Single Steping and Breakpoint debug exceptions will be used by multiple debug framworks like kprobes & kgdb. This patch implements the hooks for those frameworks to register their own handlers for handling breakpoint and single step events. Reworked the debug exception handler in entry.S: do_dbg to route software breakpoint (BRK64) exception to do_debug_exception() Signed-off-by: Sandeepa Prabhu <sandeepa.prabhu@linaro.org> Signed-off-by: Deepak Saxena <dsaxena@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19ARM64: fix framepointer check in unwind_frameKonstantin Khlebnikov
We need at least 24 bytes above frame pointer. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19ARM64: check stack pointer in get_wchanKonstantin Khlebnikov
get_wchan() is lockless. Task may wakeup at any time and change its own stack, thus each next stack frame may be overwritten and filled with random stuff. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: use generic strnlen_user and strncpy_from_user functionsWill Deacon
This patch implements the word-at-a-time interface for arm64 using the same algorithm as ARM. We use the fls64 macro, which expands to a clz instruction via a compiler builtin. Big-endian configurations make use of the implementation from asm-generic. With this implemented, we can replace our byte-at-a-time strnlen_user and strncpy_from_user functions with the optimised generic versions. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: percpu: implement optimised pcpu access using tpidr_el1Will Deacon
This patch implements optimised percpu variable accesses using the el1 r/w thread register (tpidr_el1) along the same lines as arch/arm/. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: perf: add support for percpu pmu interruptVinayak Kale
Add support for irq registration when pmu interrupt is percpu. Signed-off-by: Vinayak Kale <vkale@apm.com> Signed-off-by: Tuan Phan <tphan@apm.com> [will: tidied up cross-calling to pass &irq] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: vmlinux.lds.S: drop redundant .commentMark Rutland
We currently try to emit .comment twice, once in STABS_DEBUG, and once in the line immediately following it. As the two section definitions are identical, the latter is redundant and can be dropped. This patch drops the redundant .comment section definition. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: ptrace: avoid using HW_BREAKPOINT_EMPTY for disabled eventsWill Deacon
Commit 8f34a1da35ae ("arm64: ptrace: use HW_BREAKPOINT_EMPTY type for disabled breakpoints") fixed an issue with GDB trying to zero breakpoint control registers. The problem there is that the arch hw_breakpoint code will attempt to create a (disabled), execute breakpoint of length 0. This will fail validation and report unexpected failure to GDB. To avoid this, we treated disabled breakpoints as HW_BREAKPOINT_EMPTY, but that seems to have broken with recent kernels, causing watchpoints to be treated as TYPE_INST in the core code and returning ENOSPC for any further breakpoints. This patch fixes the problem by prioritising the `enable' field of the breakpoint: if it is cleared, we simply update the perf_event_attr to indicate that the thing is disabled and don't bother changing either the type or the length. This reinforces the behaviour that the breakpoint control register is essentially read-only apart from the enable bit when disabling a breakpoint. Cc: <stable@vger.kernel.org> Reported-by: Aaron Liu <liucy214@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-16arm64: kernel: add PM build infrastructureLorenzo Pieralisi
This patch adds the required makefile and kconfig entries to enable PM for arm64 systems. The kernel relies on the cpu_{suspend}/{resume} infrastructure to properly save the context for a CPU and put it to sleep, hence this patch adds the config option required to enable cpu_{suspend}/{resume} API. In order to rely on the CPU PM implementation for saving and restoring of CPU subsystems like GIC and PMU, the arch Kconfig must be also augmented to select the CONFIG_CPU_PM option when SUSPEND or CPU_IDLE kernel implementations are selected. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2013-12-16arm64: kernel: add CPU idle callLorenzo Pieralisi
When CPU idle is enabled, the architectural idle call should go through the idle subsystem to allow CPUs to enter idle states defined by the platform CPU idle back-end operations. This patch, mirroring other archs behaviour, adds the CPU idle call to the architectural arch_cpu_idle implementation for arm64. Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2013-12-16arm64: enable generic clockevent broadcastLorenzo Pieralisi
On platforms with power management capabilities, timers that are shut down when a CPU enters deep C-states must be emulated using an always-on timer and a timer IPI to relay the timer IRQ to target CPUs on an SMP system. This patch enables the generic clockevents broadcast infrastructure for arm64, by providing the required Kconfig entries and adding the timer IPI infrastructure. Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2013-12-16arm64: kernel: implement HW breakpoints CPU PM notifierLorenzo Pieralisi
When a CPU is shutdown either through CPU idle or suspend to RAM, the content of HW breakpoint registers must be reset or restored to proper values when CPU resume from low power states. This patch adds debug register restore operations to the HW breakpoint control function and implements a CPU PM notifier that allows to restore the content of HW breakpoint registers to allow proper suspend/resume operations. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2013-12-16arm64: kernel: refactor code to install/uninstall breakpointsLorenzo Pieralisi
Most of the code executed to install and uninstall breakpoints is common and can be factored out in a function that through a runtime operations type provides the requested implementation. This patch creates a common function that can be used to install/uninstall breakpoints and defines the set of operations that can be carried out through it. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2013-12-16arm64: kernel: implement fpsimd CPU PM notifierLorenzo Pieralisi
When a CPU enters a low power state, its FP register content is lost. This patch adds a notifier to save the FP context on CPU shutdown and restore it on CPU resume. The context is saved and restored only if the suspending thread is not a kernel thread, mirroring the current context switch behaviour. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2013-12-16arm64: kernel: cpu_{suspend/resume} implementationLorenzo Pieralisi
Kernel subsystems like CPU idle and suspend to RAM require a generic mechanism to suspend a processor, save its context and put it into a quiescent state. The cpu_{suspend}/{resume} implementation provides such a framework through a kernel interface allowing to save/restore registers, flush the context to DRAM and suspend/resume to/from low-power states where processor context may be lost. The CPU suspend implementation relies on the suspend protocol registered in CPU operations to carry out a suspend request after context is saved and flushed to DRAM. The cpu_suspend interface: int cpu_suspend(unsigned long arg); allows to pass an opaque parameter that is handed over to the suspend CPU operations back-end so that it can take action according to the semantics attached to it. The arg parameter allows suspend to RAM and CPU idle drivers to communicate to suspend protocol back-ends; it requires standardization so that the interface can be reused seamlessly across systems, paving the way for generic drivers. Context memory is allocated on the stack, whose address is stashed in a per-cpu variable to keep track of it and passed to core functions that save/restore the registers required by the architecture. Even though, upon successful execution, the cpu_suspend function shuts down the suspending processor, the warm boot resume mechanism, based on the cpu_resume function, makes the resume path operate as a cpu_suspend function return, so that cpu_suspend can be treated as a C function by the caller, which simplifies coding the PM drivers that rely on the cpu_suspend API. Upon context save, the minimal amount of memory is flushed to DRAM so that it can be retrieved when the MMU is off and caches are not searched. The suspend CPU operation, depending on the required operations (eg CPU vs Cluster shutdown) is in charge of flushing the cache hierarchy either implicitly (by calling firmware implementations like PSCI) or explicitly by executing the required cache maintainance functions. Debug exceptions are disabled during cpu_{suspend}/{resume} operations so that debug registers can be saved and restored properly preventing preemption from debug agents enabled in the kernel. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>