- 07 10月, 2015 4 次提交
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由 Andy Lutomirski 提交于
Rather than worrying about exactly where LOCKDEP_SYS_EXIT should go in the asm code, add it to prepare_exit_from_usermode() and remove all of the asm calls that are followed by prepare_exit_to_usermode(). LOCKDEP_SYS_EXIT now appears only in the syscall fast paths. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1736ebe948b845e68120b86b89091f3ec27f5e8e.1444091584.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
Clearing NT is part of the prologue, whereas loading up arg6 makes more sense to think about as part of syscall processing. Reorder them. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/19eb235828b2d2a52c53459e09f2974e15e65a35.1444091584.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
This should improve code quality a bit. It also shrinks the kernel text: Before: text data bss dec filename 21828379 5194760 1277952 28301091 vmlinux After: text data bss dec filename 21827997 5194760 1277952 28300709 vmlinux ... by 382 bytes. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/f427b8002d932e5deab9055e0074bb4e7e80ee39.1444091584.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
GCC doesn't realize that get_user(), put_user(), and their __ variants are unlikely to fail. Tell it. I noticed this while playing with the C entry code. Before: text data bss dec filename 21828763 5194760 1277952 28301475 vmlinux.baseline After: text data bss dec filename 21828379 5194760 1277952 28301091 vmlinux.new The generated code shrunk by 384 bytes. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/dc37bed7024319c3004d950d57151fca6aeacf97.1444091584.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 06 10月, 2015 1 次提交
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由 David Vrabel 提交于
With commit 633d6f17 (x86/xen: prepare p2m list for memory hotplug) the P2M may be sized to accomdate a much larger amount of memory than the domain currently has. When saving a domain, the toolstack must scan all the P2M looking for populated pages. This results in a performance regression due to the unnecessary scanning. Instead of reporting (via shared_info) the maximum possible size of the P2M, hint at the last PFN which might be populated. This hint is increased as new leaves are added to the P2M (in the expectation that they will be used for populated entries). Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com> Cc: <stable@vger.kernel.org> # 4.0+
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- 02 10月, 2015 4 次提交
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由 Ben Hutchings 提交于
On x32, gcc predefines __x86_64__ but long is only 32-bit. Use __ILP32__ to distinguish x32. Fixes this compiler error in perf: tools/include/asm-generic/bitops/__ffs.h: In function '__ffs': tools/include/asm-generic/bitops/__ffs.h:19:8: error: right shift count >= width of type [-Werror=shift-count-overflow] word >>= 32; ^ This isn't sufficient to build perf for x32, though. Signed-off-by: NBen Hutchings <ben@decadent.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443660043.2730.15.camel@decadent.org.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Stephen Smalley 提交于
Unused space between the end of __ex_table and the start of rodata can be left W+x in the kernel page tables. Extend the setting of the NX bit to cover this gap by starting from text_end rather than rodata_start. Before: ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte 0xffffffff81754000-0xffffffff81800000 688K RW GLB x pte 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd 0xffffffff82200000-0xffffffffa0000000 478M pmd After: ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte 0xffffffff81754000-0xffffffff81800000 688K RW GLB NX pte 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd 0xffffffff82200000-0xffffffffa0000000 478M pmd Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov> Acked-by: NKees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.govSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Lee, Chun-Yi 提交于
The original bug is a page fault crash that sometimes happens on big machines when preparing ELF headers: BUG: unable to handle kernel paging request at ffffc90613fc9000 IP: [<ffffffff8103d645>] prepare_elf64_ram_headers_callback+0x165/0x260 The bug is caused by us under-counting the number of memory ranges and subsequently not allocating enough ELF header space for them. The bug is typically masked on smaller systems, because the ELF header allocation is rounded up to the next page. This patch modifies the code in fill_up_crash_elf_data() by using walk_system_ram_res() instead of walk_system_ram_range() to correctly count the max number of crash memory ranges. That's because the walk_system_ram_range() filters out small memory regions that reside in the same page, but walk_system_ram_res() does not. Here's how I found the bug: After tracing prepare_elf64_headers() and prepare_elf64_ram_headers_callback(), the code uses walk_system_ram_res() to fill-in crash memory regions information to the program header, so it counts those small memory regions that reside in a page area. But, when the kernel was using walk_system_ram_range() in fill_up_crash_elf_data() to count the number of crash memory regions, it filters out small regions. I printed those small memory regions, for example: kexec: Get nr_ram ranges. vaddr=0xffff880077592258 paddr=0x77592258, sz=0xdc0 Based on the code in walk_system_ram_range(), this memory region will be filtered out: pfn = (0x77592258 + 0x1000 - 1) >> 12 = 0x77593 end_pfn = (0x77592258 + 0xfc0 -1 + 1) >> 12 = 0x77593 end_pfn - pfn = 0x77593 - 0x77593 = 0 <=== if (end_pfn > pfn) is FALSE So, the max_nr_ranges that's counted by the kernel doesn't include small memory regions - causing us to under-allocate the required space. That causes the page fault crash that happens in a later code path when preparing ELF headers. This bug is not easy to reproduce on small machines that have few CPUs, because the allocated page aligned ELF buffer has more free space to cover those small memory regions' PT_LOAD headers. Signed-off-by: NLee, Chun-Yi <jlee@suse.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1443531537-29436-1-git-send-email-jlee@suse.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andrey Ryabinin 提交于
With KMEMCHECK=y, KASAN=n: arch/x86/platform/efi/efi.c:673:3: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration] arch/x86/platform/efi/efi_64.c:139:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration] arch/x86/include/asm/desc.h:121:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration] Don't #undef memcpy if KASAN=n. Fixes: 769a8089 ("x86, efi, kasan: #undef memset/memcpy/memmove per arch") Signed-off-by: NAndrey Ryabinin <ryabinin.a.a@gmail.com> Reported-by: NIngo Molnar <mingo@kernel.org> Reported-by: NSedat Dilek <sedat.dilek@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 10月, 2015 8 次提交
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由 Dirk Müller 提交于
The cpu feature flags are not ever going to change, so warning everytime can cause a lot of kernel log spam (in our case more than 10GB/hour). The warning seems to only occur when nested virtualization is enabled, so it's probably triggered by a KVM bug. This is a sensible and safe change anyway, and the KVM bug fix might not be suitable for stable releases anyway. Cc: stable@vger.kernel.org Signed-off-by: NDirk Mueller <dmueller@suse.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
This reverts commit 3c2e7f7d. Initializing the mapping from MTRR to PAT values was reported to fail nondeterministically, and it also caused extremely slow boot (due to caching getting disabled---bug 103321) with assigned devices. Reported-by: NMarkus Trippelsdorf <markus@trippelsdorf.de> Reported-by: NSebastian Schuette <dracon@ewetel.net> Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
This reverts commit 54928303. It builds on the commit that is being reverted next. Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
This reverts commit e098223b, which has a dependency on other commits being reverted. Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
This reverts commit fd717f11. It was reported to cause Machine Check Exceptions (bug 104091). Reported-by: harn-solo@gmx.de Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Matt Fleming 提交于
Beginning with UEFI v2.5 EFI_PROPERTIES_TABLE was introduced that signals that the firmware PE/COFF loader supports splitting code and data sections of PE/COFF images into separate EFI memory map entries. This allows the kernel to map those regions with strict memory protections, e.g. EFI_MEMORY_RO for code, EFI_MEMORY_XP for data, etc. Unfortunately, an unwritten requirement of this new feature is that the regions need to be mapped with the same offsets relative to each other as observed in the EFI memory map. If this is not done crashes like this may occur, BUG: unable to handle kernel paging request at fffffffefe6086dd IP: [<fffffffefe6086dd>] 0xfffffffefe6086dd Call Trace: [<ffffffff8104c90e>] efi_call+0x7e/0x100 [<ffffffff81602091>] ? virt_efi_set_variable+0x61/0x90 [<ffffffff8104c583>] efi_delete_dummy_variable+0x63/0x70 [<ffffffff81f4e4aa>] efi_enter_virtual_mode+0x383/0x392 [<ffffffff81f37e1b>] start_kernel+0x38a/0x417 [<ffffffff81f37495>] x86_64_start_reservations+0x2a/0x2c [<ffffffff81f37582>] x86_64_start_kernel+0xeb/0xef Here 0xfffffffefe6086dd refers to an address the firmware expects to be mapped but which the OS never claimed was mapped. The issue is that included in these regions are relative addresses to other regions which were emitted by the firmware toolchain before the "splitting" of sections occurred at runtime. Needless to say, we don't satisfy this unwritten requirement on x86_64 and instead map the EFI memory map entries in reverse order. The above crash is almost certainly triggerable with any kernel newer than v3.13 because that's when we rewrote the EFI runtime region mapping code, in commit d2f7cbe7 ("x86/efi: Runtime services virtual mapping"). For kernel versions before v3.13 things may work by pure luck depending on the fragmentation of the kernel virtual address space at the time we map the EFI regions. Instead of mapping the EFI memory map entries in reverse order, where entry N has a higher virtual address than entry N+1, map them in the same order as they appear in the EFI memory map to preserve this relative offset between regions. This patch has been kept as small as possible with the intention that it should be applied aggressively to stable and distribution kernels. It is very much a bugfix rather than support for a new feature, since when EFI_PROPERTIES_TABLE is enabled we must map things as outlined above to even boot - we have no way of asking the firmware not to split the code/data regions. In fact, this patch doesn't even make use of the more strict memory protections available in UEFI v2.5. That will come later. Suggested-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NMatt Fleming <matt.fleming@intel.com> Cc: <stable@vger.kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Chun-Yi <jlee@suse.com> Cc: Dave Young <dyoung@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: James Bottomley <JBottomley@Odin.com> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443218539-7610-2-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
The stack layout and the functionality is identical. Use the 64bit version for all of x86. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Reviewed-by: NBorislav Petkov <bp@alien8.de> Reviewed-by: NDmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: kasan-dev <kasan-dev@googlegroups.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Link: http://lkml.kernel.org/r/20150930083302.779694618@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
Dmitry Vyukov reported the following using trinity and the memory error detector AddressSanitizer (https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel). [ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on address ffff88002e280000 [ 124.576801] ffff88002e280000 is located 131938492886538 bytes to the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a) [ 124.578633] Accessed by thread T10915: [ 124.579295] inlined in describe_heap_address ./arch/x86/mm/asan/report.c:164 [ 124.579295] #0 ffffffff810dd277 in asan_report_error ./arch/x86/mm/asan/report.c:278 [ 124.580137] #1 ffffffff810dc6a0 in asan_check_region ./arch/x86/mm/asan/asan.c:37 [ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0 [ 124.581893] #3 ffffffff8107c093 in get_wchan ./arch/x86/kernel/process_64.c:444 The address checks in the 64bit implementation of get_wchan() are wrong in several ways: - The lower bound of the stack is not the start of the stack page. It's the start of the stack page plus sizeof (struct thread_info) - The upper bound must be: top_of_stack - TOP_OF_KERNEL_STACK_PADDING - 2 * sizeof(unsigned long). The 2 * sizeof(unsigned long) is required because the stack pointer points at the frame pointer. The layout on the stack is: ... IP FP ... IP FP. So we need to make sure that both IP and FP are in the bounds. Fix the bound checks and get rid of the mix of numeric constants, u64 and unsigned long. Making all unsigned long allows us to use the same function for 32bit as well. Use READ_ONCE() when accessing the stack. This does not prevent a concurrent wakeup of the task and the stack changing, but at least it avoids TOCTOU. Also check task state at the end of the loop. Again that does not prevent concurrent changes, but it avoids walking for nothing. Add proper comments while at it. Reported-by: NDmitry Vyukov <dvyukov@google.com> Reported-by: NSasha Levin <sasha.levin@oracle.com> Based-on-patch-from: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Reviewed-by: NBorislav Petkov <bp@alien8.de> Reviewed-by: NDmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: kasan-dev <kasan-dev@googlegroups.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 30 9月, 2015 2 次提交
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由 Andrey Ryabinin 提交于
With KMEMCHECK=y, KASAN=n we get this build failure: arch/x86/platform/efi/efi.c:673:3: error: implicit declaration of function ‘memcpy’ [-Werror=implicit-function-declaration] arch/x86/platform/efi/efi_64.c:139:2: error: implicit declaration of function ‘memcpy’ [-Werror=implicit-function-declaration] arch/x86/include/asm/desc.h:121:2: error: implicit declaration of function ‘memcpy’ [-Werror=implicit-function-declaration] Don't #undef memcpy if KASAN=n. Reported-by: NIngo Molnar <mingo@kernel.org> Reported-by: NSedat Dilek <sedat.dilek@gmail.com> Signed-off-by: NAndrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 769a8089 ("x86, efi, kasan: #undef memset/memcpy/memmove per arch") Link: http://lkml.kernel.org/r/1443544814-20122-1-git-send-email-ryabinin.a.a@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Vitaly Kuznetsov 提交于
Recent changes in the Hyper-V driver: b4370df2 ("Drivers: hv: vmbus: add special crash handler") broke the build when CONFIG_KEXEC_CORE is not set: arch/x86/built-in.o: In function `hv_machine_crash_shutdown': arch/x86/kernel/cpu/mshyperv.c:112: undefined reference to `native_machine_crash_shutdown' Decorate all kexec related code with #ifdef CONFIG_KEXEC_CORE. Reported-by: NJim Davis <jim.epost@gmail.com> Reported-by: NStephen Hemminger <stephen@networkplumber.org> Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: devel@linuxdriverproject.org Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1443002577-25370-1-git-send-email-vkuznets@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 29 9月, 2015 1 次提交
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由 Malcolm Crossley 提交于
Sanitizing the e820 map may produce extra E820 entries which would result in the topmost E820 entries being removed. The removed entries would typically include the top E820 usable RAM region and thus result in the domain having signicantly less RAM available to it. Fix by allowing sanitize_e820_map to use the full size of the allocated E820 array. Signed-off-by: NMalcolm Crossley <malcolm.crossley@citrix.com> Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
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- 28 9月, 2015 4 次提交
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由 Vitaly Kuznetsov 提交于
Currently there is a number of issues preventing PVHVM Xen guests from doing successful kexec/kdump: - Bound event channels. - Registered vcpu_info. - PIRQ/emuirq mappings. - shared_info frame after XENMAPSPACE_shared_info operation. - Active grant mappings. Basically, newly booted kernel stumbles upon already set up Xen interfaces and there is no way to reestablish them. In Xen-4.7 a new feature called 'soft reset' is coming. A guest performing kexec/kdump operation is supposed to call SCHEDOP_shutdown hypercall with SHUTDOWN_soft_reset reason before jumping to new kernel. Hypervisor (with some help from toolstack) will do full domain cleanup (but keeping its memory and vCPU contexts intact) returning the guest to the state it had when it was first booted and thus allowing it to start over. Doing SHUTDOWN_soft_reset on Xen hypervisors which don't support it is probably OK as by default all unknown shutdown reasons cause domain destroy with a message in toolstack log: 'Unknown shutdown reason code 5. Destroying domain.' which gives a clue to what the problem is and eliminates false expectations. Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
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由 Boris Ostrovsky 提交于
For PV guests these registers are set up by hypervisor and thus should not be written by the guest. The comment in xen_write_msr_safe() says so but we still write the MSRs, causing the hypervisor to print a warning. Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
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由 Juergen Gross 提交于
HYPERVISOR_memory_op() is defined to return an "int" value. This is wrong, as the Xen hypervisor will return "long". The sub-function XENMEM_maximum_reservation returns the maximum number of pages for the current domain. An int will overflow for a domain configured with 8TB of memory or more. Correct this by using the correct type. Signed-off-by: NJuergen Gross <jgross@suse.com> Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
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由 Radim Krčmář 提交于
Shifting pvclock_vcpu_time_info.system_time on write to KVM system time MSR is a change of ABI. Probably only 2.6.16 based SLES 10 breaks due to its custom enhancements to kvmclock, but KVM never declared the MSR only for one-shot initialization. (Doc says that only one write is needed.) This reverts commit b7e60c5a. And adds a note to the definition of PVCLOCK_COUNTS_FROM_ZERO. Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com> Acked-by: NMarcelo Tosatti <mtosatti@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 25 9月, 2015 7 次提交
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由 David Hildenbrand 提交于
We observed some performance degradation on s390x with dynamic halt polling. Until we can provide a proper fix, let's enable halt_poll_ns as default only for supported architectures. Architectures are now free to set their own halt_poll_ns default value. Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
29ecd660 ("KVM: x86: avoid uninitialized variable warning", 2015-09-06) introduced a not-so-subtle problem, which probably escaped review because it was not part of the patch context. Before the patch, leaf was always equal to iterator.level. After, it is equal to iterator.level - 1 in the call to is_shadow_zero_bits_set, and when is_shadow_zero_bits_set does another "-1" the check on reserved bits becomes incorrect. Using "iterator.level" in the call fixes this call trace: WARNING: CPU: 2 PID: 17000 at arch/x86/kvm/mmu.c:3385 handle_mmio_page_fault.part.93+0x1a/0x20 [kvm]() Modules linked in: tun sha256_ssse3 sha256_generic drbg binfmt_misc ipv6 vfat fat fuse dm_crypt dm_mod kvm_amd kvm crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd fam15h_power amd64_edac_mod k10temp edac_core amdkfd amd_iommu_v2 radeon acpi_cpufreq [...] Call Trace: dump_stack+0x4e/0x84 warn_slowpath_common+0x95/0xe0 warn_slowpath_null+0x1a/0x20 handle_mmio_page_fault.part.93+0x1a/0x20 [kvm] tdp_page_fault+0x231/0x290 [kvm] ? emulator_pio_in_out+0x6e/0xf0 [kvm] kvm_mmu_page_fault+0x36/0x240 [kvm] ? svm_set_cr0+0x95/0xc0 [kvm_amd] pf_interception+0xde/0x1d0 [kvm_amd] handle_exit+0x181/0xa70 [kvm_amd] ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm] kvm_arch_vcpu_ioctl_run+0x6f6/0x1730 [kvm] ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm] ? preempt_count_sub+0x9b/0xf0 ? mutex_lock_killable_nested+0x26f/0x490 ? preempt_count_sub+0x9b/0xf0 kvm_vcpu_ioctl+0x358/0x710 [kvm] ? __fget+0x5/0x210 ? __fget+0x101/0x210 do_vfs_ioctl+0x2f4/0x560 ? __fget_light+0x29/0x90 SyS_ioctl+0x4c/0x90 entry_SYSCALL_64_fastpath+0x16/0x73 ---[ end trace 37901c8686d84de6 ]--- Reported-by: NBorislav Petkov <bp@alien8.de> Tested-by: NBorislav Petkov <bp@alien8.de> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
Intel CPUID on AMD host or vice versa is a weird case, but it can happen. Handle it by checking the host CPU vendor instead of the guest's in reset_tdp_shadow_zero_bits_mask. For speed, the check uses the fact that Intel EPT has an X (executable) bit while AMD NPT has NX. Reported-by: NBorislav Petkov <bp@alien8.de> Tested-by: NBorislav Petkov <bp@alien8.de> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
kvm_set_cr0 may want to call kvm_zap_gfn_range and thus access the memslots array (SRCU protected). Using a mini SRCU critical section is ugly, and adding it to kvm_arch_vcpu_create doesn't work because the VMX vcpu_create callback calls synchronize_srcu. Fixes this lockdep splat: =============================== [ INFO: suspicious RCU usage. ] 4.3.0-rc1+ #1 Not tainted ------------------------------- include/linux/kvm_host.h:488 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by qemu-system-i38/17000: #0: (&(&kvm->mmu_lock)->rlock){+.+...}, at: kvm_zap_gfn_range+0x24/0x1a0 [kvm] [...] Call Trace: dump_stack+0x4e/0x84 lockdep_rcu_suspicious+0xfd/0x130 kvm_zap_gfn_range+0x188/0x1a0 [kvm] kvm_set_cr0+0xde/0x1e0 [kvm] init_vmcb+0x760/0xad0 [kvm_amd] svm_create_vcpu+0x197/0x250 [kvm_amd] kvm_arch_vcpu_create+0x47/0x70 [kvm] kvm_vm_ioctl+0x302/0x7e0 [kvm] ? __lock_is_held+0x51/0x70 ? __fget+0x101/0x210 do_vfs_ioctl+0x2f4/0x560 ? __fget_light+0x29/0x90 SyS_ioctl+0x4c/0x90 entry_SYSCALL_64_fastpath+0x16/0x73 Reported-by: NBorislav Petkov <bp@alien8.de> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Denys Vlasenko 提交于
On x86, cpu_relax() simply calls rep_nop(), which generates one instruction, PAUSE (aka REP NOP). With this config: http://busybox.net/~vda/kernel_config_OPTIMIZE_INLINING_and_Os gcc-4.7.2 does not always inline rep_nop(): it generates several copies of this: <rep_nop> (16 copies, 194 calls): 55 push %rbp 48 89 e5 mov %rsp,%rbp f3 90 pause 5d pop %rbp c3 retq See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66122 This patch fixes this via s/inline/__always_inline/ on rep_nop() and cpu_relax(). ( Forcing inlining only on rep_nop() causes GCC to deinline cpu_relax(), with almost no change in generated code). text data bss dec hex filename 88118971 19905208 36421632 144445811 89c1173 vmlinux.before 88118139 19905208 36421632 144444979 89c0e33 vmlinux Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443096149-27291-1-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Geliang Tang 提交于
Fixes the following sparse warnings: arch/x86/kernel/cpu/perf_event_msr.c:13:6: warning: symbol 'test_aperfmperf' was not declared. Should it be static? arch/x86/kernel/cpu/perf_event_msr.c:18:6: warning: symbol 'test_intel' was not declared. Should it be static? Signed-off-by: NGeliang Tang <geliangtang@163.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/4588e8ab09638458f2451af572827108be3b4a36.1443123796.git.geliangtang@163.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
This reinstates the following commit: 2c7577a7 ("sched/x86_64: Don't save flags on context switch") which was reverted in: 512255a2 ("Revert 'sched/x86_64: Don't save flags on context switch'") Historically, Linux has always saved and restored EFLAGS across context switches. As far as I know, the only reason to do this is because of the NT flag. In particular, if something calls switch_to() with the NT flag set, then we don't want to leak the NT flag into a different task that might try to IRET and fail because NT is set. Before this commit: 8c7aa698 ("x86_64, entry: Filter RFLAGS.NT on entry from userspace") we could run system call bodies with NT set. This would be a DoS or possibly privilege escalation hole if scheduling in such a system call would leak NT into a different task. Importantly, we don't need to worry about NT being set while preemptible or across page faults. The only way we can schedule due to preemption or a page fault is in an interrupt entry that nests inside the SYSENTER prologue. The CPU will clear NT when entering through an interrupt gate, so we won't schedule with NT set. The only other interesting flags are IOPL and AC. Allowing switch_to() to change IOPL has no effect, as the value loaded during kernel execution doesn't matter at all except between a SYSENTER entry and the subsequent PUSHF, and anythign that interrupts in that window will restore IOPL on return. If we call __switch_to() with AC set, we have bigger problems. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/d4440fdc2a89247bffb7c003d2a9a2952bd46827.1441146105.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 23 9月, 2015 4 次提交
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由 Kristen Carlson Accardi 提交于
Because noitification just isn't right. Signed-off-by: NKristen Carlson Accardi <kristen@linux.intel.com> Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/1442944296-11737-1-git-send-email-kristen@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andrey Ryabinin 提交于
In not-instrumented code KASAN replaces instrumented memset/memcpy/memmove with not-instrumented analogues __memset/__memcpy/__memove. However, on x86 the EFI stub is not linked with the kernel. It uses not-instrumented mem*() functions from arch/x86/boot/compressed/string.c So we don't replace them with __mem*() variants in EFI stub. On ARM64 the EFI stub is linked with the kernel, so we should replace mem*() functions with __mem*(), because the EFI stub runs before KASAN sets up early shadow. So let's move these #undef mem* into arch's asm/efi.h which is also included by the EFI stub. Also, this will fix the warning in 32-bit build reported by kbuild test robot: efi-stub-helper.c:599:2: warning: implicit declaration of function 'memcpy' [akpm@linux-foundation.org: use 80 cols in comment] Signed-off-by: NAndrey Ryabinin <ryabinin.a.a@gmail.com> Reported-by: NFengguang Wu <fengguang.wu@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andy Lutomirski 提交于
The NMI entry code that switches to the normal kernel stack needs to be very careful not to clobber any extra stack slots on the NMI stack. The code is fine under the assumption that SWAPGS is just a normal instruction, but that assumption isn't really true. Use SWAPGS_UNSAFE_STACK instead. This is part of a fix for some random crashes that Sasha saw. Fixes: 9b6e6a83 ("x86/nmi/64: Switch stacks on userspace NMI entry") Reported-and-tested-by: NSasha Levin <sasha.levin@oracle.com> Signed-off-by: NAndy Lutomirski <luto@kernel.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/974bc40edffdb5c2950a5c4977f821a446b76178.1442791737.git.luto@kernel.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Andy Lutomirski 提交于
PARAVIRT_ADJUST_EXCEPTION_FRAME generates this code (using nmi as an example, trimmed for readability): ff 15 00 00 00 00 callq *0x0(%rip) # 2796 <nmi+0x6> 2792: R_X86_64_PC32 pv_irq_ops+0x2c That's a call through a function pointer to regular C function that does nothing on native boots, but that function isn't protected against kprobes, isn't marked notrace, and is certainly not guaranteed to preserve any registers if the compiler is feeling perverse. This is bad news for a CLBR_NONE operation. Of course, if everything works correctly, once paravirt ops are patched, it gets nopped out, but what if we hit this code before paravirt ops are patched in? This can potentially cause breakage that is very difficult to debug. A more subtle failure is possible here, too: if _paravirt_nop uses the stack at all (even just to push RBP), it will overwrite the "NMI executing" variable if it's called in the NMI prologue. The Xen case, perhaps surprisingly, is fine, because it's already written in asm. Fix all of the cases that default to paravirt_nop (including adjust_exception_frame) with a big hammer: replace paravirt_nop with an asm function that is just a ret instruction. The Xen case may have other problems, so document them. This is part of a fix for some random crashes that Sasha saw. Reported-and-tested-by: NSasha Levin <sasha.levin@oracle.com> Signed-off-by: NAndy Lutomirski <luto@kernel.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/8f5d2ba295f9d73751c33d97fda03e0495d9ade0.1442791737.git.luto@kernel.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 21 9月, 2015 2 次提交
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由 Borislav Petkov 提交于
Commit: 3dc33bd3 ("x86/entry/vsyscall: Add CONFIG to control default") did the ifdef/elif thing but GCC doesn't like that: arch/x86/entry/vsyscall/vsyscall_64.c:44:7: warning: "CONFIG_LEGACY_VSYSCALL_NONE" is not defined [-Wundef] #elif CONFIG_LEGACY_VSYSCALL_NONE ^ Use defined() instead. Signed-off-by: NBorislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150921074829.GA3550@pd.tnicSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Paolo Bonzini 提交于
These have roughly the same purpose as the SMRR, which we do not need to implement in KVM. However, Linux accesses MSR_K8_TSEG_ADDR at boot, which causes problems when running a Xen dom0 under KVM. Just return 0, meaning that processor protection of SMRAM is not in effect. Reported-by: NM A Young <m.a.young@durham.ac.uk> Cc: stable@vger.kernel.org Acked-by: NBorislav Petkov <bp@suse.de> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 20 9月, 2015 1 次提交
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由 Kees Cook 提交于
Most modern systems can run with vsyscall=none. In an effort to provide a way for build-time defaults to lack legacy settings, this adds a new CONFIG to select the type of vsyscall mapping to use, similar to the existing "vsyscall" command line parameter. Signed-off-by: NKees Cook <keescook@chromium.org> Acked-by: NAndy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150813005519.GA11696@www.outflux.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 18 9月, 2015 2 次提交
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由 Igor Mammedov 提交于
When INIT/SIPI sequence is sent to VCPU which before that was in use by OS, VMRUN might fail with: KVM: entry failed, hardware error 0xffffffff EAX=00000000 EBX=00000000 ECX=00000000 EDX=000006d3 ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000 EIP=00000000 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 00000000 0000ffff 00009300 CS =9a00 0009a000 0000ffff 00009a00 [...] CR0=60000010 CR2=b6f3e000 CR3=01942000 CR4=000007e0 [...] EFER=0000000000000000 with corresponding SVM error: KVM: FAILED VMRUN WITH VMCB: [...] cpl: 0 efer: 0000000000001000 cr0: 0000000080010010 cr2: 00007fd7fe85bf90 cr3: 0000000187d0c000 cr4: 0000000000000020 [...] What happens is that VCPU state right after offlinig: CR0: 0x80050033 EFER: 0xd01 CR4: 0x7e0 -> long mode with CR3 pointing to longmode page tables and when VCPU gets INIT/SIPI following transition happens CR0: 0 -> 0x60000010 EFER: 0x0 CR4: 0x7e0 -> paging disabled with stale CR3 However SVM under the hood puts VCPU in Paged Real Mode* which effectively translates CR0 0x60000010 -> 80010010 after svm_vcpu_reset() -> init_vmcb() -> kvm_set_cr0() -> svm_set_cr0() but from kvm_set_cr0() perspective CR0: 0 -> 0x60000010 only caching bits are changed and commit d81135a5 ("KVM: x86: do not reset mmu if CR0.CD and CR0.NW are changed")' regressed svm_vcpu_reset() which relied on MMU being reset. As result VMRUN after svm_vcpu_reset() tries to run VCPU in Paged Real Mode with stale MMU context (longmode page tables), which causes some AMD CPUs** to bail out with VMEXIT_INVALID. Fix issue by unconditionally resetting MMU context at init_vmcb() time. * AMD64 Architecture Programmer’s Manual, Volume 2: System Programming, rev: 3.25 15.19 Paged Real Mode ** Opteron 1216 Signed-off-by: NIgor Mammedov <imammedo@redhat.com> Fixes: d81135a5 Cc: stable@vger.kernel.org Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Andi Kleen 提交于
Stephane pointed out that the extrareg mask was one bit too short. The bubble width field was truncated by one bit. Fix that here. Also add some extra comments on the reserved bits inside the event select code. Reported-by: NStephane Eranian <eranian@google.com> Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1441835640-21347-3-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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