As commit 601255ae3c ("arm64: vdso: move data page before code pages"), the
same issue exists on riscv, testcase is shown below, make sure that vdso.so is
bigger than page size,
struct timespec tp;
clock_gettime(5, &tp);
printf("tv_sec: %ld, tv_nsec: %ld\n", tp.tv_sec, tp.tv_nsec);
without this patch, test result : tv_sec: 0, tv_nsec: 0
with this patch, test result : tv_sec: 1629271537, tv_nsec: 748000000
Move the vdso data page in front of the VDSO area to fix the issue.
Fixes: ad5d1122b8 ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
78a743cd82