mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
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>
|
|
#include <unistd.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
#include <stdlib.h>
|
|
|
|
#define BUF_SIZE 256
|
|
|
|
static __attribute__((noinline))
|
|
void urandom_read(int fd, int count)
|
|
{
|
|
char buf[BUF_SIZE];
|
|
int i;
|
|
|
|
for (i = 0; i < count; ++i)
|
|
read(fd, buf, BUF_SIZE);
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
int fd = open("/dev/urandom", O_RDONLY);
|
|
int count = 4;
|
|
|
|
if (fd < 0)
|
|
return 1;
|
|
|
|
if (argc == 2)
|
|
count = atoi(argv[1]);
|
|
|
|
urandom_read(fd, count);
|
|
|
|
close(fd);
|
|
return 0;
|
|
}
|