Commit Graph

931809 Commits

Author SHA1 Message Date
Thomas Gleixner
e88d974136 x86/entry: Change exit path of xen_failsafe_callback
xen_failsafe_callback() is invoked from XEN for two cases:

  1. Fault while reloading DS, ES, FS or GS
  2. Fault while executing IRET

 #1 retries the IRET after XEN has fixed up the segments.
 #2 injects a #GP which kills the task

For #1 there is no reason to go through the full exception return path
because the tasks TIF state is still the same. So just going straight to
the IRET path is good enough.

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/20200521202118.423224507@linutronix.de
2020-06-11 15:15:10 +02:00
Thomas Gleixner
e2dcb5f139 x86/entry: Remove the transition leftovers
Now that all exceptions are converted over the sane flag is not longer
needed. Also the vector argument of idtentry_body on 64-bit is pointless
now.

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/20200521202118.331115895@linutronix.de
2020-06-11 15:15:09 +02:00
Thomas Gleixner
91eeafea1e x86/entry: Switch page fault exception to IDTENTRY_RAW
Convert page fault exceptions to IDTENTRY_RAW:

  - Implement the C entry point with DEFINE_IDTENTRY_RAW
  - Add the CR2 read into the exception handler
  - Add the idtentry_enter/exit_cond_rcu() invocations in
    in the regular page fault handler and in the async PF
    part.
  - Emit the ASM stub with DECLARE_IDTENTRY_RAW
  - Remove the ASM idtentry in 64-bit
  - Remove the CR2 read from 64-bit
  - Remove the open coded ASM entry code in 32-bit
  - Fix up the XEN/PV code
  - Remove the old prototypes

No functional change.

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/20200521202118.238455120@linutronix.de
2020-06-11 15:15:09 +02:00
Thomas Gleixner
00cf8baf9c x86/entry/64: Simplify idtentry_body
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
2020-06-11 15:15:08 +02:00
Thomas Gleixner
2f6474e463 x86/entry: Switch XEN/PV hypercall entry to IDTENTRY
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
2020-06-11 15:15:08 +02:00
Thomas Gleixner
1de16e0c17 x86/entry: Split out idtentry_exit_cond_resched()
The XEN PV hypercall requires the ability of conditional rescheduling when
preemption is disabled because some hypercalls take ages.

Split out the rescheduling code from idtentry_exit_cond_rcu() so it can
be reused for that.

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/20200521202117.962199649@linutronix.de
2020-06-11 15:15:08 +02:00
Thomas Gleixner
eb6555c839 x86/entry/64: Move do_softirq_own_stack() to C
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
2020-06-11 15:15:07 +02:00
Thomas Gleixner
931b941459 x86/entry: Provide helpers for executing on the irqstack
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
2020-06-11 15:15:07 +02:00
Thomas Gleixner
98a3bf195e genirq: Provide __irq_enter/exit_raw()
Like __irq_enter/exit() but without time accounting. To be used for "empty"
system vectors like the scheduler IPI to avoid the overhead.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202117.671682341@linutronix.de
2020-06-11 15:15:06 +02:00
Thomas Gleixner
8a6bc4787f genirq: Provide irq_enter/exit_rcu()
irq_enter()/exit() currently include RCU handling. To properly separate the RCU
handling code, provide variants which contain only the non-RCU related
functionality.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202117.567023613@linutronix.de
2020-06-11 15:15:06 +02:00
Thomas Gleixner
9ee01e0f69 x86/entry: Clean up idtentry_enter/exit() leftovers
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 <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202117.473597954@linutronix.de
2020-06-11 15:15:06 +02:00
Thomas Gleixner
fa95d7dc1a x86/idtentry: Switch to conditional RCU handling
Switch all idtentry_enter/exit() users over to the new conditional RCU
handling scheme and make the user mode entries in #DB, #INT3 and #MCE use
the user mode idtentry functions.

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/20200521202117.382387286@linutronix.de
2020-06-11 15:15:05 +02:00
Thomas Gleixner
9f9781b60d x86/entry: Provide idtentry_enter/exit_user()
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 <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202117.289548561@linutronix.de
2020-06-11 15:15:05 +02:00
Thomas Gleixner
3eeec38584 x86/entry: Provide idtentry_entry/exit_cond_rcu()
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 <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: "Paul E. McKenney" <paulmck@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: [1] https://lkml.kernel.org/r/20200515235125.628629605@linutronix.de
Link: https://lore.kernel.org/r/20200521202117.181397835@linutronix.de
2020-06-11 15:15:04 +02:00
Thomas Gleixner
2ab70319bc nmi, tracing: Make hardware latency tracing noinstr safe
The hardware latency tracer calls into instrumentable functions. Move the
calls into the RCU watching sections and annotate them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20200521202116.904176298@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-06-11 15:15:04 +02:00
Ingo Molnar
7102cb0713 x86/entry: Fix allnoconfig build warning
The following commit:

  095b7a3e7745 ("x86/entry: Convert double fault exception to IDTENTRY_DF")

introduced a new build warning on 64-bit allnoconfig kernels, that have CONFIG_VMAP_STACK disabled:

  arch/x86/kernel/traps.c:332:16: warning: unused variable ‘address’ [-Wunused-variable]

This variable is only used if CONFIG_VMAP_STACK is defined, so make it
dependent on that, not CONFIG_X86_64.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
2020-06-11 15:15:03 +02:00
Thomas Gleixner
c29c775a55 x86/entry: Convert double fault exception to IDTENTRY_DF
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
2020-06-11 15:15:03 +02:00
Thomas Gleixner
6a8dfa8e40 x86/idtentry: Provide IDTENTRY_DF
Provide a separate macro for #DF as this needs to emit paranoid only code
and has also a special ASM stub in 32bit.

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
2020-06-11 15:15:02 +02:00
Thomas Gleixner
865d3a9afe x86/mce: Address objtools noinstr complaints
Mark the relevant functions noinstr, use the plain non-instrumented MSR
accessors. The only odd part is the instrumentation_begin()/end() pair around the
indirect machine_check_vector() call as objtool can't figure that out. The
possible invoked functions are annotated correctly.

Also use notrace variant of nmi_enter/exit(). If MCEs happen then hardware
latency tracing is the least of the worries.

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/20200505135315.476734898@linutronix.de
2020-06-11 15:15:02 +02:00
Thomas Gleixner
75347bb253 x86/traps: Address objtool noinstr complaints in #DB
The functions invoked from handle_debug() can be instrumented. Tell objtool
about it.

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/20200505135315.380927730@linutronix.de
2020-06-11 15:15:01 +02:00
Thomas Gleixner
9347f41352 x86/traps: Restructure #DB handling
Now that there are separate entry points, move the kernel/user_mode specifc
checks into the entry functions so the common handling code does not need
the extra mode checks. Make the code more readable while at it.

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/20200505135315.283276272@linutronix.de
2020-06-11 15:15:01 +02:00
Thomas Gleixner
4c0dcd8350 x86/entry: Implement user mode C entry points for #DB and #MCE
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
2020-06-11 15:15:00 +02:00
Thomas Gleixner
f08e32ec3c x86/idtentry: Provide IDTRENTRY_NOIST variants for #DB and #MC
Provide NOIST entry point macros which allows to implement NOIST variants
of the C entry points. These are invoked when #DB or #MC enter from user
space. This allows explicit handling of the difference between user mode
and kernel mode entry later.

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/20200505135315.084882104@linutronix.de
2020-06-11 15:15:00 +02:00
Thomas Gleixner
df7ccaffd2 x86/entry/64: Remove error code clearing from #DB and #MCE ASM stub
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
2020-06-11 15:15:00 +02:00
Thomas Gleixner
2bbc68f837 x86/entry: Convert Debug exception to IDTENTRY_DB
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
2020-06-11 15:14:59 +02:00
Peter Zijlstra
9f58fdde95 x86/db: Split out dr6/7 handling
DR6/7 should be handled before nmi_enter() is invoked and restore after
nmi_exit() to minimize the exposure.

Split it out into helper inlines and bring it into the correct order.

Signed-off-by: Peter Zijlstra <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/20200505135314.808628211@linutronix.de
2020-06-11 15:14:59 +02:00
Thomas Gleixner
f051f69795 x86/nmi: Protect NMI entry against instrumentation
Mark all functions in the fragile code parts noinstr or force inlining so
they can't be instrumented.

Also make the hardware latency tracer invocation explicit outside of
non-instrumentable section.

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/20200505135314.716186134@linutronix.de
2020-06-11 15:14:58 +02:00
Thomas Gleixner
6271fef00b x86/entry: Convert NMI to IDTENTRY_NMI
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
2020-06-11 15:14:58 +02:00
Thomas Gleixner
9cce81cff7 x86/idtentry: Provide IDTENTRY_XEN for XEN/PV
XEN/PV has special wrappers for NMI and DB exceptions. They redirect these
exceptions through regular IDTENTRY points. Provide the necessary IDTENTRY
macros to make this work

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/20200505135314.518622698@linutronix.de
2020-06-11 15:14:57 +02:00
Thomas Gleixner
aedbdeab00 x86/mce: Use untraced rd/wrmsr in the MCE offline/crash check
mce_check_crashing_cpu() is called right at the entry of the MCE
handler. It uses mce_rdmsr() and mce_wrmsr() which are wrappers around
rdmsr() and wrmsr() to handle the MCE error injection mechanism, which is
pointless in this context, i.e. when the MCE hits an offline CPU or the
system is already marked crashing.

The MSR access can also be traced, so use the untraceable variants. This
is also safe vs. XEN paravirt as these MSRs are not affected by XEN PV
modifications.

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/20200505135314.426347351@linutronix.de
2020-06-11 15:14:57 +02:00
Thomas Gleixner
8cd501c1fa x86/entry: Convert Machine Check to IDTENTRY_IST
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
2020-06-11 15:14:57 +02:00
Thomas Gleixner
94a46d316f x86/mce: Move nmi_enter/exit() into the entry point
There is no reason to have nmi_enter/exit() in the actual MCE
handlers. Move it to the entry point. This also covers the until now
uncovered initial handler which only prints.

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/20200505135314.243936614@linutronix.de
2020-06-11 15:14:56 +02:00
Thomas Gleixner
2c058b03cc x86/idtentry: Provide IDTENTRY_IST
Same as IDTENTRY but for exceptions which run on Interrupt Stacks (IST) on
64bit. For 32bit this maps to IDTENTRY.

There are 3 variants which will be used:
      IDTENTRY_MCE
      IDTENTRY_DB
      IDTENTRY_NMI

These map to IDTENTRY_IST, but only the MCE and DB variants are emitting
ASM code as the NMI entry needs hand crafted ASM still.

The function defines do not contain any idtenter/exit calls as these
exceptions need special treatment.

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/20200505135314.137125609@linutronix.de
2020-06-11 15:14:55 +02:00
Peter Zijlstra
21e28290b3 x86/traps: Split int3 handler up
For code simplicity split up the int3 handler into a kernel and user part
which makes the code flow simpler to understand.

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/20200505135314.045220765@linutronix.de
2020-06-11 15:14:55 +02:00
Thomas Gleixner
8edd7e37ae x86/entry: Convert INT3 exception to IDTENTRY_RAW
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
2020-06-11 15:14:55 +02:00
Thomas Gleixner
0dc6cdc21b x86/idtentry: Provide IDTENTRY_RAW
Some exception handlers need to do extra work before any of the entry
helpers are invoked. Provide IDTENTRY_RAW for this.

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/20200505135313.830540017@linutronix.de
2020-06-11 15:14:54 +02:00
Peter Zijlstra
f64366efd8 x86/int3: Inline bsearch()
Avoid calling out to bsearch() by inlining it, for normal kernel configs
this was the last external call and poke_int3_handler() is now fully self
sufficient -- no calls to external code.

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/20200505135313.731774429@linutronix.de
2020-06-11 15:14:54 +02:00
Peter Zijlstra
df65bba1dc lib/bsearch: Provide __always_inline variant
For code that needs the ultimate performance (it can inline the @cmp
function too) or simply needs to avoid calling external functions for
whatever reason, provide an __always_inline variant of bsearch().

[ tglx: Renamed to __inline_bsearch() as suggested by Andy ]

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/20200505135313.624443814@linutronix.de
2020-06-11 15:14:53 +02:00
Peter Zijlstra
ef882bfef9 x86/int3: Avoid atomic instrumentation
Use arch_atomic_*() and __READ_ONCE() to ensure nothing untoward
creeps in and ruins things.

That is; this is the INT3 text poke handler, strictly limit the code
that runs in it, lest it inadvertenly hits yet another INT3.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505135313.517429268@linutronix.de
2020-06-11 15:14:53 +02:00
Thomas Gleixner
4979fb53ab x86/int3: Ensure that poke_int3_handler() is not traced
In order to ensure poke_int3_handler() is completely self contained -- this
is called while modifying other text, imagine the fun of hitting another
INT3 -- ensure that everything it uses is not traced.

The primary means here is to force inlining; bsearch() is notrace because
all of lib/ is.

Signed-off-by: Thomas Gleixner <tglx@linutronix.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/20200505135313.410702173@linutronix.de
2020-06-11 15:14:52 +02:00
Thomas Gleixner
d77290507a x86/entry/32: Convert IRET exception to IDTENTRY_SW
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 <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/20200505134906.128769226@linutronix.de
2020-06-11 15:14:52 +02:00
Thomas Gleixner
48227e21f7 x86/entry: Convert SIMD coprocessor error exception to IDTENTRY
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
2020-06-11 15:14:52 +02:00
Thomas Gleixner
436608bb00 x86/entry: Convert Alignment check exception to IDTENTRY
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
2020-06-11 15:14:51 +02:00
Thomas Gleixner
14a8bd2aa7 x86/entry: Convert Coprocessor error exception to IDTENTRY
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
2020-06-11 15:14:51 +02:00
Thomas Gleixner
dad7106f81 x86/entry: Convert Spurious interrupt bug exception to IDTENTRY
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
2020-06-11 15:14:50 +02:00
Thomas Gleixner
be4c11afbb x86/entry: Convert General protection exception to IDTENTRY
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
2020-06-11 15:14:50 +02:00
Thomas Gleixner
fd9689bf91 x86/entry: Convert Stack segment exception to IDTENTRY
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
2020-06-11 15:14:49 +02:00
Thomas Gleixner
99a3fb8d01 x86/entry: Convert Segment not present exception to IDTENTRY
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
2020-06-11 15:14:49 +02:00
Thomas Gleixner
97b3d290b8 x86/entry: Convert Invalid TSS exception to IDTENTRY
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
2020-06-11 15:14:49 +02:00
Thomas Gleixner
aabfe5383e x86/idtentry: Provide IDTENTRY_ERRORCODE
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
2020-06-11 15:14:48 +02:00