linux/arch/x86
Josh Poimboeuf 3901336ed9 x86/kvm: Don't call kvm_spurious_fault() from .fixup
After making a change to improve objtool's sibling call detection, it
started showing the following warning:

  arch/x86/kvm/vmx/nested.o: warning: objtool: .fixup+0x15: sibling call from callable instruction with modified stack frame

The problem is the ____kvm_handle_fault_on_reboot() macro.  It does a
fake call by pushing a fake RIP and doing a jump.  That tricks the
unwinder into printing the function which triggered the exception,
rather than the .fixup code.

Instead of the hack to make it look like the original function made the
call, just change the macro so that the original function actually does
make the call.  This allows removal of the hack, and also makes objtool
happy.

I triggered a vmx instruction exception and verified that the stack
trace is still sane:

  kernel BUG at arch/x86/kvm/x86.c:358!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 28 PID: 4096 Comm: qemu-kvm Not tainted 5.2.0+ #16
  Hardware name: Lenovo THINKSYSTEM SD530 -[7X2106Z000]-/-[7X2106Z000]-, BIOS -[TEE113Z-1.00]- 07/17/2017
  RIP: 0010:kvm_spurious_fault+0x5/0x10
  Code: 00 00 00 00 00 8b 44 24 10 89 d2 45 89 c9 48 89 44 24 10 8b 44 24 08 48 89 44 24 08 e9 d4 40 22 00 0f 1f 40 00 0f 1f 44 00 00 <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 49 89 fd 41
  RSP: 0018:ffffbf91c683bd00 EFLAGS: 00010246
  RAX: 000061f040000000 RBX: ffff9e159c77bba0 RCX: ffff9e15a5c87000
  RDX: 0000000665c87000 RSI: ffff9e15a5c87000 RDI: ffff9e159c77bba0
  RBP: 0000000000000000 R08: 0000000000000000 R09: ffff9e15a5c87000
  R10: 0000000000000000 R11: fffff8f2d99721c0 R12: ffff9e159c77bba0
  R13: ffffbf91c671d960 R14: ffff9e159c778000 R15: 0000000000000000
  FS:  00007fa341cbe700(0000) GS:ffff9e15b7400000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fdd38356804 CR3: 00000006759de003 CR4: 00000000007606e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
   loaded_vmcs_init+0x4f/0xe0
   alloc_loaded_vmcs+0x38/0xd0
   vmx_create_vcpu+0xf7/0x600
   kvm_vm_ioctl+0x5e9/0x980
   ? __switch_to_asm+0x40/0x70
   ? __switch_to_asm+0x34/0x70
   ? __switch_to_asm+0x40/0x70
   ? __switch_to_asm+0x34/0x70
   ? free_one_page+0x13f/0x4e0
   do_vfs_ioctl+0xa4/0x630
   ksys_ioctl+0x60/0x90
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x55/0x1c0
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7fa349b1ee5b

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/64a9b64d127e87b6920a97afde8e96ea76f6524e.1563413318.git.jpoimboe@redhat.com
2019-07-18 21:01:04 +02:00
..
boot It's been a relatively busy cycle for docs: 2019-07-09 12:34:26 -07:00
configs x86/defconfigs: Remove useless UEVENT_HELPER_PATH 2019-06-21 19:22:08 +02:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2019-07-08 20:57:08 -07:00
entry x86/vdso: Fix flip/flop vdso build bug 2019-07-12 17:35:07 +02:00
events perf/x86/intel: Fix spurious NMI on fixed counter 2019-07-13 11:21:29 +02:00
hyperv clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic 2019-07-03 11:00:59 +02:00
ia32 clone: fix CLONE_PIDFD support 2019-07-14 20:36:12 +02:00
include x86/kvm: Don't call kvm_spurious_fault() from .fixup 2019-07-18 21:01:04 +02:00
kernel x86/paravirt: Fix callee-saved function ELF sizes 2019-07-18 21:01:03 +02:00
kvm x86/kvm: Replace vmx_vmenter()'s call to kvm_spurious_fault() with UD2 2019-07-18 21:01:03 +02:00
lib Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 10:39:56 -07:00
math-emu x86/fpu: Always init the state in fpu__clear() 2019-04-09 19:28:06 +02:00
mm mm, kprobes: generalize and rename notify_page_fault() as kprobe_page_fault() 2019-07-16 19:23:22 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-08 19:48:57 -07:00
oprofile
pci treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 387 2019-06-05 17:37:11 +02:00
platform platform-drivers-x86 for v5.3-1 2019-07-14 16:51:47 -07:00
power SPDX update for 5.2-rc4 2019-06-08 12:52:42 -07:00
purgatory treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230 2019-06-19 17:09:06 +02:00
ras RAS/CEC: Add CONFIG_RAS_CEC_DEBUG and move CEC debug features there 2019-06-08 17:39:24 +02:00
realmode x86/realmode: Make set_real_mode_mem() static inline 2019-03-29 10:16:27 +01:00
tools Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 17:34:44 -07:00
um Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2019-07-08 21:48:15 -07:00
video treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
xen Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
.gitignore
Kbuild treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
Kconfig Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
Kconfig.cpu x86/cpu: Create Zhaoxin processors architecture support file 2019-06-22 11:45:57 +02:00
Kconfig.debug It's been a relatively busy cycle for docs: 2019-07-09 12:34:26 -07:00
Makefile x86/build: Keep local relocations with ld.lld 2019-04-05 12:34:35 +02:00
Makefile_32.cpu
Makefile.um