From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Josh Poimboeuf <jpoimboe@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Paolo Bonzini <pbonzini@redhat.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.4 19/22] x86/kvm: Dont call kvm_spurious_fault() from .fixup
Date: Mon, 5 Aug 2019 15:02:56 +0200 [thread overview]
Message-ID: <20190805124923.043647306@linuxfoundation.org> (raw)
In-Reply-To: <20190805124918.070468681@linuxfoundation.org>
[ Upstream commit 3901336ed9887b075531bffaeef7742ba614058b ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/include/asm/kvm_host.h | 34 ++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2cb49ac1b2b25..39f2024620292 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1184,25 +1184,29 @@ enum {
#define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0)
#define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)
+asmlinkage void __noreturn kvm_spurious_fault(void);
+
/*
* Hardware virtualization extension instructions may fault if a
* reboot turns off virtualization while processes are running.
- * Trap the fault and ignore the instruction if that happens.
+ * Usually after catching the fault we just panic; during reboot
+ * instead the instruction is ignored.
*/
-asmlinkage void kvm_spurious_fault(void);
-
-#define ____kvm_handle_fault_on_reboot(insn, cleanup_insn) \
- "666: " insn "\n\t" \
- "668: \n\t" \
- ".pushsection .fixup, \"ax\" \n" \
- "667: \n\t" \
- cleanup_insn "\n\t" \
- "cmpb $0, kvm_rebooting \n\t" \
- "jne 668b \n\t" \
- __ASM_SIZE(push) " $666b \n\t" \
- "jmp kvm_spurious_fault \n\t" \
- ".popsection \n\t" \
- _ASM_EXTABLE(666b, 667b)
+#define ____kvm_handle_fault_on_reboot(insn, cleanup_insn) \
+ "666: \n\t" \
+ insn "\n\t" \
+ "jmp 668f \n\t" \
+ "667: \n\t" \
+ "call kvm_spurious_fault \n\t" \
+ "668: \n\t" \
+ ".pushsection .fixup, \"ax\" \n\t" \
+ "700: \n\t" \
+ cleanup_insn "\n\t" \
+ "cmpb $0, kvm_rebooting\n\t" \
+ "je 667b \n\t" \
+ "jmp 668b \n\t" \
+ ".popsection \n\t" \
+ _ASM_EXTABLE(666b, 700b)
#define __kvm_handle_fault_on_reboot(insn) \
____kvm_handle_fault_on_reboot(insn, "")
--
2.20.1
next prev parent reply other threads:[~2019-08-05 13:18 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-05 13:02 [PATCH 4.4 00/22] 4.4.188-stable review Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 01/22] ARM: riscpc: fix DMA Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 02/22] ARM: dts: rockchip: Mark that the rk3288 timer might stop in suspend Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 03/22] kernel/module.c: Only return -EEXIST for modules that have finished loading Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 04/22] MIPS: lantiq: Fix bitfield masking Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 05/22] dmaengine: rcar-dmac: Reject zero-length slave DMA requests Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 06/22] fs/adfs: super: fix use-after-free bug Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 07/22] btrfs: fix minimum number of chunk errors for DUP Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 08/22] ceph: fix improper use of smp_mb__before_atomic() Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 09/22] scsi: zfcp: fix GCC compiler warning emitted with -Wmaybe-uninitialized Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 10/22] ACPI: fix false-positive -Wuninitialized warning Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 11/22] be2net: Signal that the device cannot transmit during reconfiguration Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 12/22] x86/apic: Silence -Wtype-limits compiler warnings Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 13/22] x86: math-emu: Hide clang warnings for 16-bit overflow Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 14/22] mm/cma.c: fail if fixed declaration cant be honored Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 15/22] coda: add error handling for fget Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 16/22] coda: fix build using bare-metal toolchain Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 17/22] uapi linux/coda_psdev.h: move upc_req definition from uapi to kernel side headers Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 18/22] ipc/mqueue.c: only perform resource calculation if user valid Greg Kroah-Hartman
2019-08-05 13:02 ` Greg Kroah-Hartman [this message]
2019-08-05 13:02 ` [PATCH 4.4 20/22] selinux: fix memory leak in policydb_init() Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 21/22] s390/dasd: fix endless loop after read unit address configuration Greg Kroah-Hartman
2019-08-05 13:02 ` [PATCH 4.4 22/22] xen/swiotlb: fix condition for calling xen_destroy_contiguous_region() Greg Kroah-Hartman
2019-08-05 17:35 ` [PATCH 4.4 00/22] 4.4.188-stable review kernelci.org bot
2019-08-06 1:14 ` shuah
2019-08-06 7:26 ` Naresh Kamboju
2019-08-06 15:48 ` Guenter Roeck
2019-08-06 18:28 ` Jon Hunter
2019-08-06 18:28 ` Jon Hunter
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