xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
798,030 Commits 2 Branches 0 Tags
61647c77cb15354a329cbb36fe7a2253b36b51b1
Commit Graph

8502 Commits

Author SHA1 Message Date
Juergen Gross
882bbe56ae xen: remove unused function xen_set_domain_pte() 
The function xen_set_domain_pte() is used nowhere in the kernel.
Remove it.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
 2017-08-31 09:45:55 -04:00
Juergen Gross
82616f9599 xen: remove tests for pvh mode in pure pv paths 
Remove the last tests for XENFEAT_auto_translated_physmap in pure
PV-domain specific paths. PVH V1 is gone and the feature will always
be "false" in PV guests.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
 2017-08-31 09:45:55 -04:00
Vitaly Kuznetsov
773b79f7a7 tracing/hyper-v: Trace hyperv_mmu_flush_tlb_others() 
Add Hyper-V tracing subsystem and trace hyperv_mmu_flush_tlb_others().
Tracing is done the same way we do xen_mmu_flush_tlb_others().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: devel@linuxdriverproject.org
Link: http://lkml.kernel.org/r/20170802160921.21791-10-vkuznets@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-31 14:20:37 +02:00
Vitaly Kuznetsov
628f54cc64 x86/hyper-v: Support extended CPU ranges for TLB flush hypercalls 
Hyper-V hosts may support more than 64 vCPUs, we need to use
HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX/LIST_EX hypercalls in this
case.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: devel@linuxdriverproject.org
Link: http://lkml.kernel.org/r/20170802160921.21791-9-vkuznets@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-31 14:20:36 +02:00
Ingo Molnar
3e83dfd5d8 Merge branch 'x86/mm' into x86/platform, to pick up TLB flush dependency 
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-31 14:20:06 +02:00
Vitaly Kuznetsov
9e52fc2b50 x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y) 
There's a subtle bug in how some of the paravirt guest code handles
page table freeing on x86:

On x86 software page table walkers depend on the fact that remote TLB flush
does an IPI: walk is performed lockless but with interrupts disabled and in
case the page table is freed the freeing CPU will get blocked as remote TLB
flush is required. On other architectures which don't require an IPI to do
remote TLB flush we have an RCU-based mechanism (see
include/asm-generic/tlb.h for more details).

In virtualized environments we may want to override the ->flush_tlb_others
callback in pv_mmu_ops and use a hypercall asking the hypervisor to do a
remote TLB flush for us. This breaks the assumption about IPIs. Xen PV has
been doing this for years and the upcoming remote TLB flush for Hyper-V will
do it too.

This is not safe, as software page table walkers may step on an already
freed page.

Fix the bug by enabling the RCU-based page table freeing mechanism,
CONFIG_HAVE_RCU_TABLE_FREE=y.

Testing with kernbench and mmap/munmap microbenchmarks, and neither showed
any noticeable performance impact.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Juergen Gross <jgross@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: KY Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20170828082251.5562-1-vkuznets@redhat.com
[ Rewrote/fixed/clarified the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-31 11:07:07 +02:00
Thomas Gleixner
1d792a678c x86/idt: Remove the tracing IDT leftovers 
Stephen reported a merge conflict with the XEN tree. That also shows that the
IDT cleanup forgot to remove the now unused trace_{trap} defines.

Remove them.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>
 2017-08-31 10:56:57 +02:00
Ingo Molnar
e0563e0495 Merge branch 'perf/urgent' into perf/core, to pick up fixes 
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 15:09:03 +02:00
Thomas Gleixner
facaa3e3c8 x86/idt: Hide set_intr_gate() 
set_intr_gate() is an internal function of the IDT code. The only user left
is the KVM code which replaces the pagefault handler eventually.

Provide an explicit update_intr_gate() function and make set_intr_gate()
static. While at it replace the magic number 14 in the KVM code with the
proper trap define.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.663008004@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:29 +02:00
Thomas Gleixner
db18da78f9 x86/idt: Deinline setup functions 
None of this is performance sensitive in any way - so debloat the kernel.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.502052875@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:28 +02:00
Thomas Gleixner
485fa57bd7 x86/idt: Remove unused functions/inlines 
The IDT related inlines are not longer used. Remove them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.422083717@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:28 +02:00
Thomas Gleixner
636a7598f6 x86/idt: Move APIC gate initialization to tables 
Replace the APIC/SMP vector gate initialization with the table based
mechanism.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.260177013@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:28 +02:00
Thomas Gleixner
b70543a0b2 x86/idt: Move regular trap init to tables 
Initialize the regular traps with a table.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.182128165@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:27 +02:00
Thomas Gleixner
90f6225fba x86/idt: Move IST stack based traps to table init 
Initialize the IST based traps via a table.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.091328949@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:27 +02:00
Thomas Gleixner
0a30908b91 x86/idt: Move debug stack init to table based 
Add the debug_idt init table and make use of it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064959.006502252@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:27 +02:00
Thomas Gleixner
87e81786b1 x86/idt: Move early IDT setup out of 32-bit asm 
The early IDT setup can be done in C code like it's done on 64-bit kernels.
Reuse the 64-bit version.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.757980775@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:26 +02:00
Thomas Gleixner
588787fde7 x86/idt: Move early IDT handler setup to IDT code 
The early IDT handler setup is done in C entry code on 64-bit kernels and in
ASM entry code on 32-bit kernels.

Move the 64-bit variant to the IDT code so it can be shared with 32-bit
in the next step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.679561404@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:26 +02:00
Thomas Gleixner
e802a51ede x86/idt: Consolidate IDT invalidation 
kexec and reboot have both code to invalidate IDT. Create a common function
and use it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.600953282@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:26 +02:00
Thomas Gleixner
8f55868f9e x86/idt: Remove unused set_trap_gate() 
This inline is not used at all.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.522053134@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:26 +02:00
Thomas Gleixner
87cc037674 x86/ldttss: Clean up 32-bit descriptors 
Like the IDT descriptors, the LDT/TSS descriptors are pointlessly different
on 32 and 64 bit kernels.

Unify them and get rid of the duplicated code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.289634692@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:25 +02:00
Thomas Gleixner
38e9e81f4c x86/gdt: Use bitfields for initialization 
The GDT entry related code uses two ways to access entries via
union fields:

 - bitfields

 - macros which initialize the two 16-bit parts of the entry
   by magic shift and mask operations.

Clean it up and only use the bitfields to initialize and access entries.

( The old access patterns were partly done due to GCC optimizing bitfield
  accesses in a horrible way - that's mostly fixed these days and clarity
  of code in such low level accessors is very important. )

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.197673367@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:25 +02:00
Thomas Gleixner
9a98e77800 x86/asm: Replace access to desc_struct:a/b fields 
The union inside of desc_struct which allows access to the raw u32 parts of
the descriptors. This raw access part is about to go away.

Replace the few code parts which access those fields.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.120214366@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:25 +02:00
Thomas Gleixner
64b163fab6 x86/idt: Unify gate_struct handling for 32/64-bit kernels 
The first 32 bits of gate struct are the same for 32 and 64 bit kernels.

The 32-bit version uses desc_struct and no designated data structure,
so we need different accessors for 32 and 64 bit kernels.

Aside of that the macros which are necessary to build the 32-bit
gate descriptor are horrible to read.

Unify the gate structs and switch all code fiddling with it over.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.861974317@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:24 +02:00
Thomas Gleixner
7328552780 x86/tracing: Build tracepoints only when they are used 
The tracepoint macro magic emits code for all tracepoints in a event header
file. That code stays around even if the tracepoint is not used at all. The
linker does not discard it.

Build the various irq_vector tracepoints dependent on the appropriate CONFIG
switches.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.770651777@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 12:07:24 +02:00
Thomas Gleixner
a45525b5b4 x86/irq_work: Make it depend on APIC 
The irq work interrupt vector is only installed when CONFIG_X86_LOCAL_APIC is
enabled, but the interrupt handler is compiled in unconditionally.

Compile the cruft out when the APIC is disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.691909010@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:30 +02:00
Thomas Gleixner
0428e01a2f x86/ipi: Make platform IPI depend on APIC 
The platform IPI vector is only installed when the local APIC is enabled. All
users of it depend on the local APIC anyway.

Make the related code conditional on CONFIG_X86_LOCAL_APIC=y.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.615286163@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:29 +02:00
Thomas Gleixner
809547472e x86/tracing: Disentangle pagefault and resched IPI tracing key 
The pagefault and the resched IPI handler are the only ones where it is
worth to optimize the code further in case tracepoints are disabled. But it
makes no sense to have a single static key for both.

Seperate the static keys so the facilities are handled seperately.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.536699116@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:29 +02:00
Thomas Gleixner
6f54f3ec6c x86/idt: Clean up the i386 low level entry macros 
Some of the entry function defines for i386 were explictely using the
BUILD_INTERRUPT3() macro to prevent that the extra trace entry got added
via BUILD_INTERRUPT(). No that the trace cruft is gone, the file can be
cleaned up and converted to use BUILD_INTERRUPT() which avoids the ugly
line breaks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.456815006@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:28 +02:00
Thomas Gleixner
4b9a8dca0e x86/idt: Remove the tracing IDT completely 
No more users of the tracing IDT. All exception tracepoints have been moved
into the regular handlers. Get rid of the mess which shouldn't have been
created in the first place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.378851687@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:28 +02:00
Thomas Gleixner
3cd788c1ee x86/smp: Use static key for reschedule interrupt tracing 
It's worth to avoid the extra irq_enter()/irq_exit() pair in the case that
the reschedule interrupt tracepoints are disabled.

Use the static key which indicates that exception tracing is enabled. For
now this key is global. It will be optimized in a later step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170828064957.299808677@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:27 +02:00
Thomas Gleixner
85b77cdd8f x86/smp: Remove pointless duplicated interrupt code 
Two NOP5s are really a good tradeoff vs. the unholy IDT switching mess,
which duplicates code all over the place. The rescheduling interrupt gets
optimized in a later step.

Make the ordering of function call and statistics increment the same as in
other places. Calculate stats first, then do the function call.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.222101344@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:27 +02:00
Thomas Gleixner
0f42ae283c x86/mce: Remove duplicated tracing interrupt code 
Machine checks are not really high frequency events. The extra two NOP5s for
the disabled tracepoints are noise vs. the heavy lifting which needs to be
done in the MCE handler.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.144301907@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:26 +02:00
Thomas Gleixner
daabb8eb9a x86/irqwork: Get rid of duplicated tracing interrupt code 
Two NOP5s are a reasonable tradeoff to avoid duplicated code and the
requirement to switch the IDT.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.064746737@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:26 +02:00
Thomas Gleixner
61069de7a3 x86/apic: Remove the duplicated tracing versions of interrupts 
The error and the spurious interrupt are really rare events and not at all
performance sensitive: two NOP5s can be tolerated when tracing is disabled.

Remove the complication.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170828064956.986009402@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:25 +02:00
Thomas Gleixner
8a17116b1f x86/irq: Get rid of duplicated trace_x86_platform_ipi() code 
Two NOP5s are really a good tradeoff vs. the unholy IDT switching mess,
which duplicates code all over the place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170828064956.907209383@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:25 +02:00
Thomas Gleixner
302a98f896 x86/apic: Remove the duplicated tracing version of local_timer_interrupt() 
The two NOP5s are noise in the rest of the work which is done by the timer
interrupt and modern CPUs are pretty good in optimizing NOPs anyway.

Get rid of the interrupt handler duplication and move the tracepoints into
the regular handler.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170828064956.751247330@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:24 +02:00
Thomas Gleixner
11a7ffb017 x86/traps: Simplify pagefault tracing logic 
Make use of the new irqvector tracing static key and remove the duplicated
trace_do_pagefault() implementation.

If irq vector tracing is disabled, then the overhead of this is a single
NOP5, which is a reasonable tradeoff to avoid duplicated code and the
unholy macro mess.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064956.672965407@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:23 +02:00
Thomas Gleixner
2feb1b316d x86/tracing: Introduce a static key for exception tracing 
Switching the IDT just for avoiding tracepoints creates a completely
impenetrable macro/inline/ifdef mess.

There is no point in avoiding tracepoints for most of the traps/exceptions.
For the more expensive tracepoints, like pagefaults, this can be handled with
an explicit static key.

Preparatory patch to remove the tracing IDT.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064956.593094539@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:23 +02:00
Thomas Gleixner
9aec458ff0 x86/irq: Remove duplicated used_vectors definition 
Also remove the unparseable comment in the other place while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064956.436711634@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:21 +02:00
Thomas Gleixner
05161b9cbe x86/irq: Get rid of the 'first_system_vector' indirection bogosity 
This variable is beyond pointless. Nothing allocates a vector via
alloc_gate() below FIRST_SYSTEM_VECTOR. So nothing can change
first_system_vector.

If there is a need for a gate below FIRST_SYSTEM_VECTOR then it can be
added to the vector defines and FIRST_SYSTEM_VECTOR can be adjusted
accordingly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064956.357109735@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:21 +02:00
Thomas Gleixner
69de72ec6d x86/irq: Remove vector_used_by_percpu_irq() 
Last user (lguest) is gone. Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064956.201432430@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:20 +02:00
Ingo Molnar
416b0c0faf Merge branch 'linus' into x86/apic, to pick up fixes 
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-29 11:42:07 +02:00
Greg Kroah-Hartman
9749c37275 Merge 4.13-rc7 into char-misc-next 
We want the binder fix in here as well for testing and merge issues.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2017-08-28 10:19:01 +02:00
Linus Torvalds
c153e62105 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 
Pull x86 fixes from Ingo Molnar:
 "Two fixes: one for an ldt_struct handling bug and a cherry-picked
  objtool fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix use-after-free of ldt_struct
  objtool: Fix '-mtune=atom' decoding support in objtool 2.0
 2017-08-26 09:06:28 -07:00
Ingo Molnar
413d63d71b Merge branch 'linus' into x86/mm to pick up fixes and to fix conflicts 
Conflicts:
	arch/x86/kernel/head64.c
	arch/x86/mm/mmap.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-26 09:19:13 +02:00
Jiri Slaby
30d6e0a419 futex: Remove duplicated code and fix undefined behaviour 
There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.

Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.

This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.

And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.

Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390]
Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org>
Reviewed-by: Will Deacon <will.deacon@arm.com> [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker <dalias@libc.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn <jonas@southpole.se>
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Stafford Horne <shorne@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson <rth@twiddle.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
 2017-08-25 22:49:59 +02:00
Ingo Molnar
3a9ff4fd04 Merge branch 'linus' into sched/core, to pick up fixes 
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-25 11:07:13 +02:00
Ingo Molnar
10c9850cb2 Merge branch 'linus' into locking/core, to pick up fixes 
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-25 11:04:51 +02:00
Eric Biggers
ccd5b32351 x86/mm: Fix use-after-free of ldt_struct 
The following commit:

  39a0526fb3 ("x86/mm: Factor out LDT init from context init")

renamed init_new_context() to init_new_context_ldt() and added a new
init_new_context() which calls init_new_context_ldt().  However, the
error code of init_new_context_ldt() was ignored.  Consequently, if a
memory allocation in alloc_ldt_struct() failed during a fork(), the
->context.ldt of the new task remained the same as that of the old task
(due to the memcpy() in dup_mm()).  ldt_struct's are not intended to be
shared, so a use-after-free occurred after one task exited.

Fix the bug by making init_new_context() pass through the error code of
init_new_context_ldt().

This bug was found by syzkaller, which encountered the following splat:

    BUG: KASAN: use-after-free in free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116
    Read of size 4 at addr ffff88006d2cb7c8 by task kworker/u9:0/3710

    CPU: 1 PID: 3710 Comm: kworker/u9:0 Not tainted 4.13.0-rc4-next-20170811 #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Call Trace:
     __dump_stack lib/dump_stack.c:16 [inline]
     dump_stack+0x194/0x257 lib/dump_stack.c:52
     print_address_description+0x73/0x250 mm/kasan/report.c:252
     kasan_report_error mm/kasan/report.c:351 [inline]
     kasan_report+0x24e/0x340 mm/kasan/report.c:409
     __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
     free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116
     free_ldt_struct arch/x86/kernel/ldt.c:173 [inline]
     destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171
     destroy_context arch/x86/include/asm/mmu_context.h:157 [inline]
     __mmdrop+0xe9/0x530 kernel/fork.c:889
     mmdrop include/linux/sched/mm.h:42 [inline]
     exec_mmap fs/exec.c:1061 [inline]
     flush_old_exec+0x173c/0x1ff0 fs/exec.c:1291
     load_elf_binary+0x81f/0x4ba0 fs/binfmt_elf.c:855
     search_binary_handler+0x142/0x6b0 fs/exec.c:1652
     exec_binprm fs/exec.c:1694 [inline]
     do_execveat_common.isra.33+0x1746/0x22e0 fs/exec.c:1816
     do_execve+0x31/0x40 fs/exec.c:1860
     call_usermodehelper_exec_async+0x457/0x8f0 kernel/umh.c:100
     ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431

    Allocated by task 3700:
     save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
     save_stack+0x43/0xd0 mm/kasan/kasan.c:447
     set_track mm/kasan/kasan.c:459 [inline]
     kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
     kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627
     kmalloc include/linux/slab.h:493 [inline]
     alloc_ldt_struct+0x52/0x140 arch/x86/kernel/ldt.c:67
     write_ldt+0x7b7/0xab0 arch/x86/kernel/ldt.c:277
     sys_modify_ldt+0x1ef/0x240 arch/x86/kernel/ldt.c:307
     entry_SYSCALL_64_fastpath+0x1f/0xbe

    Freed by task 3700:
     save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
     save_stack+0x43/0xd0 mm/kasan/kasan.c:447
     set_track mm/kasan/kasan.c:459 [inline]
     kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
     __cache_free mm/slab.c:3503 [inline]
     kfree+0xca/0x250 mm/slab.c:3820
     free_ldt_struct.part.2+0xdd/0x150 arch/x86/kernel/ldt.c:121
     free_ldt_struct arch/x86/kernel/ldt.c:173 [inline]
     destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171
     destroy_context arch/x86/include/asm/mmu_context.h:157 [inline]
     __mmdrop+0xe9/0x530 kernel/fork.c:889
     mmdrop include/linux/sched/mm.h:42 [inline]
     __mmput kernel/fork.c:916 [inline]
     mmput+0x541/0x6e0 kernel/fork.c:927
     copy_process.part.36+0x22e1/0x4af0 kernel/fork.c:1931
     copy_process kernel/fork.c:1546 [inline]
     _do_fork+0x1ef/0xfb0 kernel/fork.c:2025
     SYSC_clone kernel/fork.c:2135 [inline]
     SyS_clone+0x37/0x50 kernel/fork.c:2129
     do_syscall_64+0x26c/0x8c0 arch/x86/entry/common.c:287
     return_from_SYSCALL_64+0x0/0x7a

Here is a C reproducer:

    #include <asm/ldt.h>
    #include <pthread.h>
    #include <signal.h>
    #include <stdlib.h>
    #include <sys/syscall.h>
    #include <sys/wait.h>
    #include <unistd.h>

    static void *fork_thread(void *_arg)
    {
        fork();
    }

    int main(void)
    {
        struct user_desc desc = { .entry_number = 8191 };

        syscall(__NR_modify_ldt, 1, &desc, sizeof(desc));

        for (;;) {
            if (fork() == 0) {
                pthread_t t;

                srand(getpid());
                pthread_create(&t, NULL, fork_thread, NULL);
                usleep(rand() % 10000);
                syscall(__NR_exit_group, 0);
            }
            wait(NULL);
        }
    }

Note: the reproducer takes advantage of the fact that alloc_ldt_struct()
may use vmalloc() to allocate a large ->entries array, and after
commit:

  5d17a73a2e ("vmalloc: back off when the current task is killed")

it is possible for userspace to fail a task's vmalloc() by
sending a fatal signal, e.g. via exit_group().  It would be more
difficult to reproduce this bug on kernels without that commit.

This bug only affected kernels with CONFIG_MODIFY_LDT_SYSCALL=y.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <stable@vger.kernel.org> [v4.6+]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Fixes: 39a0526fb3 ("x86/mm: Factor out LDT init from context init")
Link: http://lkml.kernel.org/r/20170824175029.76040-1-ebiggers3@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2017-08-25 09:55:52 +02:00
Paolo Bonzini
38cfd5e3df KVM, pkeys: do not use PKRU value in vcpu->arch.guest_fpu.state 
The host pkru is restored right after vcpu exit (commit 1be0e61), so
KVM_GET_XSAVE will return the host PKRU value instead.  Fix this by
using the guest PKRU explicitly in fill_xsave and load_xsave.  This
part is based on a patch by Junkang Fu.

The host PKRU data may also not match the value in vcpu->arch.guest_fpu.state,
because it could have been changed by userspace since the last time
it was saved, so skip loading it in kvm_load_guest_fpu.

Reported-by: Junkang Fu <junkang.fjk@alibaba-inc.com>
Cc: Yang Zhang <zy107165@alibaba-inc.com>
Fixes: 1be0e61c1f
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
 2017-08-25 09:28:37 +02:00