Implement /proc/uptime

fs/proc/root.c

@@ -41,6 +41,14 @@ static ssize_t proc_show_meminfo(struct proc_entry *UNUSED(entry), char *buf) {
     return n;
 }
 
+static ssize_t proc_show_uptime(struct proc_entry *UNUSED(entry), char *buf) {
+    struct uptime_info uptime_info = get_uptime();
+    unsigned uptime = uptime_info.uptime_ticks;
+    size_t n = 0;
+    n += sprintf(buf + n, "%u.%u %u.%u\n", uptime / 100, uptime % 100, uptime / 100, uptime % 100);
+    return n;
+}
+
 static int proc_readlink_self(struct proc_entry *UNUSED(entry), char *buf) {
     sprintf(buf, "%d/", current->pid);
     return 0;
@@ -51,6 +59,7 @@ struct proc_dir_entry proc_root_entries[] = {
     {"version", .show = proc_show_version},
     {"stat", .show = proc_show_stat},
     {"meminfo", .show = proc_show_meminfo},
+    {"uptime", .show = proc_show_uptime},
     {"self", S_IFLNK, .readlink = proc_readlink_self},
 };
 #define PROC_ROOT_LEN sizeof(proc_root_entries)/sizeof(proc_root_entries[0])

kernel/uname.c

@@ -1,11 +1,13 @@
 #include <sys/utsname.h>
 #include <string.h>
+#include "kernel/calls.h"
+#include "platform/platform.h"
+
 #if __APPLE__
 #include <sys/sysctl.h>
 #elif __linux__
 #include <sys/sysinfo.h>
 #endif
-#include "kernel/calls.h"
 
 void do_uname(struct uname *uts) {
     struct utsname real_uname;
@@ -38,25 +40,14 @@ static uint64_t get_total_ram() {
     sysctl((int []) {CTL_DEBUG, HW_PHYSMEM}, 2, &total_ram, NULL, NULL, 0);
     return total_ram;
 }
-static uint64_t get_uptime() {
-    uint64_t value[2];
-    size_t size = sizeof(value);
-    sysctlbyname("kern.boottime", &value, &size, NULL, 0);
-    struct timeval now;
-    gettimeofday(&now, NULL);
-    return now.tv_sec - value[0];
-}
 static void sysinfo_specific(struct sys_info *info) {
     info->totalram = get_total_ram();
-    info->uptime = get_uptime();
     // TODO: everything else
 }
 #elif __linux__
 static void sysinfo_specific(struct sys_info *info) {
     struct sysinfo host_info;
     sysinfo(&host_info);
-    memcpy(info->loads, host_info.loads, sizeof(host_info.loads));
-    info->uptime = host_info.uptime;
     info->totalram = host_info.totalram;
     info->freeram = host_info.freeram;
     info->sharedram = host_info.sharedram;
@@ -71,6 +62,11 @@ static void sysinfo_specific(struct sys_info *info) {
 
 dword_t sys_sysinfo(addr_t info_addr) {
     struct sys_info info = {0};
+    struct uptime_info uptime = get_uptime();
+    info.uptime = uptime.uptime_ticks;
+    info.loads[0] = uptime.load_1m;
+    info.loads[1] = uptime.load_5m;
+    info.loads[2] = uptime.load_15m;
     sysinfo_specific(&info);
 
     if (user_put(info_addr, info))

platform/darwin.c

@@ -1,4 +1,6 @@
 #include <mach/mach.h>
+#include <sys/sysctl.h>
+#include <sys/time.h>
 #include "platform/platform.h"
 
 struct cpu_usage get_cpu_usage() {
@@ -28,3 +30,34 @@ struct mem_usage get_mem_usage() {
     usage.inactive = vm.inactive_count * vm_page_size;
     return usage;
 }
+
+struct uptime_info get_uptime() {
+    uint64_t kern_boottime[2];
+    size_t size = sizeof(kern_boottime);
+    sysctlbyname("kern.boottime", &kern_boottime, &size, NULL, 0);
+    struct timeval now;
+    gettimeofday(&now, NULL);
+
+    struct {
+        uint32_t ldavg[3];
+        long scale;
+    } vm_loadavg;
+    size = sizeof(vm_loadavg);
+    sysctlbyname("vm.loadavg", &vm_loadavg, &size, NULL, 0);
+
+    // linux wants the scale to be 16 bits
+    for (int i = 0; i < 3; i++) {
+        if (FSHIFT < 16)
+            vm_loadavg.ldavg[i] <<= 16 - FSHIFT;
+        else
+            vm_loadavg.ldavg[i] >>= FSHIFT - 16;
+    }
+
+    struct uptime_info uptime = {
+        .uptime_ticks = now.tv_sec - kern_boottime[0],
+        .load_1m = vm_loadavg.ldavg[0],
+        .load_5m = vm_loadavg.ldavg[1],
+        .load_15m = vm_loadavg.ldavg[2],
+    };
+    return uptime;
+}

platform/linux.c

@@ -1,3 +1,4 @@
+#include <sys/sysinfo.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <string.h>
@@ -38,3 +39,15 @@ struct mem_usage get_mem_usage() {
 
     return usage;
 }
+
+struct uptime_info get_uptime() {
+    struct sysinfo info;
+    sysinfo(&info);
+    struct uptime_info uptime = {
+        .uptime_ticks = info.uptime,
+        .load_1m = info.loads[0],
+        .load_5m = info.loads[1],
+        .load_15m = info.loads[2],
+    };
+    return uptime;
+}

platform/platform.h

@@ -19,4 +19,10 @@ struct mem_usage {
 };
 struct mem_usage get_mem_usage(void);
 
+struct uptime_info {
+    uint64_t uptime_ticks;
+    uint64_t load_1m, load_5m, load_15m;
+};
+struct uptime_info get_uptime(void);
+
 #endif