56 lines
1.3 KiB
C++
56 lines
1.3 KiB
C++
#include "elf++.hh"
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#include <system_error>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/mman.h>
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#include <fcntl.h>
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#include <unistd.h>
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using namespace std;
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ELFPP_BEGIN_NAMESPACE
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class mmap_loader : public loader
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{
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void *base;
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size_t lim;
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public:
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mmap_loader(int fd)
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{
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off_t end = lseek(fd, 0, SEEK_END);
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if (end == (off_t)-1)
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throw system_error(errno, system_category(),
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"finding file length");
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lim = end;
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base = mmap(nullptr, lim, PROT_READ, MAP_SHARED, fd, 0);
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if (base == MAP_FAILED)
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throw system_error(errno, system_category(),
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"mmap'ing file");
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close(fd);
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}
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~mmap_loader()
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{
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munmap(base, lim);
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}
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const void *load(off_t offset, size_t size)
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{
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if (offset + size > lim)
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throw range_error("offset exceeds file size");
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return (const char*)base + offset;
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}
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};
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std::shared_ptr<loader>
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create_mmap_loader(int fd)
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{
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return make_shared<mmap_loader>(fd);
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}
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ELFPP_END_NAMESPACE
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