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2018-10-03x86-32, hibernate: Adjust in_suspend after resumed on 32bit systemZhimin Gu
Update the in_suspend variable to reflect the actual hibernation status. Back-port from 64bit system. Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86-32, hibernate: Set up temporary text mapping for 32bit systemZhimin Gu
Set up the temporary text mapping for the final jump address so that the system could jump to the right address after all the pages have been copied back to their original address - otherwise the final mapping for the jump address is invalid. Analogous changes were made for 64-bit in commit 65c0554b73c9 (x86/power/64: Fix kernel text mapping corruption during image restoration). Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86-32, hibernate: Switch to relocated restore code during resume on 32bit ↵Zhimin Gu
system On 64bit system, code should be executed in a safe page during page restoring, as the page where instruction is running during resume might be scribbled and causes issues. Although on 32 bit, we only suspend resuming by same kernel that did the suspend, we'd like to remove that restriction in the future. Porting corresponding code from 64bit system: Allocate a safe page, and copy the restore code to it, then jump to the safe page to run the code. Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86-32, hibernate: Switch to original page table after resumedZhimin Gu
After all the pages are restored to previous address, the page table switches back to current swapper_pg_dir. However the swapper_pg_dir currently in used might not be consistent with previous page table, which might cause issue after resume. Fix this issue by switching to original page table after resume, and the address of the original page table is saved in the hibernation image header. Move the manipulation of restore_cr3 into common code blocks. Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86-32, hibernate: Use the page size macro instead of constant valueZhimin Gu
Convert the hard code into PAGE_SIZE for better scalability. No functional change. Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86-32, hibernate: Use temp_pgt as the temporary page tableZhimin Gu
This is to reuse the temp_pgt for both 32bit and 64bit system. No intentional behavior change. Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86, hibernate: Rename temp_level4_pgt to temp_pgtZhimin Gu
As 32bit system is not using 4-level page, rename it to temp_pgt so that it can be reused for both 32bit and 64bit hibernation. No functional change. Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86-32, hibernate: Enable CONFIG_ARCH_HIBERNATION_HEADER on 32bit systemZhimin Gu
Enable CONFIG_ARCH_HIBERNATION_HEADER for 32bit system so that 1. arch_hibernation_header_save/restore() are invoked across hibernation on 32bit system. 2. The checksum handling as well as 'magic' number checking for 32bit system are enabled. Controlled by CONFIG_X86_64 in hibernate.c Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86, hibernate: Extract the common code of 64/32 bit systemZhimin Gu
Reduce the hibernation code duplication between x86-32 and x86-64 by extracting the common code into hibernate.c. Currently only pfn_is_nosave() is the activated common function in hibernate.c No functional change. Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03x86-32/asm/power: Create stack frames in hibernate_asm_32.SZhimin Gu
swsusp_arch_suspend() is callable non-leaf function which doesn't honor CONFIG_FRAME_POINTER, which can result in bad stack traces. Also it's not annotated as ELF callable function which can confuse tooling. Create a stack frame for it when CONFIG_FRAME_POINTER is enabled and give it proper ELF function annotation. Also in this patch introduces the restore_registers() symbol and gives it ELF function annotation, thus to prepare for later register restore. Analogous changes were made for 64bit before in commit ef0f3ed5a4ac (x86/asm/power: Create stack frames in hibernate_asm_64.S) and commit 4ce827b4cc58 (x86/power/64: Fix hibernation return address corruption). Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03PM / hibernate: Check the success of generating md5 digest before hibernationChen Yu
Currently if get_e820_md5() fails, then it will hibernate nevertheless. Actually the error code should be propagated to upper caller so that the hibernation could be aware of the result and terminates the process if md5 digest fails. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-08-14Merge tag 'pm-4.19-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These add a new framework for CPU idle time injection, to be used by all of the idle injection code in the kernel in the future, fix some issues and add a number of relatively small extensions in multiple places. Specifics: - Add a new framework for CPU idle time injection (Daniel Lezcano). - Add AVS support to the armada-37xx cpufreq driver (Gregory CLEMENT). - Add support for current CPU frequency reporting to the ACPI CPPC cpufreq driver (George Cherian). - Rework the cooling device registration in the imx6q/thermal driver (Bastian Stender). - Make the pcc-cpufreq driver refuse to work with dynamic scaling governors on systems with many CPUs to avoid scalability issues with it (Rafael Wysocki). - Fix the intel_pstate driver to report different maximum CPU frequencies on systems where they really are different and to ignore the turbo active ratio if hardware-managend P-states (HWP) are in use; make it use the match_string() helper (Xie Yisheng, Srinivas Pandruvada). - Fix a minor deferred probe issue in the qcom-kryo cpufreq driver (Niklas Cassel). - Add a tracepoint for the tracking of frequency limits changes (from Andriod) to the cpufreq core (Ruchi Kandoi). - Fix a circular lock dependency between CPU hotplug and sysfs locking in the cpufreq core reported by lockdep (Waiman Long). - Avoid excessive error reports on driver registration failures in the ARM cpuidle driver (Sudeep Holla). - Add a new device links flag to the driver core to make links go away automatically on supplier driver removal (Vivek Gautam). - Eliminate potential race condition between system-wide power management transitions and system shutdown (Pingfan Liu). - Add a quirk to save NVS memory on system suspend for the ASUS 1025C laptop (Willy Tarreau). - Make more systems use suspend-to-idle (instead of ACPI S3) by default (Tristian Celestin). - Get rid of stack VLA usage in the low-level hibernation code on 64-bit x86 (Kees Cook). - Fix error handling in the hibernation core and mark an expected fall-through switch in it (Chengguang Xu, Gustavo Silva). - Extend the generic power domains (genpd) framework to support attaching a device to a power domain by name (Ulf Hansson). - Fix device reference counting and user limits initialization in the devfreq core (Arvind Yadav, Matthias Kaehlcke). - Fix a few issues in the rk3399_dmc devfreq driver and improve its documentation (Enric Balletbo i Serra, Lin Huang, Nick Milner). - Drop a redundant error message from the exynos-ppmu devfreq driver (Markus Elfring)" * tag 'pm-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (35 commits) PM / reboot: Eliminate race between reboot and suspend PM / hibernate: Mark expected switch fall-through cpufreq: intel_pstate: Ignore turbo active ratio in HWP cpufreq: Fix a circular lock dependency problem cpu/hotplug: Add a cpus_read_trylock() function x86/power/hibernate_64: Remove VLA usage cpufreq: trace frequency limits change cpufreq: intel_pstate: Show different max frequency with turbo 3 and HWP cpufreq: pcc-cpufreq: Disable dynamic scaling on many-CPU systems cpufreq: qcom-kryo: Silently error out on EPROBE_DEFER cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC cpufreq: armada-37xx: Add AVS support dt-bindings: marvell: Add documentation for the Armada 3700 AVS binding PM / devfreq: rk3399_dmc: Fix duplicated opp table on reload. PM / devfreq: Init user limits from OPP limits, not viceversa PM / devfreq: rk3399_dmc: fix spelling mistakes. PM / devfreq: rk3399_dmc: do not print error when get supply and clk defer. dt-bindings: devfreq: rk3399_dmc: move interrupts to be optional. PM / devfreq: rk3399_dmc: remove wait for dcf irq event. dt-bindings: clock: add rk3399 DDR3 standard speed bins. ...
2018-07-26x86/power/hibernate_64: Remove VLA usageKees Cook
In the quest to remove all stack VLA usage from the kernel [1], this removes the discouraged use of AHASH_REQUEST_ON_STACK by switching to shash directly and allocating the descriptor in heap memory (which should be fine: the tfm has already been allocated there too). Link: https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com # [1] Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-07-03x86/asm/64: Use 32-bit XOR to zero registersJan Beulich
Some Intel CPUs don't recognize 64-bit XORs as zeroing idioms. Zeroing idioms don't require execution bandwidth, as they're being taken care of in the frontend (through register renaming). Use 32-bit XORs instead. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Andy Lutomirski <luto@kernel.org> 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 Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: herbert@gondor.apana.org.au Cc: pavel@ucw.cz Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/5B39FF1A02000078001CFB54@prv1-mh.provo.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-19x86/mm: Stop pretending pgtable_l5_enabled is a variableKirill A. Shutemov
pgtable_l5_enabled is defined using cpu_feature_enabled() but we refer to it as a variable. This is misleading. Make pgtable_l5_enabled() a function. We cannot literally define it as a function due to circular dependencies between header files. Function-alike macros is close enough. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180518103528.59260-4-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-20x86/power/64: Fix page-table setup for temporary text mappingJoerg Roedel
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 <bp@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michal Kubecek <mkubecek@suse.cz> Tested-by: Borislav Petkov <bp@suse.de> Cc: linux-pm@vger.kernel.org Cc: rjw@rjwysocki.net Cc: pavel@ucw.cz Cc: hpa@zytor.com Cc: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/1524162360-26179-1-git-send-email-joro@8bytes.org
2018-04-12x86/mm: Do not auto-massage page protectionsDave Hansen
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 <arnd@arndb.de> - boot crash fix from: Tom Lendacky <thomas.lendacky@amd.com> - crash bisected by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reported-and-fixed-by: Arnd Bergmann <arnd@arndb.de> Fixed-by: Tom Lendacky <thomas.lendacky@amd.com> Bisected-by: Mike Galbraith <efault@gmx.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180406205509.77E1D7F6@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-16x86/mm: Replace compile-time checks for 5-level paging with runtime-time checksKirill A. Shutemov
This patch converts the of CONFIG_X86_5LEVEL check to runtime checks for p4d folding. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214182542.69302-9-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-02x86/power: Fix swsusp_arch_resume prototypeArnd Bergmann
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 <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Len Brown <len.brown@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Nicolas Pitre <nico@linaro.org> Cc: linux-pm@vger.kernel.org Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Bart Van Assche <bart.vanassche@wdc.com> Link: https://lkml.kernel.org/r/20180202145634.200291-2-arnd@arndb.de
2017-12-18Merge branch 'WIP.x86-pti.entry-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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 ...
2017-12-17x86/entry: Remap the TSS into the CPU entry areaAndy Lutomirski
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 <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bpetkov@suse.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> 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 <mingo@kernel.org>
2017-12-17x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tssAndy Lutomirski
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 <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> 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 <mingo@kernel.org>
2017-12-15x86/power: Make restore_processor_context() saneAndy Lutomirski
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 <torvalds@linux-foundation.org> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> 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 <mingo@kernel.org>
2017-12-15x86/power/32: Move SYSENTER MSR restoration to fix_processor_context()Andy Lutomirski
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 <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Link: http://lkml.kernel.org/r/65158f8d7ee64dd6bbc6c1c83b3b34aaa854e3ae.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15x86/power/64: Use struct desc_ptr for the IDT in struct saved_contextAndy Lutomirski
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 <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Zhang Rui <rui.zhang@intel.com> Link: http://lkml.kernel.org/r/967909ce38d341b01d45eff53e278e2728a3a93a.1513286253.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-06x86/power: Fix some ordering bugs in __restore_processor_context()Andy Lutomirski
__restore_processor_context() had a couple of ordering bugs. It restored GSBASE after calling load_gs_index(), and the latter can call into tracing code. It also tried to restore segment registers before restoring the LDT, which is straight-up wrong. Reorder the code so that we restore GSBASE, then the descriptor tables, then the segments. This fixes two bugs. First, it fixes a regression that broke resume under certain configurations due to irqflag tracing in native_load_gs_index(). Second, it fixes resume when the userspace process that initiated suspect had funny segments. The latter can be reproduced by compiling this: // SPDX-License-Identifier: GPL-2.0 /* * ldt_echo.c - Echo argv[1] while using an LDT segment */ int main(int argc, char **argv) { int ret; size_t len; char *buf; const struct user_desc desc = { .entry_number = 0, .base_addr = 0, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0 }; if (argc != 2) errx(1, "Usage: %s STRING", argv[0]); len = asprintf(&buf, "%s\n", argv[1]); if (len < 0) errx(1, "Out of memory"); ret = syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)); if (ret < -1) errno = -ret; if (ret) err(1, "modify_ldt"); asm volatile ("movw %0, %%es" :: "rm" ((unsigned short)7)); write(1, buf, len); return 0; } and running ldt_echo >/sys/power/mem Without the fix, the latter causes a triple fault on resume. Fixes: ca37e57bbe0c ("x86/entry/64: Add missing irqflags tracing to native_load_gs_index()") Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/6b31721ea92f51ea839e79bd97ade4a75b1eeea2.1512057304.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-14dmi: Mark all struct dmi_system_id instances constChristoph Hellwig
... and __initconst if applicable. Based on similar work for an older kernel in the Grsecurity patch. [JD: fix toshiba-wmi build] [JD: add htcpen] [JD: move __initconst where checkscript wants it] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jean Delvare <jdelvare@suse.de>
2017-09-13x86/hibernate/64: Mask off CR3's PCID bits in the saved CR3Andy Lutomirski
Jiri reported a resume-from-hibernation failure triggered by PCID. The root cause appears to be rather odd. The hibernation asm restores a CR3 value that comes from the image header. If the image kernel has PCID on, it's entirely reasonable for this CR3 value to have one of the low 12 bits set. The restore code restores it with CR4.PCIDE=0, which means that those low 12 bits are accepted by the CPU but are either ignored or interpreted as a caching mode. This is odd, but still works. We blow up later when the image kernel restores CR4, though, since changing CR4.PCIDE with CR3[11:0] != 0 is illegal. Boom! FWIW, it's entirely unclear to me what's supposed to happen if a PAE kernel restores a non-PAE image or vice versa. Ditto for LA57. Reported-by: Jiri Kosina <jikos@kernel.org> Tested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 660da7c9228f ("x86/mm: Enable CR4.PCIDE on supported systems") Link: http://lkml.kernel.org/r/18ca57090651a6341e97083883f9e814c4f14684.1504847163.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-06x86/mm: Reinitialize TLB state on hotplug and resumeAndy Lutomirski
When Linux brings a CPU down and back up, it switches to init_mm and then loads swapper_pg_dir into CR3. With PCID enabled, this has the side effect of masking off the ASID bits in CR3. This can result in some confusion in the TLB handling code. If we bring a CPU down and back up with any ASID other than 0, we end up with the wrong ASID active on the CPU after resume. This could cause our internal state to become corrupt, although major corruption is unlikely because init_mm doesn't have any user pages. More obviously, if CONFIG_DEBUG_VM=y, we'll trip over an assertion in the next context switch. The result of *that* is a failure to resume from suspend with probability 1 - 1/6^(cpus-1). Fix it by reinitializing cpu_tlbstate on resume and CPU bringup. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jiri Kosina <jikos@kernel.org> Fixes: 10af6235e0d3 ("x86/mm: Implement PCID based optimization: try to preserve old TLB entries using PCID") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-04Merge tag 'pm-4.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "The big ticket items here are the rework of suspend-to-idle in order to add proper support for power button wakeup from it on recent Dell laptops and the rework of interfaces exporting the current CPU frequency on x86. In addition to that, support for a few new pieces of hardware is added, the PCI/ACPI device wakeup infrastructure is simplified significantly and the wakeup IRQ framework is fixed to unbreak the IRQ bus locking infrastructure. Also, there are some functional improvements for intel_pstate, tools updates and small fixes and cleanups all over. Specifics: - Rework suspend-to-idle to allow it to take wakeup events signaled by the EC into account on ACPI-based platforms in order to properly support power button wakeup from suspend-to-idle on recent Dell laptops (Rafael Wysocki). That includes the core suspend-to-idle code rework, support for the Low Power S0 _DSM interface, and support for the ACPI INT0002 Virtual GPIO device from Hans de Goede (required for USB keyboard wakeup from suspend-to-idle to work on some machines). - Stop trying to export the current CPU frequency via /proc/cpuinfo on x86 as that is inaccurate and confusing (Len Brown). - Rework the way in which the current CPU frequency is exported by the kernel (over the cpufreq sysfs interface) on x86 systems with the APERF and MPERF registers by always using values read from these registers, when available, to compute the current frequency regardless of which cpufreq driver is in use (Len Brown). - Rework the PCI/ACPI device wakeup infrastructure to remove the questionable and artificial distinction between "devices that can wake up the system from sleep states" and "devices that can generate wakeup signals in the working state" from it, which allows the code to be simplified quite a bit (Rafael Wysocki). - Fix the wakeup IRQ framework by making it use SRCU instead of RCU which doesn't allow sleeping in the read-side critical sections, but which in turn is expected to be allowed by the IRQ bus locking infrastructure (Thomas Gleixner). - Modify some computations in the intel_pstate driver to avoid rounding errors resulting from them (Srinivas Pandruvada). - Reduce the overhead of the intel_pstate driver in the HWP (hardware-managed P-states) mode and when the "performance" P-state selection algorithm is in use by making it avoid registering scheduler callbacks in those cases (Len Brown). - Rework the energy_performance_preference sysfs knob in intel_pstate by changing the values that correspond to different symbolic hint names used by it (Len Brown). - Make it possible to use more than one cpuidle driver at the same time on ARM (Daniel Lezcano). - Make it possible to prevent the cpuidle menu governor from using the 0 state by disabling it via sysfs (Nicholas Piggin). - Add support for FFH (Fixed Functional Hardware) MWAIT in ACPI C1 on AMD systems (Yazen Ghannam). - Make the CPPC cpufreq driver take the lowest nonlinear performance information into account (Prashanth Prakash). - Add support for hi3660 to the cpufreq-dt driver, fix the imx6q driver and clean up the sfi, exynos5440 and intel_pstate drivers (Colin Ian King, Krzysztof Kozlowski, Octavian Purdila, Rafael Wysocki, Tao Wang). - Fix a few minor issues in the generic power domains (genpd) framework and clean it up somewhat (Krzysztof Kozlowski, Mikko Perttunen, Viresh Kumar). - Fix a couple of minor issues in the operating performance points (OPP) framework and clean it up somewhat (Viresh Kumar). - Fix a CONFIG dependency in the hibernation core and clean it up slightly (Balbir Singh, Arvind Yadav, BaoJun Luo). - Add rk3228 support to the rockchip-io adaptive voltage scaling (AVS) driver (David Wu). - Fix an incorrect bit shift operation in the RAPL power capping driver (Adam Lessnau). - Add support for the EPP field in the HWP (hardware managed P-states) control register, HWP.EPP, to the x86_energy_perf_policy tool and update msr-index.h with HWP.EPP values (Len Brown). - Fix some minor issues in the turbostat tool (Len Brown). - Add support for AMD family 0x17 CPUs to the cpupower tool and fix a minor issue in it (Sherry Hurwitz). - Assorted cleanups, mostly related to the constification of some data structures (Arvind Yadav, Joe Perches, Kees Cook, Krzysztof Kozlowski)" * tag 'pm-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (69 commits) cpufreq: Update scaling_cur_freq documentation cpufreq: intel_pstate: Clean up after performance governor changes PM: hibernate: constify attribute_group structures. cpuidle: menu: allow state 0 to be disabled intel_idle: Use more common logging style PM / Domains: Fix missing default_power_down_ok comment PM / Domains: Fix unsafe iteration over modified list of domains PM / Domains: Fix unsafe iteration over modified list of domain providers PM / Domains: Fix unsafe iteration over modified list of device links PM / Domains: Handle safely genpd_syscore_switch() call on non-genpd device PM / Domains: Call driver's noirq callbacks PM / core: Drop run_wake flag from struct dev_pm_info PCI / PM: Simplify device wakeup settings code PCI / PM: Drop pme_interrupt flag from struct pci_dev ACPI / PM: Consolidate device wakeup settings code ACPI / PM: Drop run_wake from struct acpi_device_wakeup_flags PM / QoS: constify *_attribute_group. PM / AVS: rockchip-io: add io selectors and supplies for rk3228 powercap/RAPL: prevent overridding bits outside of the mask PM / sysfs: Constify attribute groups ...
2017-07-03Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "The main changes in this cycle were: - Continued work to add support for 5-level paging provided by future Intel CPUs. In particular we switch the x86 GUP code to the generic implementation. (Kirill A. Shutemov) - Continued work to add PCID CPU support to native kernels as well. In this round most of the focus is on reworking/refreshing the TLB flush infrastructure for the upcoming PCID changes. (Andy Lutomirski)" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) x86/mm: Delete a big outdated comment about TLB flushing x86/mm: Don't reenter flush_tlb_func_common() x86/KASLR: Fix detection 32/64 bit bootloaders for 5-level paging x86/ftrace: Exclude functions in head64.c from function-tracing x86/mmap, ASLR: Do not treat unlimited-stack tasks as legacy mmap x86/mm: Remove reset_lazy_tlbstate() x86/ldt: Simplify the LDT switching logic x86/boot/64: Put __startup_64() into .head.text x86/mm: Add support for 5-level paging for KASLR x86/mm: Make kernel_physical_mapping_init() support 5-level paging x86/mm: Add sync_global_pgds() for configuration with 5-level paging x86/boot/64: Add support of additional page table level during early boot x86/boot/64: Rename init_level4_pgt and early_level4_pgt x86/boot/64: Rewrite startup_64() in C x86/boot/compressed: Enable 5-level paging during decompression stage x86/boot/efi: Define __KERNEL32_CS GDT on 64-bit configurations x86/boot/efi: Fix __KERNEL_CS definition of GDT entry on 64-bit configurations x86/boot/efi: Cleanup initialization of GDT entries x86/asm: Fix comment in return_from_SYSCALL_64() x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation ...
2017-06-30objtool, x86: Add several functions and files to the objtool whitelistJosh Poimboeuf
In preparation for an objtool rewrite which will have broader checks, whitelist functions and files which cause problems because they do unusual things with the stack. These whitelists serve as a TODO list for which functions and files don't yet have undwarf unwinder coverage. Eventually most of the whitelists can be removed in favor of manual CFI hint annotations or objtool improvements. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/7f934a5d707a574bda33ea282e9478e627fb1829.1498659915.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-22x86/power/64: Use char arrays for asm function namesKees Cook
This switches the hibernate_64.S function names into character arrays to match other areas of the kernel where this is done (e.g., linker scripts). Specifically this fixes a compile-time error noticed by the future CONFIG_FORTIFY_SOURCE routines that complained about PAGE_SIZE being copied out of the "single byte" core_restore_code variable. Additionally drops the "acpi_save_state_mem" exern which does not appear to be used anywhere else in the kernel. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-13x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3()Andy Lutomirski
The kernel has several code paths that read CR3. Most of them assume that CR3 contains the PGD's physical address, whereas some of them awkwardly use PHYSICAL_PAGE_MASK to mask off low bits. Add explicit mask macros for CR3 and convert all of the CR3 readers. This will keep them from breaking when PCID is enabled. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> 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 Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-08x86/mm: Add support for gbpages to kernel_ident_mapping_init()Xunlei Pang
Kernel identity mappings on x86-64 kernels are created in two ways: by the early x86 boot code, or by kernel_ident_mapping_init(). Native kernels (which is the dominant usecase) use the former, but the kexec and the hibernation code uses kernel_ident_mapping_init(). There's a subtle difference between these two ways of how identity mappings are created, the current kernel_ident_mapping_init() code creates identity mappings always using 2MB page(PMD level) - while the native kernel boot path also utilizes gbpages where available. This difference is suboptimal both for performance and for memory usage: kernel_ident_mapping_init() needs to allocate pages for the page tables when creating the new identity mappings. This patch adds 1GB page(PUD level) support to kernel_ident_mapping_init() to address these concerns. The primary advantage would be better TLB coverage/performance, because we'd utilize 1GB TLBs instead of 2MB ones. It is also useful for machines with large number of memory to save paging structure allocations(around 4MB/TB using 2MB page) when setting identity mappings for all the memory, after using 1GB page it will consume only 8KB/TB. ( Note that this change alone does not activate gbpages in kexec, we are doing that in a separate patch. ) Signed-off-by: Xunlei Pang <xlpang@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: akpm@linux-foundation.org Cc: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/1493862171-8799-1-git-send-email-xlpang@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-11Merge branch 'x86/boot' into x86/mm, to avoid conflictIngo Molnar
There's a conflict between ongoing level-5 paging support and the E820 rewrite. Since the E820 rewrite is essentially ready, merge it into x86/mm to reduce tree conflicts. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16x86: Remap GDT tables in the fixmap sectionThomas Garnier
Each processor holds a GDT in its per-cpu structure. The sgdt instruction gives the base address of the current GDT. This address can be used to bypass KASLR memory randomization. With another bug, an attacker could target other per-cpu structures or deduce the base of the main memory section (PAGE_OFFSET). This patch relocates the GDT table for each processor inside the fixmap section. The space is reserved based on number of supported processors. For consistency, the remapping is done by default on 32 and 64-bit. Each processor switches to its remapped GDT at the end of initialization. For hibernation, the main processor returns with the original GDT and switches back to the remapping at completion. This patch was tested on both architectures. Hibernation and KVM were both tested specially for their usage of the GDT. Thanks to Boris Ostrovsky <boris.ostrovsky@oracle.com> for testing and recommending changes for Xen support. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@suse.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Luis R . Rodriguez <mcgrof@kernel.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rafael J . Wysocki <rjw@rjwysocki.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: kasan-dev@googlegroups.com Cc: kernel-hardening@lists.openwall.com Cc: kvm@vger.kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pm@vger.kernel.org Cc: xen-devel@lists.xenproject.org Cc: zijun_hu <zijun_hu@htc.com> Link: http://lkml.kernel.org/r/20170314170508.100882-2-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-14x86/power: Add 5-level paging supportKirill A. Shutemov
set_up_temporary_text_mapping() and relocate_restore_code() require adjustments to handle additional page table level. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170313143309.16020-7-kirill.shutemov@linux.intel.com [ Minor readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-14x86/mm: Convert trivial cases of page table walk to 5-level pagingKirill A. Shutemov
This patch only covers simple cases. Less trivial cases will be converted with separate patches. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170313143309.16020-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Rename e820_table_saved to e820_table_firmware and improve ↵Ingo Molnar
the description So the 'e820_table_saved' is a bit of a misnomer that hides its real purpose. At first sight the name suggests that it's some sort save/restore mechanism, as this is how we typically name such facilities in the kernel. But that is not so, e820_table_saved is the original firmware version of the e820 table, not modified by the kernel. This table is displayed in the /sys/firmware/memmap file, and it's also used by the hibernation code to calculate a physical memory layout MD5 fingerprint checksum which is invariant of the kernel. So rename it to 'e820_table_firmware' and update all the comments to better describe the main e820 data strutures. Also rename: 'initial_e820_table_saved' => 'e820_table_firmware_init' 'e820_update_range_saved' => 'e820_update_range_firmware' ... to better match the new nomenclature. No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Harmonize the 'struct e820_table' fieldsIngo Molnar
So the e820_table->map and e820_table->nr_map names are a bit confusing, because it's not clear what a 'map' really means (it could be a bitmap, or some other data structure), nor is it clear what nr_map means (is it a current index, or some other count). Rename the fields from: e820_table->map => e820_table->entries e820_table->nr_map => e820_table->nr_entries which makes it abundantly clear that these are entries of the table, and that the size of the table is ->nr_entries. Propagate the changes to all affected files. Where necessary, adjust local variable names to better reflect the new field names. No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Rename everything to e820_tableIngo Molnar
No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Rename 'e820_map' variables to 'e820_array'Ingo Molnar
In line with the rename to 'struct e820_array', harmonize the naming of common e820 table variable names as well: e820 => e820_array e820_saved => e820_array_saved e820_map => e820_array initial_e820 => e820_array_init This makes the variable names more consistent and easier to grep for. No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Rename the basic e820 data types to 'struct e820_entry' and ↵Ingo Molnar
'struct e820_array' The 'e820entry' and 'e820map' names have various annoyances: - the missing underscore departs from the usual kernel style and makes the code look weird, - in the past I kept confusing the 'map' with the 'entry', because a 'map' is ambiguous in that regard, - it's not really clear from the 'e820map' that this is a regular C array. Rename them to 'struct e820_entry' and 'struct e820_array' accordingly. ( Leave the legacy UAPI header alone but do the rename in the bootparam.h and e820/types.h file - outside tools relying on these defines should either adjust their code, or should use the legacy header, or should create their private copies for the definitions. ) No change in functionality. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28x86/boot/e820: Remove spurious asm/e820/api.h inclusionsIngo Molnar
A commonly used lowlevel x86 header, asm/pgtable.h, includes asm/e820/api.h spuriously, without making direct use of it. Removing it is not simple: over the years various .c code learned to rely on this indirect inclusion. Remove the unnecessary include - this should speed up the kernel build a bit, as a large header is not included anymore in totally unrelated code. Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-18Merge branch 'x86-timers-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "This is the last functional update from the tip tree for 4.10. It got delayed due to a newly reported and anlyzed variant of BIOS bug and the resulting wreckage: - Seperation of TSC being marked realiable and the fact that the platform provides the TSC frequency via CPUID/MSRs and making use for it for GOLDMONT. - TSC adjust MSR validation and sanitizing: The TSC adjust MSR contains the offset to the hardware counter. The sum of the adjust MSR and the counter is the TSC value which is read via RDTSC. On at least two machines from different vendors the BIOS sets the TSC adjust MSR to negative values. This happens on cold and warm boot. While on cold boot the offset is a few milliseconds, on warm boot it basically compensates the power on time of the system. The BIOSes are not even using the adjust MSR to set all CPUs in the package to the same offset. The offsets are different which renders the TSC unusable, What's worse is that the TSC deadline timer has a HW feature^Wbug. It malfunctions when the TSC adjust value is negative or greater equal 0x80000000 resulting in silent boot failures, hard lockups or non firing timers. This looks like some hardware internal 32/64bit issue with a sign extension problem. Intel has been silent so far on the issue. The update contains sanity checks and keeps the adjust register within working limits and in sync on the package. As it looks like this disease is spreading via BIOS crapware, we need to address this urgently as the boot failures are hard to debug for users" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tsc: Limit the adjust value further x86/tsc: Annotate printouts as firmware bug x86/tsc: Force TSC_ADJUST register to value >= zero x86/tsc: Validate TSC_ADJUST after resume x86/tsc: Validate cpumask pointer before accessing it x86/tsc: Fix broken CONFIG_X86_TSC=n build x86/tsc: Try to adjust TSC if sync test fails x86/tsc: Prepare warp test for TSC adjustment x86/tsc: Move sync cleanup to a safe place x86/tsc: Sync test only for the first cpu in a package x86/tsc: Verify TSC_ADJUST from idle x86/tsc: Store and check TSC ADJUST MSR x86/tsc: Detect random warps x86/tsc: Use X86_FEATURE_TSC_ADJUST in detect_art() x86/tsc: Finalize the split of the TSC_RELIABLE flag x86/tsc: Set TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Atom SoCs x86/tsc: Mark Intel ATOM_GOLDMONT TSC reliable x86/tsc: Mark TSC frequency determined by CPUID as known x86/tsc: Add X86_FEATURE_TSC_KNOWN_FREQ flag
2016-12-15x86/tsc: Validate TSC_ADJUST after resumeThomas Gleixner
Some 'feature' BIOSes fiddle with the TSC_ADJUST register during suspend/resume which renders the TSC unusable. Add sanity checks into the resume path and restore the original value if it was adjusted. Reported-and-tested-by: Roland Scheidegger <rscheidegger_lists@hispeed.ch> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Bruce Schlobohm <bruce.schlobohm@intel.com> Cc: Kevin Stanton <kevin.b.stanton@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Allen Hung <allen_hung@dell.com> Cc: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/20161213131211.317654500@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-14PM / hibernate: Verify the consistent of e820 memory map by md5 digestChen Yu
On some platforms, there is occasional panic triggered when trying to resume from hibernation, a typical panic looks like: "BUG: unable to handle kernel paging request at ffff880085894000 IP: [<ffffffff810c5dc2>] load_image_lzo+0x8c2/0xe70" Investigation carried out by Lee Chun-Yi shows that this is because e820 map has been changed by BIOS across hibernation, and one of the page frames from suspend kernel is right located in restore kernel's unmapped region, so panic comes out when accessing unmapped kernel address. In order to expose this issue earlier, the md5 hash of e820 map is passed from suspend kernel to restore kernel, and the restore kernel will terminate the resume process once it finds the md5 hash are not the same. As the format of image header has been modified, the magic number should also be adjusted as kernels with the same RESTORE_MAGIC have to use the same header format and interpret all of the fields in it in the same way. If the suspend kernel is built without md5 support, and the restore kernel has md5 support, then the latter will bypass the check process. Vice versa the restore kernel will bypass the check if it does not support md5 operation. Note: 1. Without this patch applied, it is possible that BIOS has provided an inconsistent memory map, but the resume kernel is still able to restore the image anyway(e.g, E820_RAM region is the superset of the previous one), although the system might be unstable. So this patch tries to treat any inconsistent e820 as illegal. 2. Another case is, this patch replies on comparing the e820_saved, but currently the e820_save might not be strictly the same across hibernation, even if BIOS has provided consistent e820 map - In theory mptable might modify the BIOS-provided e820_saved dynamically in early_reserve_e820_mpc_new, which would allocate a buffer from E820_RAM, and marks it from E820_RAM to E820_RESERVED). This is a potential and rare case we need to deal with in OS in the future. Suggested-by: Pavel Machek <pavel@ucw.cz> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Reviewed-by: Lee, Chun-Yi <jlee@suse.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-30x86/asm: Get rid of __read_cr4_safe()Andy Lutomirski
We use __read_cr4() vs __read_cr4_safe() inconsistently. On CR4-less CPUs, all CR4 bits are effectively clear, so we can make the code simpler and more robust by making __read_cr4() always fix up faults on 32-bit kernels. This may fix some bugs on old 486-like CPUs, but I don't have any easy way to test that. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: david@saggiorato.net Link: http://lkml.kernel.org/r/ea647033d357d9ce2ad2bbde5a631045f5052fb6.1475178370.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>