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f682752627
After some experiences I found that urandom_read does not need to be linked statically. When the 'read' syscall call is moved to separate non-inlined function then bpf_get_stackid() is able to find the executable in stack trace and extract its build_id from it. Signed-off-by: Ivan Vecera <ivecera@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
35 lines
552 B
C
35 lines
552 B
C
#include <stdio.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#define BUF_SIZE 256
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static __attribute__((noinline))
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void urandom_read(int fd, int count)
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{
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char buf[BUF_SIZE];
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int i;
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for (i = 0; i < count; ++i)
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read(fd, buf, BUF_SIZE);
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}
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int main(int argc, char *argv[])
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{
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int fd = open("/dev/urandom", O_RDONLY);
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int count = 4;
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if (fd < 0)
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return 1;
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if (argc == 2)
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count = atoi(argv[1]);
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urandom_read(fd, count);
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close(fd);
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return 0;
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}
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