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2020-06-11x86/entry/64: Simplify idtentry_bodyThomas Gleixner
All C functions which do not have an error code have been converted to the new IDTENTRY interface which does not expect an error code in the arguments. Spare the XORL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202118.145811853@linutronix.de
2020-06-11x86/entry: Switch XEN/PV hypercall entry to IDTENTRYThomas Gleixner
Convert the XEN/PV hypercall to IDTENTRY: - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64-bit - Remove the open coded ASM entry code in 32-bit - Remove the old prototypes The handler stubs need to stay in ASM code as they need corner case handling and adjustment of the stack pointer. Provide a new C function which invokes the entry/exit handling and calls into the XEN handler on the interrupt stack if required. The exit code is slightly different from the regular idtentry_exit() on non-preemptible kernels. If the hypercall is preemptible and need_resched() is set then XEN provides a preempt hypercall scheduling function. Move this functionality into the entry code so it can use the existing idtentry functionality. [ mingo: Build fixes. ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Juergen Gross <jgross@suse.com> Tested-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20200521202118.055270078@linutronix.de
2020-06-11x86/entry/64: Move do_softirq_own_stack() to CThomas Gleixner
The first step to get rid of the ENTER/LEAVE_IRQ_STACK ASM macro maze. Use the new C code helpers to move do_softirq_own_stack() out of ASM code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202117.870911120@linutronix.de
2020-06-11x86/entry: Provide helpers for executing on the irqstackThomas Gleixner
Device interrupt handlers and system vector handlers are executed on the interrupt stack. The stack switch happens in the low level assembly entry code. This conflicts with the efforts to consolidate the exit code in C to ensure correctness vs. RCU and tracing. As there is no way to move #DB away from IST due to the MOV SS issue, the requirements vs. #DB and NMI for switching to the interrupt stack do not exist anymore. The only requirement is that interrupts are disabled. That allows the moving of the stack switching to C code, which simplifies the entry/exit handling further, because it allows the switching of stacks after handling the entry and on exit before handling RCU, returning to usermode and kernel preemption in the same way as for regular exceptions. The initial attempt of having the stack switching in inline ASM caused too much headache vs. objtool and the unwinder. After analysing the use cases it was agreed on that having the stack switch in ASM for the price of an indirect call is acceptable, as the main users are indirect call heavy anyway and the few system vectors which are empty shells (scheduler IPI and KVM posted interrupt vectors) can run from the regular stack. Provide helper functions to check whether the interrupt stack is already active and whether stack switching is required. 64-bit only for now, as 32-bit has a variant of that already. Once this is cleaned up, the two implementations might be consolidated as an additional cleanup on top. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202117.763775313@linutronix.de
2020-06-11x86/entry: Convert double fault exception to IDTENTRY_DFThomas Gleixner
Convert #DF to IDTENTRY_DF - Implement the C entry point with DEFINE_IDTENTRY_DF - Emit the ASM stub with DECLARE_IDTENTRY_DF on 64bit - Remove the ASM idtentry in 64bit - Adjust the 32bit shim code - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135315.583415264@linutronix.de
2020-06-11x86/entry: Implement user mode C entry points for #DB and #MCEThomas Gleixner
The MCE entry point uses the same mechanism as the IST entry point for now. For #DB split the inner workings and just keep the nmi_enter/exit() magic in the IST variant. Fixup the ASM code to emit the proper noist_##cfunc call. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135315.177564104@linutronix.de
2020-06-11x86/entry/64: Remove error code clearing from #DB and #MCE ASM stubThomas Gleixner
The C entry points do not expect an error code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135314.992621707@linutronix.de
2020-06-11x86/entry: Convert Debug exception to IDTENTRY_DBThomas Gleixner
Convert #DB to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY_DB - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135314.900297476@linutronix.de
2020-06-11x86/entry: Convert NMI to IDTENTRY_NMIThomas Gleixner
Convert #NMI to IDTENTRY_NMI: - Implement the C entry point with DEFINE_IDTENTRY_NMI - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135314.609932306@linutronix.de
2020-06-11x86/entry: Convert Machine Check to IDTENTRY_ISTThomas Gleixner
Convert #MC to IDTENTRY_MCE: - Implement the C entry points with DEFINE_IDTENTRY_MCE - Emit the ASM stub with DECLARE_IDTENTRY_MCE - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the error code from *machine_check_vector() as it is always 0 and not used by any of the functions it can point to. Fixup all the functions as well. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135314.334980426@linutronix.de
2020-06-11x86/entry: Convert INT3 exception to IDTENTRY_RAWThomas Gleixner
Convert #BP to IDTENTRY_RAW: - Implement the C entry point with DEFINE_IDTENTRY_RAW - Invoke idtentry_enter/exit() from the function body - Emit the ASM stub with DECLARE_IDTENTRY_RAW - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. This could be a plain IDTENTRY, but as Peter pointed out INT3 is broken vs. the static key in the context tracking code as this static key might be in the state of being patched and has an int3 which would recurse forever. IDTENTRY_RAW is therefore chosen to allow addressing this issue without lots of code churn. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135313.938474960@linutronix.de
2020-06-11x86/entry: Convert SIMD coprocessor error exception to IDTENTRYThomas Gleixner
Convert #XF to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Handle INVD_BUG in C - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134906.021552202@linutronix.de
2020-06-11x86/entry: Convert Alignment check exception to IDTENTRYThomas Gleixner
Convert #AC to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134905.928967113@linutronix.de
2020-06-11x86/entry: Convert Coprocessor error exception to IDTENTRYThomas Gleixner
Convert #MF to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134905.838823510@linutronix.de
2020-06-11x86/entry: Convert Spurious interrupt bug exception to IDTENTRYThomas Gleixner
Convert #SPURIOUS to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134905.728077036@linutronix.de
2020-06-11x86/entry: Convert General protection exception to IDTENTRYThomas Gleixner
Convert #GP to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134905.637269946@linutronix.de
2020-06-11x86/entry: Convert Stack segment exception to IDTENTRYThomas Gleixner
Convert #SS to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134905.539867572@linutronix.de
2020-06-11x86/entry: Convert Segment not present exception to IDTENTRYThomas Gleixner
Convert #NP to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134905.443591450@linutronix.de
2020-06-11x86/entry: Convert Invalid TSS exception to IDTENTRYThomas Gleixner
Convert #TS to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134905.350676449@linutronix.de
2020-06-11x86/entry: Convert Coprocessor segment overrun exception to IDTENTRYThomas Gleixner
Convert #OLD_MF to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134905.838823510@linutronix.de
2020-06-11x86/entry: Convert Device not available exception to IDTENTRYThomas Gleixner
Convert #NM to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134905.056243863@linutronix.de
2020-06-11x86/entry: Convert Invalid Opcode exception to IDTENTRYThomas Gleixner
Convert #UD to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Fixup the FOOF bug call in fault.c - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134904.955511913@linutronix.de
2020-06-11x86/entry: Convert Bounds exception to IDTENTRYThomas Gleixner
Convert #BR to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes - Remove the RCU warning as the new entry macro ensures correctness No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134904.863001309@linutronix.de
2020-06-11x86/entry: Convert Overflow exception to IDTENTRYThomas Gleixner
Convert #OF to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134904.771457898@linutronix.de
2020-06-11x86/entry: Convert Divide Error to IDTENTRYThomas Gleixner
Convert #DE to IDTENTRY: - Implement the C entry point with DEFINE_IDTENTRY - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134904.663914713@linutronix.de
2020-06-11x86/idtentry: Provide macros to define/declare IDT entry pointsThomas Gleixner
Provide DECLARE/DEFINE_IDTENTRY() macros. DEFINE_IDTENTRY() provides a wrapper which acts as the function definition. The exception handler body is just appended to it with curly brackets. The entry point is marked noinstr so that irq tracing and the enter_from_user_mode() can be moved into the C-entry point. As all C-entries use the same macro (or a later variant) the necessary entry handling can be implemented at one central place. DECLARE_IDTENTRY() provides the function prototypes: - The C entry point cfunc - The ASM entry point asm_cfunc - The XEN/PV entry point xen_asm_cfunc They all follow the same naming convention. When included from ASM code DECLARE_IDTENTRY() is a macro which emits the low level entry point in assembly by instantiating idtentry. IDTENTRY is the simplest variant which just has a pt_regs argument. It's going to be used for all exceptions which have no error code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134904.273363275@linutronix.de
2020-06-11x86/entry/64: Provide sane error entry/exitThomas Gleixner
For gradual conversion provide a macro parameter and the required code which allows to handle instrumentation and interrupt flags tracking in C. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134904.058904490@linutronix.de
2020-06-11x86/entry: Distangle idtentryThomas Gleixner
idtentry is a completely unreadable maze. Split it into distinct idtentry variants which only contain the minimal code: - idtentry for regular exceptions - idtentry_mce_debug for #MCE and #DB - idtentry_df for #DF The generated binary code is equivalent. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134903.949227617@linutronix.de
2020-06-11x86/entry/64: Reorder idtentriesThomas Gleixner
Move them all together so verifying the cleanup patches for binary equivalence will be easier. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134903.841853522@linutronix.de
2020-06-11x86/entry/64: Use native swapgs in asm_load_gs_index()Thomas Gleixner
When PARAVIRT_XXL is in use, then load_gs_index() uses xen_load_gs_index() and asm_load_gs_index() is unused. It's therefore pointless to use the paravirtualized SWAPGS implementation in asm_load_gs_index(). Switch it to a plain swapgs. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Juergen Gross <jgross@suse.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200512213809.583980272@linutronix.de
2020-06-11x86/entry: Disable interrupts for native_load_gs_index() in C codeThomas Gleixner
There is absolutely no point in doing this in ASM code. Move it to C. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134903.531534675@linutronix.de
2020-06-11x86/entry: Move irq flags tracing to prepare_exit_to_usermode()Thomas Gleixner
This is another step towards more C-code and less convoluted ASM. Similar to the entry path, invoke the tracer before context tracking which might turn off RCU and invoke lockdep as the last step before going back to user space. Annotate the code sections in exit_to_user_mode() accordingly so objtool won't complain about the tracer invocation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134340.703783926@linutronix.de
2020-06-11x86/entry: Move irq tracing on syscall entry to C-codeThomas Gleixner
Now that the C entry points are safe, move the irq flags tracing code into the entry helper: - Invoke lockdep before calling into context tracking - Use the safe trace_hardirqs_on_prepare() trace function after context tracking established state and RCU is watching. enter_from_user_mode() is also still invoked from the exception/interrupt entry code which still contains the ASM irq flags tracing. So this is just a redundant and harmless invocation of tracing / lockdep until these are removed as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134340.611961721@linutronix.de
2020-06-11x86/entry/64: Move non entry code into .text sectionThomas Gleixner
All ASM code which is not part of the entry functionality can move out into the .text section. No reason to keep it in the non-instrumentable entry section. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134340.227579223@linutronix.de
2020-06-11x86/entry/64: Avoid pointless code when CONTEXT_TRACKING=nThomas Gleixner
GAS cannot optimize out the test and conditional jump when context tracking is disabled and CALL_enter_from_user_mode is an empty macro. Wrap it in #ifdeffery. Will go away once all this is moved to C. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134058.955968069@linutronix.de
2020-06-11x86/entry/64: Remove unneeded kernel CR3 switchingLai Jiangshan
When native_load_gs_index() fails on .Lgs_change, CR3 must be kernel CR3. No need to switch it. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200419144049.1906-2-laijs@linux.alibaba.com
2020-06-11x86/entry/64: Remove an unused labelLai Jiangshan
The label .Lcommon_\sym was introduced by 39e9543344fa. (x86-64: Reduce amount of redundant code generated for invalidate_interruptNN) And all the other relevant information was removed by 52aec3308db8 (x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR) Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200419144049.1906-4-laijs@linux.alibaba.com
2020-06-03Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - Move the arch-specific code into arch/arm64/kvm - Start the post-32bit cleanup - Cherry-pick a few non-invasive pre-NV patches x86: - Rework of TLB flushing - Rework of event injection, especially with respect to nested virtualization - Nested AMD event injection facelift, building on the rework of generic code and fixing a lot of corner cases - Nested AMD live migration support - Optimization for TSC deadline MSR writes and IPIs - Various cleanups - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree) - Interrupt-based delivery of asynchronous "page ready" events (host side) - Hyper-V MSRs and hypercalls for guest debugging - VMX preemption timer fixes s390: - Cleanups Generic: - switch vCPU thread wakeup from swait to rcuwait The other architectures, and the guest side of the asynchronous page fault work, will come next week" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits) KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test KVM: check userspace_addr for all memslots KVM: selftests: update hyperv_cpuid with SynDBG tests x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls x86/kvm/hyper-v: enable hypercalls regardless of hypercall page x86/kvm/hyper-v: Add support for synthetic debugger interface x86/hyper-v: Add synthetic debugger definitions KVM: selftests: VMX preemption timer migration test KVM: nVMX: Fix VMX preemption timer migration x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit KVM: x86/pmu: Support full width counting KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT KVM: x86: acknowledgment mechanism for async pf page ready notifications KVM: x86: interrupt based APF 'page ready' event delivery KVM: introduce kvm_read_guest_offset_cached() KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present() KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously" KVM: VMX: Replace zero-length array with flexible-array ...
2020-05-19x86/kvm: Handle async page faults directly through do_page_fault()Andy Lutomirski
KVM overloads #PF to indicate two types of not-actually-page-fault events. Right now, the KVM guest code intercepts them by modifying the IDT and hooking the #PF vector. This makes the already fragile fault code even harder to understand, and it also pollutes call traces with async_page_fault and do_async_page_fault for normal page faults. Clean it up by moving the logic into do_page_fault() using a static branch. This gets rid of the platform trap_init override mechanism completely. [ tglx: Fixed up 32bit, removed error code from the async functions and massaged coding style ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134059.169270470@linutronix.de
2020-05-18Merge tag 'v5.7-rc6' into objtool/core, to pick up fixes and resolve ↵Ingo Molnar
semantic conflict Resolve structural conflict between: 59566b0b622e: ("x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up") which introduced a new reference to 'ftrace_epilogue', and: 0298739b7983: ("x86,ftrace: Fix ftrace_regs_caller() unwind") Which renamed it to 'ftrace_caller_end'. Rename the new usage site in the merge commit. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-30x86: Change {JMP,CALL}_NOSPEC argumentPeter Zijlstra
In order to change the {JMP,CALL}_NOSPEC macros to call out-of-line versions of the retpoline magic, we need to remove the '%' from the argument, such that we can paste it onto symbol names. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200428191700.151623523@infradead.org
2020-04-25x86/unwind/orc: Fix premature unwind stoppage due to IRET framesJosh Poimboeuf
The following execution path is possible: fsnotify() [ realign the stack and store previous SP in R10 ] <IRQ> [ only IRET regs saved ] common_interrupt() interrupt_entry() <NMI> [ full pt_regs saved ] ... [ unwind stack ] When the unwinder goes through the NMI and the IRQ on the stack, and then sees fsnotify(), it doesn't have access to the value of R10, because it only has the five IRET registers. So the unwind stops prematurely. However, because the interrupt_entry() code is careful not to clobber R10 before saving the full regs, the unwinder should be able to read R10 from the previously saved full pt_regs associated with the NMI. Handle this case properly. When encountering an IRET regs frame immediately after a full pt_regs frame, use the pt_regs as a backup which can be used to get the C register values. Also, note that a call frame resets the 'prev_regs' value, because a function is free to clobber the registers. For this fix to work, the IRET and full regs frames must be adjacent, with no FUNC frames in between. So replace the FUNC hint in interrupt_entry() with an IRET_REGS hint. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/97a408167cc09f1cfa0de31a7b70dd88868d743f.1587808742.git.jpoimboe@redhat.com
2020-04-25x86/entry/64: Fix unwind hints in rewind_stack_do_exit()Jann Horn
The LEAQ instruction in rewind_stack_do_exit() moves the stack pointer directly below the pt_regs at the top of the task stack before calling do_exit(). Tell the unwinder to expect pt_regs. Fixes: 8c1f75587a18 ("x86/entry/64: Add unwind hint annotations") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/68c33e17ae5963854916a46f522624f8e1d264f2.1587808742.git.jpoimboe@redhat.com
2020-04-25x86/entry/64: Fix unwind hints in __switch_to_asm()Josh Poimboeuf
UNWIND_HINT_FUNC has some limitations: specifically, it doesn't reset all the registers to undefined. This causes objtool to get confused about the RBP push in __switch_to_asm(), resulting in bad ORC data. While __switch_to_asm() does do some stack magic, it's otherwise a normal callable-from-C function, so just annotate it as a function, which makes objtool happy and allows it to produces the correct hints automatically. Fixes: 8c1f75587a18 ("x86/entry/64: Add unwind hint annotations") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Jones <dsj@fb.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lore.kernel.org/r/03d0411920d10f7418f2e909210d8e9a3b2ab081.1587808742.git.jpoimboe@redhat.com
2020-04-25x86/entry/64: Fix unwind hints in kernel exit pathJosh Poimboeuf
In swapgs_restore_regs_and_return_to_usermode, after the stack is switched to the trampoline stack, the existing UNWIND_HINT_REGS hint is no longer valid, which can result in the following ORC unwinder warning: WARNING: can't dereference registers at 000000003aeb0cdd for ip swapgs_restore_regs_and_return_to_usermode+0x93/0xa0 For full correctness, we could try to add complicated unwind hints so the unwinder could continue to find the registers, but when when it's this close to kernel exit, unwind hints aren't really needed anymore and it's fine to just use an empty hint which tells the unwinder to stop. For consistency, also move the UNWIND_HINT_EMPTY in entry_SYSCALL_64_after_hwframe to a similar location. Fixes: 3e3b9293d392 ("x86/entry/64: Return to userspace from the trampoline stack") Reported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Dave Jones <dsj@fb.com> Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reported-by: Joe Mario <jmario@redhat.com> Reported-by: Jann Horn <jannh@google.com> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/60ea8f562987ed2d9ace2977502fe481c0d7c9a0.1587808742.git.jpoimboe@redhat.com
2020-03-10x86/entry/64: Trace irqflags unconditionally as ON when returning to user spaceThomas Gleixner
User space cannot disable interrupts any longer so trace return to user space unconditionally as IRQS_ON. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/20200308222609.314596327@linutronix.de
2020-01-09x86/entry/64: Add instruction suffix to SYSRETJan Beulich
ignore_sysret() contains an unsuffixed SYSRET instruction. gas correctly interprets this as SYSRETL, but leaving it up to gas to guess when there is no register operand that implies a size is bad practice, and upstream gas is likely to warn about this in the future. Use SYSRETL explicitly. This does not change the assembled output. Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/038a7c35-062b-a285-c6d2-653b56585844@suse.com
2019-11-16x86/entry/64: Remove pointless jump in paranoid_exitThomas Gleixner
Jump directly to restore_regs_and_return_to_kernel instead of making a pointless extra jump through .Lparanoid_exit_restore Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191023123117.779277679@linutronix.de
2019-10-18x86/asm: Change all ENTRY+ENDPROC to SYM_FUNC_*Jiri Slaby
These are all functions which are invoked from elsewhere, so annotate them as global using the new SYM_FUNC_START and their ENDPROC's by SYM_FUNC_END. Make sure ENTRY/ENDPROC is not defined on X86_64, given these were the last users. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [hibernate] Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> [xen bits] Acked-by: Herbert Xu <herbert@gondor.apana.org.au> [crypto] Cc: Allison Randal <allison@lohutok.net> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Shevchenko <andy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Armijn Hemel <armijn@tjaldur.nl> Cc: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Enrico Weigelt <info@metux.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Len Brown <len.brown@intel.com> Cc: linux-arch@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-efi <linux-efi@vger.kernel.org> Cc: linux-efi@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: platform-driver-x86@vger.kernel.org Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Wei Huang <wei@redhat.com> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Cc: Xiaoyao Li <xiaoyao.li@linux.intel.com> Link: https://lkml.kernel.org/r/20191011115108.12392-25-jslaby@suse.cz
2019-10-18x86/asm/64: Change all ENTRY+END to SYM_CODE_*Jiri Slaby
Change all assembly code which is marked using END (and not ENDPROC). Switch all these to the appropriate new annotation SYM_CODE_START and SYM_CODE_END. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> [xen bits] Cc: Andy Lutomirski <luto@kernel.org> Cc: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: linux-arch@vger.kernel.org Cc: Maran Wilson <maran.wilson@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/20191011115108.12392-24-jslaby@suse.cz