Add support to read zlib compressed files, like vmlinux.gz #103
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I am not particularly happy on how this is implemented. Let me elaborate:
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The magic number comparison could be in a separate function, either a static function in ElfObject class or a auxiliary function in NonLLVMMisc.cpp. Maybe even creating a separate class for this and return an
enumwith all known magic numbers. -
Be careful to initialize the file buffers correctly.
readcan fail in many ways, such as simple as it not being able to read the file because of permission errors. -
"Guessing" the deflated file size without any kind of fail mechanism is very dangerous. You should do it in a loop and call
reallocif things go south. -
Make sure the provided library doesn't provide a way of stream-decompress the file without preloading the file on memory by yourself. This is usually much faster on today machines because of asynchronous disk operations: disk access is slow, CPU is blazing fast.
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| Elf *elf = elf_memory((char *)dest, ret); | ||
| if (elf == nullptr) { | ||
| free(dest); |
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In this case the fd will leak. Once you decompressed the file you do not need the File Descriptor anymore. Furthermore, this function is called in ElfObject constructor. If this throws, then the destructor will not be called!
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| unsigned char buf[4] = { 0 }; | ||
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If the file descriptor is not in the beginning of file, this will fail.
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| Elf *elf = elf_memory((char *)dest, ret); | ||
| if (elf == nullptr) { | ||
| free(dest); |
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In this case the fd will leak. Once you decompressed the file you do not need the File Descriptor anymore. Furthermore, this function is called in ElfObject constructor. If this throws, then the destructor will not be called!
This class will contain a static method to detect which file we are dealing with w.r.t ELF files. Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
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This is useful for decompressing vmlinux files and kernel modules compressed using zlib/gzip. Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
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This is useful for decompressing vmlinux files and kernel modules compressed using zlib/gzip.