[Linux] vdso 32bit vs 64bit

不实践还真是不知道，vdso，在32位和64位之间还有差别。
https://github.com/mzhan017/dump-vdso
32bit的vdso提供的接口函数：

mzhan017@:/mnt/d/dump-vdso$ ./dump-vdso-32 -s Name Address Offset ---- ------- ------ __kernel_vsyscall 0xf7fa1560 0x00000560 __vdso_gettimeofday 0xf7fa1790 0x00000790 __vdso_clock_getres 0xf7fa2520 0x00001520 __vdso_clock_gettime64 0xf7fa2030 0x00001030 __kernel_sigreturn 0xf7fa1580 0x00000580 __vdso_time 0xf7fa1b40 0x00000b40 __kernel_rt_sigreturn 0xf7fa1590 0x00000590 __vdso_clock_gettime 0xf7fa1b80 0x00000b80 __vdso_getcpu 0xf7fa25b0 0x000015b0

64bit提供的

mzhan017@:/mnt/d/dump-vdso$ ./dump-vdso -s Name Address Offset ---- ------- ------ clock_gettime 0x00007fffc1f8fa70 0x00000a70 __vdso_gettimeofday 0x00007fffc1f8f7b0 0x000007b0 clock_getres 0x00007fffc1f8fdd0 0x00000dd0 __vdso_clock_getres 0x00007fffc1f8fdd0 0x00000dd0 gettimeofday 0x00007fffc1f8f7b0 0x000007b0 __vdso_time 0x00007fffc1f8fa40 0x00000a40 __vdso_sgx_enter_enclave 0x00007fffc1f8fe70 0x00000e70 time 0x00007fffc1f8fa40 0x00000a40 __vdso_clock_gettime 0x00007fffc1f8fa70 0x00000a70 __vdso_getcpu 0x00007fffc1f8fe40 0x00000e40 getcpu 0x00007fffc1f8fe40 0x00000e40

差异介绍：
https://zhuanlan.zhihu.com/p/436454953