check_gfp_dma.c

   1 /*
   2  * sparse/check_gfp_dma.c
   3  *
   4  * Copyright (C) 2010 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include "smatch.h"
  11
  12 static int my_id;
  13
  14 /* this is stolen from the kernel but it's totally fair use dude...  */
  15 #define __GFP_DMA       (0x01u)
  16 #define __GFP_HIGHMEM   (0x02u)
  17 #define __GFP_DMA32     (0x04u)
  18 #define __GFP_MOVABLE   (0x08u)
  19 #define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
  20
  21 static void match_alloc(const char *fn, struct expression *expr, void *_arg)
  22 {
  23         int arg_nr = PTR_INT(_arg);
  24         struct expression *arg_expr;
  25         sval_t sval;
  26
  27         arg_expr = get_argument_from_call_expr(expr->args, arg_nr);
  28         if (!get_value(arg_expr, &sval))
  29                 return;
  30         if (sval.uvalue == 0) /* GFP_NOWAIT */
  31                 return;
  32         if (!(sval.uvalue & ~GFP_ZONEMASK))
  33                 sm_msg("error: no modifiers for allocation.");
  34 }
  35
  36 void check_gfp_dma(int id)
  37 {
  38         my_id = id;
  39         if (option_project != PROJ_KERNEL)
  40                 return;
  41         add_function_hook("kmalloc", &match_alloc, INT_PTR(1));
  42         add_function_hook("kzalloc", &match_alloc, INT_PTR(1));
  43 }