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2020-06-11x86/entry/64: Move do_softirq_own_stack() to CThomas Gleixner1-13/+0
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 <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-06-11x86/entry: Provide helpers for executing on the irqstackThomas Gleixner1-0/+39
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 <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-06-11x86/entry: Clean up idtentry_enter/exit() leftoversThomas Gleixner1-38/+29
Now that everything is converted to conditional RCU handling remove idtentry_enter/exit() and tidy up the conditional functions. This does not remove rcu_irq_exit_preempt(), to avoid conflicts with the RCU tree. Will be removed once all of this hits Linus's tree. Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-06-11x86/entry: Provide idtentry_enter/exit_user()Thomas Gleixner1-0/+31
As there are exceptions which already handle entry from user mode and from kernel mode separately, providing explicit user entry/exit handling callbacks makes sense and makes the code easier to understand. Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-06-11x86/entry: Provide idtentry_entry/exit_cond_rcu()Thomas Gleixner1-15/+64
After a lengthy discussion [1] it turned out that RCU does not need a full rcu_irq_enter/exit() when RCU is already watching. All it needs if NOHZ_FULL is active is to check whether the tick needs to be restarted. This allows to avoid a separate variant for the pagefault handler which cannot invoke rcu_irq_enter() on a kernel pagefault which might sleep. The cond_rcu argument is only temporary and will be removed once the existing users of idtentry_enter/exit() have been cleaned up. After that the code can be significantly simplified. [ mingo: Simplified the control flow ] Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: "Paul E. McKenney" <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: [1] https://lkml.kernel.org/r/[email protected] Link: https://lore.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert double fault exception to IDTENTRY_DFThomas Gleixner2-11/+3
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Implement user mode C entry points for #DB and #MCEThomas Gleixner1-1/+1
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/64: Remove error code clearing from #DB and #MCE ASM stubThomas Gleixner1-1/+0
The C entry points do not expect an error code. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Debug exception to IDTENTRY_DBThomas Gleixner2-12/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert NMI to IDTENTRY_NMIThomas Gleixner2-12/+11
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Machine Check to IDTENTRY_ISTThomas Gleixner2-12/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert INT3 exception to IDTENTRY_RAWThomas Gleixner2-9/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/32: Convert IRET exception to IDTENTRY_SWThomas Gleixner1-7/+7
Convert the IRET exception handler to IDTENTRY_SW. This is slightly different than the conversions of hardware exceptions as the IRET exception is invoked via an exception table when IRET faults. So it just uses the IDTENTRY_SW mechanism for consistency. It does not emit ASM code as it does not fit the other idtentry exceptions. - Implement the C entry point with DEFINE_IDTENTRY_SW() which maps to DEFINE_IDTENTRY() - 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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert SIMD coprocessor error exception to IDTENTRYThomas Gleixner2-15/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Alignment check exception to IDTENTRYThomas Gleixner2-7/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Coprocessor error exception to IDTENTRYThomas Gleixner2-8/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Spurious interrupt bug exception to IDTENTRYThomas Gleixner2-8/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert General protection exception to IDTENTRYThomas Gleixner2-9/+2
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Stack segment exception to IDTENTRYThomas Gleixner2-7/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Segment not present exception to IDTENTRYThomas Gleixner2-7/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Invalid TSS exception to IDTENTRYThomas Gleixner2-7/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Coprocessor segment overrun exception to IDTENTRYThomas Gleixner2-8/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Device not available exception to IDTENTRYThomas Gleixner2-8/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Invalid Opcode exception to IDTENTRYThomas Gleixner2-8/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Bounds exception to IDTENTRYThomas Gleixner2-8/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Overflow exception to IDTENTRYThomas Gleixner2-8/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Convert Divide Error to IDTENTRYThomas Gleixner2-8/+0
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/common: Provide idtentry_enter/exit()Thomas Gleixner1-0/+99
Provide functions which handle the low level entry and exit similar to enter/exit from user mode. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/idtentry: Provide macros to define/declare IDT entry pointsThomas Gleixner2-0/+12
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/32: Provide macro to emit IDT entry stubsThomas Gleixner1-0/+68
32 and 64 bit have unnecessary different ways to populate the exception entry code. Provide a idtentry macro which allows to consolidate all of that. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/64: Provide sane error entry/exitThomas Gleixner1-3/+19
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Distangle idtentryThomas Gleixner1-183/+220
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/64: Reorder idtentriesThomas Gleixner1-19/+17
Move them all together so verifying the cleanup patches for binary equivalence will be easier. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/64: Use native swapgs in asm_load_gs_index()Thomas Gleixner1-3/+3
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 <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Acked-by: Juergen Gross <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Disable interrupts for native_load_gs_index() in C codeThomas Gleixner1-8/+3
There is absolutely no point in doing this in ASM code. Move it to C. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Make entry_64_compat.S objtool cleanPeter Zijlstra2-7/+20
Currently entry_64_compat is exempt from objtool, but with vmlinux mode there is no hiding it. Make the following changes to make it pass: - change entry_SYSENTER_compat to STT_NOTYPE; it's not a function and doesn't have function type stack setup. - mark all STT_NOTYPE symbols with UNWIND_HINT_EMPTY; so we do validate them and don't treat them as unreachable. - don't abuse RSP as a temp register, this confuses objtool mightily as it (rightfully) thinks we're doing unspeakable things to the stack. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Move irq flags tracing to prepare_exit_to_usermode()Thomas Gleixner4-22/+27
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Move irq tracing on syscall entry to C-codeThomas Gleixner4-34/+19
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/common: Protect against instrumentationThomas Gleixner1-44/+89
Mark the various syscall entries with noinstr to protect them against instrumentation and add the noinstrumentation_begin()/end() annotations to mark the parts of the functions which are safe to call out into instrumentable code. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Mark enter_from_user_mode() noinstrThomas Gleixner1-1/+1
Both the callers in the low level ASM code and __context_tracking_exit() which is invoked from enter_from_user_mode() via user_exit_irqoff() are marked NOKPROBE. Allowing enter_from_user_mode() to be probed is inconsistent at best. Aside of that while function tracing per se is safe the function trace entry/exit points can be used via BPF as well which is not safe to use before context tracking has reached CONTEXT_KERNEL and adjusted RCU. Mark it noinstr which moves it into the instrumentation protected text section and includes notrace. Note, this needs further fixups in context tracking to ensure that the full call chain is protected. Will be addressed in follow up changes. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Masami Hiramatsu <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/32: Move non entry code into .text sectionThomas Gleixner1-0/+9
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/64: Move non entry code into .text sectionThomas Gleixner1-4/+14
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 <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Exclude low level entry code from sanitizingPeter Zijlstra1-0/+8
The sanitizers are not really applicable to the fragile low level entry code. Entry code needs to carefully setup a normal 'runtime' environment. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry: Remove the unused LOCKDEP_SYSEXIT cruftThomas Gleixner1-5/+0
No users left since two years due to commit 21d375b6b34f ("x86/entry/64: Remove the SYSCALL64 fast path") Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/64: Avoid pointless code when CONTEXT_TRACKING=nThomas Gleixner1-0/+2
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 <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Frederic Weisbecker <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/64: Remove unneeded kernel CR3 switchingLai Jiangshan1-1/+0
When native_load_gs_index() fails on .Lgs_change, CR3 must be kernel CR3. No need to switch it. Signed-off-by: Lai Jiangshan <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-11x86/entry/64: Remove an unused labelLai Jiangshan1-1/+0
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 <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-09mmap locking API: use coccinelle to convert mmap_sem rwsem call sitesMichel Lespinasse1-7/+7
This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Daniel Jordan <[email protected]> Reviewed-by: Laurent Dufour <[email protected]> Reviewed-by: Vlastimil Babka <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: David Rientjes <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: John Hubbard <[email protected]> Cc: Liam Howlett <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ying Han <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
2020-06-03Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-12/+0
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 ...
2020-06-01Merge branch 'from-miklos' of ↵Linus Torvalds2-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "Assorted patches from Miklos. An interesting part here is /proc/mounts stuff..." The "/proc/mounts stuff" is using a cursor for keeeping the location data while traversing the mount listing. Also probably worth noting is the addition of faccessat2(), which takes an additional set of flags to specify how the lookup is done (AT_EACCESS, AT_SYMLINK_NOFOLLOW, AT_EMPTY_PATH). * 'from-miklos' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: add faccessat2 syscall vfs: don't parse "silent" option vfs: don't parse "posixacl" option vfs: don't parse forbidden flags statx: add mount_root statx: add mount ID statx: don't clear STATX_ATIME on SB_RDONLY uapi: deprecate STATX_ALL utimensat: AT_EMPTY_PATH support vfs: split out access_override_creds() proc/mounts: add cursor aio: fix async fsync creds vfs: allow unprivileged whiteout creation
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