Filter: use hash table to check merge points
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Mon, 16 Jul 2012 19:46:57 +0000 (15:46 -0400)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Mon, 16 Jul 2012 19:46:57 +0000 (15:46 -0400)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
README
configure.ac
liblttng-ust/Makefile.am
liblttng-ust/lttng-filter-validator.c
liblttng-ust/lttng-hash-helper.h [new file with mode: 0644]

diff --git a/README b/README
index 52aebd8940c7cf01770f949beb944f2e63b54a1a..55c72df72cf43b05b06605907a5e36941a2da2fa 100644 (file)
--- a/README
+++ b/README
@@ -16,7 +16,7 @@ PREREQUISITES:
   - liburcu
     Userspace RCU library, by Mathieu Desnoyers and Paul E. McKenney
 
-    -> This release depends on liburcu v0.6.6
+    -> This release depends on liburcu v0.7.2
 
       * Debian/Ubuntu package: liburcu-dev
       * Website:  http://lttng.org/urcu
index edd3c20934744ef49d0461f86436613f7b114843..4d40f753cb861839bbc05ca74c72f1c6adedb0a1 100644 (file)
@@ -116,6 +116,11 @@ CFLAGS="-Wall $CFLAGS"
 AC_CHECK_HEADERS([urcu-bp.h], [], [AC_MSG_ERROR([Cannot find [URCU] headers (urcu-bp.h). Use [CPPFLAGS]=-Idir to specify their location.
 This error can also occur when the liburcu package's configure script has not been run.])])
 
+# urcu-cds - check that URCU Concurrent Data Structure lib is available to compilation
+# Part of Userspace RCU library 0.7.2 or better.
+AC_CHECK_LIB([urcu-cds], [_cds_lfht_new], [], [AC_MSG_ERROR([Cannot find
+liburcu-cds lib, part of Userspace RCU 0.7 or better. Use [LDFLAGS]=-Ldir to specify its location.])])
+
 AC_MSG_CHECKING([caa_likely()])
 AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
 #include <urcu/compiler.h>
index 9ec0591549bbd2627b0c613adb7b4f36314f2dcf..cc36e20e38d7573d0e8d231ed1413d0a961a9e64 100644 (file)
@@ -33,6 +33,7 @@ liblttng_ust_runtime_la_SOURCES = \
        lttng-filter-specialize.c \
        lttng-filter-interpreter.c \
        filter-bytecode.h \
+       lttng-hash-helper.h \
        tracepoint-internal.h \
        clock.h \
        compat.h \
@@ -61,6 +62,7 @@ liblttng_ust_support_la_LIBADD = \
 liblttng_ust_la_LIBADD = \
        -lpthread \
        -lrt \
+       -lurcu-cds \
        -llttng-ust-tracepoint \
        $(top_builddir)/snprintf/libustsnprintf.la \
        $(top_builddir)/liblttng-ust-comm/liblttng-ust-comm.la \
index 6991931b94287c346870c501488a34677ad0bc6b..b164cbbfc421d3c555a3b61c08bb81c6692a9a29 100644 (file)
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define _LGPL_SOURCE
+#include <urcu-bp.h>
+#include <time.h>
 #include "lttng-filter.h"
 
+#include <urcu/rculfhash.h>
+#include "lttng-hash-helper.h"
+
+/* merge point table node */
+struct lfht_mp_node {
+       struct cds_lfht_node node;
+
+       /* Context at merge point */
+       struct vreg reg[NR_REG];
+       unsigned long target_pc;
+};
+
+static unsigned long lttng_hash_seed;
+static unsigned int lttng_hash_seed_ready;
+
+static
+int lttng_hash_match(struct cds_lfht_node *node, const void *key)
+{
+       struct lfht_mp_node *mp_node =
+               caa_container_of(node, struct lfht_mp_node, node);
+       unsigned long key_pc = (unsigned long) key;
+
+       if (mp_node->target_pc == key_pc)
+               return 1;
+       else
+               return 0;
+}
+
+static
+int merge_point_add(struct cds_lfht *ht, unsigned long target_pc,
+               const struct vreg reg[NR_REG])
+{
+       struct lfht_mp_node *node;
+       unsigned long hash = lttng_hash_mix((const void *) target_pc,
+                               sizeof(target_pc),
+                               lttng_hash_seed);
+
+       dbg_printf("Filter: adding merge point at offset %lu, hash %lu\n",
+                       target_pc, hash);
+       node = zmalloc(sizeof(struct lfht_mp_node));
+       if (!node)
+               return -ENOMEM;
+       node->target_pc = target_pc;
+       memcpy(node->reg, reg, sizeof(node->reg));
+       cds_lfht_add(ht, hash, &node->node);
+       return 0;
+}
+
+/*
+ * Number of merge points for hash table size. Hash table initialized to
+ * that size, and we do not resize, because we do not want to trigger
+ * RCU worker thread execution: fall-back on linear traversal if number
+ * of merge points exceeds this value.
+ */
+#define DEFAULT_NR_MERGE_POINTS                128
+#define MIN_NR_BUCKETS                 128
+#define MAX_NR_BUCKETS                 128
+
 static
-int bin_op_compare_check(struct vreg reg[NR_REG], const char *str)
+int bin_op_compare_check(const struct vreg reg[NR_REG], const char *str)
 {
        switch (reg[REG_R0].type) {
        default:
@@ -72,7 +133,7 @@ error_mismatch:
  */
 static
 int bytecode_validate_overflow(struct bytecode_runtime *bytecode,
-                       void *start_pc, void *pc)
+               void *start_pc, void *pc)
 {
        int ret = 0;
 
@@ -246,426 +307,726 @@ int bytecode_validate_overflow(struct bytecode_runtime *bytecode,
        return ret;
 }
 
-int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode)
+static
+unsigned long delete_all_nodes(struct cds_lfht *ht)
 {
-       void *pc, *next_pc, *start_pc;
-       int ret = -EINVAL;
-       struct vreg reg[NR_REG];
-       int i;
+       struct cds_lfht_iter iter;
+       struct lfht_mp_node *node;
+       unsigned long nr_nodes = 0;
 
-       for (i = 0; i < NR_REG; i++) {
-               reg[i].type = REG_TYPE_UNKNOWN;
-               reg[i].literal = 0;
+       cds_lfht_for_each_entry(ht, &iter, node, node) {
+               int ret;
+
+               ret = cds_lfht_del(ht, cds_lfht_iter_get_node(&iter));
+               assert(!ret);
+               /* note: this hash table is never used concurrently */
+               free(node);
+               nr_nodes++;
        }
+       return nr_nodes;
+}
 
-       start_pc = &bytecode->data[0];
-       for (pc = next_pc = start_pc; pc - start_pc < bytecode->len;
-                       pc = next_pc) {
-               if (bytecode_validate_overflow(bytecode, start_pc, pc) != 0) {
-                       ERR("filter bytecode overflow\n");
-                       ret = -EINVAL;
-                       goto end;
-               }
-               dbg_printf("Validating op %s (%u)\n",
-                       print_op((unsigned int) *(filter_opcode_t *) pc),
+/*
+ * Return value:
+ * 0: success
+ * <0: error
+ */
+static
+int validate_instruction_context(struct bytecode_runtime *bytecode,
+               const struct vreg reg[NR_REG],
+               void *start_pc,
+               void *pc)
+{
+       int ret = 0;
+
+       switch (*(filter_opcode_t *) pc) {
+       case FILTER_OP_UNKNOWN:
+       default:
+       {
+               ERR("unknown bytecode op %u\n",
                        (unsigned int) *(filter_opcode_t *) pc);
-               switch (*(filter_opcode_t *) pc) {
-               case FILTER_OP_UNKNOWN:
-               default:
-                       ERR("unknown bytecode op %u\n",
-                               (unsigned int) *(filter_opcode_t *) pc);
-                       ret = -EINVAL;
-                       goto end;
+               ret = -EINVAL;
+               goto end;
+       }
+
+       case FILTER_OP_RETURN:
+       {
+               goto end;
+       }
+
+       /* binary */
+       case FILTER_OP_MUL:
+       case FILTER_OP_DIV:
+       case FILTER_OP_MOD:
+       case FILTER_OP_PLUS:
+       case FILTER_OP_MINUS:
+       case FILTER_OP_RSHIFT:
+       case FILTER_OP_LSHIFT:
+       case FILTER_OP_BIN_AND:
+       case FILTER_OP_BIN_OR:
+       case FILTER_OP_BIN_XOR:
+       {
+               ERR("unsupported bytecode op %u\n",
+                       (unsigned int) *(filter_opcode_t *) pc);
+               ret = -EINVAL;
+               goto end;
+       }
 
-               case FILTER_OP_RETURN:
-                       ret = 0;
+       case FILTER_OP_EQ:
+       {
+               ret = bin_op_compare_check(reg, "==");
+               if (ret)
+                       goto end;
+               break;
+       }
+       case FILTER_OP_NE:
+       {
+               ret = bin_op_compare_check(reg, "!=");
+               if (ret)
+                       goto end;
+               break;
+       }
+       case FILTER_OP_GT:
+       {
+               ret = bin_op_compare_check(reg, ">");
+               if (ret)
+                       goto end;
+               break;
+       }
+       case FILTER_OP_LT:
+       {
+               ret = bin_op_compare_check(reg, "<");
+               if (ret)
+                       goto end;
+               break;
+       }
+       case FILTER_OP_GE:
+       {
+               ret = bin_op_compare_check(reg, ">=");
+               if (ret)
+                       goto end;
+               break;
+       }
+       case FILTER_OP_LE:
+       {
+               ret = bin_op_compare_check(reg, "<=");
+               if (ret)
                        goto end;
+               break;
+       }
 
-               /* binary */
-               case FILTER_OP_MUL:
-               case FILTER_OP_DIV:
-               case FILTER_OP_MOD:
-               case FILTER_OP_PLUS:
-               case FILTER_OP_MINUS:
-               case FILTER_OP_RSHIFT:
-               case FILTER_OP_LSHIFT:
-               case FILTER_OP_BIN_AND:
-               case FILTER_OP_BIN_OR:
-               case FILTER_OP_BIN_XOR:
-                       ERR("unsupported bytecode op %u\n",
-                               (unsigned int) *(filter_opcode_t *) pc);
+       case FILTER_OP_EQ_STRING:
+       case FILTER_OP_NE_STRING:
+       case FILTER_OP_GT_STRING:
+       case FILTER_OP_LT_STRING:
+       case FILTER_OP_GE_STRING:
+       case FILTER_OP_LE_STRING:
+       {
+               if (reg[REG_R0].type != REG_STRING
+                               || reg[REG_R1].type != REG_STRING) {
+                       ERR("Unexpected register type for string comparator\n");
                        ret = -EINVAL;
                        goto end;
-
-               case FILTER_OP_EQ:
-               {
-                       ret = bin_op_compare_check(reg, "==");
-                       if (ret)
-                               goto end;
-                       reg[REG_R0].type = REG_S64;
-                       next_pc += sizeof(struct binary_op);
-                       break;
-               }
-               case FILTER_OP_NE:
-               {
-                       ret = bin_op_compare_check(reg, "!=");
-                       if (ret)
-                               goto end;
-                       reg[REG_R0].type = REG_S64;
-                       next_pc += sizeof(struct binary_op);
-                       break;
-               }
-               case FILTER_OP_GT:
-               {
-                       ret = bin_op_compare_check(reg, ">");
-                       if (ret)
-                               goto end;
-                       reg[REG_R0].type = REG_S64;
-                       next_pc += sizeof(struct binary_op);
-                       break;
-               }
-               case FILTER_OP_LT:
-               {
-                       ret = bin_op_compare_check(reg, "<");
-                       if (ret)
-                               goto end;
-                       reg[REG_R0].type = REG_S64;
-                       next_pc += sizeof(struct binary_op);
-                       break;
-               }
-               case FILTER_OP_GE:
-               {
-                       ret = bin_op_compare_check(reg, ">=");
-                       if (ret)
-                               goto end;
-                       reg[REG_R0].type = REG_S64;
-                       next_pc += sizeof(struct binary_op);
-                       break;
-               }
-               case FILTER_OP_LE:
-               {
-                       ret = bin_op_compare_check(reg, "<=");
-                       if (ret)
-                               goto end;
-                       reg[REG_R0].type = REG_S64;
-                       next_pc += sizeof(struct binary_op);
-                       break;
                }
+               break;
+       }
 
-               case FILTER_OP_EQ_STRING:
-               case FILTER_OP_NE_STRING:
-               case FILTER_OP_GT_STRING:
-               case FILTER_OP_LT_STRING:
-               case FILTER_OP_GE_STRING:
-               case FILTER_OP_LE_STRING:
-               {
-                       if (reg[REG_R0].type != REG_STRING
-                                       || reg[REG_R1].type != REG_STRING) {
-                               ERR("Unexpected register type for string comparator\n");
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       reg[REG_R0].type = REG_S64;
-                       next_pc += sizeof(struct binary_op);
-                       break;
+       case FILTER_OP_EQ_S64:
+       case FILTER_OP_NE_S64:
+       case FILTER_OP_GT_S64:
+       case FILTER_OP_LT_S64:
+       case FILTER_OP_GE_S64:
+       case FILTER_OP_LE_S64:
+       {
+               if (reg[REG_R0].type != REG_S64
+                               || reg[REG_R1].type != REG_S64) {
+                       ERR("Unexpected register type for s64 comparator\n");
+                       ret = -EINVAL;
+                       goto end;
                }
+               break;
+       }
 
-               case FILTER_OP_EQ_S64:
-               case FILTER_OP_NE_S64:
-               case FILTER_OP_GT_S64:
-               case FILTER_OP_LT_S64:
-               case FILTER_OP_GE_S64:
-               case FILTER_OP_LE_S64:
-               {
-                       if (reg[REG_R0].type != REG_S64
-                                       || reg[REG_R1].type != REG_S64) {
-                               ERR("Unexpected register type for s64 comparator\n");
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       reg[REG_R0].type = REG_S64;
-                       next_pc += sizeof(struct binary_op);
-                       break;
+       case FILTER_OP_EQ_DOUBLE:
+       case FILTER_OP_NE_DOUBLE:
+       case FILTER_OP_GT_DOUBLE:
+       case FILTER_OP_LT_DOUBLE:
+       case FILTER_OP_GE_DOUBLE:
+       case FILTER_OP_LE_DOUBLE:
+       {
+               if ((reg[REG_R0].type != REG_DOUBLE && reg[REG_R0].type != REG_S64)
+                               || (reg[REG_R1].type != REG_DOUBLE && reg[REG_R1].type != REG_S64)) {
+                       ERR("Unexpected register type for double comparator\n");
+                       ret = -EINVAL;
+                       goto end;
                }
-
-               case FILTER_OP_EQ_DOUBLE:
-               case FILTER_OP_NE_DOUBLE:
-               case FILTER_OP_GT_DOUBLE:
-               case FILTER_OP_LT_DOUBLE:
-               case FILTER_OP_GE_DOUBLE:
-               case FILTER_OP_LE_DOUBLE:
-               {
-                       if ((reg[REG_R0].type != REG_DOUBLE && reg[REG_R0].type != REG_S64)
-                                       || (reg[REG_R1].type != REG_DOUBLE && reg[REG_R1].type != REG_S64)) {
-                               ERR("Unexpected register type for double comparator\n");
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       if (reg[REG_R0].type != REG_DOUBLE && reg[REG_R1].type != REG_DOUBLE) {
-                               ERR("Double operator should have at least one double register\n");
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       reg[REG_R0].type = REG_DOUBLE;
-                       next_pc += sizeof(struct binary_op);
-                       break;
+               if (reg[REG_R0].type != REG_DOUBLE && reg[REG_R1].type != REG_DOUBLE) {
+                       ERR("Double operator should have at least one double register\n");
+                       ret = -EINVAL;
+                       goto end;
                }
+               break;
+       }
 
-               /* unary */
-               case FILTER_OP_UNARY_PLUS:
-               case FILTER_OP_UNARY_MINUS:
-               case FILTER_OP_UNARY_NOT:
-               {
-                       struct unary_op *insn = (struct unary_op *) pc;
+       /* unary */
+       case FILTER_OP_UNARY_PLUS:
+       case FILTER_OP_UNARY_MINUS:
+       case FILTER_OP_UNARY_NOT:
+       {
+               struct unary_op *insn = (struct unary_op *) pc;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       switch (reg[insn->reg].type) {
-                       default:
-                               ERR("unknown register type\n");
-                               ret = -EINVAL;
-                               goto end;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
+               }
+               switch (reg[insn->reg].type) {
+               default:
+                       ERR("unknown register type\n");
+                       ret = -EINVAL;
+                       goto end;
 
-                       case REG_STRING:
-                               ERR("Unary op can only be applied to numeric or floating point registers\n");
-                               ret = -EINVAL;
-                               goto end;
-                       case REG_S64:
-                               break;
-                       case REG_DOUBLE:
-                               break;
-                       }
-                       next_pc += sizeof(struct unary_op);
+               case REG_STRING:
+                       ERR("Unary op can only be applied to numeric or floating point registers\n");
+                       ret = -EINVAL;
+                       goto end;
+               case REG_S64:
+                       break;
+               case REG_DOUBLE:
                        break;
                }
+               break;
+       }
 
-               case FILTER_OP_UNARY_PLUS_S64:
-               case FILTER_OP_UNARY_MINUS_S64:
-               case FILTER_OP_UNARY_NOT_S64:
-               {
-                       struct unary_op *insn = (struct unary_op *) pc;
+       case FILTER_OP_UNARY_PLUS_S64:
+       case FILTER_OP_UNARY_MINUS_S64:
+       case FILTER_OP_UNARY_NOT_S64:
+       {
+               struct unary_op *insn = (struct unary_op *) pc;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       if (reg[insn->reg].type != REG_S64) {
-                               ERR("Invalid register type\n");
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       next_pc += sizeof(struct unary_op);
-                       break;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
+               }
+               if (reg[insn->reg].type != REG_S64) {
+                       ERR("Invalid register type\n");
+                       ret = -EINVAL;
+                       goto end;
                }
+               break;
+       }
 
-               case FILTER_OP_UNARY_PLUS_DOUBLE:
-               case FILTER_OP_UNARY_MINUS_DOUBLE:
-               case FILTER_OP_UNARY_NOT_DOUBLE:
-               {
-                       struct unary_op *insn = (struct unary_op *) pc;
+       case FILTER_OP_UNARY_PLUS_DOUBLE:
+       case FILTER_OP_UNARY_MINUS_DOUBLE:
+       case FILTER_OP_UNARY_NOT_DOUBLE:
+       {
+               struct unary_op *insn = (struct unary_op *) pc;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       if (reg[insn->reg].type != REG_DOUBLE) {
-                               ERR("Invalid register type\n");
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       next_pc += sizeof(struct unary_op);
-                       break;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
                }
+               if (reg[insn->reg].type != REG_DOUBLE) {
+                       ERR("Invalid register type\n");
+                       ret = -EINVAL;
+                       goto end;
+               }
+               break;
+       }
 
-               /* logical */
-               case FILTER_OP_AND:
-               case FILTER_OP_OR:
-               {
-                       struct logical_op *insn = (struct logical_op *) pc;
-
-                       if (reg[REG_R0].type != REG_S64) {
-                               ERR("Logical comparator expects S64 register\n");
-                               ret = -EINVAL;
-                               goto end;
-                       }
+       /* logical */
+       case FILTER_OP_AND:
+       case FILTER_OP_OR:
+       {
+               struct logical_op *insn = (struct logical_op *) pc;
 
-                       dbg_printf("Validate jumping to bytecode offset %u\n",
-                               (unsigned int) insn->skip_offset);
-                       if (unlikely(start_pc + insn->skip_offset <= pc)) {
-                               ERR("Loops are not allowed in bytecode\n");
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       next_pc += sizeof(struct logical_op);
-                       break;
+               if (reg[REG_R0].type != REG_S64) {
+                       ERR("Logical comparator expects S64 register\n");
+                       ret = -EINVAL;
+                       goto end;
                }
 
-               /* load */
-               case FILTER_OP_LOAD_FIELD_REF:
-               {
-                       ERR("Unknown field ref type\n");
+               dbg_printf("Validate jumping to bytecode offset %u\n",
+                       (unsigned int) insn->skip_offset);
+               if (unlikely(start_pc + insn->skip_offset <= pc)) {
+                       ERR("Loops are not allowed in bytecode\n");
                        ret = -EINVAL;
                        goto end;
                }
-               case FILTER_OP_LOAD_FIELD_REF_STRING:
-               case FILTER_OP_LOAD_FIELD_REF_SEQUENCE:
-               {
-                       struct load_op *insn = (struct load_op *) pc;
-                       struct field_ref *ref = (struct field_ref *) insn->data;
+               break;
+       }
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       dbg_printf("Validate load field ref offset %u type string\n",
-                               ref->offset);
-                       reg[insn->reg].type = REG_STRING;
-                       reg[insn->reg].literal = 0;
-                       next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
-                       break;
+       /* load */
+       case FILTER_OP_LOAD_FIELD_REF:
+       {
+               ERR("Unknown field ref type\n");
+               ret = -EINVAL;
+               goto end;
+       }
+       case FILTER_OP_LOAD_FIELD_REF_STRING:
+       case FILTER_OP_LOAD_FIELD_REF_SEQUENCE:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+               struct field_ref *ref = (struct field_ref *) insn->data;
+
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
                }
-               case FILTER_OP_LOAD_FIELD_REF_S64:
-               {
-                       struct load_op *insn = (struct load_op *) pc;
-                       struct field_ref *ref = (struct field_ref *) insn->data;
+               dbg_printf("Validate load field ref offset %u type string\n",
+                       ref->offset);
+               break;
+       }
+       case FILTER_OP_LOAD_FIELD_REF_S64:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+               struct field_ref *ref = (struct field_ref *) insn->data;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       dbg_printf("Validate load field ref offset %u type s64\n",
-                               ref->offset);
-                       reg[insn->reg].type = REG_S64;
-                       reg[insn->reg].literal = 0;
-                       next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
-                       break;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
                }
-               case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
-               {
-                       struct load_op *insn = (struct load_op *) pc;
-                       struct field_ref *ref = (struct field_ref *) insn->data;
+               dbg_printf("Validate load field ref offset %u type s64\n",
+                       ref->offset);
+               break;
+       }
+       case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+               struct field_ref *ref = (struct field_ref *) insn->data;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       dbg_printf("Validate load field ref offset %u type double\n",
-                               ref->offset);
-                       reg[insn->reg].type = REG_DOUBLE;
-                       reg[insn->reg].literal = 0;
-                       next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
-                       break;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
                }
+               dbg_printf("Validate load field ref offset %u type double\n",
+                       ref->offset);
+               break;
+       }
 
-               case FILTER_OP_LOAD_STRING:
-               {
-                       struct load_op *insn = (struct load_op *) pc;
+       case FILTER_OP_LOAD_STRING:
+       {
+               struct load_op *insn = (struct load_op *) pc;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       reg[insn->reg].type = REG_STRING;
-                       reg[insn->reg].literal = 1;
-                       next_pc += sizeof(struct load_op) + strlen(insn->data) + 1;
-                       break;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
                }
+               break;
+       }
 
-               case FILTER_OP_LOAD_S64:
-               {
-                       struct load_op *insn = (struct load_op *) pc;
+       case FILTER_OP_LOAD_S64:
+       {
+               struct load_op *insn = (struct load_op *) pc;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       reg[insn->reg].type = REG_S64;
-                       reg[insn->reg].literal = 1;
-                       next_pc += sizeof(struct load_op)
-                                       + sizeof(struct literal_numeric);
-                       break;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
                }
+               break;
+       }
 
-               case FILTER_OP_LOAD_DOUBLE:
-               {
-                       struct load_op *insn = (struct load_op *) pc;
+       case FILTER_OP_LOAD_DOUBLE:
+       {
+               struct load_op *insn = (struct load_op *) pc;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       reg[insn->reg].type = REG_DOUBLE;
-                       reg[insn->reg].literal = 1;
-                       next_pc += sizeof(struct load_op)
-                                       + sizeof(struct literal_double);
-                       break;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
                }
+               break;
+       }
 
-               case FILTER_OP_CAST_TO_S64:
-               case FILTER_OP_CAST_DOUBLE_TO_S64:
-               {
-                       struct cast_op *insn = (struct cast_op *) pc;
+       case FILTER_OP_CAST_TO_S64:
+       case FILTER_OP_CAST_DOUBLE_TO_S64:
+       {
+               struct cast_op *insn = (struct cast_op *) pc;
 
-                       if (unlikely(insn->reg >= REG_ERROR)) {
-                               ERR("invalid register %u\n",
-                                       (unsigned int) insn->reg);
-                               ret = -EINVAL;
-                               goto end;
-                       }
-                       switch (reg[insn->reg].type) {
-                       default:
-                               ERR("unknown register type\n");
-                               ret = -EINVAL;
-                               goto end;
+               if (unlikely(insn->reg >= REG_ERROR)) {
+                       ERR("invalid register %u\n",
+                               (unsigned int) insn->reg);
+                       ret = -EINVAL;
+                       goto end;
+               }
+               switch (reg[insn->reg].type) {
+               default:
+                       ERR("unknown register type\n");
+                       ret = -EINVAL;
+                       goto end;
 
-                       case REG_STRING:
-                               ERR("Cast op can only be applied to numeric or floating point registers\n");
+               case REG_STRING:
+                       ERR("Cast op can only be applied to numeric or floating point registers\n");
+                       ret = -EINVAL;
+                       goto end;
+               case REG_S64:
+                       break;
+               case REG_DOUBLE:
+                       break;
+               }
+               if (insn->op == FILTER_OP_CAST_DOUBLE_TO_S64) {
+                       if (reg[insn->reg].type != REG_DOUBLE) {
+                               ERR("Cast expects double\n");
                                ret = -EINVAL;
                                goto end;
-                       case REG_S64:
-                               break;
-                       case REG_DOUBLE:
-                               break;
-                       }
-                       if (insn->op == FILTER_OP_CAST_DOUBLE_TO_S64) {
-                               if (reg[insn->reg].type != REG_DOUBLE) {
-                                       ERR("Cast expects double\n");
-                                       ret = -EINVAL;
-                                       goto end;
-                               }
                        }
-                       reg[insn->reg].type = REG_S64;
-                       next_pc += sizeof(struct cast_op);
-                       break;
                }
-               case FILTER_OP_CAST_NOP:
-               {
-                       next_pc += sizeof(struct cast_op);
-                       break;
+               break;
+       }
+       case FILTER_OP_CAST_NOP:
+       {
+               break;
+       }
+
+       }
+end:
+       return ret;
+}
+
+/*
+ * Return value:
+ * 0: success
+ * <0: error
+ */
+static
+int validate_instruction_all_contexts(struct bytecode_runtime *bytecode,
+               struct cds_lfht *merge_points,
+               const struct vreg reg[NR_REG],
+               void *start_pc,
+               void *pc)
+{
+       int ret;
+       unsigned long target_pc = pc - start_pc;
+       struct cds_lfht_iter iter;
+       struct cds_lfht_node *node;
+       unsigned long hash;
+
+       /* Validate the context resulting from the previous instruction */
+       ret = validate_instruction_context(bytecode, reg, start_pc, pc);
+       if (ret)
+               return ret;
+
+       /* Validate merge points */
+       hash = lttng_hash_mix((const void *) target_pc, sizeof(target_pc),
+                       lttng_hash_seed);
+       cds_lfht_for_each_duplicate(merge_points, hash, lttng_hash_match,
+                       (const void *) target_pc, &iter, node) {
+               struct lfht_mp_node *mp_node =
+                       caa_container_of(node, struct lfht_mp_node, node);
+               
+               dbg_printf("Filter: validate merge point at offset %lu\n",
+                               target_pc);
+               ret = validate_instruction_context(bytecode, mp_node->reg,
+                               start_pc, pc);
+               if (ret)
+                       return ret;
+               /* Once validated, we can remove the merge point */
+               dbg_printf("Filter: remove one merge point at offset %lu\n",
+                               target_pc);
+               ret = cds_lfht_del(merge_points, node);
+               assert(!ret);
+       }
+       return 0;
+}
+
+/*
+ * Return value:
+ * >0: going to next insn.
+ * 0: success, stop iteration.
+ * <0: error
+ */
+static
+int exec_insn(struct bytecode_runtime *bytecode,
+               struct cds_lfht *merge_points,
+               struct vreg reg[NR_REG],
+               void **_next_pc,
+               void *pc)
+{
+       int ret = 1;
+       void *next_pc = *_next_pc;
+
+       switch (*(filter_opcode_t *) pc) {
+       case FILTER_OP_UNKNOWN:
+       default:
+       {
+               ERR("unknown bytecode op %u\n",
+                       (unsigned int) *(filter_opcode_t *) pc);
+               ret = -EINVAL;
+               goto end;
+       }
+
+       case FILTER_OP_RETURN:
+       {
+               ret = 0;
+               goto end;
+       }
+
+       /* binary */
+       case FILTER_OP_MUL:
+       case FILTER_OP_DIV:
+       case FILTER_OP_MOD:
+       case FILTER_OP_PLUS:
+       case FILTER_OP_MINUS:
+       case FILTER_OP_RSHIFT:
+       case FILTER_OP_LSHIFT:
+       case FILTER_OP_BIN_AND:
+       case FILTER_OP_BIN_OR:
+       case FILTER_OP_BIN_XOR:
+       {
+               ERR("unsupported bytecode op %u\n",
+                       (unsigned int) *(filter_opcode_t *) pc);
+               ret = -EINVAL;
+               goto end;
+       }
+
+       case FILTER_OP_EQ:
+       case FILTER_OP_NE:
+       case FILTER_OP_GT:
+       case FILTER_OP_LT:
+       case FILTER_OP_GE:
+       case FILTER_OP_LE:
+       case FILTER_OP_EQ_STRING:
+       case FILTER_OP_NE_STRING:
+       case FILTER_OP_GT_STRING:
+       case FILTER_OP_LT_STRING:
+       case FILTER_OP_GE_STRING:
+       case FILTER_OP_LE_STRING:
+       case FILTER_OP_EQ_S64:
+       case FILTER_OP_NE_S64:
+       case FILTER_OP_GT_S64:
+       case FILTER_OP_LT_S64:
+       case FILTER_OP_GE_S64:
+       case FILTER_OP_LE_S64:
+       {
+               reg[REG_R0].type = REG_S64;
+               next_pc += sizeof(struct binary_op);
+               break;
+       }
+
+       case FILTER_OP_EQ_DOUBLE:
+       case FILTER_OP_NE_DOUBLE:
+       case FILTER_OP_GT_DOUBLE:
+       case FILTER_OP_LT_DOUBLE:
+       case FILTER_OP_GE_DOUBLE:
+       case FILTER_OP_LE_DOUBLE:
+       {
+               reg[REG_R0].type = REG_DOUBLE;
+               next_pc += sizeof(struct binary_op);
+               break;
+       }
+
+       /* unary */
+       case FILTER_OP_UNARY_PLUS:
+       case FILTER_OP_UNARY_MINUS:
+       case FILTER_OP_UNARY_NOT:
+       case FILTER_OP_UNARY_PLUS_S64:
+       case FILTER_OP_UNARY_MINUS_S64:
+       case FILTER_OP_UNARY_NOT_S64:
+       {
+               reg[REG_R0].type = REG_S64;
+               next_pc += sizeof(struct unary_op);
+               break;
+       }
+
+       case FILTER_OP_UNARY_PLUS_DOUBLE:
+       case FILTER_OP_UNARY_MINUS_DOUBLE:
+       case FILTER_OP_UNARY_NOT_DOUBLE:
+       {
+               reg[REG_R0].type = REG_DOUBLE;
+               next_pc += sizeof(struct unary_op);
+               break;
+       }
+
+       /* logical */
+       case FILTER_OP_AND:
+       case FILTER_OP_OR:
+       {
+               struct logical_op *insn = (struct logical_op *) pc;
+               int merge_ret;
+
+               /* Add merge point to table */
+               merge_ret = merge_point_add(merge_points, insn->skip_offset, reg);
+               if (merge_ret) {
+                       ret = merge_ret;
+                       goto end;
                }
+               /* Continue to next instruction */
+               next_pc += sizeof(struct logical_op);
+               break;
+       }
+
+       /* load */
+       case FILTER_OP_LOAD_FIELD_REF:
+       {
+               ERR("Unknown field ref type\n");
+               ret = -EINVAL;
+               goto end;
+       }
+       case FILTER_OP_LOAD_FIELD_REF_STRING:
+       case FILTER_OP_LOAD_FIELD_REF_SEQUENCE:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+
+               reg[insn->reg].type = REG_STRING;
+               reg[insn->reg].literal = 0;
+               next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
+               break;
+       }
+       case FILTER_OP_LOAD_FIELD_REF_S64:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+
+               reg[insn->reg].type = REG_S64;
+               reg[insn->reg].literal = 0;
+               next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
+               break;
+       }
+       case FILTER_OP_LOAD_FIELD_REF_DOUBLE:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+
+               reg[insn->reg].type = REG_DOUBLE;
+               reg[insn->reg].literal = 0;
+               next_pc += sizeof(struct load_op) + sizeof(struct field_ref);
+               break;
+       }
+
+       case FILTER_OP_LOAD_STRING:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+
+               reg[insn->reg].type = REG_STRING;
+               reg[insn->reg].literal = 1;
+               next_pc += sizeof(struct load_op) + strlen(insn->data) + 1;
+               break;
+       }
+
+       case FILTER_OP_LOAD_S64:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+
+               reg[insn->reg].type = REG_S64;
+               reg[insn->reg].literal = 1;
+               next_pc += sizeof(struct load_op)
+                               + sizeof(struct literal_numeric);
+               break;
+       }
+
+       case FILTER_OP_LOAD_DOUBLE:
+       {
+               struct load_op *insn = (struct load_op *) pc;
+
+               reg[insn->reg].type = REG_DOUBLE;
+               reg[insn->reg].literal = 1;
+               next_pc += sizeof(struct load_op)
+                               + sizeof(struct literal_double);
+               break;
+       }
+
+       case FILTER_OP_CAST_TO_S64:
+       case FILTER_OP_CAST_DOUBLE_TO_S64:
+       {
+               struct cast_op *insn = (struct cast_op *) pc;
+
+               reg[insn->reg].type = REG_S64;
+               next_pc += sizeof(struct cast_op);
+               break;
+       }
+       case FILTER_OP_CAST_NOP:
+       {
+               next_pc += sizeof(struct cast_op);
+               break;
+       }
 
+       }
+end:
+       *_next_pc = next_pc;
+       return ret;
+}
+
+/*
+ * Never called concurrently (hash seed is shared).
+ */
+int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode)
+{
+       struct cds_lfht *merge_points;
+       void *pc, *next_pc, *start_pc;
+       int ret = -EINVAL;
+       struct vreg reg[NR_REG];
+       int i;
+
+       for (i = 0; i < NR_REG; i++) {
+               reg[i].type = REG_TYPE_UNKNOWN;
+               reg[i].literal = 0;
+       }
+
+       if (!lttng_hash_seed_ready) {
+               lttng_hash_seed = time(NULL);
+               lttng_hash_seed_ready = 1;
+       }
+       /*
+        * Note: merge_points hash table used by single thread, and
+        * never concurrently resized. Therefore, we can use it without
+        * holding RCU read-side lock and free nodes without using
+        * call_rcu.
+        */
+       merge_points = cds_lfht_new(DEFAULT_NR_MERGE_POINTS,
+                       MIN_NR_BUCKETS, MAX_NR_BUCKETS,
+                       0, NULL);
+       if (!merge_points) {
+               ERR("Error allocating hash table for bytecode validation\n");
+               return -ENOMEM;
+       }
+       start_pc = &bytecode->data[0];
+       for (pc = next_pc = start_pc; pc - start_pc < bytecode->len;
+                       pc = next_pc) {
+               if (bytecode_validate_overflow(bytecode, start_pc, pc) != 0) {
+                       ERR("filter bytecode overflow\n");
+                       ret = -EINVAL;
+                       goto end;
                }
+               dbg_printf("Validating op %s (%u)\n",
+                       print_op((unsigned int) *(filter_opcode_t *) pc),
+                       (unsigned int) *(filter_opcode_t *) pc);
+
+               /*
+                * For each instruction, validate the current context
+                * (traversal of entire execution flow), and validate
+                * all  merge points targeting this instruction.
+                */
+               ret = validate_instruction_all_contexts(bytecode, merge_points,
+                                       reg, start_pc, pc);
+               if (ret)
+                       goto end;
+               ret = exec_insn(bytecode, merge_points, reg, &next_pc, pc);
+               if (ret <= 0)
+                       goto end;
        }
 end:
+       if (delete_all_nodes(merge_points)) {
+               if (!ret) {
+                       ERR("Unexpected merge points\n");
+                       ret = -EINVAL;
+               }
+       }
+       if (cds_lfht_destroy(merge_points, NULL)) {
+               ERR("Error destroying hash table\n");
+       }
        return ret;
 }
diff --git a/liblttng-ust/lttng-hash-helper.h b/liblttng-ust/lttng-hash-helper.h
new file mode 100644 (file)
index 0000000..bddc7c4
--- /dev/null
@@ -0,0 +1,160 @@
+#ifndef _LTTNG_HASH_HELPER_H
+#define _LTTNG_HASH_HELPER_H
+
+/*
+ * lttng-hash-helper.h
+ *
+ * LTTng hash table helpers.
+ *
+ * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <assert.h>
+#include <stdint.h>
+#include <urcu/compiler.h>
+
+/*
+ * Hash function
+ * Source: http://burtleburtle.net/bob/c/lookup3.c
+ * Originally Public Domain
+ */
+
+#define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k))))
+
+#define mix(a, b, c) \
+do { \
+       a -= c; a ^= rot(c,  4); c += b; \
+       b -= a; b ^= rot(a,  6); a += c; \
+       c -= b; c ^= rot(b,  8); b += a; \
+       a -= c; a ^= rot(c, 16); c += b; \
+       b -= a; b ^= rot(a, 19); a += c; \
+       c -= b; c ^= rot(b,  4); b += a; \
+} while (0)
+
+#define final(a, b, c) \
+{ \
+       c ^= b; c -= rot(b, 14); \
+       a ^= c; a -= rot(c, 11); \
+       b ^= a; b -= rot(a, 25); \
+       c ^= b; c -= rot(b, 16); \
+       a ^= c; a -= rot(c,  4);\
+       b ^= a; b -= rot(a, 14); \
+       c ^= b; c -= rot(b, 24); \
+}
+
+static inline __attribute__((unused))
+uint32_t lttng_hash_u32(
+       const uint32_t *k,      /* the key, an array of uint32_t values */
+       size_t length,          /* the length of the key, in uint32_ts */
+       uint32_t initval)       /* the previous hash, or an arbitrary value */
+{
+       uint32_t a, b, c;
+
+       /* Set up the internal state */
+       a = b = c = 0xdeadbeef + (((uint32_t) length) << 2) + initval;
+
+       /*----------------------------------------- handle most of the key */
+       while (length > 3) {
+               a += k[0];
+               b += k[1];
+               c += k[2];
+               mix(a, b, c);
+               length -= 3;
+               k += 3;
+       }
+
+       /*----------------------------------- handle the last 3 uint32_t's */
+       switch (length) {       /* all the case statements fall through */
+       case 3: c += k[2];
+       case 2: b += k[1];
+       case 1: a += k[0];
+               final(a, b, c);
+       case 0:                 /* case 0: nothing left to add */
+               break;
+       }
+       /*---------------------------------------------- report the result */
+       return c;
+}
+
+static inline
+void lttng_hashword2(
+       const uint32_t *k,      /* the key, an array of uint32_t values */
+       size_t length,          /* the length of the key, in uint32_ts */
+       uint32_t *pc,           /* IN: seed OUT: primary hash value */
+       uint32_t *pb)           /* IN: more seed OUT: secondary hash value */
+{
+       uint32_t a, b, c;
+
+       /* Set up the internal state */
+       a = b = c = 0xdeadbeef + ((uint32_t) (length << 2)) + *pc;
+       c += *pb;
+
+       /*----------------------------------------- handle most of the key */
+       while (length > 3) {
+               a += k[0];
+               b += k[1];
+               c += k[2];
+               mix(a, b, c);
+               length -= 3;
+               k += 3;
+       }
+
+       /*----------------------------------- handle the last 3 uint32_t's */
+       switch (length) {       /* all the case statements fall through */
+       case 3: c += k[2];
+       case 2: b += k[1];
+       case 1: a += k[0];
+               final(a, b, c);
+       case 0:                 /* case 0: nothing left to add */
+               break;
+       }
+       /*---------------------------------------------- report the result */
+       *pc = c;
+       *pb = b;
+}
+
+#if (CAA_BITS_PER_LONG == 32)
+static inline
+unsigned long lttng_hash_mix(const void *_key, size_t length, unsigned long seed)
+{
+       unsigned int key = (unsigned int) _key;
+
+       assert(length == sizeof(unsigned int));
+       return lttng_hash_u32(&key, 1, seed);
+}
+#else
+static inline
+unsigned long lttng_hash_mix(const void *_key, size_t length, unsigned long seed)
+{
+       union {
+               uint64_t v64;
+               uint32_t v32[2];
+       } v;
+       union {
+               uint64_t v64;
+               uint32_t v32[2];
+       } key;
+
+       assert(length == sizeof(unsigned long));
+       v.v64 = (uint64_t) seed;
+       key.v64 = (uint64_t) _key;
+       lttng_hashword2(key.v32, 2, &v.v32[0], &v.v32[1]);
+       return v.v64;
+}
+#endif
+
+#endif /* _LTTNG_HASH_HELPER_H */
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