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2020-06-11x86/idtentry: Provide IDTENTRY_ERRORCODEThomas Gleixner
Same as IDTENTRY but the C entry point has an error code argument. 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/20200505134905.258989060@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/traps: Prepare for using DEFINE_IDTENTRYThomas Gleixner
Prepare for using IDTENTRY to define the C exception/trap entry points. It would be possible to glue this into the existing macro maze, but it's simpler and better to read at the end to just make them distinct. Provide a trivial inline helper to read the trap address and add a comment explaining the logic behind it. The existing macros will be removed once all instances are converted. 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/20200505134904.556327833@linutronix.de
2020-06-11x86/entry/common: Provide idtentry_enter/exit()Thomas Gleixner
Provide functions which handle the low level entry and exit similar to enter/exit from user mode. 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/20200505134904.457578656@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/32: Provide macro to emit IDT entry stubsThomas Gleixner
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 <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/20200505134904.166735365@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/traps: Split trap numbers out in a separate headerThomas Gleixner
So they can be used in ASM code. For this it is also necessary to convert them to defines. Will be used for the rework of the entry code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134903.731004084@linutronix.de
2020-06-11x86/traps: Make interrupt enable/disable symmetric in C codeThomas Gleixner
Traps enable interrupts conditionally but rely on the ASM return code to disable them again. That results in redundant interrupt disable and trace calls. Make the trap handlers disable interrupts before returning to avoid that, which allows simplification of the ASM entry code in follow up changes. Originally-by: Peter Zijlstra <peterz@infradead.org> 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/20200505134903.622702796@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/traps: Mark sync_regs() noinstrThomas Gleixner
Replace the notrace and NOKPROBE annotations with noinstr. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134903.439765290@linutronix.de
2020-06-11x86/traps: Mark fixup_bad_iret() noinstrThomas Gleixner
This is called from deep entry ASM in a situation where instrumentation will cause more harm than providing useful information. Switch from memmove() to memcpy() because memmove() can't be called from noinstr code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134903.346741553@linutronix.de
2020-06-11x86/entry: Make entry_64_compat.S objtool cleanPeter Zijlstra
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) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134341.272248024@linutronix.de
2020-06-11x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inlineThomas Gleixner
Prevent the compiler from uninlining and creating traceable/probable functions as this is invoked _after_ context tracking switched to CONTEXT_USER and rcu idle. 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/20200505134340.902709267@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/common: Protect against instrumentationThomas Gleixner
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 <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134340.520277507@linutronix.de
2020-06-11x86/entry: Mark enter_from_user_mode() noinstrThomas Gleixner
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 <tglx@linutronix.de> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134340.429059405@linutronix.de
2020-06-11x86/entry/32: 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: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134340.320164650@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/idt: Remove update_intr_gate()Thomas Gleixner
No more users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-06-11bug: Annotate WARN/BUG/stackfail as noinstr safeThomas Gleixner
Warnings, bugs and stack protection fails from noinstr sections, e.g. low level and early entry code, are likely to be fatal. Mark them as "safe" to be invoked from noinstr protected code to avoid annotating all usage sites. Getting the information out is important. 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/20200505134100.376598577@linutronix.de
2020-06-11lib/smp_processor_id: Move it into noinstr sectionThomas Gleixner
That code is already not traceable. Move it into the noinstr section so the objtool section validation does not trigger. Annotate the warning code as "safe". While it might be not under all circumstances, getting the information out is important enough. Should this ever trigger from the sensitive code which is shielded against instrumentation, e.g. low level entry, then the printk is the least of the worries. Addresses the objtool warnings: vmlinux.o: warning: objtool: context_tracking_recursion_enter()+0x7: call to __this_cpu_preempt_check() leaves .noinstr.text section vmlinux.o: warning: objtool: __context_tracking_exit()+0x17: call to __this_cpu_preempt_check() leaves .noinstr.text section vmlinux.o: warning: objtool: __context_tracking_enter()+0x2a: call to __this_cpu_preempt_check() leaves .noinstr.text section 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/20200505134340.902709267@linutronix.de
2020-06-11context_tracking: Ensure that the critical path cannot be instrumentedThomas Gleixner
context tracking lacks a few protection mechanisms against instrumentation: - While the core functions are marked NOKPROBE they lack protection against function tracing which is required as the function entry/exit points can be utilized by BPF. - static functions invoked from the protected functions need to be marked as well as they can be instrumented otherwise. - using plain inline allows the compiler to emit traceable and probable functions. Fix this by marking the functions noinstr and converting the plain inlines to __always_inline. The NOKPROBE_SYMBOL() annotations are removed as the .noinstr.text section is already excluded from being probed. Cures the following objtool warnings: vmlinux.o: warning: objtool: enter_from_user_mode()+0x34: call to __context_tracking_exit() leaves .noinstr.text section vmlinux.o: warning: objtool: prepare_exit_to_usermode()+0x29: call to __context_tracking_enter() leaves .noinstr.text section vmlinux.o: warning: objtool: syscall_return_slowpath()+0x29: call to __context_tracking_enter() leaves .noinstr.text section vmlinux.o: warning: objtool: do_syscall_64()+0x7f: call to __context_tracking_enter() leaves .noinstr.text section vmlinux.o: warning: objtool: do_int80_syscall_32()+0x3d: call to __context_tracking_enter() leaves .noinstr.text section vmlinux.o: warning: objtool: do_fast_syscall_32()+0x9c: call to __context_tracking_enter() leaves .noinstr.text section and generates new ones... Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134340.811520478@linutronix.de
2020-06-11x86/entry: Exclude low level entry code from sanitizingPeter Zijlstra
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) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/20200505134059.970057117@linutronix.de
2020-06-11x86/entry: Remove the unused LOCKDEP_SYSEXIT cruftThomas Gleixner
No users left since two years due to commit 21d375b6b34f ("x86/entry/64: Remove the SYSCALL64 fast path") 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/20200505134059.061301403@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/doublefault: Remove memmove() callPeter Zijlstra
Use of memmove() in #DF is problematic considered tracing and other instrumentation. Remove the memmove() call and simply write out what needs doing; this even clarifies the code, win-win! The code copies from the espfix64 stack to the normal task stack, there is no possible way for that to overlap. Survives selftests/x86, specifically sigreturn_64. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505134058.863038566@linutronix.de
2020-06-11x86/hw_breakpoint: Prevent data breakpoints on cpu_entry_areaAndy Lutomirski
A data breakpoint near the top of an IST stack will cause unrecoverable recursion. A data breakpoint on the GDT, IDT, or TSS is terrifying. Prevent either of these from happening. Co-developed-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/20200505134058.272448010@linutronix.de
2020-06-11x86/idt: Keep spurious entries unset in system_vectorsVitaly Kuznetsov
With commit dc20b2d52653 ("x86/idt: Move interrupt gate initialization to IDT code") non assigned system vectors are also marked as used in 'used_vectors' (now 'system_vectors') bitmap. This makes checks in arch_show_interrupts() whether a particular system vector is allocated to always pass and e.g. 'Hyper-V reenlightenment interrupts' entry always shows up in /proc/interrupts. Another side effect of having all unassigned system vectors marked as used is that irq_matrix_debug_show() will wrongly count them among 'System' vectors. As it is now ensured that alloc_intr_gate() is not called after init, it is possible to leave unused entries in 'system_vectors' unset to fix these issues. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200428093824.1451532-4-vkuznets@redhat.com
2020-06-11x86/idt: Annotate alloc_intr_gate() with __initVitaly Kuznetsov
There seems to be no reason to allocate interrupt gates after init. Mark alloc_intr_gate() as __init and add WARN_ON() checks making sure it is only used before idt_setup_apic_and_irq_gates() finalizes IDT setup and maps all un-allocated entries to spurious entries. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200428093824.1451532-3-vkuznets@redhat.com
2020-06-11x86/xen: Split HVM vector callback setup and interrupt gate allocationVitaly Kuznetsov
As a preparatory change for making alloc_intr_gate() __init split xen_callback_vector() into callback vector setup via hypercall (xen_setup_callback_vector()) and interrupt gate allocation (xen_alloc_callback_vector()). xen_setup_callback_vector() is being called twice: on init and upon system resume from xen_hvm_post_suspend(). alloc_intr_gate() only needs to be called once. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200428093824.1451532-2-vkuznets@redhat.com
2020-06-11x86/idt: Remove address operator on function machine_check()Lai Jiangshan
machine_check is function address, the address operator on it is nop for compiler. Make it consistent with the other function addresses in the same file. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200419144049.1906-3-laijs@linux.alibaba.com
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
2020-06-11arm64: warn on incorrect placement of the kernel by the bootloaderArd Biesheuvel
Commit cfa7ede20f133c ("arm64: set TEXT_OFFSET to 0x0 in preparation for removing it entirely") results in boot failures when booting kernels that are built without KASLR support on broken bootloaders that ignore the TEXT_OFFSET value passed via the header, and use the default of 0x80000 instead. To work around this, turn CONFIG_RELOCATABLE on by default, even if KASLR itself (CONFIG_RANDOMIZE_BASE) is turned off, and require CONFIG_EXPERT to be enabled to deviate from this. Then, emit a warning into the kernel log if we are not booting via the EFI stub (which is permitted to deviate from the placement restrictions) and the kernel base address is not placed according to the rules as laid out in Documentation/arm64/booting.rst. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20200611124330.252163-1-ardb@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-06-11kbuild: fix broken builds because of GZIP,BZIP2,LZOP variablesDenis Efremov
Redefine GZIP, BZIP2, LZOP variables as KGZIP, KBZIP2, KLZOP resp. GZIP, BZIP2, LZOP env variables are reserved by the tools. The original attempt to redefine them internally doesn't work in makefiles/scripts intercall scenarios, e.g., "make GZIP=gzip bindeb-pkg" and results in broken builds. There can be other broken build commands because of this, so the universal solution is to use non-reserved env variables for the compression tools. Fixes: 8dfb61dcbace ("kbuild: add variables for compression tools") Signed-off-by: Denis Efremov <efremov@linux.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-11samples: binderfs: really compile this sample and fix build issuesMasahiro Yamada
Even after commit c624adc9cb6e ("samples: fix binderfs sample"), this sample is never compiled. 'hostprogs' teaches Kbuild that this is a host program, but not enough to order to compile it. You must add it to 'always-y' to really compile it. Since this sample has never been compiled in upstream, various issues are left unnoticed. [1] compilers without <linux/android/binderfs.h> are still widely used <linux/android/binderfs.h> is only available since commit c13295ad219d ("binderfs: rename header to binderfs.h"), i.e., Linux 5.0 If your compiler is based on UAPI headers older than Linux 5.0, you will see the following error: samples/binderfs/binderfs_example.c:16:10: fatal error: linux/android/binderfs.h: No such file or directory #include <linux/android/binderfs.h> ^~~~~~~~~~~~~~~~~~~~~~~~~~ compilation terminated. You cannot rely on compilers having such a new header. The common approach is to install UAPI headers of this kernel into usr/include, and then add it to the header search path. I added 'depends on HEADERS_INSTALL' in Kconfig, and '-I usr/include' compiler flag in Makefile. [2] compile the sample for target architecture Because headers_install works for the target architecture, only the native compiler was able to build sample code that requires '-I usr/include'. Commit 7f3a59db274c ("kbuild: add infrastructure to build userspace programs") added the new syntax 'userprogs' to compile user-space programs for the target architecture. Use it, and then 'ifndef CROSS_COMPILE' will go away. I added 'depends on CC_CAN_LINK' because $(CC) is not necessarily capable of linking user-space programs. [3] use subdir-y to descend into samples/binderfs Since this directory does not contain any kernel-space code, it has no point in generating built-in.a or modules.order. Replace obj-$(CONFIG_...) with subdir-$(CONFIG_...). [4] -Wunused-variable warning If I compile this, I see the following warning. samples/binderfs/binderfs_example.c: In function 'main': samples/binderfs/binderfs_example.c:21:9: warning: unused variable 'len' [-Wunused-variable] 21 | size_t len; | ^~~ I removed the unused 'len'. [5] CONFIG_ANDROID_BINDERFS is not required Since this is a user-space standalone program, it is independent of the kernel configuration. Remove 'depends on ANDROID_BINDERFS'. Fixes: 9762dc1432e1 ("samples: add binderfs sample program") Fixes: c624adc9cb6e ("samples: fix binderfs sample") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-06-11i2c: Drop stray comma in MODULE_AUTHOR statementsJean Delvare
It is not the common usage to have a comma between the name and the email address, so remove it. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Kukjin Kim <kgene@kernel.org> Cc: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-06-11i2c: npcm7xx: npcm_i2caddr[] can be statickernel test robot
Fixes: f54736925a4f ("i2c: npcm7xx: Add support for slave mode for Nuvoton") Signed-off-by: kernel test robot <lkp@intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-06-11Merge tag 'drm-misc-next-fixes-2020-06-11' of ↵Dave Airlie
git://anongit.freedesktop.org/drm/drm-misc into drm-next In core, DRM connectors now notify userspace of hotplug events via sysfs. In drivers, sun4i now uses 4 bits to store the clock's m divider; ast sets up 24/32-bit color mode correctly. Signed-off-by: Dave Airlie <airlied@redhat.com> From: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20200611075007.GA15098@linux-uq9g
2020-06-11drm/ast: fix missing break in switch statement for format->cpp[0] case 4Colin Ian King
Currently the switch statement for format->cpp[0] value 4 assigns color_index which is never read again and then falls through to the default case and returns. This looks like a missing break statement bug. Fix this by adding a break statement. Addresses-Coverity: ("Unused value") Fixes: 259d14a76a27 ("drm/ast: Split ast_set_vbios_mode_info()") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Tested-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20200610115804.1132338-1-colin.king@canonical.com
generated by cgit v1.2.3 (git 2.39.1) at 2025-08-05 15:29:47 +0000