tests/qtest/fuzz/fuzz.h

   1 /*
   2  * fuzzing driver
   3  *
   4  * Copyright Red Hat Inc., 2019
   5  *
   6  * Authors:
   7  *  Alexander Bulekov   <alxndr@bu.edu>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #ifndef FUZZER_H_
  15 #define FUZZER_H_
  16
  17 #include "qemu/osdep.h"
  18 #include "qemu/units.h"
  19 #include "qapi/error.h"
  20
  21 #include "tests/qtest/libqtest.h"
  22
  23 /**
  24  * A libfuzzer fuzzing target
  25  *
  26  * The QEMU fuzzing binary is built with all available targets, each
  27  * with a unique @name that can be specified on the command-line to
  28  * select which target should run.
  29  *
  30  * A target must implement ->fuzz() to process a random input.  If QEMU
  31  * crashes in ->fuzz() then libfuzzer will record a failure.
  32  *
  33  * Fuzzing targets are registered with fuzz_add_target():
  34  *
  35  *   static const FuzzTarget fuzz_target = {
  36  *       .name = "my-device-fifo",
  37  *       .description = "Fuzz the FIFO buffer registers of my-device",
  38  *       ...
  39  *   };
  40  *
  41  *   static void register_fuzz_target(void)
  42  *   {
  43  *       fuzz_add_target(&fuzz_target);
  44  *   }
  45  *   fuzz_target_init(register_fuzz_target);
  46  */
  47 typedef struct FuzzTarget {
  48     const char *name;         /* target identifier (passed to --fuzz-target=)*/
  49     const char *description;  /* help text */
  50
  51
  52     /*
  53      * Returns the arguments that are passed to qemu/softmmu init(). Freed by
  54      * the caller.
  55      */
  56     GString *(*get_init_cmdline)(struct FuzzTarget *);
  57
  58     /*
  59      * will run once, prior to running qemu/softmmu init.
  60      * eg: set up shared-memory for communication with the child-process
  61      * Can be NULL
  62      */
  63     void(*pre_vm_init)(void);
  64
  65     /*
  66      * will run once, after QEMU has been initialized, prior to the fuzz-loop.
  67      * eg: detect the memory map
  68      * Can be NULL
  69      */
  70     void(*pre_fuzz)(QTestState *);
  71
  72     /*
  73      * accepts and executes an input from libfuzzer. this is repeatedly
  74      * executed during the fuzzing loop. Its should handle setup, input
  75      * execution and cleanup.
  76      * Cannot be NULL
  77      */
  78     void(*fuzz)(QTestState *, const unsigned char *, size_t);
  79
  80 } FuzzTarget;
  81
  82 void flush_events(QTestState *);
  83 void reboot(QTestState *);
  84
  85 /* Use the QTest ASCII protocol or call address_space API directly?*/
  86 void fuzz_qtest_set_serialize(bool option);
  87
  88 /*
  89  * makes a copy of *target and adds it to the target-list.
  90  * i.e. fine to set up target on the caller's stack
  91  */
  92 void fuzz_add_target(const FuzzTarget *target);
  93
  94 int LLVMFuzzerTestOneInput(const unsigned char *Data, size_t Size);
  95 int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp);
  96
  97 #endif
  98