Merge pull request #17 from qmonnet/master

Add BPF_J{LT,LE,SLT,SLE} instructions
iovisor · Nov 13, 2017 · 2e06fd4 · 2e06fd4
2 parents b8c87d2 + a0a78eb
commit 2e06fd4
Show file tree

Hide file tree

Showing 14 changed files with 198 additions and 1 deletion.
diff --git a/tests/jle-imm.data b/tests/jle-imm.data
@@ -0,0 +1,12 @@
+-- asm
+mov32 r0, 0
+mov32 r1, 5
+jle r1, 4, +1 # Not taken
+jle r1, 6, +1 # Taken
+exit
+jle r1, 5, +1 # Taken
+exit
+mov32 r0, 1
+exit
+-- result
+0x1
diff --git a/tests/jle-reg.data b/tests/jle-reg.data
@@ -0,0 +1,14 @@
+-- asm
+mov r0, 0
+mov r1, 5
+mov r2, 4
+mov r3, 6
+jle r1, r2, +2 # Not taken
+jle r1, r1, +1 # Taken
+exit
+jle r1, r3, +1 # Taken
+exit
+mov r0, 1
+exit
+-- result
+0x1
diff --git a/tests/jlt-imm.data b/tests/jlt-imm.data
@@ -0,0 +1,11 @@
+-- asm
+mov32 r0, 0
+mov32 r1, 5
+jlt r1, 4, +2 # Not taken
+jlt r1, 5, +1 # Not taken
+jlt r1, 6, +1 # Taken
+exit
+mov32 r0, 1
+exit
+-- result
+0x1
diff --git a/tests/jlt-reg.data b/tests/jlt-reg.data
@@ -0,0 +1,13 @@
+-- asm
+mov r0, 0
+mov r1, 5
+mov r2, 4
+mov r3, 6
+jlt r1, r2, +2 # Not taken
+jlt r1, r1, +1 # Not taken
+jlt r1, r3, +1 # Taken
+exit
+mov r0, 1
+exit
+-- result
+0x1
diff --git a/tests/jsle-imm.data b/tests/jsle-imm.data
@@ -0,0 +1,12 @@
+-- asm
+mov32 r0, 0
+mov r1, 0xfffffffe
+jsle r1, 0xfffffffd, +1 # Not taken
+jsle r1, 0xffffffff, +1 # Taken
+exit
+mov32 r0, 1
+jsle r1, 0xfffffffe, +1 # Taken
+mov32 r0, 2
+exit
+-- result
+0x1
diff --git a/tests/jsle-reg.data b/tests/jsle-reg.data
@@ -0,0 +1,15 @@
+-- asm
+mov32 r0, 0
+mov r1, 0xffffffff
+mov r2, 0xfffffffe
+mov32 r3, 0
+jsle r1, r2, +1 # Not taken
+jsle r1, r3, +1 # Taken
+exit
+mov32 r0, 1
+mov r1, r2
+jsle r1, r2, +1 # Taken
+mov32 r0, 2
+exit
+-- result
+0x1
diff --git a/tests/jslt-imm.data b/tests/jslt-imm.data
@@ -0,0 +1,11 @@
+-- asm
+mov32 r0, 0
+mov r1, 0xfffffffe
+jslt r1, 0xfffffffd, +2 # Not taken
+jslt r1, 0xfffffffe, +1 # Not taken
+jslt r1, 0xffffffff, +1 # Taken
+exit
+mov32 r0, 1
+exit
+-- result
+0x1
diff --git a/tests/jslt-reg.data b/tests/jslt-reg.data
@@ -0,0 +1,13 @@
+-- asm
+mov32 r0, 0
+mov r1, 0xfffffffe
+mov r2, 0xfffffffd
+mov r3, 0xffffffff
+jslt r1, r1, +2 # Not taken
+jslt r1, r2, +1 # Not taken
+jslt r1, r3, +1 # Taken
+exit
+mov32 r0, 1
+exit
+-- result
+0x1
diff --git a/ubpf/asm_parser.py b/ubpf/asm_parser.py
@@ -39,7 +39,7 @@ def keywords(vs):
     (keywords(mem_load_ops) + reg + "," + memref) | \
     (keywords(["lddw"]) + reg + "," + imm)
 
-jmp_cmp_ops = ['jeq', 'jgt', 'jge', 'jset', 'jne', 'jsgt', 'jsge']
+jmp_cmp_ops = ['jeq', 'jgt', 'jge', 'jlt', 'jle', 'jset', 'jne', 'jsgt', 'jsge', 'jslt', 'jsle']
 jmp_instruction = \
     (keywords(jmp_cmp_ops) + reg + "," + (reg | imm) + "," + offset) | \
     (keywords(['ja']) + offset) | \

diff --git a/ubpf/assembler.py b/ubpf/assembler.py
@@ -54,6 +54,10 @@
     'jne': 5,
     'jsgt': 6,
     'jsge': 7,
+    'jlt': 10,
+    'jle': 11,
+    'jslt': 12,
+    'jsle': 13,
 }
 
 JMP_MISC_OPS = {

diff --git a/ubpf/disassembler.py b/ubpf/disassembler.py
@@ -41,6 +41,10 @@
     7: 'jsge',
     8: 'call',
     9: 'exit',
+    10: 'jlt',
+    11: 'jle',
+    12: 'jslt',
+    13: 'jsle',
 }
 
 MODES = {

diff --git a/vm/ebpf.h b/vm/ebpf.h
@@ -137,5 +137,13 @@ struct ebpf_inst {
 #define EBPF_OP_JSGE_REG (EBPF_CLS_JMP|EBPF_SRC_REG|0x70)
 #define EBPF_OP_CALL     (EBPF_CLS_JMP|0x80)
 #define EBPF_OP_EXIT     (EBPF_CLS_JMP|0x90)
+#define EBPF_OP_JLT_IMM  (EBPF_CLS_JMP|EBPF_SRC_IMM|0xa0)
+#define EBPF_OP_JLT_REG  (EBPF_CLS_JMP|EBPF_SRC_REG|0xa0)
+#define EBPF_OP_JLE_IMM  (EBPF_CLS_JMP|EBPF_SRC_IMM|0xb0)
+#define EBPF_OP_JLE_REG  (EBPF_CLS_JMP|EBPF_SRC_REG|0xb0)
+#define EBPF_OP_JSLT_IMM (EBPF_CLS_JMP|EBPF_SRC_IMM|0xc0)
+#define EBPF_OP_JSLT_REG (EBPF_CLS_JMP|EBPF_SRC_REG|0xc0)
+#define EBPF_OP_JSLE_IMM (EBPF_CLS_JMP|EBPF_SRC_IMM|0xd0)
+#define EBPF_OP_JSLE_REG (EBPF_CLS_JMP|EBPF_SRC_REG|0xd0)
 
 #endif
diff --git a/vm/ubpf_jit_x86_64.c b/vm/ubpf_jit_x86_64.c
@@ -293,6 +293,22 @@ translate(struct ubpf_vm *vm, struct jit_state *state, char **errmsg)
             emit_cmp(state, src, dst);
             emit_jcc(state, 0x83, target_pc);
             break;
+        case EBPF_OP_JLT_IMM:
+            emit_cmp_imm32(state, dst, inst.imm);
+            emit_jcc(state, 0x82, target_pc);
+            break;
+        case EBPF_OP_JLT_REG:
+            emit_cmp(state, src, dst);
+            emit_jcc(state, 0x82, target_pc);
+            break;
+        case EBPF_OP_JLE_IMM:
+            emit_cmp_imm32(state, dst, inst.imm);
+            emit_jcc(state, 0x86, target_pc);
+            break;
+        case EBPF_OP_JLE_REG:
+            emit_cmp(state, src, dst);
+            emit_jcc(state, 0x86, target_pc);
+            break;
         case EBPF_OP_JSET_IMM:
             emit_alu64_imm32(state, 0xf7, 0, dst, inst.imm);
             emit_jcc(state, 0x85, target_pc);
@@ -325,6 +341,22 @@ translate(struct ubpf_vm *vm, struct jit_state *state, char **errmsg)
             emit_cmp(state, src, dst);
             emit_jcc(state, 0x8d, target_pc);
             break;
+        case EBPF_OP_JSLT_IMM:
+            emit_cmp_imm32(state, dst, inst.imm);
+            emit_jcc(state, 0x8c, target_pc);
+            break;
+        case EBPF_OP_JSLT_REG:
+            emit_cmp(state, src, dst);
+            emit_jcc(state, 0x8c, target_pc);
+            break;
+        case EBPF_OP_JSLE_IMM:
+            emit_cmp_imm32(state, dst, inst.imm);
+            emit_jcc(state, 0x8e, target_pc);
+            break;
+        case EBPF_OP_JSLE_REG:
+            emit_cmp(state, src, dst);
+            emit_jcc(state, 0x8e, target_pc);
+            break;
         case EBPF_OP_CALL:
             /* We reserve RCX for shifts */
             emit_mov(state, R9, RCX);

diff --git a/vm/ubpf_vm.c b/vm/ubpf_vm.c
@@ -465,6 +465,26 @@ ubpf_exec(const struct ubpf_vm *vm, void *mem, size_t mem_len)
                 pc += inst.offset;
             }
             break;
+        case EBPF_OP_JLT_IMM:
+            if (reg[inst.dst] < (uint32_t)inst.imm) {
+                pc += inst.offset;
+            }
+            break;
+        case EBPF_OP_JLT_REG:
+            if (reg[inst.dst] < reg[inst.src]) {
+                pc += inst.offset;
+            }
+            break;
+        case EBPF_OP_JLE_IMM:
+            if (reg[inst.dst] <= (uint32_t)inst.imm) {
+                pc += inst.offset;
+            }
+            break;
+        case EBPF_OP_JLE_REG:
+            if (reg[inst.dst] <= reg[inst.src]) {
+                pc += inst.offset;
+            }
+            break;
         case EBPF_OP_JSET_IMM:
             if (reg[inst.dst] & inst.imm) {
                 pc += inst.offset;
@@ -505,6 +525,26 @@ ubpf_exec(const struct ubpf_vm *vm, void *mem, size_t mem_len)
                 pc += inst.offset;
             }
             break;
+        case EBPF_OP_JSLT_IMM:
+            if ((int64_t)reg[inst.dst] < inst.imm) {
+                pc += inst.offset;
+            }
+            break;
+        case EBPF_OP_JSLT_REG:
+            if ((int64_t)reg[inst.dst] < (int64_t)reg[inst.src]) {
+                pc += inst.offset;
+            }
+            break;
+        case EBPF_OP_JSLE_IMM:
+            if ((int64_t)reg[inst.dst] <= inst.imm) {
+                pc += inst.offset;
+            }
+            break;
+        case EBPF_OP_JSLE_REG:
+            if ((int64_t)reg[inst.dst] <= (int64_t)reg[inst.src]) {
+                pc += inst.offset;
+            }
+            break;
         case EBPF_OP_EXIT:
             return reg[0];
         case EBPF_OP_CALL:
@@ -623,6 +663,10 @@ validate(const struct ubpf_vm *vm, const struct ebpf_inst *insts, uint32_t num_i
         case EBPF_OP_JGT_IMM:
         case EBPF_OP_JGE_REG:
         case EBPF_OP_JGE_IMM:
+        case EBPF_OP_JLT_REG:
+        case EBPF_OP_JLT_IMM:
+        case EBPF_OP_JLE_REG:
+        case EBPF_OP_JLE_IMM:
         case EBPF_OP_JSET_REG:
         case EBPF_OP_JSET_IMM:
         case EBPF_OP_JNE_REG:
@@ -631,6 +675,10 @@ validate(const struct ubpf_vm *vm, const struct ebpf_inst *insts, uint32_t num_i
         case EBPF_OP_JSGT_REG:
         case EBPF_OP_JSGE_IMM:
         case EBPF_OP_JSGE_REG:
+        case EBPF_OP_JSLT_IMM:
+        case EBPF_OP_JSLT_REG:
+        case EBPF_OP_JSLE_IMM:
+        case EBPF_OP_JSLE_REG:
             if (inst.offset == -1) {
                 *errmsg = ubpf_error("infinite loop at PC %d", i);
                 return false;