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2015-10-31x86/vm86: Set thread.vm86 to NULL on fork/cloneAndy Lutomirski1-0/+3
thread.vm86 points to per-task information -- the pointer should not be copied on clone. Fixes: d4ce0f26c790 ("x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86'") Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Stas Sergeev <stsp@list.ru> Link: http://lkml.kernel.org/r/71c5d6985d70ec8197c8d72f003823c81b7dcf99.1446270067.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-10-20x86/mm, kasan: Silence KASAN warnings in get_wchan()Andrey Ryabinin1-3/+3
get_wchan() is racy by design, it may access volatile stack of running task, thus it may access redzone in a stack frame and cause KASAN to warn about this. Use READ_ONCE_NOCHECK() to silence these warnings. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Cc: kasan-dev <kasan-dev@googlegroups.com> Link: http://lkml.kernel.org/r/1445243838-17763-3-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-30x86/process: Unify 32bit and 64bit implementations of get_wchan()Thomas Gleixner1-0/+55
The stack layout and the functionality is identical. Use the 64bit version for all of x86. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Dmitry 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.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-01Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm changes from Ingo Molnar: "The biggest changes in this cycle were: - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC) primitives. (Andy Lutomirski) - Add new, comprehensible entry and exit handlers written in C. (Andy Lutomirski) - vm86 mode cleanups and fixes. (Brian Gerst) - 32-bit compat code cleanups. (Brian Gerst) The amount of simplification in low level assembly code is already palpable: arch/x86/entry/entry_32.S | 130 +---- arch/x86/entry/entry_64.S | 197 ++----- but more simplifications are planned. There's also the usual laudry mix of low level changes - see the changelog for details" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits) x86/asm: Drop repeated macro of X86_EFLAGS_AC definition x86/asm/msr: Make wrmsrl() a function x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer x86/asm: Add MONITORX/MWAITX instruction support x86/traps: Weaken context tracking entry assertions x86/asm/tsc: Add rdtscll() merge helper selftests/x86: Add syscall_nt selftest selftests/x86: Disable sigreturn_64 x86/vdso: Emit a GNU hash x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks x86/entry/32: Migrate to C exit path x86/entry/32: Remove 32-bit syscall audit optimizations x86/vm86: Rename vm86->v86flags and v86mask x86/vm86: Rename vm86->vm86_info to user_vm86 x86/vm86: Clean up vm86.h includes x86/vm86: Move the vm86 IRQ definitions to vm86.h x86/vm86: Use the normal pt_regs area for vm86 x86/vm86: Eliminate 'struct kernel_vm86_struct' x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86' x86/vm86: Move vm86 fields out of 'thread_struct' ...
2015-08-31Merge branch 'ras-core-for-linus' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RAS updates from Ingo Molnar: "MCE handling updates, but also some generic drivers/edac/ changes to better organize the Kconfig space" * 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ras: Move AMD MCE injector to arch/x86/ras/ x86/mce: Add a wrapper around mce_log() for injection x86/mce: Rename rcu_dereference_check_mce() to mce_log_get_idx_check() RAS: Add a menuconfig option with descriptive text x86/mce: Reenable CMCI banks when swiching back to interrupt mode x86/mce: Clear Local MCE opt-in before kexec x86/mce: Remove unused function declarations x86/mce: Kill drain_mcelog_buffer() x86/mce: Avoid potential deadlock due to printk() in MCE context x86/mce: Remove the MCE ring for Action Optional errors x86/mce: Don't use percpu workqueues x86/mce: Provide a lockless memory pool to save error records x86/mce: Reuse one of the u16 padding fields in 'struct mce'
2015-08-20x86/idle: Restore trace_cpu_idle to mwait_idle() callsJisheng Zhang1-0/+2
Commit b253149b843f ("sched/idle/x86: Restore mwait_idle() to fix boot hangs, to improve power savings and to improve performance") restores mwait_idle(), but the trace_cpu_idle related calls are missing. This causes powertop on my old desktop powered by Intel Core2 E6550 to report zero wakeups and zero events. Add them back to restore the proper behaviour. Fixes: b253149b843f ("sched/idle/x86: Restore mwait_idle() to ...") Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Cc: <len.brown@intel.com> Cc: stable@vger.kernel.org # 4.1 Link: http://lkml.kernel.org/r/1440046479-4262-1-git-send-email-jszhang@marvell.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-13x86/mce: Clear Local MCE opt-in before kexecAshok Raj1-0/+2
kexec could boot a kernel that could be legacy with no knowledge of LMCE. Hence we should make sure we clear LMCE optin before kexec reboot. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1439396985-12812-9-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-31x86/vm86: Move vm86 fields out of 'thread_struct'Brian Gerst1-0/+3
Allocate a separate structure for the vm86 fields. Signed-off-by: Brian Gerst <brgerst@gmail.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> 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/1438148483-11932-2-git-send-email-brgerst@gmail.com [ Build fixes. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-18x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it ↵Ingo Molnar1-1/+1
on x86 Don't burden architectures without dynamic task_struct sizing with the overhead of dynamic sizing. Also optimize the x86 code a bit by caching task_struct_size. Acked-and-Tested-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1437128892-9831-3-git-send-email-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-18x86/fpu, sched: Dynamically allocate 'struct fpu'Dave Hansen1-1/+1
The FPU rewrite removed the dynamic allocations of 'struct fpu'. But, this potentially wastes massive amounts of memory (2k per task on systems that do not have AVX-512 for instance). Instead of having a separate slab, this patch just appends the space that we need to the 'task_struct' which we dynamically allocate already. This saves from doing an extra slab allocation at fork(). The only real downside here is that we have to stick everything and the end of the task_struct. But, I think the BUILD_BUG_ON()s I stuck in there should keep that from being too fragile. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1437128892-9831-2-git-send-email-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-22Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds1-49/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 FPU updates from Ingo Molnar: "This tree contains two main changes: - The big FPU code rewrite: wide reaching cleanups and reorganization that pulls all the FPU code together into a clean base in arch/x86/fpu/. The resulting code is leaner and faster, and much easier to understand. This enables future work to further simplify the FPU code (such as removing lazy FPU restores). By its nature these changes have a substantial regression risk: FPU code related bugs are long lived, because races are often subtle and bugs mask as user-space failures that are difficult to track back to kernel side backs. I'm aware of no unfixed (or even suspected) FPU related regression so far. - MPX support rework/fixes. As this is still not a released CPU feature, there were some buglets in the code - should be much more robust now (Dave Hansen)" * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (250 commits) x86/fpu: Fix double-increment in setup_xstate_features() x86/mpx: Allow 32-bit binaries on 64-bit kernels again x86/mpx: Do not count MPX VMAs as neighbors when unmapping x86/mpx: Rewrite the unmap code x86/mpx: Support 32-bit binaries on 64-bit kernels x86/mpx: Use 32-bit-only cmpxchg() for 32-bit apps x86/mpx: Introduce new 'directory entry' to 'addr' helper function x86/mpx: Add temporary variable to reduce masking x86: Make is_64bit_mm() widely available x86/mpx: Trace allocation of new bounds tables x86/mpx: Trace the attempts to find bounds tables x86/mpx: Trace entry to bounds exception paths x86/mpx: Trace #BR exceptions x86/mpx: Introduce a boot-time disable flag x86/mpx: Restrict the mmap() size check to bounds tables x86/mpx: Remove redundant MPX_BNDCFG_ADDR_MASK x86/mpx: Clean up the code by not passing a task pointer around when unnecessary x86/mpx: Use the new get_xsave_field_ptr()API x86/fpu/xstate: Wrap get_xsave_addr() to make it safer x86/fpu/xstate: Fix up bad get_xsave_addr() assumptions ...
2015-05-27sched/x86: Drop repeated word from mwait_idle() commentHuang Rui1-4/+3
A single "default" is fine. Signed-off-by: Huang Rui <ray.huang@amd.com> [ Fix another typo and reflow comment. ] Signed-off-by: Borislav Petkov <bp@suse.de> 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/1432022472-2224-5-git-send-email-ray.huang@amd.com Link: http://lkml.kernel.org/r/1432628901-18044-7-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Move fpu__clear() to 'struct fpu *' parameter passingIngo Molnar1-1/+1
Do it like all other high level FPU state handling functions: they only know about struct fpu, not about the task. (Also remove a dead prototype while at it.) Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Synchronize the naming of drop_fpu() and fpu_reset_state()Ingo Molnar1-1/+1
drop_fpu() and fpu_reset_state() are similar in functionality and in scope, yet this is not apparent from their names. drop_fpu() deactivates FPU contents (both the fpregs and the fpstate), but leaves register contents intact in the eager-FPU case, mostly as an optimization. It disables fpregs in the lazy FPU case. The drop_fpu() method can be used to destroy FPU state in an optimized way, when we know that a new state will be loaded before user-space might see any remains of the old FPU state: - such as in sys_exit()'s exit_thread() where we know this task won't execute any user-space instructions anymore and the next context switch cleans up the FPU. The old FPU state might still be around in the eagerfpu case but won't be saved. - in __restore_xstate_sig(), where we use drop_fpu() before copying a new state into the fpstate and activating that one. No user-pace instructions can execute between those steps. - in sys_execve()'s fpu__clear(): there we use drop_fpu() in the !eagerfpu case, where it's equivalent to a full reinit. fpu_reset_state() is a stronger version of drop_fpu(): both in the eagerfpu and the lazy-FPU case it guarantees that fpregs are reinitialized to init state. This method is used in cases where we need a full reset: - handle_signal() uses fpu_reset_state() to reset the FPU state to init before executing a user-space signal handler. While we have already saved the original FPU state at this point, and always restore the original state, the signal handling code still has to do this reinit, because signals may interrupt any user-space instruction, and the FPU might be in various intermediate states (such as an unbalanced x87 stack) that is not immediately usable for general C signal handler code. - __restore_xstate_sig() uses fpu_reset_state() when the signal frame has no FP context. Since the signal handler may have modified the FPU state, it gets reset back to init state. - in another branch __restore_xstate_sig() uses fpu_reset_state() to handle a restoration error: when restore_user_xstate() fails to restore FPU state and we might have inconsistent FPU data, fpu_reset_state() is used to reset it back to a known good state. - __kernel_fpu_end() uses fpu_reset_state() in an error branch. This is in a 'must not trigger' error branch, so on bug-free kernels this never triggers. - fpu__restore() uses fpu_reset_state() in an error path as well: if the fpstate was set up with invalid FPU state (via ptrace or via a signal handler), then it's reset back to init state. - likewise, the scheduler's switch_fpu_finish() uses it in a restoration error path too. Move both drop_fpu() and fpu_reset_state() to the fpu__*() namespace and harmonize their naming with their function: fpu__drop() fpu__reset() This clearly shows that both methods operate on the full state of the FPU, just like fpu__restore(). Also add comments to explain what each function does. Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Remove failure paths from fpstate-alloc low level functionsIngo Molnar1-10/+0
Now that we always allocate the FPU context as part of task_struct there's no need for separate allocations - remove them and their primary failure handling code. ( Note that there's still secondary error codes that have become superfluous, those will be removed in separate patches. ) Move the somewhat misplaced setup_xstate_comp() call to the core. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Rename fpu-internal.h to fpu/internal.hIngo Molnar1-1/+1
This unifies all the FPU related header files under a unified, hiearchical naming scheme: - asm/fpu/types.h: FPU related data types, needed for 'struct task_struct', widely included in almost all kernel code, and hence kept as small as possible. - asm/fpu/api.h: FPU related 'public' methods exported to other subsystems. - asm/fpu/internal.h: FPU subsystem internal methods - asm/fpu/xsave.h: XSAVE support internal methods (Also standardize the header guard in asm/fpu/internal.h.) Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Rename fpu__flush_thread() to fpu__clear()Ingo Molnar1-1/+1
The primary purpose of this function is to clear the current task's FPU before an exec(), to not leak information from the previous task, and to allow the new task to start with freshly initialized FPU registers. Rename the function to reflect this primary purpose. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Use 'struct fpu' in fpu__copy()Ingo Molnar1-1/+1
Migrate this function to pure 'struct fpu' usage. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Remove 'struct task_struct' usage from drop_fpu()Ingo Molnar1-1/+2
Migrate this function to pure 'struct fpu' usage. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Factor out fpu__copy()Ingo Molnar1-11/+1
Introduce fpu__copy() and use it in arch_dup_task_struct(), thus moving another chunk of FPU logic to fpu/core.c. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Move task_xstate_cachep handling to core.cIngo Molnar1-8/+1
This code was historically in process.c, now we have FPU core internals in fpu/core.c instead - move it there. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Factor out fpu__flush_thread() from flush_thread()Ingo Molnar1-13/+1
flush_thread() open codes a lot of FPU internals - create a separate function for it in fpu/core.c. Turns out that this does not hurt performance: text data bss dec hex filename 11843039 1884440 1130496 14857975 e2b6f7 vmlinux.before 11843039 1884440 1130496 14857975 e2b6f7 vmlinux.after and since this is a slowpath clarity comes first anyway. We can reconsider inlining decisions after the FPU code has been cleaned up. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Remove the free_thread_xstate() complicationIngo Molnar1-7/+2
Use fpstate_free() directly to manage FPU state. Only process.c was using this method, so this is a speedup as well, as it removes the extra function call and related clobbers. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Fix header file dependencies of fpu-internal.hIngo Molnar1-1/+0
Fix a minor header file dependency bug in asm/fpu-internal.h: it relies on i387.h but does not include it. All users of fpu-internal.h included it explicitly. Also remove unnecessary includes, to reduce compilation time. This also makes it easier to use it as a standalone header file for FPU internals, such as an upcoming C module in arch/x86/kernel/fpu/. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Move thread_info::fpu_counter into thread_info::fpu.counterIngo Molnar1-1/+1
This field is kept separate from the main FPU state structure for no good reason. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Rename fpu_free() to fpstate_free()Ingo Molnar1-1/+1
Use the fpu__*() namespace. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Rename fpu_alloc() to fpstate_alloc()Ingo Molnar1-1/+1
Use the fpu__*() namespace for fpstate_alloc() as well. Also add a comment about FPU state alignment. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19x86/fpu: Split an fpstate_alloc_init() function out of init_fpu()Ingo Molnar1-1/+1
Most init_fpu() users don't want the register-saving aspect of the function, they are calling it for 'current' and when FPU registers are not allocated and initialized yet. Split out a simplified API that does just that (and add debug-checks for these conditions): fpstate_alloc_init(). Use it where appropriate. Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-06x86/fpu: Always restore_xinit_state() when use_eager_cpu()Bobby Powers1-5/+7
The following commit: f893959b0898 ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()") removed drop_init_fpu() usage from flush_thread(). This seems to break things for me - the Go 1.4 test suite fails all over the place with floating point comparision errors (offending commit found through bisection). The functional change was that flush_thread() after this commit only calls restore_init_xstate() when both use_eager_fpu() and !used_math() are true. drop_init_fpu() (now fpu_reset_state()) calls restore_init_xstate() regardless of whether current used_math() - apply the same logic here. Switch used_math() -> tsk_used_math(tsk) to consistently use the grabbed tsk instead of current, like in the rest of flush_thread(). Tested-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Bobby Powers <bobbypowers@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: f893959b ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()") Link: http://lkml.kernel.org/r/1430147441-9820-1-git-send-email-bobbypowers@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-05x86: Make cpu_tss available to external modulesMarc Dionne1-1/+1
Commit 75182b1632 ("x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()") changed current_thread_info to use this_cpu_sp0, and indirectly made it rely on init_tss which was exported with EXPORT_PER_CPU_SYMBOL_GPL. As a result some macros and inline functions such as set/get_fs, test_thread_flag and variants have been made unusable for external modules. Make cpu_tss exported with EXPORT_PER_CPU_SYMBOL so that these functions are accessible again, as they were previously. Signed-off-by: Marc Dionne <marc.dionne@your-file-system.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/1430763404-21221-1-git-send-email-marc.dionne@your-file-system.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-13Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds1-7/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu changes from Ingo Molnar: "Various x86 FPU handling cleanups, refactorings and fixes (Borislav Petkov, Oleg Nesterov, Rik van Riel)" * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) x86/fpu: Kill eager_fpu_init_bp() x86/fpu: Don't allocate fpu->state for swapper/0 x86/fpu: Rename drop_init_fpu() to fpu_reset_state() x86/fpu: Fold __drop_fpu() into its sole user x86/fpu: Don't abuse drop_init_fpu() in flush_thread() x86/fpu: Use restore_init_xstate() instead of math_state_restore() on kthread exec x86/fpu: Introduce restore_init_xstate() x86/fpu: Document user_fpu_begin() x86/fpu: Factor out memset(xstate, 0) in fpu_finit() paths x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave x86/fpu: Don't abuse FPU in kernel threads if use_eager_fpu() x86/fpu: Always allow FPU in interrupt if use_eager_fpu() x86/fpu: __kernel_fpu_begin() should clear fpu_owner_task even if use_eager_fpu() x86/fpu: Also check fpu_lazy_restore() when use_eager_fpu() x86/fpu: Use task_disable_lazy_fpu_restore() helper x86/fpu: Use an explicit if/else in switch_fpu_prepare() x86/fpu: Introduce task_disable_lazy_fpu_restore() helper x86/fpu: Move lazy restore functions up a few lines x86/fpu: Change math_error() to use unlazy_fpu(), kill (now) unused save_init_fpu() x86/fpu: Don't do __thread_fpu_end() if use_eager_fpu() ...
2015-04-13Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds1-2/+21
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm changes from Ingo Molnar: "There were lots of changes in this development cycle: - over 100 separate cleanups, restructuring changes, speedups and fixes in the x86 system call, irq, trap and other entry code, part of a heroic effort to deobfuscate a decade old spaghetti asm code and its C code dependencies (Denys Vlasenko, Andy Lutomirski) - alternatives code fixes and enhancements (Borislav Petkov) - simplifications and cleanups to the compat code (Brian Gerst) - signal handling fixes and new x86 testcases (Andy Lutomirski) - various other fixes and cleanups By their nature many of these changes are risky - we tried to test them well on many different x86 systems (there are no known regressions), and they are split up finely to help bisection - but there's still a fair bit of residual risk left so caveat emptor" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (148 commits) perf/x86/64: Report regs_user->ax too in get_regs_user() perf/x86/64: Simplify regs_user->abi setting code in get_regs_user() perf/x86/64: Do report user_regs->cx while we are in syscall, in get_regs_user() perf/x86/64: Do not guess user_regs->cs, ss, sp in get_regs_user() x86/asm/entry/32: Tidy up JNZ instructions after TESTs x86/asm/entry/64: Reduce padding in execve stubs x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork x86/asm/entry/64: Simplify jumps in ret_from_fork x86/asm/entry/64: Remove a redundant jump x86/asm/entry/64: Optimize [v]fork/clone stubs x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat() x86/asm/entry/64: Use common code for rt_sigreturn() epilogue x86/asm/entry/64: Add forgotten CFI annotation x86/asm/entry/irq: Simplify interrupt dispatch table (IDT) layout x86/asm/entry/64: Move opportunistic sysret code to syscall code path x86, selftests: Add sigreturn selftest x86/alternatives: Guard NOPs optimization x86/asm/entry: Clear EXTRA_REGS for all executable formats x86/signal: Remove pax argument from restore_sigcontext ...
2015-04-13Merge branch 'timers-core-for-linus' of ↵Linus Torvalds1-8/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Ingo Molnar: "The main changes in this cycle were: - clockevents state machine cleanups and enhancements (Viresh Kumar) - clockevents broadcast notifier horror to state machine conversion and related cleanups (Thomas Gleixner, Rafael J Wysocki) - clocksource and timekeeping core updates (John Stultz) - clocksource driver updates and fixes (Ben Dooks, Dmitry Osipenko, Hans de Goede, Laurent Pinchart, Maxime Ripard, Xunlei Pang) - y2038 fixes (Xunlei Pang, John Stultz) - NMI-safe ktime_get_raw_fast() and general refactoring of the clock code, in preparation to perf's per event clock ID support (Peter Zijlstra) - generic sched/clock fixes, optimizations and cleanups (Daniel Thompson) - clockevents cpu_down() race fix (Preeti U Murthy)" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (94 commits) timers/PM: Drop unnecessary braces from tick_freeze() timers/PM: Fix up tick_unfreeze() timekeeping: Get rid of stale comment clockevents: Cleanup dead cpu explicitely clockevents: Make tick handover explicit clockevents: Remove broadcast oneshot control leftovers sched/idle: Use explicit broadcast oneshot control function ARM: Tegra: Use explicit broadcast oneshot control function ARM: OMAP: Use explicit broadcast oneshot control function intel_idle: Use explicit broadcast oneshot control function ACPI/idle: Use explicit broadcast control function ACPI/PAD: Use explicit broadcast oneshot control function x86/amd/idle, clockevents: Use explicit broadcast oneshot control functions clockevents: Provide explicit broadcast oneshot control functions clockevents: Remove the broadcast control leftovers ARM: OMAP: Use explicit broadcast control function intel_idle: Use explicit broadcast control function cpuidle: Use explicit broadcast control function ACPI/processor: Use explicit broadcast control function ACPI/PAD: Use explicit broadcast control function ...
2015-04-03x86/amd/idle, clockevents: Use explicit broadcast oneshot control functionsThomas Gleixner1-2/+2
Replace the clockevents_notify() call with an explicit function call. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/8569669.lgxIty9PKW@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03x86/amd/idle, clockevents: Use explicit broadcast control functionThomas Gleixner1-6/+3
Replace the clockevents_notify() call with an explicit function call. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1528188.S1pjqkSL1P@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23Merge branch 'sched/urgent' into sched/core, to pick up fixes before ↵Ingo Molnar1-2/+3
applying new patches Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/fpu: Don't abuse drop_init_fpu() in flush_thread()Oleg Nesterov1-9/+6
flush_thread() -> drop_init_fpu() is suboptimal and confusing. It does drop_fpu() or restore_init_xstate() depending on !use_eager_fpu(). But flush_thread() too checks eagerfpu right after that, and if it is true then restore_init_xstate() just burns CPU for no reason. We are going to load init_xstate_buf again after we set used_math()/user_has_fpu(), until then the FPU state can't survive after switch_to(). Remove it, and change the "if (!use_eager_fpu())" to call drop_fpu(). While at it, clean up the tsk/current usage. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Link: http://lkml.kernel.org/r/20150313173030.GA31217@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/fpu: Use restore_init_xstate() instead of math_state_restore() on ↵Oleg Nesterov1-1/+2
kthread exec Change flush_thread() to do user_fpu_begin() and restore_init_xstate() instead of math_state_restore(). Note: "TODO: cleanup this horror" is still valid. We do not need init_fpu() at all, we only need fpu_alloc() and memset(0). But this needs other changes, in particular user_fpu_begin() should set used_math(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Link: http://lkml.kernel.org/r/20150311173449.GE5032@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23Merge tag 'v4.0-rc5' into x86/fpu, to prevent conflictsIngo Molnar1-2/+3
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/asm/entry: Unify and fix initial thread_struct::sp0 valuesAndy Lutomirski1-1/+1
x86_32 and x86_64 need slightly different thread_struct::sp0 values, and x86_32's was incorrect for init. This never mattered -- the init thread never runs user code, so we never used thread_struct::sp0 for anything. Fix it and mostly unify them. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1b810c1d2e797e27bb4a7708c426101161edd1f6.1426009661.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-16sched/idle/x86: Optimize unnecessary mwait_idle() resched IPIsMike Galbraith1-4/+8
To fully take advantage of MWAIT, apparently the CLFLUSH instruction needs another quirk on certain CPUs: proper barriers around it on certain machines. On a Q6600 SMP system, pipe-test scheduling performance, cross core, improves significantly: 3.8.13 487.2 KHz 1.000 3.13.0-master 415.5 KHz .852 3.13.0-master+ 415.2 KHz .852 + restore mwait_idle 3.13.0-master++ 488.5 KHz 1.002 + restore mwait_idle + IPI fix Since X86_BUG_CLFLUSH_MONITOR is already a quirk, don't create a separate quirk for the extra smp_mb()s. Signed-off-by: Mike Galbraith <bitbucket@online.de> Cc: <stable@vger.kernel.org> # 3.10+ Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ian Malone <ibmalone@gmail.com> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Len Brown <lenb@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> Link: http://lkml.kernel.org/r/1390061684.5566.4.camel@marge.simpson.net [ Ported to recent kernel, added comments about the quirk. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-16sched/idle/x86: Restore mwait_idle() to fix boot hangs, to improve power ↵Len Brown1-0/+47
savings and to improve performance In Linux-3.9 we removed the mwait_idle() loop: 69fb3676df33 ("x86 idle: remove mwait_idle() and "idle=mwait" cmdline param") The reasoning was that modern machines should be sufficiently happy during the boot process using the default_idle() HALT loop, until cpuidle loads and either acpi_idle or intel_idle invoke the newer MWAIT-with-hints idle loop. But two machines reported problems: 1. Certain Core2-era machines support MWAIT-C1 and HALT only. MWAIT-C1 is preferred for optimal power and performance. But if they support just C1, cpuidle never loads and so they use the boot-time default idle loop forever. 2. Some laptops will boot-hang if HALT is used, but will boot successfully if MWAIT is used. This appears to be a hidden assumption in BIOS SMI, that is presumably valid on the proprietary OS where the BIOS was validated. https://bugzilla.kernel.org/show_bug.cgi?id=60770 So here we effectively revert the patch above, restoring the mwait_idle() loop. However, we don't bother restoring the idle=mwait cmdline parameter, since it appears to add no value. Maintainer notes: For 3.9, simply revert 69fb3676df for 3.10, patch -F3 applies, fuzz needed due to __cpuinit use in context For 3.11, 3.12, 3.13, this patch applies cleanly Tested-by: Mike Galbraith <bitbucket@online.de> Signed-off-by: Len Brown <len.brown@intel.com> Acked-by: Mike Galbraith <bitbucket@online.de> Cc: <stable@vger.kernel.org> # 3.9+ Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ian Malone <ibmalone@gmail.com> Cc: Josh Boyer <jwboyer@redhat.com> 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> Link: http://lkml.kernel.org/r/345254a551eb5a6a866e048d7ab570fd2193aca4.1389763084.git.len.brown@intel.com [ Ported to recent kernels. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06x86/asm/entry: Remove INIT_TSS and fold the definitions into 'cpu_tss'Andy Lutomirski1-1/+19
The INIT_TSS is unnecessary. Just define the initial TSS where 'cpu_tss' is defined. While we're at it, merge the 32-bit and 64-bit definitions. The only syntactic change is that 32-bit kernels were computing sp0 as long, but now they compute it as unsigned long. Verified by objdump: the contents and relocations of .data..percpu..shared_aligned are unchanged on 32-bit and 64-bit kernels. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8fc39fa3f6c5d635e93afbdd1a0fe0678a6d7913.1425611534.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06x86/asm/entry: Rename 'init_tss' to 'cpu_tss'Andy Lutomirski1-3/+3
It has nothing to do with init -- there's only one TSS per cpu. Other names considered include: - current_tss: Confusing because we never switch the tss. - singleton_tss: Too long. This patch was generated with 's/init_tss/cpu_tss/g'. Followup patches will fix INIT_TSS and INIT_TSS_IST by hand. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/da29fb2a793e4f649d93ce2d1ed320ebe8516262.1425611534.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06x86/asm/entry: Add this_cpu_sp0() to read sp0 for the current cpuAndy Lutomirski1-0/+1
We currently store references to the top of the kernel stack in multiple places: kernel_stack (with an offset) and init_tss.x86_tss.sp0 (no offset). The latter is defined by hardware and is a clean canonical way to find the top of the stack. Add an accessor so we can start using it. This needs minor paravirt tweaks. On native, sp0 defines the top of the kernel stack and is therefore always correct. On Xen and lguest, the hypervisor tracks the top of the stack, but we want to start reading sp0 in the kernel. Fixing this is simple: just update our local copy of sp0 as well as the hypervisor's copy on task switches. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8d675581859712bee09a055ed8f785d80dac1eca.1425611534.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-23x86/fpu: Don't abuse FPU in kernel threads if use_eager_fpu()Oleg Nesterov1-0/+7
AFAICS, there is no reason why kernel threads should have FPU context even if use_eager_fpu() == T. Now that interrupted_kernel_fpu_idle() does not check __thread_has_fpu() in the use_eager_fpu() case, we can remove the init_fpu() code from eager_fpu_init() and change flush_thread() called by do_execve() to initialize FPU. Note: of course, the change in flush_thread() is horrible and must be cleanuped. We need the new helper, and flush_thread() should return the error if init_fpu() fails. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/20150119185212.GD16427@redhat.com Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19x86/fpu: Use task_disable_lazy_fpu_restore() helperRik van Riel1-1/+1
Replace magic assignments of fpu.last_cpu = ~0 with more explicit task_disable_lazy_fpu_restore() calls. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1423252925-14451-8-git-send-email-riel@redhat.com Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-04x86: Clean up cr4 manipulationAndy Lutomirski1-2/+3
CR4 manipulation was split, seemingly at random, between direct (write_cr4) and using a helper (set/clear_in_cr4). Unfortunately, the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code, which only a small subset of users actually wanted. This patch replaces all cr4 access in functions that don't leave cr4 exactly the way they found it with new helpers cr4_set_bits, cr4_clear_bits, and cr4_set_bits_and_update_boot. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Vince Weaver <vince@deater.net> Cc: "hillf.zj" <hillf.zj@alibaba-inc.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-02x86, fpu: Shift "fpu_counter = 0" from copy_thread() to arch_dup_task_struct()Oleg Nesterov1-0/+1
Cosmetic, but I think thread.fpu_counter should be initialized in arch_dup_task_struct() too, along with other "fpu" variables. And probably it make sense to turn it into thread.fpu->counter. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175730.GA21669@redhat.com Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-09-02x86, fpu: copy_process: Sanitize fpu->last_cpu initializationOleg Nesterov1-1/+3
Cosmetic, but imho memset(&dst->thread.fpu, 0) is not good simply because it hides the (important) usage of ->has_fpu/etc from grep. Change this code to initialize the members explicitly. And note that ->last_cpu = 0 looks simply wrong, this can confuse fpu_lazy_restore() if per_cpu(fpu_owner_task, 0) has already exited and copy_process() re-allocated the same task_struct. Fortunately this is not actually possible because child->fpu_counter == 0 and thus fpu_lazy_restore() will not be called, but still this is not clean/robust. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20140902175727.GA21666@redhat.com Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 10:49:00 +0000