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/*
* Example trivial client program that uses the sparse library
* to tokenize, preprocess and parse a C file, and prints out
* the results.
*
* Copyright (C) 2003 Transmeta Corp.
* 2003-2004 Linus Torvalds
*
* Licensed under the Open Software License version 1.1
*/
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <fcntl.h>
#include "lib.h"
#include "allocate.h"
#include "token.h"
#include "parse.h"
#include "symbol.h"
#include "expression.h"
#include "linearize.h"
static int context_increase(struct basic_block *bb, int entry)
{
int sum = 0;
struct instruction *insn;
FOR_EACH_PTR(bb->insns, insn) {
int val;
if (insn->opcode != OP_CONTEXT)
continue;
val = insn->increment;
if (insn->check) {
int current = sum + entry;
if (!val) {
if (!current)
continue;
} else if (current >= val)
continue;
warning(insn->pos, "context check failure");
continue;
}
sum += val;
} END_FOR_EACH_PTR(insn);
return sum;
}
static int imbalance(struct entrypoint *ep, struct basic_block *bb, int entry, int exit, const char *why)
{
if (Wcontext) {
struct symbol *sym = ep->name;
warning(bb->pos, "context imbalance in '%s' - %s", show_ident(sym->ident), why);
}
return -1;
}
static int check_bb_context(struct entrypoint *ep, struct basic_block *bb, int entry, int exit);
static int check_children(struct entrypoint *ep, struct basic_block *bb, int entry, int exit)
{
struct instruction *insn;
struct basic_block *child;
insn = last_instruction(bb->insns);
if (!insn)
return 0;
if (insn->opcode == OP_RET)
return entry != exit ? imbalance(ep, bb, entry, exit, "wrong count at exit") : 0;
FOR_EACH_PTR(bb->children, child) {
if (check_bb_context(ep, child, entry, exit))
return -1;
} END_FOR_EACH_PTR(child);
return 0;
}
static int check_bb_context(struct entrypoint *ep, struct basic_block *bb, int entry, int exit)
{
if (!bb)
return 0;
if (bb->context == entry)
return 0;
/* Now that's not good.. */
if (bb->context >= 0)
return imbalance(ep, bb, entry, bb->context, "different lock contexts for basic block");
bb->context = entry;
entry += context_increase(bb, entry);
if (entry < 0)
return imbalance(ep, bb, entry, exit, "unexpected unlock");
return check_children(ep, bb, entry, exit);
}
static void check_cast_instruction(struct instruction *insn)
{
struct symbol *orig_type = insn->orig_type;
if (orig_type) {
int old = orig_type->bit_size;
int new = insn->size;
int oldsigned = (orig_type->ctype.modifiers & MOD_SIGNED) != 0;
int newsigned = insn->opcode == OP_SCAST;
if (new > old) {
if (oldsigned == newsigned)
return;
if (newsigned)
return;
warning(insn->pos, "cast loses sign");
return;
}
if (new < old) {
warning(insn->pos, "cast drops bits");
return;
}
if (oldsigned == newsigned) {
warning(insn->pos, "cast wasn't removed");
return;
}
warning(insn->pos, "cast changes sign");
}
}
static void check_range_instruction(struct instruction *insn)
{
warning(insn->pos, "value out of range");
}
static void check_byte_count(struct instruction *insn, pseudo_t count)
{
if (!count)
return;
if (count->type == PSEUDO_VAL) {
long long val = count->value;
if (val <= 0 || val > 100000)
warning(insn->pos, "%s with byte count of %lld",
show_ident(insn->func->sym->ident), val);
return;
}
/* OK, we could try to do the range analysis here */
}
static pseudo_t argument(struct instruction *call, unsigned int argno)
{
pseudo_t args[8];
struct ptr_list *arg_list = (struct ptr_list *) call->arguments;
argno--;
if (linearize_ptr_list(arg_list, (void *)args, 8) > argno)
return args[argno];
return NULL;
}
static void check_memset(struct instruction *insn)
{
check_byte_count(insn, argument(insn, 3));
}
#define check_memcpy check_memset
#define check_ctu check_memset
#define check_cfu check_memset
struct checkfn {
struct ident *id;
void (*check)(struct instruction *insn);
};
static void check_call_instruction(struct instruction *insn)
{
pseudo_t fn = insn->func;
struct ident *ident;
static const struct checkfn check_fn[] = {
{ &memset_ident, check_memset },
{ &memcpy_ident, check_memcpy },
{ ©_to_user_ident, check_ctu },
{ ©_from_user_ident, check_cfu },
};
int i;
if (fn->type != PSEUDO_SYM)
return;
ident = fn->sym->ident;
if (!ident)
return;
for (i = 0; i < sizeof(check_fn)/sizeof(struct checkfn) ; i++) {
if (check_fn[i].id != ident)
continue;
check_fn[i].check(insn);
break;
}
}
static void check_one_instruction(struct instruction *insn)
{
switch (insn->opcode) {
case OP_CAST: case OP_SCAST:
if (verbose)
check_cast_instruction(insn);
break;
case OP_RANGE:
check_range_instruction(insn);
break;
case OP_CALL:
check_call_instruction(insn);
break;
default:
break;
}
}
static void check_bb_instructions(struct basic_block *bb)
{
struct instruction *insn;
FOR_EACH_PTR(bb->insns, insn) {
if (!insn->bb)
continue;
check_one_instruction(insn);
} END_FOR_EACH_PTR(insn);
}
static void check_instructions(struct entrypoint *ep)
{
struct basic_block *bb;
FOR_EACH_PTR(ep->bbs, bb) {
check_bb_instructions(bb);
} END_FOR_EACH_PTR(bb);
}
static void check_context(struct entrypoint *ep)
{
struct symbol *sym = ep->name;
struct context *context;
unsigned int in_context = 0, out_context = 0;
if (Wuninitialized && verbose && ep->entry->bb->needs) {
pseudo_t pseudo;
FOR_EACH_PTR(ep->entry->bb->needs, pseudo) {
if (pseudo->type != PSEUDO_ARG)
warning(sym->pos, "%s: possible uninitialized variable (%s)",
show_ident(sym->ident), show_pseudo(pseudo));
} END_FOR_EACH_PTR(pseudo);
}
check_instructions(ep);
FOR_EACH_PTR(sym->ctype.contexts, context) {
in_context += context->in;
out_context += context->out;
} END_FOR_EACH_PTR(context);
check_bb_context(ep, ep->entry->bb, in_context, out_context);
}
static void check_symbols(struct symbol_list *list)
{
struct symbol *sym;
FOR_EACH_PTR(list, sym) {
struct entrypoint *ep;
expand_symbol(sym);
ep = linearize_symbol(sym);
if (ep) {
if (dbg_entry)
show_entry(ep);
check_context(ep);
}
} END_FOR_EACH_PTR(sym);
}
int main(int argc, char **argv)
{
struct string_list *filelist = NULL;
char *file;
// Expand, linearize and show it.
check_symbols(sparse_initialize(argc, argv, &filelist));
FOR_EACH_PTR_NOTAG(filelist, file) {
check_symbols(sparse(file));
} END_FOR_EACH_PTR_NOTAG(file);
return 0;
}
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