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2021-12-01MIPS: loongson64: fix FTLB configurationHuang Pei1-2/+2
[ Upstream commit 7db5e9e9e5e6c10d7d26f8df7f8fd8841cb15ee7 ] It turns out that 'decode_configs' -> 'set_ftlb_enable' is called under c->cputype unset, which leaves FTLB disabled on BOTH 3A2000 and 3A3000 Fix it by calling "decode_configs" after c->cputype is initialized Fixes: da1bd29742b1 ("MIPS: Loongson64: Probe CPU features via CPUCFG") Signed-off-by: Huang Pei <huangpei@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18mips: cm: Convert to bitfield API to fix out-of-bounds accessGeert Uytterhoeven1-11/+10
[ Upstream commit 18b8f5b6fc53d097cadb94a93d8d6566ba88e389 ] mips_cm_error_report() extracts the cause and other cause from the error register using shifts. This works fine for the former, as it is stored in the top bits, and the shift will thus remove all non-related bits. However, the latter is stored in the bottom bits, hence thus needs masking to get rid of non-related bits. Without such masking, using it as an index into the cm2_causes[] array will lead to an out-of-bounds access, probably causing a crash. Fix this by using FIELD_GET() instead. Bite the bullet and convert all MIPS CM handling to the bitfield API, to improve readability and safety. Fixes: 3885c2b463f6a236 ("MIPS: CM: Add support for reporting CM cache errors") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULTEric W. Biederman2-11/+2
commit 95bf9d646c3c3f95cb0be7e703b371db8da5be68 upstream. When an instruction to save or restore a register from the stack fails in _save_fp_context or _restore_fp_context return with -EFAULT. This change was made to r2300_fpu.S[1] but it looks like it got lost with the introduction of EX2[2]. This is also what the other implementation of _save_fp_context and _restore_fp_context in r4k_fpu.S does, and what is needed for the callers to be able to handle the error. Furthermore calling do_exit(SIGSEGV) from bad_stack is wrong because it does not terminate the entire process it just terminates a single thread. As the changed code was the only caller of arch/mips/kernel/syscall.c:bad_stack remove the problematic and now unused helper function. Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Maciej Rozycki <macro@orcam.me.uk> Cc: linux-mips@vger.kernel.org [1] 35938a00ba86 ("MIPS: Fix ISA I FP sigcontext access violation handling") [2] f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout") Cc: stable@vger.kernel.org Fixes: f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout") Acked-by: Maciej W. Rozycki <macro@orcam.me.uk> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Link: https://lkml.kernel.org/r/20211020174406.17889-5-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-26drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()Thomas Gleixner1-5/+2
[ Upstream commit 4b92d4add5f6dcf21275185c997d6ecb800054cd ] DEFINE_SMP_CALL_CACHE_FUNCTION() was usefel before the CPU hotplug rework to ensure that the cache related functions are called on the upcoming CPU because the notifier itself could run on any online CPU. The hotplug state machine guarantees that the callbacks are invoked on the upcoming CPU. So there is no need to have this SMP function call obfuscation. That indirection was missed when the hotplug notifiers were converted. This also solves the problem of ARM64 init_cache_level() invoking ACPI functions which take a semaphore in that context. That's invalid as SMP function calls run with interrupts disabled. Running it just from the callback in context of the CPU hotplug thread solves this. Fixes: 8571890e1513 ("arm64: Add support for ACPI based firmware tables") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Will Deacon <will@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/871r69ersb.ffs@tglx Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19MIPS: cpu-probe: Fix FPU detection on Ingenic JZ4760(B)Paul Cercueil1-0/+5
[ Upstream commit fc52f92a653215fbd6bc522ac5311857b335e589 ] Ingenic JZ4760 and JZ4760B do have a FPU, but the config registers don't report it. Force the FPU detection in case the processor ID match the JZ4760(B) one. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14sched/core: Initialize the idle task with preemption disabledValentin Schneider1-1/+0
[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ] As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-19MIPS: Loongson64: Use _CACHE_UNCACHED instead of _CACHE_UNCACHED_ACCELERATEDTiezhu Yang1-3/+0
[ Upstream commit 5e65c52ec716af6e8f51dacdaeb4a4d872249af1 ] Loongson64 processors have a writecombine issue that maybe failed to write back framebuffer used with ATI Radeon or AMD GPU at times, after commit 8a08e50cee66 ("drm: Permit video-buffers writecombine mapping for MIPS"), there exists some errors such as blurred screen and lockup, and so on. [ 60.958721] radeon 0000:03:00.0: ring 0 stalled for more than 10079msec [ 60.965315] radeon 0000:03:00.0: GPU lockup (current fence id 0x0000000000000112 last fence id 0x000000000000011d on ring 0) [ 60.976525] radeon 0000:03:00.0: ring 3 stalled for more than 10086msec [ 60.983156] radeon 0000:03:00.0: GPU lockup (current fence id 0x0000000000000374 last fence id 0x00000000000003a8 on ring 3) As discussed earlier [1], it might be better to disable writecombine on the CPU detection side because the root cause is unknown now. Actually, this patch is a temporary solution to just make it work well, it is not a proper and final solution, I hope someone will have a better solution to fix this issue in the future. [1] https://lore.kernel.org/patchwork/patch/1285542/ Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04MIPS: Ingenic: Disable HPTLB for D0 XBurst CPUs tooPaul Cercueil1-7/+8
commit a5360958a3cd1d876aae1f504ae014658513e1af upstream. The JZ4760 has the HPTLB as well, but has a XBurst CPU with a D0 CPUID. Disable the HPTLB for all XBurst CPUs with a D0 CPUID. In the case where there is no HPTLB (e.g. for older SoCs), this won't have any side effect. Fixes: b02efeb05699 ("MIPS: Ingenic: Disable abandoned HPTLB function.") Cc: <stable@vger.kernel.org> # 5.4 Signed-off-by: Paul Cercueil <paul@crapouillou.net> Reviewed-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04MIPS: properly stop .eh_frame generationAlexander Lobakin1-1/+0
[ Upstream commit 894ef530012fb5078466efdfb2c15d8b2f1565cd ] Commit 866b6a89c6d1 ("MIPS: Add DWARF unwinding to assembly") added -fno-asynchronous-unwind-tables to KBUILD_CFLAGS to prevent compiler from emitting .eh_frame symbols. However, as MIPS heavily uses CFI, that's not enough. Use the approach taken for x86 (as it also uses CFI) and explicitly put CFI symbols into the .debug_frame section (except for VDSO). This allows us to drop .eh_frame from DISCARDS as it's no longer being generated. Fixes: 866b6a89c6d1 ("MIPS: Add DWARF unwinding to assembly") Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Alexander Lobakin <alobakin@pm.me> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() sectionAlexander Lobakin1-0/+1
commit 8ac7c87acdcac156670f9920c8acbd84308ff4b1 upstream. MIPS uses its own declaration of rwdata, and thus it should be kept in sync with the asm-generic one. Currently PAGE_ALIGNED_DATA() is missing from the linker script, which emits the following ld warnings: mips-alpine-linux-musl-ld: warning: orphan section `.data..page_aligned' from `arch/mips/kernel/vdso.o' being placed in section `.data..page_aligned' mips-alpine-linux-musl-ld: warning: orphan section `.data..page_aligned' from `arch/mips/vdso/vdso-image.o' being placed in section `.data..page_aligned' Add the necessary declaration, so the mentioned structures will be placed in vmlinux as intended: ffffffff80630580 D __end_once ffffffff80630580 D __start___dyndbg ffffffff80630580 D __start_once ffffffff80630580 D __stop___dyndbg ffffffff80634000 d mips_vdso_data ffffffff80638000 d vdso_data ffffffff80638580 D _gp ffffffff8063c000 T __init_begin ffffffff8063c000 D _edata ffffffff8063c000 T _sinittext -> ffffffff805a4000 D __end_init_task ffffffff805a4000 D __nosave_begin ffffffff805a4000 D __nosave_end ffffffff805a4000 d mips_vdso_data ffffffff805a8000 d vdso_data ffffffff805ac000 D mmlist_lock ffffffff805ac080 D tasklist_lock Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Signed-off-by: Alexander Lobakin <alobakin@pm.me> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19MIPS: relocatable: fix possible boot hangup with KASLR enabledAlexander Lobakin1-2/+8
commit 69e976831cd53f9ba304fd20305b2025ecc78eab upstream. LLVM-built Linux triggered a boot hangup with KASLR enabled. arch/mips/kernel/relocate.c:get_random_boot() uses linux_banner, which is a string constant, as a random seed, but accesses it as an array of unsigned long (in rotate_xor()). When the address of linux_banner is not aligned to sizeof(long), such access emits unaligned access exception and hangs the kernel. Use PTR_ALIGN() to align input address to sizeof(long) and also align down the input length to prevent possible access-beyond-end. Fixes: 405bc8fd12f5 ("MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE") Cc: stable@vger.kernel.org # 4.7+ Signed-off-by: Alexander Lobakin <alobakin@pm.me> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19MIPS: Fix malformed NT_FILE and NT_SIGINFO in 32bit coredumpsAl Viro2-0/+14
commit 698222457465ce343443be81c5512edda86e5914 upstream. Patches that introduced NT_FILE and NT_SIGINFO notes back in 2012 had taken care of native (fs/binfmt_elf.c) and compat (fs/compat_binfmt_elf.c) coredumps; unfortunately, compat on mips (which does not go through the usual compat_binfmt_elf.c) had not been noticed. As the result, both N32 and O32 coredumps on 64bit mips kernels have those sections malformed enough to confuse the living hell out of all gdb and readelf versions (up to and including the tip of binutils-gdb.git). Longer term solution is to make both O32 and N32 compat use the regular compat_binfmt_elf.c, but that's too much for backports. The minimal solution is to do in arch/mips/kernel/binfmt_elf[on]32.c the same thing those patches have done in fs/compat_binfmt_elf.c Cc: stable@kernel.org # v3.7+ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30MIPS: Don't round up kernel sections size for memblock_add()Alexander Sverdlin1-2/+2
[ Upstream commit d121f125af22a16f0f679293756d28a9691fa46d ] Linux doesn't own the memory immediately after the kernel image. On Octeon bootloader places a shared structure right close after the kernel _end, refer to "struct cvmx_bootinfo *octeon_bootinfo" in cavium-octeon/setup.c. If check_kernel_sections_mem() rounds the PFNs up, first memblock_alloc() inside early_init_dt_alloc_memory_arch() <= device_tree_init() returns memory block overlapping with the above octeon_bootinfo structure, which is being overwritten afterwards. Fixes: a94e4f24ec83 ("MIPS: init: Drop boot_mem_map") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-29Merge tag 'locking-urgent-2020-11-29' of ↵Linus Torvalds1-6/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "Two more places which invoke tracing from RCU disabled regions in the idle path. Similar to the entry path the low level idle functions have to be non-instrumentable" * tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: intel_idle: Fix intel_idle() vs tracing sched/idle: Fix arch_cpu_idle() vs tracing
2020-11-24sched/idle: Fix arch_cpu_idle() vs tracingPeter Zijlstra1-6/+6
We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU. Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry. (XXX: we really should change arch_cpu_idle() to not return with interrupts enabled) Reported-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
2020-11-17MIPS: kernel: Fix for_each_memblock conversionThomas Bogendoerfer1-3/+3
The loop over all memblocks works with PFNs and not physical addresses, so we need for_each_mem_pfn_range(). Fixes: b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
2020-10-25treewide: Convert macro and uses of __section(foo) to __section("foo")Joe Perches1-1/+1
Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-23Merge tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+0
Pull arch task_work cleanups from Jens Axboe: "Two cleanups that don't fit other categories: - Finally get the task_work_add() cleanup done properly, so we don't have random 0/1/false/true/TWA_SIGNAL confusing use cases. Updates all callers, and also fixes up the documentation for task_work_add(). - While working on some TIF related changes for 5.11, this TIF_NOTIFY_RESUME cleanup fell out of that. Remove some arch duplication for how that is handled" * tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block: task_work: cleanup notification modes tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
2020-10-18mm/madvise: introduce process_madvise() syscall: an external memory hinting APIMinchan Kim3-0/+3
There is usecase that System Management Software(SMS) want to give a memory hint like MADV_[COLD|PAGEEOUT] to other processes and in the case of Android, it is the ActivityManagerService. The information required to make the reclaim decision is not known to the app. Instead, it is known to the centralized userspace daemon(ActivityManagerService), and that daemon must be able to initiate reclaim on its own without any app involvement. To solve the issue, this patch introduces a new syscall process_madvise(2). It uses pidfd of an external process to give the hint. It also supports vector address range because Android app has thousands of vmas due to zygote so it's totally waste of CPU and power if we should call the syscall one by one for each vma.(With testing 2000-vma syscall vs 1-vector syscall, it showed 15% performance improvement. I think it would be bigger in real practice because the testing ran very cache friendly environment). Another potential use case for the vector range is to amortize the cost ofTLB shootdowns for multiple ranges when using MADV_DONTNEED; this could benefit users like TCP receive zerocopy and malloc implementations. In future, we could find more usecases for other advises so let's make it happens as API since we introduce a new syscall at this moment. With that, existing madvise(2) user could replace it with process_madvise(2) with their own pid if they want to have batch address ranges support feature. ince it could affect other process's address range, only privileged process(PTRACE_MODE_ATTACH_FSCREDS) or something else(e.g., being the same UID) gives it the right to ptrace the process could use it successfully. The flag argument is reserved for future use if we need to extend the API. I think supporting all hints madvise has/will supported/support to process_madvise is rather risky. Because we are not sure all hints make sense from external process and implementation for the hint may rely on the caller being in the current context so it could be error-prone. Thus, I just limited hints as MADV_[COLD|PAGEOUT] in this patch. If someone want to add other hints, we could hear the usecase and review it for each hint. It's safer for maintenance rather than introducing a buggy syscall but hard to fix it later. So finally, the API is as follows, ssize_t process_madvise(int pidfd, const struct iovec *iovec, unsigned long vlen, int advice, unsigned int flags); DESCRIPTION The process_madvise() system call is used to give advice or directions to the kernel about the address ranges from external process as well as local process. It provides the advice to address ranges of process described by iovec and vlen. The goal of such advice is to improve system or application performance. The pidfd selects the process referred to by the PID file descriptor specified in pidfd. (See pidofd_open(2) for further information) The pointer iovec points to an array of iovec structures, defined in <sys/uio.h> as: struct iovec { void *iov_base; /* starting address */ size_t iov_len; /* number of bytes to be advised */ }; The iovec describes address ranges beginning at address(iov_base) and with size length of bytes(iov_len). The vlen represents the number of elements in iovec. The advice is indicated in the advice argument, which is one of the following at this moment if the target process specified by pidfd is external. MADV_COLD MADV_PAGEOUT Permission to provide a hint to external process is governed by a ptrace access mode PTRACE_MODE_ATTACH_FSCREDS check; see ptrace(2). The process_madvise supports every advice madvise(2) has if target process is in same thread group with calling process so user could use process_madvise(2) to extend existing madvise(2) to support vector address ranges. RETURN VALUE On success, process_madvise() returns the number of bytes advised. This return value may be less than the total number of requested bytes, if an error occurred. The caller should check return value to determine whether a partial advice occurred. FAQ: Q.1 - Why does any external entity have better knowledge? Quote from Sandeep "For Android, every application (including the special SystemServer) are forked from Zygote. The reason of course is to share as many libraries and classes between the two as possible to benefit from the preloading during boot. After applications start, (almost) all of the APIs end up calling into this SystemServer process over IPC (binder) and back to the application. In a fully running system, the SystemServer monitors every single process periodically to calculate their PSS / RSS and also decides which process is "important" to the user for interactivity. So, because of how these processes start _and_ the fact that the SystemServer is looping to monitor each process, it does tend to *know* which address range of the application is not used / useful. Besides, we can never rely on applications to clean things up themselves. We've had the "hey app1, the system is low on memory, please trim your memory usage down" notifications for a long time[1]. They rely on applications honoring the broadcasts and very few do. So, if we want to avoid the inevitable killing of the application and restarting it, some way to be able to tell the OS about unimportant memory in these applications will be useful. - ssp Q.2 - How to guarantee the race(i.e., object validation) between when giving a hint from an external process and get the hint from the target process? process_madvise operates on the target process's address space as it exists at the instant that process_madvise is called. If the space target process can run between the time the process_madvise process inspects the target process address space and the time that process_madvise is actually called, process_madvise may operate on memory regions that the calling process does not expect. It's the responsibility of the process calling process_madvise to close this race condition. For example, the calling process can suspend the target process with ptrace, SIGSTOP, or the freezer cgroup so that it doesn't have an opportunity to change its own address space before process_madvise is called. Another option is to operate on memory regions that the caller knows a priori will be unchanged in the target process. Yet another option is to accept the race for certain process_madvise calls after reasoning that mistargeting will do no harm. The suggested API itself does not provide synchronization. It also apply other APIs like move_pages, process_vm_write. The race isn't really a problem though. Why is it so wrong to require that callers do their own synchronization in some manner? Nobody objects to write(2) merely because it's possible for two processes to open the same file and clobber each other's writes --- instead, we tell people to use flock or something. Think about mmap. It never guarantees newly allocated address space is still valid when the user tries to access it because other threads could unmap the memory right before. That's where we need synchronization by using other API or design from userside. It shouldn't be part of API itself. If someone needs more fine-grained synchronization rather than process level, there were two ideas suggested - cookie[2] and anon-fd[3]. Both are applicable via using last reserved argument of the API but I don't think it's necessary right now since we have already ways to prevent the race so don't want to add additional complexity with more fine-grained optimization model. To make the API extend, it reserved an unsigned long as last argument so we could support it in future if someone really needs it. Q.3 - Why doesn't ptrace work? Injecting an madvise in the target process using ptrace would not work for us because such injected madvise would have to be executed by the target process, which means that process would have to be runnable and that creates the risk of the abovementioned race and hinting a wrong VMA. Furthermore, we want to act the hint in caller's context, not the callee's, because the callee is usually limited in cpuset/cgroups or even freezed state so they can't act by themselves quick enough, which causes more thrashing/kill. It doesn't work if the target process are ptraced(e.g., strace, debugger, minidump) because a process can have at most one ptracer. [1] https://developer.android.com/topic/performance/memory" [2] process_getinfo for getting the cookie which is updated whenever vma of process address layout are changed - Daniel Colascione - https://lore.kernel.org/lkml/20190520035254.57579-1-minchan@kernel.org/T/#m7694416fd179b2066a2c62b5b139b14e3894e224 [3] anonymous fd which is used for the object(i.e., address range) validation - Michal Hocko - https://lore.kernel.org/lkml/20200120112722.GY18451@dhcp22.suse.cz/ [minchan@kernel.org: fix process_madvise build break for arm64] Link: http://lkml.kernel.org/r/20200303145756.GA219683@google.com [minchan@kernel.org: fix build error for mips of process_madvise] Link: http://lkml.kernel.org/r/20200508052517.GA197378@google.com [akpm@linux-foundation.org: fix patch ordering issue] [akpm@linux-foundation.org: fix arm64 whoops] [minchan@kernel.org: make process_madvise() vlen arg have type size_t, per Florian] [akpm@linux-foundation.org: fix i386 build] [sfr@canb.auug.org.au: fix syscall numbering] Link: https://lkml.kernel.org/r/20200905142639.49fc3f1a@canb.auug.org.au [sfr@canb.auug.org.au: madvise.c needs compat.h] Link: https://lkml.kernel.org/r/20200908204547.285646b4@canb.auug.org.au [minchan@kernel.org: fix mips build] Link: https://lkml.kernel.org/r/20200909173655.GC2435453@google.com [yuehaibing@huawei.com: remove duplicate header which is included twice] Link: https://lkml.kernel.org/r/20200915121550.30584-1-yuehaibing@huawei.com [minchan@kernel.org: do not use helper functions for process_madvise] Link: https://lkml.kernel.org/r/20200921175539.GB387368@google.com [akpm@linux-foundation.org: pidfd_get_pid() gained an argument] [sfr@canb.auug.org.au: fix up for "iov_iter: transparently handle compat iovecs in import_iovec"] Link: https://lkml.kernel.org/r/20200928212542.468e1fef@canb.auug.org.au Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <christian@brauner.io> Cc: Daniel Colascione <dancol@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Dias <joaodias@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksandr Natalenko <oleksandr@redhat.com> Cc: Sandeep Patil <sspatil@google.com> Cc: SeongJae Park <sj38.park@gmail.com> Cc: SeongJae Park <sjpark@amazon.de> Cc: Shakeel Butt <shakeelb@google.com> Cc: Sonny Rao <sonnyrao@google.com> Cc: Tim Murray <timmurray@google.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Florian Weimer <fw@deneb.enyo.de> Cc: <linux-man@vger.kernel.org> Link: http://lkml.kernel.org/r/20200302193630.68771-3-minchan@kernel.org Link: http://lkml.kernel.org/r/20200508183320.GA125527@google.com Link: http://lkml.kernel.org/r/20200622192900.22757-4-minchan@kernel.org Link: https://lkml.kernel.org/r/20200901000633.1920247-4-minchan@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-17tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()Jens Axboe1-1/+0
All the callers currently do this, clean it up and move the clearing into tracehook_notify_resume() instead. Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-16Merge tag 'mips_5.10' of ↵Linus Torvalds15-419/+612
git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux Pull MIPS updates from Thomas Bogendoerfer: - removed support for PNX833x alias NXT_STB22x - included Ingenic SoC support into generic MIPS kernels - added support for new Ingenic SoCs - converted workaround selection to use Kconfig - replaced old boot mem functions by memblock_* - enabled COP2 usage in kernel for Loongson64 to make use of 16byte load/stores possible - cleanups and fixes * tag 'mips_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (92 commits) MIPS: DEC: Restore bootmem reservation for firmware working memory area MIPS: dec: fix section mismatch bcm963xx_tag.h: fix duplicated word mips: ralink: enable zboot support MIPS: ingenic: Remove CPU_SUPPORTS_HUGEPAGES MIPS: cpu-probe: remove MIPS_CPU_BP_GHIST option bit MIPS: cpu-probe: introduce exclusive R3k CPU probe MIPS: cpu-probe: move fpu probing/handling into its own file MIPS: replace add_memory_region with memblock MIPS: Loongson64: Clean up numa.c MIPS: Loongson64: Select SMP in Kconfig to avoid build error mips: octeon: Add Ubiquiti E200 and E220 boards MIPS: SGI-IP28: disable use of ll/sc in kernel MIPS: tx49xx: move tx4939_add_memory_regions into only user MIPS: pgtable: Remove used PAGE_USERIO define MIPS: alchemy: Share prom_init implementation MIPS: alchemy: Fix build breakage, if TOUCHSCREEN_WM97XX is disabled MIPS: process: include exec.h header in process.c MIPS: process: Add prototype for function arch_dup_task_struct MIPS: idle: Add prototype for function check_wait ...
2020-10-15Merge tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds1-1/+1
Pull dma-mapping updates from Christoph Hellwig: - rework the non-coherent DMA allocator - move private definitions out of <linux/dma-mapping.h> - lower CMA_ALIGNMENT (Paul Cercueil) - remove the omap1 dma address translation in favor of the common code - make dma-direct aware of multiple dma offset ranges (Jim Quinlan) - support per-node DMA CMA areas (Barry Song) - increase the default seg boundary limit (Nicolin Chen) - misc fixes (Robin Murphy, Thomas Tai, Xu Wang) - various cleanups * tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping: (63 commits) ARM/ixp4xx: add a missing include of dma-map-ops.h dma-direct: simplify the DMA_ATTR_NO_KERNEL_MAPPING handling dma-direct: factor out a dma_direct_alloc_from_pool helper dma-direct check for highmem pages in dma_direct_alloc_pages dma-mapping: merge <linux/dma-noncoherent.h> into <linux/dma-map-ops.h> dma-mapping: move large parts of <linux/dma-direct.h> to kernel/dma dma-mapping: move dma-debug.h to kernel/dma/ dma-mapping: remove <asm/dma-contiguous.h> dma-mapping: merge <linux/dma-contiguous.h> into <linux/dma-map-ops.h> dma-contiguous: remove dma_contiguous_set_default dma-contiguous: remove dev_set_cma_area dma-contiguous: remove dma_declare_contiguous dma-mapping: split <linux/dma-mapping.h> cma: decrease CMA_ALIGNMENT lower limit to 2 firewire-ohci: use dma_alloc_pages dma-iommu: implement ->alloc_noncoherent dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods dma-mapping: add a new dma_alloc_pages API dma-mapping: remove dma_cache_sync 53c700: convert to dma_alloc_noncoherent ...
2020-10-13arch, drivers: replace for_each_membock() with for_each_mem_range()Mike Rapoport1-16/+15
There are several occurrences of the following pattern: for_each_memblock(memory, reg) { start = __pfn_to_phys(memblock_region_memory_base_pfn(reg); end = __pfn_to_phys(memblock_region_memory_end_pfn(reg)); /* do something with start and end */ } Using for_each_mem_range() iterator is more appropriate in such cases and allows simpler and cleaner code. [akpm@linux-foundation.org: fix arch/arm/mm/pmsa-v7.c build] [rppt@linux.ibm.com: mips: fix cavium-octeon build caused by memblock refactoring] Link: http://lkml.kernel.org/r/20200827124549.GD167163@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Axtens <dja@axtens.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Emil Renner Berthing <kernel@esmil.dk> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20200818151634.14343-13-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-12Merge branch 'compat.mount' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull compat mount cleanups from Al Viro: "The last remnants of mount(2) compat buried by Christoph. Buried into NFS, that is. Generally I'm less enthusiastic about "let's use in_compat_syscall() deep in call chain" kind of approach than Christoph seems to be, but in this case it's warranted - that had been an NFS-specific wart, hopefully not to be repeated in any other filesystems (read: any new filesystem introducing non-text mount options will get NAKed even if it doesn't mess the layout up). IOW, not worth trying to grow an infrastructure that would avoid that use of in_compat_syscall()..." * 'compat.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: remove compat_sys_mount fs,nfs: lift compat nfs4 mount data handling into the nfs code nfs: simplify nfs4_parse_monolithic
2020-10-12Merge branch 'work.iov_iter' of ↵Linus Torvalds2-10/+10
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull compat iovec cleanups from Al Viro: "Christoph's series around import_iovec() and compat variant thereof" * 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: security/keys: remove compat_keyctl_instantiate_key_iov mm: remove compat_process_vm_{readv,writev} fs: remove compat_sys_vmsplice fs: remove the compat readv/writev syscalls fs: remove various compat readv/writev helpers iov_iter: transparently handle compat iovecs in import_iovec iov_iter: refactor rw_copy_check_uvector and import_iovec iov_iter: move rw_copy_check_uvector() into lib/iov_iter.c compat.h: fix a spelling error in <linux/compat.h>
2020-10-12Merge tag 'perf-kprobes-2020-10-12' of ↵Linus Torvalds1-51/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf/kprobes updates from Ingo Molnar: "This prepares to unify the kretprobe trampoline handler and make kretprobe lockless (those patches are still work in progress)" * tag 'perf-kprobes-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kprobes: Fix to check probe enabled before disarm_kprobe_ftrace() kprobes: Make local functions static kprobes: Free kretprobe_instance with RCU callback kprobes: Remove NMI context check sparc: kprobes: Use generic kretprobe trampoline handler sh: kprobes: Use generic kretprobe trampoline handler s390: kprobes: Use generic kretprobe trampoline handler powerpc: kprobes: Use generic kretprobe trampoline handler parisc: kprobes: Use generic kretprobe trampoline handler mips: kprobes: Use generic kretprobe trampoline handler ia64: kprobes: Use generic kretprobe trampoline handler csky: kprobes: Use generic kretprobe trampoline handler arc: kprobes: Use generic kretprobe trampoline handler arm64: kprobes: Use generic kretprobe trampoline handler arm: kprobes: Use generic kretprobe trampoline handler x86/kprobes: Use generic kretprobe trampoline handler kprobes: Add generic kretprobe trampoline handler
2020-10-12Merge tag 'core-build-2020-10-12' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull orphan section checking from Ingo Molnar: "Orphan link sections were a long-standing source of obscure bugs, because the heuristics that various linkers & compilers use to handle them (include these bits into the output image vs discarding them silently) are both highly idiosyncratic and also version dependent. Instead of this historically problematic mess, this tree by Kees Cook (et al) adds build time asserts and build time warnings if there's any orphan section in the kernel or if a section is not sized as expected. And because we relied on so many silent assumptions in this area, fix a metric ton of dependencies and some outright bugs related to this, before we can finally enable the checks on the x86, ARM and ARM64 platforms" * tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/boot/compressed: Warn on orphan section placement x86/build: Warn on orphan section placement arm/boot: Warn on orphan section placement arm/build: Warn on orphan section placement arm64/build: Warn on orphan section placement x86/boot/compressed: Add missing debugging sections to output x86/boot/compressed: Remove, discard, or assert for unwanted sections x86/boot/compressed: Reorganize zero-size section asserts x86/build: Add asserts for unwanted sections x86/build: Enforce an empty .got.plt section x86/asm: Avoid generating unused kprobe sections arm/boot: Handle all sections explicitly arm/build: Assert for unwanted sections arm/build: Add missing sections arm/build: Explicitly keep .ARM.attributes sections arm/build: Refactor linker script headers arm64/build: Assert for unwanted sections arm64/build: Add missing DWARF sections arm64/build: Use common DISCARDS in linker script arm64/build: Remove .eh_frame* sections due to unwind tables ...
2020-10-12MIPS: cpu-probe: remove MIPS_CPU_BP_GHIST option bitThomas Bogendoerfer1-6/+4
MIPS_CPU_BP_GHIST is only set two times and more or less immediately used in cpu-probe.c itself. Remove this option to make room in options word. Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-10-12MIPS: cpu-probe: introduce exclusive R3k CPU probeThomas Bogendoerfer2-1/+178
Running a kernel on a R3k of machine definitly will never see one of the newer CPU cores. And since R3k system usually are low on memory we could save quite some kbytes: text data bss dec hex filename 15070 88 32 15190 3b56 arch/mips/kernel/cpu-probe.o 844 4 16 864 360 arch/mips/kernel/cpu-r3k-probe.o Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-10-12MIPS: cpu-probe: move fpu probing/handling into its own fileThomas Bogendoerfer4-324/+364
cpu-probe.c has grown when supporting more and more CPUs and there are use cases where probing for all the CPUs isn't useful like running on a R3k system. But still the fpu handling is nearly the same. For sharing put the fpu code into it's own file. Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-10-12MIPS: replace add_memory_region with memblockThomas Bogendoerfer2-69/+6
add_memory_region was the old interface for registering memory and was already changed to used memblock internaly. Replace it by directly calling memblock functions. Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-10-06dma-mapping: merge <linux/dma-contiguous.h> into <linux/dma-map-ops.h>Christoph Hellwig1-1/+1
Merge dma-contiguous.h into dma-map-ops.h, after removing the comment describing the contiguous allocator into kernel/dma/contigous.c. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-03mm: remove compat_process_vm_{readv,writev}Christoph Hellwig2-4/+4
Now that import_iovec handles compat iovecs, the native syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-03fs: remove compat_sys_vmspliceChristoph Hellwig2-2/+2
Now that import_iovec handles compat iovecs, the native vmsplice syscall can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-03fs: remove the compat readv/writev syscallsChristoph Hellwig2-4/+4
Now that import_iovec handles compat iovecs, the native readv and writev syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-09-30MIPS: process: include exec.h header in process.cPujin Shi1-0/+1
arch/mips/kernel/process.c:696:15: error: no previous prototype for 'arch_align_stack' [-Werror=missing-prototypes] Signed-off-by: Pujin Shi <shipujin.t@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-09-22fs: remove compat_sys_mountChristoph Hellwig2-2/+2
compat_sys_mount is identical to the regular sys_mount now, so remove it and use the native version everywhere. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-09-21MIPS: kexec: Add crashkernel=YM handlingYouling Tang1-3/+21
When the kernel crashkernel parameter is specified with just a size, we are supposed to allocate a region from RAM to store the crashkernel. However, MIPS merely reserves physical address zero with no checking that there is even RAM there. Fix this by lifting similar code from x86, importing it to MIPS with the MIPS specific parameters added. In the absence of any platform specific information, we allocate the crashkernel region from the first 512MB of physical memory (limited to CKSEG0 or KSEG0 address range). When X is not specified, crash_base defaults to 0 (crashkernel=YM@XM). E.g. without this patch: The environment as follows: [ 0.000000] MIPS: machine is loongson,loongson64c-4core-ls7a ... [ 0.000000] Kernel command line: root=/dev/sda2 crashkernel=96M ... The warning as follows: [ 0.000000] Invalid memory region reserved for crash kernel And the iomem as follows: 00200000-0effffff : System RAM 00200000-00b47f87 : Kernel code 00b47f88-00dfffff : Kernel data 00e60000-01f73c7f : Kernel bss 1a000000-1bffffff : pci@1a000000 ... With this patch: After increasing crash_base <= 0 handling. And the iomem as follows: 00200000-0effffff : System RAM 00200000-00b47f87 : Kernel code 00b47f88-00dfffff : Kernel data 00e60000-01f73c7f : Kernel bss 04000000-09ffffff : Crash kernel 1a000000-1bffffff : pci@1a000000 ... Signed-off-by: Youling Tang <tangyouling@loongson