kernel.git/arch/x86/power, branch linux-4.17.y

x86/power/64: Fix page-table setup for temporary text mapping

2018-04-20T09:52:00Z

On a system with 4-level page-tables there is no p4d, so the pud in the pgd should be mapped. The old code before commit fb43d6cb91ef already did that. The change from above commit causes an invalid page-table which causes undefined behavior. In one report it caused triple faults. Fix it by changing the p4d back to pud. Fixes: fb43d6cb91ef ('x86/mm: Do not auto-massage page protections') Reported-by: Borislav Petkov Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Tested-by: Michal Kubecek Tested-by: Borislav Petkov Cc: linux-pm@vger.kernel.org Cc: rjw@rjwysocki.net Cc: pavel@ucw.cz Cc: hpa@zytor.com Cc: Dave Hansen Link: https://lkml.kernel.org/r/1524162360-26179-1-git-send-email-joro@8bytes.org

x86/mm: Do not auto-massage page protections

2018-04-12T07:04:22Z

A PTE is constructed from a physical address and a pgprotval_t. __PAGE_KERNEL, for instance, is a pgprot_t and must be converted into a pgprotval_t before it can be used to create a PTE. This is done implicitly within functions like pfn_pte() by massage_pgprot(). However, this makes it very challenging to set bits (and keep them set) if your bit is being filtered out by massage_pgprot(). This moves the bit filtering out of pfn_pte() and friends. For users of PAGE_KERNEL*, filtering will be done automatically inside those macros but for users of __PAGE_KERNEL*, they need to do their own filtering now. Note that we also just move pfn_pte/pmd/pud() over to check_pgprot() instead of massage_pgprot(). This way, we still *look* for unsupported bits and properly warn about them if we find them. This might happen if an unfiltered __PAGE_KERNEL* value was passed in, for instance. - printk format warning fix from: Arnd Bergmann - boot crash fix from: Tom Lendacky - crash bisected by: Mike Galbraith Signed-off-by: Dave Hansen Reported-and-fixed-by: Arnd Bergmann Fixed-by: Tom Lendacky Bisected-by: Mike Galbraith Cc: Andrea Arcangeli Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kees Cook Cc: Linus Torvalds Cc: Nadav Amit Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180406205509.77E1D7F6@viggo.jf.intel.com Signed-off-by: Ingo Molnar

x86/mm: Replace compile-time checks for 5-level paging with runtime-time checks

2018-02-16T09:48:49Z

This patch converts the of CONFIG_X86_5LEVEL check to runtime checks for p4d folding. Signed-off-by: Kirill A. Shutemov Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: Dave Hansen Cc: David Woodhouse Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214182542.69302-9-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar

x86/power: Fix swsusp_arch_resume prototype

2018-02-02T22:33:50Z

The declaration for swsusp_arch_resume marks it as 'asmlinkage', but the definition in x86-32 does not, and it fails to include the header with the declaration. This leads to a warning when building with link-time-optimizations: kernel/power/power.h:108:23: error: type of 'swsusp_arch_resume' does not match original declaration [-Werror=lto-type-mismatch] extern asmlinkage int swsusp_arch_resume(void); ^ arch/x86/power/hibernate_32.c:148:0: note: 'swsusp_arch_resume' was previously declared here int swsusp_arch_resume(void) This moves the declaration into a globally visible header file and fixes up both x86 definitions to match it. Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Cc: Len Brown Cc: Andi Kleen Cc: Nicolas Pitre Cc: linux-pm@vger.kernel.org Cc: "Rafael J. Wysocki" Cc: Pavel Machek Cc: Bart Van Assche Link: https://lkml.kernel.org/r/20180202145634.200291-2-arnd@arndb.de

Merge branch 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-12-18T16:59:15Z

Pull x86 syscall entry code changes for PTI from Ingo Molnar: "The main changes here are Andy Lutomirski's changes to switch the x86-64 entry code to use the 'per CPU entry trampoline stack'. This, besides helping fix KASLR leaks (the pending Page Table Isolation (PTI) work), also robustifies the x86 entry code" * 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) x86/cpufeatures: Make CPU bugs sticky x86/paravirt: Provide a way to check for hypervisors x86/paravirt: Dont patch flush_tlb_single x86/entry/64: Make cpu_entry_area.tss read-only x86/entry: Clean up the SYSENTER_stack code x86/entry/64: Remove the SYSENTER stack canary x86/entry/64: Move the IST stacks into struct cpu_entry_area x86/entry/64: Create a per-CPU SYSCALL entry trampoline x86/entry/64: Return to userspace from the trampoline stack x86/entry/64: Use a per-CPU trampoline stack for IDT entries x86/espfix/64: Stop assuming that pt_regs is on the entry stack x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0 x86/entry: Remap the TSS into the CPU entry area x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct x86/dumpstack: Handle stack overflow on all stacks x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss x86/kasan/64: Teach KASAN about the cpu_entry_area x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area x86/entry/gdt: Put per-CPU GDT remaps in ascending order x86/dumpstack: Add get_stack_info() support for the SYSENTER stack ...

x86/entry: Remap the TSS into the CPU entry area

2017-12-17T12:59:56Z

This has a secondary purpose: it puts the entry stack into a region with a well-controlled layout. A subsequent patch will take advantage of this to streamline the SYSCALL entry code to be able to find it more easily. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Reviewed-by: Borislav Petkov Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Dave Hansen Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150605.962042855@linutronix.de Signed-off-by: Ingo Molnar

x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss

2017-12-17T12:59:55Z

A future patch will move SYSENTER_stack to the beginning of cpu_tss to help detect overflow. Before this can happen, fix several code paths that hardcode assumptions about the old layout. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Reviewed-by: Borislav Petkov Reviewed-by: Dave Hansen Reviewed-by: Thomas Gleixner Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150605.722425540@linutronix.de Signed-off-by: Ingo Molnar

x86/power: Make restore_processor_context() sane

2017-12-15T11:21:38Z

My previous attempt to fix a couple of bugs in __restore_processor_context(): 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") ... introduced yet another bug, breaking suspend-resume. Rather than trying to come up with a minimal fix, let's try to clean it up for real. This patch fixes quite a few things: - The old code saved a nonsensical subset of segment registers. The only registers that need to be saved are those that contain userspace state or those that can't be trivially restored without percpu access working. (On x86_32, we can restore percpu access by writing __KERNEL_PERCPU to %fs. On x86_64, it's easier to save and restore the kernel's GSBASE.) With this patch, we restore hardcoded values to the kernel state where applicable and explicitly restore the user state after fixing all the descriptor tables. - We used to use an unholy mix of inline asm and C helpers for segment register access. Let's get rid of the inline asm. This fixes the reported s2ram hangs and make the code all around more logical. Analyzed-by: Linus Torvalds Reported-by: Jarkko Nikula Reported-by: Pavel Machek Tested-by: Jarkko Nikula Tested-by: Pavel Machek Signed-off-by: Andy Lutomirski Acked-by: Rafael J. Wysocki Acked-by: Thomas Gleixner Cc: Borislav Petkov Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Zhang Rui Fixes: 5b06bbcfc2c6 ("x86/power: Fix some ordering bugs in __restore_processor_context()") Link: http://lkml.kernel.org/r/398ee68e5c0f766425a7b746becfc810840770ff.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar

x86/power/32: Move SYSENTER MSR restoration to fix_processor_context()

2017-12-15T11:18:29Z

x86_64 restores system call MSRs in fix_processor_context(), and x86_32 restored them along with segment registers. The 64-bit variant makes more sense, so move the 32-bit code to match the 64-bit code. No side effects are expected to runtime behavior. Tested-by: Jarkko Nikula Signed-off-by: Andy Lutomirski Acked-by: Rafael J. Wysocki Acked-by: Thomas Gleixner Cc: Borislav Petkov Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Zhang Rui Link: http://lkml.kernel.org/r/65158f8d7ee64dd6bbc6c1c83b3b34aaa854e3ae.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar

x86/power/64: Use struct desc_ptr for the IDT in struct saved_context

2017-12-15T11:18:29Z

x86_64's saved_context nonsensically used separate idt_limit and idt_base fields and then cast &idt_limit to struct desc_ptr *. This was correct (with -fno-strict-aliasing), but it's confusing, served no purpose, and required #ifdeffery. Simplify this by using struct desc_ptr directly. No change in functionality. Tested-by: Jarkko Nikula Signed-off-by: Andy Lutomirski Acked-by: Rafael J. Wysocki Acked-by: Thomas Gleixner Cc: Borislav Petkov Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Zhang Rui Link: http://lkml.kernel.org/r/967909ce38d341b01d45eff53e278e2728a3a93a.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar