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2024-09-12um: Remove the redundant newpage check in update_pte_rangeTiwei Bie1-10/+6
The two checks have been identical since commit ef714f15027c ("um: remove force_flush_all from fork_handler"). And the inner one isn't necessary anymore. Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-07-03um: refactor TLB update handlingBenjamin Berg1-118/+12
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 <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Johannes Berg <[email protected]>
2024-07-03um: simplify and consolidate TLB updatesBenjamin Berg1-305/+81
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 <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Johannes Berg <[email protected]>
2024-07-03um: remove force_flush_all from fork_handlerBenjamin Berg1-29/+15
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 <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Johannes Berg <[email protected]>
2024-07-03um: Delay flushing syscalls until the thread is restartedBenjamin Berg1-19/+2
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 <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Johannes Berg <[email protected]>
2024-07-03um: Rework syscall handlingBenjamin Berg1-22/+20
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 <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Johannes Berg <[email protected]>
2024-04-22um: Add missing headersTiwei Bie1-0/+1
This will address below -Wmissing-prototypes warnings: arch/um/kernel/mem.c:202:8: warning: no previous prototype for ‘pgd_alloc’ [-Wmissing-prototypes] arch/um/kernel/mem.c:215:7: warning: no previous prototype for ‘uml_kmalloc’ [-Wmissing-prototypes] arch/um/kernel/process.c:207:6: warning: no previous prototype for ‘arch_cpu_idle’ [-Wmissing-prototypes] arch/um/kernel/process.c:328:15: warning: no previous prototype for ‘arch_align_stack’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:45:6: warning: no previous prototype for ‘machine_restart’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:51:6: warning: no previous prototype for ‘machine_power_off’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:57:6: warning: no previous prototype for ‘machine_halt’ [-Wmissing-prototypes] arch/um/kernel/skas/mmu.c:17:5: warning: no previous prototype for ‘init_new_context’ [-Wmissing-prototypes] arch/um/kernel/skas/mmu.c:60:6: warning: no previous prototype for ‘destroy_context’ [-Wmissing-prototypes] arch/um/kernel/skas/process.c:36:12: warning: no previous prototype for ‘start_uml’ [-Wmissing-prototypes] arch/um/kernel/time.c:807:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes] arch/um/kernel/tlb.c:594:6: warning: no previous prototype for ‘force_flush_all’ [-Wmissing-prototypes] arch/x86/um/bugs_32.c:22:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes] arch/x86/um/bugs_32.c:44:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes] arch/x86/um/bugs_64.c:9:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes] arch/x86/um/bugs_64.c:13:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:10:12: warning: no previous prototype for ‘elf_core_extra_phdrs’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:15:5: warning: no previous prototype for ‘elf_core_write_extra_phdrs’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:42:5: warning: no previous prototype for ‘elf_core_write_extra_data’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:63:8: warning: no previous prototype for ‘elf_core_extra_data_size’ [-Wmissing-prototypes] arch/x86/um/fault.c:18:5: warning: no previous prototype for ‘arch_fixup’ [-Wmissing-prototypes] arch/x86/um/os-Linux/mcontext.c:7:6: warning: no previous prototype for ‘get_regs_from_mc’ [-Wmissing-prototypes] arch/x86/um/os-Linux/tls.c:22:6: warning: no previous prototype for ‘check_host_supports_tls’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2024-04-22um: Remove unused functionsTiwei Bie1-6/+0
These functions are not used anymore. Removing them will also address below -Wmissing-prototypes warnings: arch/um/kernel/process.c:51:5: warning: no previous prototype for ‘pid_to_processor_id’ [-Wmissing-prototypes] arch/um/kernel/process.c:253:5: warning: no previous prototype for ‘copy_to_user_proc’ [-Wmissing-prototypes] arch/um/kernel/process.c:263:5: warning: no previous prototype for ‘clear_user_proc’ [-Wmissing-prototypes] arch/um/kernel/tlb.c:579:6: warning: no previous prototype for ‘flush_tlb_mm_range’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2023-02-01um: Declare fix_range_common as a static functionBenjamin Berg1-2/+2
It is only used within the same file. Signed-off-by: Benjamin Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2023-02-01um: protect VMA iterationJohannes Berg1-0/+2
Due to changes in the iteration, there are now lockdep checks indicating that we're missing locking here. Add the missing locking where it's needed. Signed-off-by: Johannes Berg <[email protected]> Acked-By: Anton Ivanov <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2022-09-26um: remove vma linked list walkMatthew Wilcox (Oracle)1-8/+6
Use the VMA iterator instead. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Signed-off-by: Liam R. Howlett <[email protected]> Reviewed-by: Davidlohr Bueso <[email protected]> Tested-by: Yu Zhao <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: David Howells <[email protected]> Cc: SeongJae Park <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2021-02-12um: remove process stub VMAJohannes Berg1-15/+0
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 <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2021-02-12um: defer killing userspace on page table update failuresJohannes Berg1-4/+3
In some cases we can get to fix_range_common() with mmap_sem held, and in others we get there without it being held. For example, we get there with it held from sys_mprotect(), and without it held from fork_handler(). Avoid any issues in this and simply defer killing the task until it runs the next time. Do it on the mm so that another task that shares the same mm can't continue running afterwards. Cc: [email protected] Fixes: 468f65976a8d ("um: Fix hung task in fix_range_common()") Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2021-02-12um: mm: check more comprehensively for stub changesJohannes Berg1-1/+11
If userspace tries to change the stub, we need to kill it, because otherwise it can escape the virtual machine. In a few cases the stub checks weren't good, e.g. if userspace just tries to mmap(0x100000 - 0x1000, 0x3000, ...) it could succeed to get a new private/anonymous mapping replacing the stubs. Fix this by checking everywhere, and checking for _overlap_, not just direct changes. Cc: [email protected] Fixes: 3963333fe676 ("uml: cover stubs with a VMA") Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2021-01-26Revert "um: support some of ARCH_HAS_SET_MEMORY"Johannes Berg1-54/+0
This reverts commit 963285b0b47a ("um: support some of ARCH_HAS_SET_MEMORY"), as it turns out that it's not only not working (due to um never using the protection bits in the page tables) but also corrupts the page tables if used on a non-vmalloc page, since um never allocates proper page tables for the 'physmem' in the first place. Fixing all this will take more effort, so for now revert it. Reported-by: Benjamin Berg <[email protected]> Fixes: 963285b0b47a ("um: support some of ARCH_HAS_SET_MEMORY") Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-12-13um: support some of ARCH_HAS_SET_MEMORYJohannes Berg1-0/+54
For now, only support set_memory_ro()/rw() which we need for the stack protection in the next patch. Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2020-06-09mmap locking API: convert mmap_sem commentsMichel Lespinasse1-1/+1
Convert comments that reference mmap_sem to reference mmap_lock instead. [[email protected]: fix up linux-next leftovers] [[email protected]: s/lockaphore/lock/, per Vlastimil] [[email protected]: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Vlastimil Babka <[email protected]> Reviewed-by: Daniel Jordan <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: David Rientjes <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: John Hubbard <[email protected]> Cc: Laurent Dufour <[email protected]> Cc: Liam Howlett <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ying Han <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-06-09mmap locking API: use coccinelle to convert mmap_sem rwsem call sitesMichel Lespinasse1-1/+1
This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Daniel Jordan <[email protected]> Reviewed-by: Laurent Dufour <[email protected]> Reviewed-by: Vlastimil Babka <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: David Rientjes <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: John Hubbard <[email protected]> Cc: Liam Howlett <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ying Han <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport1-1/+0
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 <asm/pgtable.h> 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 <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Cain <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chris Zankel <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Greentime Hu <[email protected]> Cc: Greg Ungerer <[email protected]> Cc: Guan Xuetao <[email protected]> Cc: Guo Ren <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Helge Deller <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Ley Foon Tan <[email protected]> Cc: Mark Salter <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Matt Turner <[email protected]> Cc: Max Filippov <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Michal Simek <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Nick Hu <[email protected]> Cc: Paul Walmsley <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Rich Felker <[email protected]> Cc: Russell King <[email protected]> Cc: Stafford Horne <[email protected]> Cc: Thomas Bogendoerfer <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: Vincent Chen <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Will Deacon <[email protected]> Cc: Yoshinori Sato <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2019-12-04um: add support for folded p4d page tablesMike Rapoport1-6/+50
The UML port uses 4 and 5 level fixups to support higher level page table directories in the generic VM code. Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate and drop usage of __ARCH_USE_5LEVEL_HACK. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Mike Rapoport <[email protected]> Cc: Anatoly Pugachev <[email protected]> Cc: Anton Ivanov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Greentime Hu <[email protected]> Cc: Greg Ungerer <[email protected]> Cc: Helge Deller <[email protected]> Cc: "James E.J. Bottomley" <[email protected]> Cc: Jeff Dike <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Mark Salter <[email protected]> Cc: Matt Turner <[email protected]> Cc: Michal Simek <[email protected]> Cc: Peter Rosin <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Rolf Eike Beer <[email protected]> Cc: Russell King <[email protected]> Cc: Russell King <[email protected]> Cc: Sam Creasey <[email protected]> Cc: Vincent Chen <[email protected]> Cc: Vineet Gupta <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-12-04um: remove unused pxx_offset_proc() and addr_pte() functionsMike Rapoport1-29/+0
The pxx_offset_proc() and addr_pte() functions are never used. Remove them. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Mike Rapoport <[email protected]> Acked-by: Richard Weinberger <[email protected]> Cc: Anatoly Pugachev <[email protected]> Cc: Anton Ivanov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Greentime Hu <[email protected]> Cc: Greg Ungerer <[email protected]> Cc: Helge Deller <[email protected]> Cc: "James E.J. Bottomley" <[email protected]> Cc: Jeff Dike <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Mark Salter <[email protected]> Cc: Matt Turner <[email protected]> Cc: Michal Simek <[email protected]> Cc: Peter Rosin <[email protected]> Cc: Rolf Eike Beer <[email protected]> Cc: Russell King <[email protected]> Cc: Russell King <[email protected]> Cc: Sam Creasey <[email protected]> Cc: Vincent Chen <[email protected]> Cc: Vineet Gupta <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2019-09-15um: Add SPDX headers to files in arch/um/kernel/Alex Dewar1-1/+1
Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2019-05-27signal: Remove task parameter from force_sigEric W. Biederman1-2/+2
All of the remaining callers pass current into force_sig so remove the task parameter to make this obvious and to make misuse more difficult in the future. This also makes it clear force_sig passes current into force_sig_info. Signed-off-by: "Eric W. Biederman" <[email protected]>
2018-12-27um: Optimize Flush TLB for force/fork caseAnton Ivanov1-4/+5
When UML handles a fork the page tables need to be brought up to date. That was done using brute force - full tlb flush. This is actually unnecessary, because the mapped-in mappings are all correct and the only mappings which need to be updated after a flush are any unmaps (so that paging works) as well as any pending protection changes. This optimization squeezes out up to 3% from a full kernel rebuild time under memory pressure. Signed-off-by: Anton Ivanov <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2018-12-27um: Skip TLB flushing where not neededAnton Ivanov1-7/+14
Skip TLB flushing for all cases where it is not needed, not just flush_tlb_mm_range Signed-off-by: Anton Ivanov <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2018-12-27um: Optimize TLB operations v2Anton Ivanov1-28/+57
Make the code to merge mmap/munmap/mprotect operations in tlb.c common for userspace and kernel. Kernel tlb operations can now be merged as well. Signed-off-by: Anton Ivanov <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar1-1/+2
<linux/sched/signal.h> We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>
2015-11-06um: Report host OOM more nicelyRichard Weinberger1-1/+15
If UML runs on the host side out of memory, report this condition more nicely. Signed-off-by: Richard Weinberger <[email protected]>
2015-07-07um: Fix do_signal() prototypeIngo Molnar1-1/+1
Once x86 exports its do_signal(), the prototypes will clash. Fix the clash and also improve the code a bit: remove the unnecessary kern_do_signal() indirection. This allows interrupt_end() to share the 'regs' parameter calculation. Also remove the unused return code to match x86. Minimally build and boot tested. Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Andy Lutomirski <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Kees Cook <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/67c57eac09a589bac3c6c5ff22f9623ec55a184a.1435952415.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2014-07-20um: Fix hung task in fix_range_common()Richard Weinberger1-1/+5
If do_ops() fails we have to release current->mm->mmap_sem otherwise the failing task will never terminate. Reported-by: Toralf Förster <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2014-07-20um: Ensure that a stub page cannot get unmappedRichard Weinberger1-0/+3
Trinity discovered an execution path such that a task can unmap his stub page. Reported-by: Toralf Förster <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2012-10-09um: get rid of pointless include "..." where include <...> will doAl Viro1-4/+4
Signed-off-by: Al Viro <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2012-05-21um: Add BUG() to do_ops()'s error pathRichard Weinberger1-0/+1
In case we encounter a bad operation in do_ops() something is really broken and it's better to BUG(). Signed-off-by: Richard Weinberger <[email protected]>
2011-11-02um: distribute exports to where exported stuff is definedAl Viro1-0/+2
ksyms.c is down to the stuff defined in various USER_OBJS Signed-off-by: Al Viro <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2011-11-02um: kill shared/tlb.hAl Viro1-1/+0
Signed-off-by: Al Viro <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2011-11-02um: make flush_tlb_kernel_range_common() staticAl Viro1-1/+1
Signed-off-by: Al Viro <[email protected]> Signed-off-by: Richard Weinberger <[email protected]>
2008-02-05uml: style fixes in arch/um/kernelJeff Dike1-1/+1
Joe Perches noticed some printks in smp.c that needed fixing. While I was in there, I did the usual tidying in arch/um/kernel, which should be fairly style-clean at this point: copyright updates emacs formatting comments removal include tidying style fixes Cc: Joe Perches <[email protected]> Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2008-02-05uml: customize tlb.hJeff Dike1-7/+18
Customize the hooks in tlb.h to optimize TLB flushing some more. Add start and end fields to tlb_gather_mmu, which are used to limit the address space range scanned when a region is unmapped. The interfaces which just free page tables, without actually changing mappings, don't need to cause a TLB flush. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2008-02-05uml: 64-bit tlb fixesJeff Dike1-4/+4
Some 64-bit tlb fixes - moved pmd_page_vaddr to pgtable.h since it's the same for both 2-level and 3-level page tables fixed a bogus cast on pud_page_vaddr made the address checking in update_*_range more careful Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2008-02-05uml: cover stubs with a VMAJeff Dike1-7/+4
Give the stubs a VMA. This allows the removal of a truly nasty kludge to make sure that mm->nr_ptes was correct in exit_mmap. The underlying problem was always that the stubs, which have ptes, and thus allocated a page table, weren't covered by a VMA. This patch fixes that by using install_special_mapping in arch_dup_mmap and activate_context to create the VMA. The stubs have to be moved, since shift_arg_pages seems to assume that the stack is the only VMA present at that point during exec, and uses vma_adjust to fiddle its VMA. However, that extends the stub VMA by the amount removed from the stack VMA. To avoid this problem, the stubs were moved to a different fixed location at the start of the address space. The init_stub_pte calls were moved from init_new_context to arch_dup_mmap because I was occasionally seeing arch_dup_mmap not being called, causing exit_mmap to die. Rather than figure out what was really happening, I decided it was cleaner to just move the calls so that there's no doubt that both the pte and VMA creation happen, no matter what. arch_exit_mmap is used to clear the stub ptes at exit time. The STUB_* constants in as-layout.h no longer depend on UM_TASK_SIZE, that that definition is removed, along with the comments complaining about gcc. Because the stubs are no longer at the top of the address space, some care is needed while flushing TLBs. update_pte_range checks for addresses in the stub range and skips them. flush_thread now issues two unmaps, one for the range before STUB_START and one for the range after STUB_END. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2008-02-05uml: clean up TASK_SIZE usageJeff Dike1-1/+1
Clean up the calculation and use of the usable address space size on the host. task_size is gone, replaced with TASK_SIZE, which is calculated from CONFIG_TOP_ADDR. get_kmem_end and set_task_sizes_skas are also gone. host_task_size, which refers to the entire address space usable by the UML kernel and which may be larger than the address space usable by a UML process, since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR. STACK_TOP is now TASK_SIZE minus the two stub pages. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2008-02-05uml: header untanglingJeff Dike1-3/+4
Untangle UML headers somewhat and add some includes where they were needed explicitly, but gotten accidentally via some other header. arch/um/include/um_uaccess.h loses asm/fixmap.h because it uses no fixmap stuff and gains elf.h, because it needs FIXADDR_USER_*, and archsetjmp.h, because it needs jmp_buf. pmd_alloc_one is uninlined because it needs mm_struct, and that's inconvenient to provide in asm-um/pgtable-3level.h. elf_core_copy_fpregs is also uninlined from elf-i386.h and elf-x86_64.h, which duplicated the code anyway, to arch/um/kernel/process.c, so that the reference to current_thread doesn't pull sched.h or anything related into asm/elf.h. arch/um/sys-i386/ldt.c, arch/um/kernel/tlb.c and arch/um/kernel/skas/uaccess.c got sched.h because they dereference task_structs. Its includes of linux and asm headers got turned from "" to <>. arch/um/sys-i386/bug.c gets asm/errno.h because it needs errno constants. asm/elf-i386 gets asm/user.h because it needs user_regs_struct. asm/fixmap.h gets page.h because it needs PAGE_SIZE and PAGE_MASK and system.h for BUG_ON. asm/pgtable doesn't need sched.h. asm/processor-generic.h defined mm_segment_t, but didn't use it. So, that definition is moved to uaccess.h, which defines a bunch of mm_segment_t-related stuff. thread_info.h uses mm_segment_t, and includes uaccess.h, which causes a recursion. So, the definition is placed above the include of thread_info. in uaccess.h. thread_info.h also gets page.h because it needs PAGE_SIZE. ObCheckpatchViolationJustification - I'm not adding a typedef; I'm moving mm_segment_t from one place to another. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2007-10-16uml: fix stub address calculationsJeff Dike1-3/+3
The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the cold. I'd rather not duplicate the four known host vmsplit cases for each of these symbols. I'd also like to calculate them based on the highest userspace address. The Kconfig language seems not to allow calculation of hex constants, so I moved this to as-layout.h. CONFIG_STUB_CODE, CONFIG_STUB_DATA, and CONFIG_STUB_START are now gone. In their place are STUB_CODE, STUB_DATA, and STUB_START in as-layout.h. i386 and x86_64 seem to differ as to whether an unadorned constant is an int or a long, so I cast them to unsigned long so they can be printed consistently. However, they are also used in stub.S, where C types don't work so well. So, there are ASM_ versions of these constants for use in stub.S. I also ifdef-ed the non-asm-friendly portion of as-layout.h. With this in place, most of the rest of this patch is changing CONFIG_STUB_* to STUB_*, except in stub.S, where they are changed to ASM_STUB_*. defconfig has the old symbols deleted. I also print these addresses out in case there is any problem mapping them on the host. The two stub.S files had some trailing whitespace, so that is cleaned up here. [[email protected]: coding-style fixes] Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2007-10-16uml: clean up tlb flush pathJeff Dike1-131/+127
Tidy the tlb flushing code. With tt mode gone, there is no reason to have the capability to have called directly from do_mmap, do_mprotect, and do_munmap, rather than calling a function pointer that it is given. There was a large amount of data that was passed from function to function, being used at the lowest level, without being changed. This stuff is now encapsulated in a structure which is initialized at the top layer and passed down. This simplifies the code, reduces the amount of code needed to pass the parameters around, and saves on stack space. A somewhat more subtle change is the meaning of the current operation index. It used to start at -1, being pre-incremented when adding an operation. It now starts at 0, being post-incremented, with associated adjustments of +/- 1 on comparisons. In addition, tlb.h contained a couple of declarations which had no users outside of tlb.c, so they could be moved or deleted. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2007-10-16uml: fold mmu_context_skas into mm_contextJeff Dike1-22/+21
This patch folds mmu_context_skas into struct mm_context, changing all users of these structures as needed. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2007-10-16uml: style fixes pass 3Jeff Dike1-79/+79
Formatting changes in the files which have been changed in the course of folding foo_skas functions into their callers. These include: copyright updates header file trimming style fixes adding severity to printks These changes should be entirely non-functional. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2007-10-16uml: remove code made redundant by CHOOSE_MODE removalJeff Dike1-5/+129
This patch makes a number of simplifications enabled by the removal of CHOOSE_MODE. There were lots of functions that looked like int foo(args){ foo_skas(args); } The bodies of foo_skas are now folded into foo, and their declarations (and sometimes entire header files) are deleted. In addition, the union uml_pt_regs, which was a union between the tt and skas register formats, is now a struct, with the tt-mode arm of the union being removed. It turns out that usr2_handler was unused, so it is gone. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2007-10-16uml: throw out CHOOSE_MODEJeff Dike1-11/+6
The next stage after removing code which depends on CONFIG_MODE_TT is removing the CHOOSE_MODE abstraction, which provided both compile-time and run-time branching to either tt-mode or skas-mode code. This patch removes choose-mode.h and all inclusions of it, and replaces all CHOOSE_MODE invocations with the skas branch. This leaves a number of trivial functions which will be dealt with in a later patch. There are some changes in the uaccess and tls support which go somewhat beyond this and eliminate some of the now-redundant functions. Signed-off-by: Jeff Dike <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2007-05-07uml: more page fault path trimmingJeff Dike1-28/+14
More trimming of the page fault path. Permissions are passed around in a single int rather than one bit per int. The permission values are copied from libc so that they can be passed to mmap and mprotect without any further conversion. The register sets used by do_syscall_stub and copy_context_skas0 are initialized once, at boot time, rather than once per call. wait_stub_done checks whether it is getting the signals it expects by comparing the wait status to a mask containing bits for the signals of interest rather than comparing individually to the signal numbers. It also has one check for a wait failure instead of two. The caller is expected to do the initial continue of the stub. This gets rid of an argument and some logic. The fname argument is gone, as that can be had from a stack trace. user_signal() is collapsed into userspace() as it is basically one or two lines of code afterwards. The physical memory remapping stuff is gone, as it is unused. flush_tlb_page is inlined. Signed-off-by: Jeff Dike <[email protected]> Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2007-05-07uml: eliminate a piece of debugging codeJeff Dike1-1/+0
I missed removing another piece of debugging in an earlier patch. Signed-off-by: Jeff Dike <[email protected]> Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>