8324280: RISC-V: Incorrect implementation in VM_Version::parse_satp_mode

Backport-of: e7fdac9d5ce56d2f589df59a7fd2869e35ba2991

Author: zifeihan

src/hotspot/os_cpu/linux_riscv/vm_version_linux_riscv.cpp

@@ -168,13 +168,13 @@ void VM_Version::os_aux_features() {
 }
 
 VM_Version::VM_MODE VM_Version::parse_satp_mode(const char* vm_mode) {
-  if (!strcmp(vm_mode, "sv39")) {
+  if (!strncmp(vm_mode, "sv39", sizeof "sv39" - 1)) {
     return VM_SV39;
-  } else if (!strcmp(vm_mode, "sv48")) {
+  } else if (!strncmp(vm_mode, "sv48", sizeof "sv48" - 1)) {
     return VM_SV48;
-  } else if (!strcmp(vm_mode, "sv57")) {
+  } else if (!strncmp(vm_mode, "sv57", sizeof "sv57" - 1)) {
     return VM_SV57;
-  } else if (!strcmp(vm_mode, "sv64")) {
+  } else if (!strncmp(vm_mode, "sv64", sizeof "sv64" - 1)) {
     return VM_SV64;
   } else {
     return VM_MBARE;
@@ -196,7 +196,7 @@ char* VM_Version::os_uarch_additional_features() {
     if ((p = strchr(buf, ':')) != nullptr) {
       if (mode == VM_NOTSET) {
         if (strncmp(buf, "mmu", sizeof "mmu" - 1) == 0) {
-          mode = VM_Version::parse_satp_mode(p);
+          mode = VM_Version::parse_satp_mode(p + 2);
         }
       }
       if (ret == nullptr) {