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2025-01-30Merge tag 'uml-for-linus-6.14-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux Pull UML updates from Richard Weinberger: - hostfs: Convert to writepages - many cleanups: removal of dead macros, missing __init * tag 'uml-for-linus-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: um: Remove unused asm/archparam.h header um: Include missing headers in asm/pgtable.h hostfs: Convert to writepages um: rtc: use RTC time when calculating the alarm um: Remove unused user_context function um: Remove unused THREAD_NAME_LEN macro um: Remove unused PGD_BOUND macro um: Mark setup_env_path as __init um: Mark install_fatal_handler as __init um: Mark set_stklim as __init um: Mark get_top_address as __init um: Mark parse_cache_line as __init um: Mark parse_host_cpu_flags as __init um: Count iomem_size only once in physmem calculation um: Remove obsolete fixmap support um: Remove unused MODULES_LEN macro
2025-01-25mm: pgtable: introduce pagetable_dtor()Qi Zheng
The pagetable_p*_dtor() are exactly the same except for the handling of ptlock. If we make ptlock_free() handle the case where ptdesc->ptl is NULL and remove VM_BUG_ON_PAGE() from pmd_ptlock_free(), we can unify pagetable_p*_dtor() into one function. Let's introduce pagetable_dtor() to do this. Later, pagetable_dtor() will be moved to tlb_remove_ptdesc(), so that ptlock and page table pages can be freed together (regardless of whether RCU is used). This prevents the use-after-free problem where the ptlock is freed immediately but the page table pages is freed later via RCU. Link: https://lkml.kernel.org/r/47f44fff9dc68d9d9e9a0d6c036df275f820598a.1736317725.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13um: Include missing headers in asm/pgtable.hTiwei Bie
Formerly, asm/pgtable.h relied on the implicit inclusion of asm/page.h and linux/mm_types.h via asm/fixmap.h. With the removal of asm/fixmap.h, these headers need to be included explicitly in asm/pgtable.h now. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202501131814.E6CxjulL-lkp@intel.com/ Fixes: 5bfc4a3a0af3 ("um: Remove obsolete fixmap support") Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20250113153218.3331321-2-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2025-01-10um: Remove obsolete fixmap supportTiwei Bie
It was added to support highmem. But since the highmem support has been removed by commit a98a6d864d3b ("um: Remove broken highmem support"), it is no longer needed. Remove it to simplify the code. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128081939.2216246-3-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2025-01-10um: Remove unused MODULES_LEN macroTiwei Bie
It's not used anywhere. And its definition doesn't seem right. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241128081939.2216246-2-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-11-30Merge tag 'uml-for-linus-6.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux Pull UML updates from Richard Weinberger: - Lots of cleanups, mostly from Benjamin Berg and Tiwei Bie - Removal of unused code - Fix for sparse warnings - Cleanup around stub_exe() * tag 'uml-for-linus-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (68 commits) hostfs: Fix the NULL vs IS_ERR() bug for __filemap_get_folio() um: move thread info into task um: Always dump trace for specified task in show_stack um: vector: Do not use drvdata in release um: net: Do not use drvdata in release um: ubd: Do not use drvdata in release um: ubd: Initialize ubd's disk pointer in ubd_add um: virtio_uml: query the number of vqs if supported um: virtio_uml: fix call_fd IRQ allocation um: virtio_uml: send SET_MEM_TABLE message with the exact size um: remove broken double fault detection um: remove duplicate UM_NSEC_PER_SEC definition um: remove file sync for stub data um: always include kconfig.h and compiler-version.h um: set DONTDUMP and DONTFORK flags on KASAN shadow memory um: fix sparse warnings in signal code um: fix sparse warnings from regset refactor um: Remove double zero check um: fix stub exe build with CONFIG_GCOV um: Use os_set_pdeathsig helper in winch thread/process ...
2024-11-20Merge tag 'asm-generic-3.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic updates from Arnd Bergmann: "These are a number of unrelated cleanups, generally simplifying the architecture specific header files: - A series from Al Viro simplifies asm/vga.h, after it turns out that most of it can be generalized. - A series from Julian Vetter adds a common version of memcpy_{to,from}io() and memset_io() and changes most architectures to use that instead of their own implementation - A series from Niklas Schnelle concludes his work to make PC style inb()/outb() optional - Nicolas Pitre contributes improvements for the generic do_div() helper - Christoph Hellwig adds a generic version of page_to_phys() and phys_to_page(), replacing the slightly different architecture specific definitions. - Uwe Kleine-Koenig has a minor cleanup for ioctl definitions" * tag 'asm-generic-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (24 commits) empty include/asm-generic/vga.h sparc: get rid of asm/vga.h asm/vga.h: don't bother with scr_mem{cpy,move}v() unless we need to vt_buffer.h: get rid of dead code in default scr_...() instances tty: serial: export serial_8250_warn_need_ioport lib/iomem_copy: fix kerneldoc format style hexagon: simplify asm/io.h for !HAS_IOPORT loongarch: Use new fallback IO memcpy/memset csky: Use new fallback IO memcpy/memset arm64: Use new fallback IO memcpy/memset New implementation for IO memcpy and IO memset watchdog: Add HAS_IOPORT dependency for SBC8360 and SBC7240 __arch_xprod64(): make __always_inline when optimizing for performance ARM: div64: improve __arch_xprod_64() asm-generic/div64: optimize/simplify __div64_const32() lib/math/test_div64: add some edge cases relevant to __div64_const32() asm-generic: add an optional pfn_valid check to page_to_phys asm-generic: provide generic page_to_phys and phys_to_page implementations asm-generic/io.h: Remove I/O port accessors for HAS_IOPORT=n tty: serial: handle HAS_IOPORT dependencies ...
2024-11-12um: move thread info into taskBenjamin Berg
This selects the THREAD_INFO_IN_TASK option for UM and changes the way that the current task is discovered. This is trivial though, as UML already tracks the current task in cpu_tasks[] and this can be used to retrieve it. Also remove the signal handler code that copies the thread information into the IRQ stack. It is obsolete now, which also means that the mentioned race condition cannot happen anymore. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Reviewed-by: Hajime Tazaki <thehajime@gmail.com> Link: https://patch.msgid.link/20241111102910.46512-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-11-07um: remove broken double fault detectionBenjamin Berg
The show_stack function had some code to detect double faults. However, the logic is wrong and it would e.g. trigger if a WARNING happened inside an IRQ. Remove it without trying to add a new logic. The current behaviour, which will just fault repeatedly until the IRQ stack is used up and the host kills UML, seems to be good enough. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241103150506.1367695-5-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-11-07um: remove duplicate UM_NSEC_PER_SEC definitionBenjamin Berg
Just remove the first entry as there is a second later on. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241103150506.1367695-4-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-11-07um: remove file sync for stub dataBenjamin Berg
There is no need to sync the stub code to "disk" for the other process to see the correct memory. Drop the fsync there and remove the helper function. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241103150506.1367695-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-11-07um: always include kconfig.h and compiler-version.hBenjamin Berg
Since commit a95b37e20db9 ("kbuild: get <linux/compiler_types.h> out of <linux/kconfig.h>") we can safely include these files in userspace code. Doing so simplifies matters as options do not need to be exported via asm-offsets.h anymore. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241103150506.1367695-2-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-28asm-generic: provide generic page_to_phys and phys_to_page implementationsChristoph Hellwig
page_to_phys is duplicated by all architectures, and from some strange reason placed in <asm/io.h> where it doesn't fit at all. phys_to_page is only provided by a few architectures despite having a lot of open coded users. Provide generic versions in <asm-generic/memory_model.h> to make these helpers more easily usable. Note with this patch powerpc loses the CONFIG_DEBUG_VIRTUAL pfn_valid check. It will be added back in a generic version later. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-10-25um: Add os_set_pdeathsig helper functionTiwei Bie
This helper can be used to set the parent-death signal of the calling process to SIGKILL to ensure that the process will be killed if the UML kernel dies unexpectedly without proper cleanup. This helper will be used in the follow-up patches. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241024142828.2612828-2-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-23um: switch to regset API and depend on XSTATEBenjamin Berg
The PTRACE_GETREGSET API has now existed since Linux 2.6.33. The XSAVE CPU feature should also be sufficiently common to be able to rely on it. With this, define our internal FP state to be the hosts XSAVE data. Add discovery for the hosts XSAVE size and place the FP registers at the end of task_struct so that we can adjust the size at runtime. Next we can implement the regset API on top and update the signal handling as well as ptrace APIs to use them. Also switch coredump creation to use the regset API and finally set HAVE_ARCH_TRACEHOOK. This considerably improves the signal frames. Previously they might not have contained all the registers (i386) and also did not have the sizes and magic values set to the correct values to permit userspace to decode the frame. As a side effect, this will permit UML to run on hosts with newer CPU extensions (such as AMX) that need even more register state. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241023094120.4083426-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-23um: insert scheduler ticks when userspace does not yieldBenjamin Berg
In time-travel mode userspace can do a lot of work without any time passing. Unfortunately, this can result in OOM situations as the RCU core code will never be run. Work around this by keeping track of userspace processes that do not yield for a lot of operations. When this happens, insert a jiffie into the sched_clock clock to account time against the process and cause the bookkeeping to run. As sched_clock is used for tracing, it is useful to keep it in sync between the different VMs. As such, try to remove added ticks again when the actual clock ticks. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241010142537.1134685-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-23um: Rename _PAGE_NEWPAGE to _PAGE_NEEDSYNCTiwei Bie
The _PAGE_NEWPAGE bit does not really indicate that this is a new page, but rather whether this entry needs to be synced or not. Renaming it to _PAGE_NEEDSYNC will make it more clear how everything ties together. Suggested-by: Benjamin Berg <benjamin.berg@intel.com> Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241011102354.1682626-3-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-23um: Abandon the _PAGE_NEWPROT bitTiwei Bie
When a PTE is updated in the page table, the _PAGE_NEWPAGE bit will always be set. And the corresponding page will always be mapped or unmapped depending on whether the PTE is present or not. The check on the _PAGE_NEWPROT bit is not really reachable. Abandoning it will allow us to simplify the code and remove the unreachable code. Reviewed-by: Benjamin Berg <benjamin.berg@intel.com> Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241011102354.1682626-2-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-23um: remove fault_catcher infrastructureJohannes Berg
This was perhaps intended to do _nofault copies, but the real reason is lost to history. Remove this, it's not needed, and using longjmp() out of the middle of the signal handler with all the state it has modified is not going to be a good idea anyway. Link: https://patch.msgid.link/20241010224513.901c4d390b3e.Ia74742668b44603c1ca23dd36f90e964e6e7ee55@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-16vdso: Introduce vdso/page.hVincenzo Frascino
The VDSO implementation includes headers from outside of the vdso/ namespace. Introduce vdso/page.h to make sure that the generic library uses only the allowed namespace. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Link: https://lore.kernel.org/all/20241014151340.1639555-3-vincenzo.frascino@arm.com
2024-10-10um: Switch to 4 level page tables on 64 bitBenjamin Berg
The larger memory space is useful to support more applications inside UML. One example for this is ASAN instrumentation of userspace applications which requires addresses that would otherwise not be available. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240919124511.282088-11-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: Discover host_task_size from envpBenjamin Berg
When loading the UML binary, the host kernel will place the stack at the highest possible address. It will then map the program name and environment variables onto the start of the stack. As such, an easy way to figure out the host_task_size is to use the highest pointer to an environment variable as a reference. Ensure that this works by disabling address layout randomization and re-executing UML in case it was enabled. This increases the available TASK_SIZE for 64 bit UML considerably. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240919124511.282088-9-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: use execveat to create userspace MMsBenjamin Berg
Using clone will not undo features that have been enabled by libc. An example of this already happening is rseq, which could cause the kernel to read/write memory of the userspace process. In the future the standard library might also use mseal by default to protect itself, which would also thwart our attempts at unmapping everything. Solve all this by taking a step back and doing an execve into a tiny static binary that sets up the minimal environment required for the stub without using any standard library. That way we have a clean execution environment that is fully under the control of UML. Note that this changes things a bit as the FDs are not anymore shared with the kernel. Instead, we explicitly share the FDs for the physical memory and all existing iomem regions. Doing this is fine, as iomem regions cannot be added at runtime. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240919124511.282088-3-benjamin@sipsolutions.net [use pipe() instead of pipe2(), remove unneeded close() calls] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: remove auxiliary FP registersBenjamin Berg
We do not need the extra save/restore of the FP registers when getting the fault information. This was originally added in commit 2f56debd77a8 ("uml: fix FP register corruption") but at that time the code was not saving/restoring the FP registers when switching to userspace. This was fixed in commit fbfe9c847edf ("um: Save FPU registers between task switches") and since then the auxiliary registers have not been useful. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20241004233821.2130874-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: Remove 3-level page table support on i386Tiwei Bie
The highmem support has been removed by commit a98a6d864d3b ("um: Remove broken highmem support"). The 2-level page table is sufficient on UML/i386 now. Remove the 3-level page table support on UML/i386 which is still marked as experimental. Suggested-by: Benjamin Berg <benjamin@sipsolutions.net> Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20240918061702.614837-1-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: always use the internal copy of the FP registersBenjamin Berg
When switching from userspace to the kernel, all registers including the FP registers are copied into the kernel and restored later on. As such, the true source for the FP register state is actually already in the kernel and they should never be grabbed from the userspace process. Change the various places to simply copy the data from the internal FP register storage area. Note that on i386 the format of PTRACE_GETFPREGS and PTRACE_GETFPXREGS is different enough that conversion would be needed. With this patch, -EINVAL is returned if the non-native format is requested. The upside is, that this patchset fixes setting registers via ptrace (which simply did not work before) as well as fixing setting floating point registers using the mcontext on signal return on i386. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240913133845.964292-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: Fix the definition for physmem_sizeTiwei Bie
Currently physmem_size is defined as long long but declared locally as unsigned long long before using it in separate .c files. Make them match by defining physmem_size as unsigned long long and also move the declaration to a common header to allow the compiler to check it. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20240916045950.508910-5-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: Remove highmem leftoversTiwei Bie
Highmem was only supported on UML/i386. And the support has been removed by commit a98a6d864d3b ("um: Remove broken highmem support"). Remove the leftovers and stop UML from trying to setup highmem when the sum of physmem_size and iomem_size exceeds max_physmem. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20240916045950.508910-4-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: Remove unused os_getpgrp functionBenjamin Berg
The function is not used anywhere. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240913134442.967599-5-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: Remove unused os_stop_processBenjamin Berg
The function is not used anywhere. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240913134442.967599-4-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: Remove unused os_process_parentBenjamin Berg
The function is not used anywhere. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240913134442.967599-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-10um: Remove unused os_process_pcBenjamin Berg
The function is not used anywhere in the codebase. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240913134442.967599-2-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-10-02move asm/unaligned.h to linux/unaligned.hAl Viro
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-09-12um: Remove outdated asm/sysrq.h headerTiwei Bie
This header no longer serves a purpose after show_trace was removed by commit 9d1ee8ce92e1 ("um: Rewrite show_stack()"). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12um: Remove the declaration of user_thread functionTiwei Bie
This function has never been defined since its declaration was introduced by commit 1da177e4c3f4 ("Linux-2.6.12-rc2"). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12um: Remove unused mm_fd field from mm_idTiwei Bie
It's no longer used since the removal of the SKAS3/4 support. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12um: Remove unused fields from thread_structTiwei Bie
These fields are no longer used since the removal of tt mode. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12um: Remove unused kpte_clear_flush macroTiwei Bie
This macro has no users, and __flush_tlb_one doesn't exist either. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12um: Remove obsoleted declaration for execute_syscall_skasGaosheng Cui
The execute_syscall_skas() have been removed since commit e32dacb9f481 ("[PATCH] uml: system call path cleanup"), and now it is useless, so remove it. Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Richard Weinberger <richard@nod.at>
2024-07-25Merge tag 'uml-for-linus-6.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux Pull UML updates from Richard Weinberger: - Support for preemption - i386 Rust support - Huge cleanup by Benjamin Berg - UBSAN support - Removal of dead code * tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits) um: vector: always reset vp->opened um: vector: remove vp->lock um: register power-off handler um: line: always fill *error_out in setup_one_line() um: remove pcap driver from documentation um: Enable preemption in UML um: refactor TLB update handling um: simplify and consolidate TLB updates um: remove force_flush_all from fork_handler um: Do not flush MM in flush_thread um: Delay flushing syscalls until the thread is restarted um: remove copy_context_skas0 um: remove LDT support um: compress memory related stub syscalls while adding them um: Rework syscall handling um: Add generic stub_syscall6 function um: Create signal stack memory assignment in stub_data um: Remove stub-data.h include from common-offsets.h um: time-travel: fix signal blocking race/hang um: time-travel: remove time_exit() ...
2024-07-16um: Use generic runtime constant implementationLinus Torvalds
UML should not be using the architecture native runtime constants, since that requires also having the appropriate instruction fixups (and all the linker script details). Not that using that code would be impossible, but it's not worth it. Just point UML at the generic version. Reported-by: Nathan Chancellor <nathan@kernel.org> Fixes: e3c92e81711d ("runtime constants: add x86 architecture support") Link: https://lore.kernel.org/all/20240716143644.GA1827132@thelio-3990X/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-10um: don't generate asm/bpf_perf_event.hArnd Bergmann
If we start validating the existence of the asm-generic side of generated headers, this one causes a warning: make[3]: *** No rule to make target 'arch/um/include/generated/asm/bpf_perf_event.h', needed by 'all'. Stop. The problem is that the asm-generic header only exists for the uapi variant, but arch/um has no uapi headers and instead uses the x86 userspace API. Add a custom file with an explicit redirect to avoid this. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-07-03um: refactor TLB update handlingBenjamin Berg
Conceptually, we want the memory mappings to always be up to date and represent whatever is in the TLB. To ensure that, we need to sync them over in the userspace case and for the kernel we need to process the mappings. The kernel will call flush_tlb_* if page table entries that were valid before become invalid. Unfortunately, this is not the case if entries are added. As such, change both flush_tlb_* and set_ptes to track the memory range that has to be synchronized. For the kernel, we need to execute a flush_tlb_kern_* immediately but we can wait for the first page fault in case of set_ptes. For userspace in contrast we only store that a range of memory needs to be synced and do so whenever we switch to that process. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240703134536.1161108-13-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03um: simplify and consolidate TLB updatesBenjamin Berg
The HVC update was mostly used to compress consecutive calls into one. This is mostly relevant for userspace where it is already handled by the syscall stub code. Simplify the whole logic and consolidate it for both kernel and userspace. This does remove the sequential syscall compression for the kernel, however that shouldn't be the main factor in most runs. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240703134536.1161108-12-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03um: remove force_flush_all from fork_handlerBenjamin Berg
There should be no need for this. It may be that this used to work around another issue where after a clone the MM was in a bad state. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240703134536.1161108-11-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03um: Delay flushing syscalls until the thread is restartedBenjamin Berg
As running the syscalls is expensive due to context switches, we should do so as late as possible in case more syscalls need to be queued later on. This will also benefit a later move to a SECCOMP enabled userspace as in that case the need for extra context switches is removed entirely. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Link: https://patch.msgid.link/20240703134536.1161108-9-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03um: remove copy_context_skas0Benjamin Berg
The kernel flushes the memory ranges anyway for CoW and does not assume that the userspace process has anything set up already. So, start with a fresh process for the new mm context. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240703134536.1161108-8-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03um: remove LDT supportBenjamin Berg
The current LDT code has a few issues that mean it should be redone in a different way once we always start with a fresh MM even when cloning. In a new and better world, the kernel would just ensure its own LDT is clear at startup. At that point, all that is needed is a simple function to populate the LDT from another MM in arch_dup_mmap combined with some tracking of the installed LDT entries for each MM. Note that the old implementation was even incorrect with regard to reading, as it copied out the LDT entries in the internal format rather than converting them to the userspace structure. Removal should be fine as the LDT is not used for thread-local storage anymore. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Link: https://patch.msgid.link/20240703134536.1161108-7-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03um: Rework syscall handlingBenjamin Berg
Rework syscall handling to be platform independent. Also create a clean split between queueing of syscalls and flushing them out, removing the need to keep state in the code that triggers the syscalls. The code adds syscall_data_len to the global mm_id structure. This will be used later to allow surrounding code to track whether syscalls still need to run and if errors occurred. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Link: https://patch.msgid.link/20240703134536.1161108-5-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03um: Create signal stack memory assignment in stub_dataBenjamin Berg
When we switch to use seccomp, we need both the signal stack and other data (i.e. syscall information) to co-exist in the stub data. To facilitate this, start by defining separate memory areas for the stack and syscall data. This moves the signal stack onto a new page as the memory area is not sufficient to hold both signal stack and syscall information. Only change the signal stack setup for now, as the syscall code will be reworked later. Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net> Link: https://patch.msgid.link/20240703134536.1161108-3-benjamin@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>