kernel.git/arch/x86/include/asm/thread_info.h, branch linux-4.6.y

x86/thread_info: Merge two !ASSEMBLY sections

2016-03-29T09:12:10Z

We have #ifndef __ASSEMBLY__ ... #endif #ifndef __ASSEMBLY__ ... #endif Merge the two. No functionality change. Signed-off-by: Borislav Petkov Link: http://lkml.kernel.org/r/1459189217-25532-1-git-send-email-bp@alien8.de Signed-off-by: Thomas Gleixner

x86/entry: Call enter_from_user_mode() with IRQs off

2016-03-10T09:53:26Z

Now that slow-path syscalls always enter C before enabling interrupts, it's straightforward to call enter_from_user_mode() before enabling interrupts rather than doing it as part of entry tracing. With this change, we should finally be able to retire exception_enter(). This will also enable optimizations based on knowing that we never change context tracking state with interrupts on. Signed-off-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Frédéric Weisbecker Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/bc376ecf87921a495e874ff98139b1ca2f5c5dd7.1457558566.git.luto@kernel.org Signed-off-by: Ingo Molnar

x86/entry: Remove TIF_SINGLESTEP entry work

2016-03-10T08:48:14Z

Now that SYSENTER with TF set puts X86_EFLAGS_TF directly into regs->flags, we don't need a TIF_SINGLESTEP fixup in the syscall entry code. Remove it. Signed-off-by: Andy Lutomirski Cc: Andrew Cooper Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/2d15f24da52dafc9d2f0b8d76f55544f4779c517.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar

x86/cpufeature: Carve out X86_FEATURE_*

2016-01-30T10:22:17Z

Move them to a separate header and have the following dependency: x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h This makes it easier to use the header in asm code and not include the whole cpufeature.h and add guards for asm. Suggested-by: H. Peter Anvin Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar

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

2015-11-04T02:59:10Z

Pull x86 asm changes from Ingo Molnar: "The main change in this cycle is another step in the big x86 system call interface rework by Andy Lutomirski, which moves most of the low level x86 entry code from assembly to C, for all syscall entries except native 64-bit system calls: arch/x86/entry/entry_32.S | 182 ++++------ arch/x86/entry/entry_64_compat.S | 547 ++++++++----------------------- 194 insertions(+), 535 deletions(-) ... our hope is that the final remaining step (converting native 64-bit system calls) will be less painful as all the previous steps, given that most of the legacies and quirks are concentrated around native 32-bit and compat environments" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) x86/entry/32: Fix FS and GS restore in opportunistic SYSEXIT x86/entry/32: Fix entry_INT80_32() to expect interrupts to be on um/x86: Fix build after x86 syscall changes x86/asm: Remove the xyz_cfi macros from dwarf2.h selftests/x86: Style fixes for the 'unwind_vdso' test x86/entry/64/compat: Document sysenter_fix_flags's reason for existence x86/entry: Split and inline syscall_return_slowpath() x86/entry: Split and inline prepare_exit_to_usermode() x86/entry: Use pt_regs_to_thread_info() in syscall entry tracing x86/entry: Hide two syscall entry assertions behind CONFIG_DEBUG_ENTRY x86/entry: Micro-optimize compat fast syscall arg fetch x86/entry: Force inlining of 32-bit syscall code x86/entry: Make irqs_disabled checks in exit code depend on lockdep x86/entry: Remove unnecessary IRQ twiddling in fast 32-bit syscalls x86/asm: Remove thread_info.sysenter_return x86/entry/32: Re-implement SYSENTER using the new C path x86/entry/32: Switch INT80 to the new C syscall path x86/entry/32: Open-code return tracking from fork and kthreads x86/entry/compat: Implement opportunistic SYSRETL for compat syscalls x86/vdso/compat: Wire up SYSENTER and SYSCSALL for compat userspace ...

x86/asm: Remove thread_info.sysenter_return

2015-10-09T07:41:11Z

It's no longer needed. We could reinstate something like it as an optimization, which would remove two cachelines from the fast syscall entry working set. I benchmarked it, and it makes no difference whatsoever to the performance of cache-hot compat syscalls on Sandy Bridge. Signed-off-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/f08cc0cff30201afe9bb565c47134c0a6c1a96a2.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar

sched/core, sched/x86: Kill thread_info::saved_preempt_count

2015-10-06T15:08:18Z

With the introduction of the context switch preempt_count invariant, and the demise of PREEMPT_ACTIVE, its pointless to save/restore the per-cpu preemption count, it must always be 2. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks

2015-08-05T08:54:35Z

They are no longer used. Good riddance! Deleting the TIF_ macros is really nice. It was never clear why there were so many variants. Signed-off-by: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Eric Paris Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/22c61682f446628573dde0f1d573ab821677e06da.1438378274.git.luto@kernel.org Signed-off-by: Ingo Molnar

x86/vm86: Use the normal pt_regs area for vm86

2015-07-31T11:31:09Z

Change to use the normal pt_regs area to enter and exit vm86 mode. This is done by increasing the padding at the top of the stack to make room for the extra vm86 segment slots in the IRET frame. It then saves the 32-bit regs in the off-stack vm86 data, and copies in the vm86 regs. Exiting back to 32-bit mode does the reverse. This allows removing the hacks to jump directly into the exit asm code due to having to change the stack pointer. Returning normally from the vm86 syscall and the exception handlers allows things like ptrace and auditing to work properly. Signed-off-by: Brian Gerst Acked-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1438148483-11932-5-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar

x86/entry: Define 'cpu_current_top_of_stack' for 64-bit code

2015-05-08T11:50:02Z

32-bit code has PER_CPU_VAR(cpu_current_top_of_stack). 64-bit code uses somewhat more obscure: PER_CPU_VAR(cpu_tss + TSS_sp0). Define the 'cpu_current_top_of_stack' macro on CONFIG_X86_64 as well so that the PER_CPU_VAR(cpu_current_top_of_stack) expression can be used in both 32-bit and 64-bit code. Signed-off-by: Denys Vlasenko Cc: Alexei Starovoitov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Will Drewry Link: http://lkml.kernel.org/r/1429889495-27850-3-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar