projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 79473355 GKH |
1 | From aabba3c6abd50b05b1fc2c6ec44244aa6bcda576 Mon Sep 17 00:00:00 2001 |
| 2 | From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@redhat.com> | |
| 3 | Date: Tue, 8 Nov 2016 20:54:18 +0100 | |
| 4 | Subject: KVM: x86: add asm_safe wrapper | |
| 5 | MIME-Version: 1.0 | |
| 6 | Content-Type: text/plain; charset=UTF-8 | |
| 7 | Content-Transfer-Encoding: 8bit | |
| 8 | ||
| 9 | From: Radim Krčmář <rkrcmar@redhat.com> | |
| 10 | ||
| 11 | commit aabba3c6abd50b05b1fc2c6ec44244aa6bcda576 upstream. | |
| 12 | ||
| 13 | Move the existing exception handling for inline assembly into a macro | |
| 14 | and switch its return values to X86EMUL type. | |
| 15 | ||
| 16 | Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> | |
| 17 | Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> | |
| 18 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 19 | ||
| 20 | --- | |
| 21 | arch/x86/kvm/emulate.c | 34 +++++++++++++++++++++++----------- | |
| 22 | 1 file changed, 23 insertions(+), 11 deletions(-) | |
| 23 | ||
| 24 | --- a/arch/x86/kvm/emulate.c | |
| 25 | +++ b/arch/x86/kvm/emulate.c | |
| 26 | @@ -435,6 +435,26 @@ FOP_END; | |
| 27 | FOP_START(salc) "pushf; sbb %al, %al; popf \n\t" FOP_RET | |
| 28 | FOP_END; | |
| 29 | ||
| 30 | +/* | |
| 31 | + * XXX: inoutclob user must know where the argument is being expanded. | |
| 32 | + * Relying on CC_HAVE_ASM_GOTO would allow us to remove _fault. | |
| 33 | + */ | |
| 34 | +#define asm_safe(insn, inoutclob...) \ | |
| 35 | +({ \ | |
| 36 | + int _fault = 0; \ | |
| 37 | + \ | |
| 38 | + asm volatile("1:" insn "\n" \ | |
| 39 | + "2:\n" \ | |
| 40 | + ".pushsection .fixup, \"ax\"\n" \ | |
| 41 | + "3: movl $1, %[_fault]\n" \ | |
| 42 | + " jmp 2b\n" \ | |
| 43 | + ".popsection\n" \ | |
| 44 | + _ASM_EXTABLE(1b, 3b) \ | |
| 45 | + : [_fault] "+qm"(_fault) inoutclob ); \ | |
| 46 | + \ | |
| 47 | + _fault ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE; \ | |
| 48 | +}) | |
| 49 | + | |
| 50 | static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt, | |
| 51 | enum x86_intercept intercept, | |
| 52 | enum x86_intercept_stage stage) | |
| 53 | @@ -5086,21 +5106,13 @@ static bool string_insn_completed(struct | |
| 54 | ||
| 55 | static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt) | |
| 56 | { | |
| 57 | - bool fault = false; | |
| 58 | + int rc; | |
| 59 | ||
| 60 | ctxt->ops->get_fpu(ctxt); | |
| 61 | - asm volatile("1: fwait \n\t" | |
| 62 | - "2: \n\t" | |
| 63 | - ".pushsection .fixup,\"ax\" \n\t" | |
| 64 | - "3: \n\t" | |
| 65 | - "movb $1, %[fault] \n\t" | |
| 66 | - "jmp 2b \n\t" | |
| 67 | - ".popsection \n\t" | |
| 68 | - _ASM_EXTABLE(1b, 3b) | |
| 69 | - : [fault]"+qm"(fault)); | |
| 70 | + rc = asm_safe("fwait"); | |
| 71 | ctxt->ops->put_fpu(ctxt); | |
| 72 | ||
| 73 | - if (unlikely(fault)) | |
| 74 | + if (unlikely(rc != X86EMUL_CONTINUE)) | |
| 75 | return emulate_exception(ctxt, MF_VECTOR, 0, false); | |
| 76 | ||
| 77 | return X86EMUL_CONTINUE; |