kernel.git/arch/um/kernel/um_arch.c, branch linux-5.13.y

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

um: stdio_console: Make preferred console

2021-01-26T21:11:37Z

The addition of the "ttynull" console driver did break the ordering of the UML stdio console driver. The UML stdio console driver is added in late_initcall (7), whereby the ttynull driver is added in device_initcall (6), which always does make the ttynull driver the default console. Fix it by explicitly adding the UML stdio console as the preferred console, in case no 'console=' command line option was specified. Signed-off-by: Thomas Meyer Signed-off-by: Richard Weinberger

um: Fix build w/o CONFIG_PM_SLEEP

2020-12-14T20:15:32Z

uml_pm_wake() is unconditionally called from the SIGUSR1 wakeup handler since that's in the userspace portion of UML, and thus a bit tricky to ifdef out. Since pm_system_wakeup() can always be called (but may be an empty inline), also simply always have uml_pm_wake() to fix the build. Reported-by: Randy Dunlap Acked-by: Randy Dunlap # build-tested Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: Support suspend to RAM

2020-12-13T21:22:49Z

With all the previous bits in place, we can now also support suspend to RAM, in the sense that everything is suspended, not just most, including userspace, processes like in s2idle. Since um_idle_sleep() now waits forever, we can simply call that to "suspend" the system. As before, you can wake it up using SIGUSR1 since we're just in a pause() call that only needs to return. In order to implement selective resume from certain devices, and not have any arbitrary device interrupt wake up, suspend interrupts by removing SIGIO notification (O_ASYNC) from all the FDs that are not supposed to wake up the system. However, swap out the handler so we don't actually handle the SIGIO as an interrupt. Since we're in pause(), the mere act of receiving SIGIO wakes us up, and then after things have been restored enough, re-set O_ASYNC for all previously suspended FDs, reinstall the proper SIGIO handler, and send SIGIO to self to process anything that might now be pending. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: Allow PM with suspend-to-idle

2020-12-13T21:22:46Z

In order to be able to experiment with suspend in UML, add the minimal work to be able to suspend (s2idle) an instance of UML, and be able to wake it back up from that state with the USR1 signal sent to the main UML process. Signed-off-by: Johannes Berg Acked-By: Anton Ivanov Signed-off-by: Richard Weinberger

treewide: Convert macro and uses of section(foo) to section("foo")

2020-10-25T21:51:49Z

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 Reviewed-by: Nick Desaulniers Reviewed-by: Miguel Ojeda Signed-off-by: Linus Torvalds

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09T16:39:13Z

Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include in the files that include . The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include ") ; do sed -i -e '/include / d' $f done Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Cain Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Ungerer Cc: Guan Xuetao Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Ley Foon Tan Cc: Mark Salter Cc: Matthew Wilcox Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Rapoport Cc: Nick Hu Cc: Paul Walmsley Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Tony Luck Cc: Vincent Chen Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds

x86/module: Use text_poke() for late relocations

2020-05-07T22:12:43Z

Because of late module patching, a livepatch module needs to be able to apply some of its relocations well after it has been loaded. Instead of playing games with module_{dis,en}able_ro(), use existing text poking mechanisms to apply relocations after module loading. So far only x86, s390 and Power have HAVE_LIVEPATCH but only the first two also have STRICT_MODULE_RWX. This will allow removal of the last module_disable_ro() usage in livepatch. The ultimate goal is to completely disallow making executable mappings writable. [ jpoimboe: Split up patches. Use mod state to determine whether memcpy() can be used. Implement text_poke() for UML. ] Cc: x86@kernel.org Suggested-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Josh Poimboeuf Acked-by: Peter Zijlstra (Intel) Acked-by: Joe Lawrence Acked-by: Miroslav Benes Signed-off-by: Jiri Kosina

um: Add SPDX headers to files in arch/um/kernel/

2019-09-15T19:37:17Z

Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar Signed-off-by: Richard Weinberger

um: drivers: Add virtio vhost-user driver

2019-09-15T19:37:15Z

This module allows virtio devices to be used over a vhost-user socket. Signed-off-by: Erel Geron Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger