Check for invalid alignment values when decoding VLDn/VSTn (single ln) instructions.

Patch by Chris Lidbury.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163321 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 131 insertions, 8 deletions

diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index c394ed1..657c103 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -3710,8 +3710,16 @@ static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
       if (fieldFromInstruction(Insn, 6, 1))
         return MCDisassembler::Fail; // UNDEFINED
       index = fieldFromInstruction(Insn, 7, 1);
-      if (fieldFromInstruction(Insn, 4, 2) != 0)
-        align = 4;
+
+      switch (fieldFromInstruction(Insn, 4, 2)) {
+        case 0 :
+          align = 0; break;
+        case 3:
+          align = 4; break;
+        default:
+          return MCDisassembler::Fail;
+      }
+      break;
   }
 
   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
@@ -3769,8 +3777,16 @@ static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
       if (fieldFromInstruction(Insn, 6, 1))
         return MCDisassembler::Fail; // UNDEFINED
       index = fieldFromInstruction(Insn, 7, 1);
-      if (fieldFromInstruction(Insn, 4, 2) != 0)
-        align = 4;
+
+      switch (fieldFromInstruction(Insn, 4, 2)) {
+        case 0: 
+          align = 0; break;
+        case 3:
+          align = 4; break;
+        default:
+          return MCDisassembler::Fail;
+      }
+      break;
   }
 
   if (Rm != 0xF) { // Writeback
@@ -4090,8 +4106,15 @@ static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
         inc = 2;
       break;
     case 2:
-      if (fieldFromInstruction(Insn, 4, 2))
-        align = 4 << fieldFromInstruction(Insn, 4, 2);
+      switch (fieldFromInstruction(Insn, 4, 2)) {
+        case 0:
+          align = 0; break;
+        case 3:
+          return MCDisassembler::Fail;
+        default:
+          align = 4 << fieldFromInstruction(Insn, 4, 2); break;
+      }
+
       index = fieldFromInstruction(Insn, 7, 1);
       if (fieldFromInstruction(Insn, 6, 1))
         inc = 2;
@@ -4164,8 +4187,15 @@ static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
         inc = 2;
       break;
     case 2:
-      if (fieldFromInstruction(Insn, 4, 2))
-        align = 4 << fieldFromInstruction(Insn, 4, 2);
+      switch (fieldFromInstruction(Insn, 4, 2)) {
+        case 0:
+          align = 0; break;
+        case 3:
+          return MCDisassembler::Fail;
+        default:
+          align = 4 << fieldFromInstruction(Insn, 4, 2); break;
+      }
+
       index = fieldFromInstruction(Insn, 7, 1);
       if (fieldFromInstruction(Insn, 6, 1))
         inc = 2;
diff --git a/test/MC/Disassembler/ARM/invalid-VLD1LNd32_UPD-thumb.txt b/test/MC/Disassembler/ARM/invalid-VLD1LNd32_UPD-thumb.txt
new file mode 100644
index 0000000..9bb0995
--- /dev/null
+++ b/test/MC/Disassembler/ARM/invalid-VLD1LNd32_UPD-thumb.txt
@@ -0,0 +1,4 @@
+# RUN: llvm-mc -triple thumbv7 -show-encoding -disassemble < %s 2>&1 | FileCheck %s
+
+0xa0 0xf9 0x10 0x08
+# CHECK: invalid instruction encoding
diff --git a/test/MC/Disassembler/ARM/invalid-VLD4LNd32_UPD-thumb.txt b/test/MC/Disassembler/ARM/invalid-VLD4LNd32_UPD-thumb.txt
new file mode 100644
index 0000000..9024b09
--- /dev/null
+++ b/test/MC/Disassembler/ARM/invalid-VLD4LNd32_UPD-thumb.txt
@@ -0,0 +1,4 @@
+# RUN: llvm-mc -triple thumbv7 -show-encoding -disassemble < %s 2>&1 | FileCheck %s
+
+0xa0 0xf9 0x30 0x0b
+# CHECK: invalid instruction encoding
diff --git a/test/MC/Disassembler/ARM/invalid-VST1LNd32_UPD-thumb.txt b/test/MC/Disassembler/ARM/invalid-VST1LNd32_UPD-thumb.txt
new file mode 100644
index 0000000..9462812
--- /dev/null
+++ b/test/MC/Disassembler/ARM/invalid-VST1LNd32_UPD-thumb.txt
@@ -0,0 +1,4 @@
+# RUN: llvm-mc -triple thumbv7 -show-encoding -disassemble < %s 2>&1 | FileCheck %s
+
+0x80 0xf9 0x10 0x08
+# CHECK: invalid instruction encoding
diff --git a/test/MC/Disassembler/ARM/invalid-VST4LNd32_UPD-thumb.txt b/test/MC/Disassembler/ARM/invalid-VST4LNd32_UPD-thumb.txt
new file mode 100644
index 0000000..f6e71bc
--- /dev/null
+++ b/test/MC/Disassembler/ARM/invalid-VST4LNd32_UPD-thumb.txt
@@ -0,0 +1,4 @@
+# RUN: llvm-mc -triple thumbv7 -show-encoding -disassemble < %s 2>&1 | FileCheck %s
+
+0x80 0xf9 0x30 0x0b
+# CHECK: invalid instruction encoding
diff --git a/test/MC/Disassembler/ARM/neont-VLD-reencoding.txt b/test/MC/Disassembler/ARM/neont-VLD-reencoding.txt
new file mode 100644
index 0000000..e53739e
--- /dev/null
+++ b/test/MC/Disassembler/ARM/neont-VLD-reencoding.txt
@@ -0,0 +1,77 @@
+# RUN: llvm-mc -triple thumbv7 -show-encoding -disassemble < %s | FileCheck %s
+
+0xa0 0xf9 0x00 0x00
+0xa0 0xf9 0x20 0x00
+0xa0 0xf9 0x40 0x00
+0xa0 0xf9 0x60 0x00
+0xa0 0xf9 0x80 0x00
+0xa0 0xf9 0xa0 0x00
+0xa0 0xf9 0xc0 0x00
+0xa0 0xf9 0xe0 0x00
+
+# CHECK: vld1.8  {d0[0]}, [r0], r0 @ encoding: [0xa0,0xf9,0x00,0x00]
+# CHECK: vld1.8  {d0[1]}, [r0], r0 @ encoding: [0xa0,0xf9,0x20,0x00]
+# CHECK: vld1.8  {d0[2]}, [r0], r0 @ encoding: [0xa0,0xf9,0x40,0x00]
+# CHECK: vld1.8  {d0[3]}, [r0], r0 @ encoding: [0xa0,0xf9,0x60,0x00]
+# CHECK: vld1.8  {d0[4]}, [r0], r0 @ encoding: [0xa0,0xf9,0x80,0x00]
+# CHECK: vld1.8  {d0[5]}, [r0], r0 @ encoding: [0xa0,0xf9,0xa0,0x00]
+# CHECK: vld1.8  {d0[6]}, [r0], r0 @ encoding: [0xa0,0xf9,0xc0,0x00]
+# CHECK: vld1.8  {d0[7]}, [r0], r0 @ encoding: [0xa0,0xf9,0xe0,0x00]
+
+0xa0 0xf9 0x00 0x04
+0xa0 0xf9 0x10 0x04
+0xa0 0xf9 0x40 0x04
+0xa0 0xf9 0x50 0x04
+0xa0 0xf9 0x80 0x04
+0xa0 0xf9 0x90 0x04
+0xa0 0xf9 0xc0 0x04
+0xa0 0xf9 0xd0 0x04
+
+# CHECK: vld1.16 {d0[0]}, [r0], r0      @ encoding: [0xa0,0xf9,0x00,0x04]
+# CHECK: vld1.16 {d0[0]}, [r0, :16], r0 @ encoding: [0xa0,0xf9,0x10,0x04]
+# CHECK: vld1.16 {d0[1]}, [r0], r0      @ encoding: [0xa0,0xf9,0x40,0x04]
+# CHECK: vld1.16 {d0[1]}, [r0, :16], r0 @ encoding: [0xa0,0xf9,0x50,0x04]
+# CHECK: vld1.16 {d0[2]}, [r0], r0      @ encoding: [0xa0,0xf9,0x80,0x04]
+# CHECK: vld1.16 {d0[2]}, [r0, :16], r0 @ encoding: [0xa0,0xf9,0x90,0x04]
+# CHECK: vld1.16 {d0[3]}, [r0], r0      @ encoding: [0xa0,0xf9,0xc0,0x04]
+# CHECK: vld1.16 {d0[3]}, [r0, :16], r0 @ encoding: [0xa0,0xf9,0xd0,0x04]
+
+0xa0 0xf9 0x00 0x08
+0xa0 0xf9 0x30 0x08
+0xa0 0xf9 0x80 0x08
+0xa0 0xf9 0xb0 0x08
+
+# CHECK: vld1.32 {d0[0]}, [r0], r0      @ encoding: [0xa0,0xf9,0x00,0x08]
+# CHECK: vld1.32 {d0[0]}, [r0, :32], r0 @ encoding: [0xa0,0xf9,0x30,0x08]
+# CHECK: vld1.32 {d0[1]}, [r0], r0      @ encoding: [0xa0,0xf9,0x80,0x08]
+# CHECK: vld1.32 {d0[1]}, [r0, :32], r0 @ encoding: [0xa0,0xf9,0xb0,0x08]
+
+0xa0 0xf9 0x1f 0x04
+0xa0 0xf9 0x8f 0x00
+
+# CHECK: vld1.16 {d0[0]}, [r0, :16] @ encoding: [0xa0,0xf9,0x1f,0x04]
+# CHECK: vld1.8  {d0[4]}, [r0]      @ encoding: [0xa0,0xf9,0x8f,0x00]
+
+0xa0 0xf9 0x1d 0x04
+0xa0 0xf9 0x8d 0x00
+
+# CHECK: vld1.16 {d0[0]}, [r0, :16]! @ encoding: [0xa0,0xf9,0x1d,0x04]
+# CHECK: vld1.8  {d0[4]}, [r0]!      @ encoding: [0xa0,0xf9,0x8d,0x00]
+
+0xa5 0xf9 0x10 0x04
+0xa5 0xf9 0x1a 0x04
+0xae 0xf9 0x1a 0x04
+0xa5 0xf9 0x1a 0x94
+
+# CHECK: vld1.16 {d0[0]}, [r5, :16], r0  @ encoding: [0xa5,0xf9,0x10,0x04]
+# CHECK: vld1.16 {d0[0]}, [r5, :16], r10 @ encoding: [0xa5,0xf9,0x1a,0x04]
+# CHECK: vld1.16 {d0[0]}, [lr, :16], r10 @ encoding: [0xae,0xf9,0x1a,0x04]
+# CHECK: vld1.16 {d9[0]}, [r5, :16], r10 @ encoding: [0xa5,0xf9,0x1a,0x94]
+
+0xa0 0xf9 0x20 0x0b
+0xa0 0xf9 0x20 0x07
+0xa0 0xf9 0x20 0x03
+
+# CHECK: vld4.32 {d0[0], d1[0], d2[0], d3[0]}, [r0, :128], r0 @ encoding: [0xa0,0xf9,0x20,0x0b]
+# CHECK: vld4.16 {d0[0], d2[0], d4[0], d6[0]}, [r0], r0       @ encoding: [0xa0,0xf9,0x20,0x07]
+# CHECK: vld4.8  {d0[1], d1[1], d2[1], d3[1]}, [r0], r0       @ encoding: [0xa0,0xf9,0x20,0x03]