kernel.git/arch/um/include/asm/Kbuild, branch linux-5.16.y

um: add a UML specific futex implementation

2021-06-17T20:01:45Z

The generic asm futex implementation emulates atomic access to memory by doing a get_user followed by put_user. These translate to two mapping operations on UML with paging enabled in the meantime. This, in turn may end up changing interrupts, invoking the signal loop, etc. This replaces the generic implementation by a mapping followed by an operation on the mapped segment. Signed-off-by: Anton Ivanov Signed-off-by: Richard Weinberger

um: add PCI over virtio emulation driver

2021-06-17T19:45:43Z

To support testing of PCI/PCIe drivers in UML, add a PCI bus support driver. This driver uses virtio, which in UML is really just vhost-user, to talk to devices, and adds the devices to the virtual PCI bus in the system. Since virtio already allows DMA/bus mastering this really isn't all that hard, of course we need the logic_iomem infrastructure that was added by a previous patch. The protocol to talk to the device is has a few fairly simple messages for reading to/writing from config and IO spaces, and messages for the device to send the various interrupts (INT#, MSI/MSI-X and while suspended PME#). Note that currently no offical virtio device ID is assigned for this protocol, as a consequence this patch requires defining it in the Kconfig, with a default that makes the driver refuse to work at all. Finally, in order to add support for MSI/MSI-X interrupts, some small changes are needed in the UML IRQ code, it needs to have more interrupts, changing NR_IRQS from 64 to 128 if this driver is enabled, but not actually use them for anything so that the generic IRQ domain/MSI infrastructure can allocate IRQ numbers. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: allow disabling NO_IOMEM

2021-06-17T19:44:50Z

Adjust the kconfig a little to allow disabling NO_IOMEM in UML. To make an "allyesconfig" with CONFIG_NO_IOMEM=n build, adjust a few Kconfig things elsewhere and add dummy asm/fb.h and asm/vga.h files. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

Merge tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-02-25T00:32:23Z

Pull x86 irq entry updates from Thomas Gleixner: "The irq stack switching was moved out of the ASM entry code in course of the entry code consolidation. It ended up being suboptimal in various ways. This reworks the X86 irq stack handling: - Make the stack switching inline so the stackpointer manipulation is not longer at an easy to find place. - Get rid of the unnecessary indirect call. - Avoid the double stack switching in interrupt return and reuse the interrupt stack for softirq handling. - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused about the stack pointer manipulation" * tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix stack-swizzle for FRAME_POINTER=y um: Enforce the usage of asm-generic/softirq_stack.h x86/softirq/64: Inline do_softirq_own_stack() softirq: Move do_softirq_own_stack() to generic asm header softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK x86/softirq: Remove indirection in do_softirq_own_stack() x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall x86/entry: Convert device interrupts to inline stack switching x86/entry: Convert system vectors to irq stack macro x86/irq: Provide macro for inlining irq stack switching x86/apic: Split out spurious handling code x86/irq/64: Adjust the per CPU irq stack pointer by 8 x86/irq: Sanitize irq stack tracking x86/entry: Fix instrumentation annotation

um: Enforce the usage of asm-generic/softirq_stack.h

2021-02-16T09:23:14Z

The recent rework of the X86 irq stack switching mechanism broke UM as UM pulls in the X86 specific variant of softirq_stack.h. Enforce the usage of the asm-generic variant. Fixes: 72f40a2823d6 ("x86/softirq/64: Inline do_softirq_own_stack()") Reported-by: Guenter Roeck Signed-off-by: Thomas Gleixner Cc: Richard Weinberger

um: remove process stub VMA

2021-02-12T20:37:38Z

This mostly reverts the old commit 3963333fe676 ("uml: cover stubs with a VMA") which had added a VMA to the existing PTEs. However, there's no real reason to have the PTEs in the first place and the VMA cannot be 'fixed' in place, which leads to bugs that userspace could try to unmap them and be forcefully killed, or such. Also, there's a bit of an ugly hole in userspace's address space. Simplify all this: just install the stub code/page at the top of the (inner) address space, i.e. put it just above TASK_SIZE. The pages are simply hard-coded to be mapped in the userspace process we use to implement an mm context, and they're out of reach of the inner mmap/munmap/mprotect etc. since they're above TASK_SIZE. Getting rid of the VMA also makes vma_merge() no longer hit one of the VM_WARN_ON()s there because we installed a VMA while the code assumes the stack VMA is the first one. It also removes a lockdep warning about mmap_sem usage since we no longer have uml_setup_stubs() and thus no longer need to do any manipulation that would require mmap_sem in activate_mm(). Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

mm: Remove arch_remap() and mm-arch-hooks.h

2021-02-12T20:27:43Z

powerpc was the last provider of arch_remap() and the last user of mm-arch-hooks.h. Since commit 526a9c4a7234 ("powerpc/vdso: Provide vdso_remap()"), arch_remap() hence mm-arch-hooks.h are not used anymore. Remove them. Signed-off-by: Christophe Leroy Signed-off-by: Richard Weinberger

kbuild: preprocess module linker script

2020-09-24T15:36:41Z

There was a request to preprocess the module linker script like we do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512) The difference between vmlinux.lds and module.lds is that the latter is needed for external module builds, thus must be cleaned up by 'make mrproper' instead of 'make clean'. Also, it must be created by 'make modules_prepare'. You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by 'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to arch/$(SRCARCH)/include/asm/module.lds.h, which is included from scripts/module.lds.S. scripts/module.lds is fine because 'make clean' keeps all the build artifacts under scripts/. You can add arch-specific sections in . Signed-off-by: Masahiro Yamada Tested-by: Jessica Yu Acked-by: Will Deacon Acked-by: Geert Uytterhoeven Acked-by: Palmer Dabbelt Reviewed-by: Kees Cook Acked-by: Jessica Yu

um: Implement ndelay/udelay in time-travel mode

2020-03-29T21:29:52Z

In external or inf-cpu time-travel mode, ndelay/udelay currently just waste CPU time since the simulation time doesn't advance. Implement them properly in this case. Note that the "if (time_travel_mode == ...)" parts compile out if CONFIG_UML_TIME_TRAVEL_SUPPORT isn't set, time_travel_mode is defined to TT_MODE_OFF in that case. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: Fix time-travel=inf-cpu with xor/raid6

2020-01-19T21:42:06Z

Today, I erroneously built a time-travel configuration with btrfs enabled, and noticed it cannot boot in time-travel=inf-cpu mode, both xor and raid6 speed measurement gets stuck. For xor, work around it by picking the first algorithm if inf-cpu mode is enabled. For raid6, I didn't find such a workaround, so disallow enabling time-travel mode if RAID6_PQ_BENCHMARK is enabled. With this, and RAID6_PQ_BENCHMARK disabled, I can boot a kernel that has btrfs enabled in time-travel=inf-cpu mode. Signed-off-by: Johannes Berg Acked-by: Anton Ivanov Signed-off-by: Richard Weinberger