1911acb84f
if calloc() doesn't allocate memory for struct tvm_ctx, there may be NULL pointer dereferencing, i.e. vm->mem, vm->prog. So the vm pointer verification must be before it is used. Also, there is the same situation with vm->mem and stack creation.
89 lines
1.8 KiB
C
89 lines
1.8 KiB
C
#include <tvm/tvm.h>
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#include <tvm/tvm_lexer.h>
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#include <tvm/tvm_parser.h>
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struct tvm_ctx *tvm_vm_create()
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{
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struct tvm_ctx *vm =
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(struct tvm_ctx *)calloc(1, sizeof(struct tvm_ctx));
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if (!vm)
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return NULL;
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vm->mem = tvm_mem_create(MIN_MEMORY_SIZE);
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vm->prog = tvm_prog_create();
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if (!vm->mem || !vm->prog) {
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tvm_vm_destroy(vm);
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return NULL;
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}
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tvm_stack_create(vm->mem, MIN_STACK_SIZE);
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return vm;
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}
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int tvm_vm_interpret(struct tvm_ctx *vm, char *filename)
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{
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FILE *filp = NULL;
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int source_length = 0;
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/* Attempt to open the file.
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* If the file cannot be opened, try once more.
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*/
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if (filename) {
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for (int i = 0; i < 2; i++) {
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if (!filp)
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filp = tvm_fopen(filename, ".vm", "r");
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}
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}
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if (!filp) {
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printf("File was not found, or does not exist. Unable to interpret.\n");
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return 1;
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}
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source_length = tvm_flength(filp);
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char *source = calloc(source_length, sizeof(char));
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tvm_fcopy(source, source_length, filp);
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fclose(filp);
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int err = tvm_preprocess(&source, &source_length, vm->prog->defines);
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/* The preprocessor encountered a problem. */
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if (err < 0)
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return 1;
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struct tvm_lexer_ctx *lexer_ctx = lexer_create();
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tvm_lex(lexer_ctx, source, vm->prog->defines);
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free(source);
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if (tvm_parse_labels(vm, (const char ***)lexer_ctx->tokens) != 0)
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return 1;
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if (tvm_parse_program(vm, (const char ***)lexer_ctx->tokens) != 0)
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return 1;
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tvm_lexer_destroy(lexer_ctx);
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return 0;
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}
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void tvm_vm_run(struct tvm_ctx *vm)
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{
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int *instr_idx = &vm->mem->registers[0x8].i32;
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*instr_idx = vm->prog->start;
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for (; vm->prog->instr[*instr_idx] != -0x1; ++(*instr_idx))
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tvm_step(vm, instr_idx);
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}
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void tvm_vm_destroy(struct tvm_ctx *vm)
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{
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if (vm && vm->mem)
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tvm_mem_destroy(vm->mem);
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if (vm && vm->prog)
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tvm_prog_destroy(vm->prog);
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if (vm)
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free(vm);
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}
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