Coverage Report

Created: 2024-05-21 06:29

/src/binutils-gdb/fuzz/fuzz_disassemble.c
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Count
Source
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/* Copyright 2020 Google Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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      http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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#include "sysdep.h"
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#include "bfd.h"
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#include "dis-asm.h"
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#include "disassemble.h"
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#include <stdint.h>
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179M
#define MAX_TEXT_SIZE 256
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typedef struct
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{
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    char *buffer;
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    size_t pos;
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} SFILE;
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static int
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fuzz_disasm_null_styled_printf (void *stream,
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             enum disassembler_style style,
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             const char *format, ...)
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50.2M
{
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50.2M
  return 0;
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50.2M
}
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static int objdump_sprintf (void *vf, const char *format, ...)
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89.5M
{
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89.5M
    SFILE *f = (SFILE *) vf;
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89.5M
    size_t n;
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89.5M
    va_list args;
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89.5M
    va_start (args, format);
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89.5M
    if (f->pos >= MAX_TEXT_SIZE){
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1.00k
        printf("buffer needs more space\n");
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        //reset
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1.00k
        f->pos=0;
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1.00k
        return 0;
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1.00k
    }
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89.5M
    n = vsnprintf (f->buffer + f->pos, MAX_TEXT_SIZE - f->pos, format, args);
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    //vfprintf(stdout, format, args);
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89.5M
    va_end (args);
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89.5M
    f->pos += n;
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89.5M
    return n;
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89.5M
}
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24.4k
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
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24.4k
    char AssemblyText[MAX_TEXT_SIZE];
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24.4k
    struct disassemble_info disasm_info;
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24.4k
    SFILE s;
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24.4k
    if (Size < 10 || Size > 16394) {
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        // 10 bytes for options
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        // 16394 limit code to prevent timeouts
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13
        return 0;
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13
    }
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24.4k
    init_disassemble_info (&disasm_info, stdout, (fprintf_ftype) fprintf, fuzz_disasm_null_styled_printf);
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24.4k
    disasm_info.fprintf_func = objdump_sprintf;
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24.4k
    disasm_info.print_address_func = generic_print_address;
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24.4k
    disasm_info.display_endian = disasm_info.endian = BFD_ENDIAN_LITTLE;
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24.4k
    disasm_info.buffer = (bfd_byte *) Data;
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24.4k
    disasm_info.buffer_vma = 0x1000;
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24.4k
    disasm_info.buffer_length = Size-10;
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24.4k
    disasm_info.insn_info_valid = 0;
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24.4k
    disasm_info.created_styled_output = false;
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24.4k
    s.buffer = AssemblyText;
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24.4k
    s.pos = 0;
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24.4k
    disasm_info.stream = &s;
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24.4k
    disasm_info.bytes_per_line = 0;
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24.4k
    disasm_info.arch = Data[Size-1];
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24.4k
    disasm_info.mach = bfd_getl64(&Data[Size-9]);
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24.4k
    disasm_info.flavour = Data[Size-10];
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24.4k
    if (bfd_lookup_arch (disasm_info.arch, disasm_info.mach) != NULL) {
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24.3k
        disassembler_ftype disasfunc = disassembler(disasm_info.arch, 0, disasm_info.mach, NULL);
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24.3k
        if (disasfunc != NULL) {
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24.3k
            disassemble_init_for_target(&disasm_info);
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26.0M
            while (1) {
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26.0M
                s.pos = 0;
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26.0M
                int octets = disasfunc(disasm_info.buffer_vma, &disasm_info);
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26.0M
                if (octets < (int) disasm_info.octets_per_byte)
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13.5k
                    break;
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26.0M
                if (disasm_info.buffer_length <= (size_t) octets)
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10.8k
                    break;
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26.0M
                disasm_info.buffer += octets;
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26.0M
                disasm_info.buffer_vma += octets / disasm_info.octets_per_byte;
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26.0M
                disasm_info.buffer_length -= octets;
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26.0M
            }
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24.3k
            disassemble_free_target(&disasm_info);
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24.3k
        }
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24.3k
    }
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24.4k
    return 0;
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24.4k
}