代码

#include <sys/syscall.h>
#include <stdio.h>
#define uint64_t unsigned long long
struct DuckInfo_t {
    uint64_t abi_version;

    const char *stdin_ptr;   // stdin pointer (read-only contents)
    uint64_t stdin_size;     // stdin size

    char *stdout_ptr;        // stdout pointer
    uint64_t stdout_limit;   // [IN] stdout maximum size
    uint64_t stdout_size;    // [OUT] stdout actual size

    char *stderr_ptr;        // stderr pointer
    uint64_t stderr_limit;   // [IN] stderr maximum size
    uint64_t stderr_size;    // [OUT] stderr actual size

    const char *IB_ptr;      // IB (Input Buffer) pointer
    uint64_t IB_limit;       // IB limit

    char *OB_ptr;            // OB (Output Buffer) pointer
    uint64_t OB_limit;       // OB limit

    uint64_t tsc_frequency;  // TSC (Time Stamp Counter) frequency
} __attribute__((packed));

int main() {
    struct DuckInfo_t *duckinfo = (struct DuckInfo_t *) getauxval(0x6b637564);
    printf ("%p", duckinfo);
    fprintf (stderr, "吃鸭肉");
    duckinfo->stdout_size = -1;
}

评测结果