x32: fix sysinfo()

the kernel uses long longs in the struct, but the documentation
says they're long. so we need to fixup the mismatch between the
userspace and kernelspace structs.
since the struct offers a mem_unit member, we can avoid truncation
by adjusting that value.

arch/x32/src/sysinfo.c

@@ -0,0 +1,47 @@
+#include <sys/sysinfo.h>
+#include "syscall.h"
+
+#define klong long long
+#define kulong unsigned long long
+
+struct kernel_sysinfo {
+	klong uptime;
+	kulong loads[3];
+	kulong totalram;
+	kulong freeram;
+	kulong sharedram;
+	kulong bufferram;
+	kulong totalswap;
+	kulong freeswap;
+	short procs;
+	short pad;
+	kulong totalhigh;
+	kulong freehigh;
+	unsigned mem_unit;
+};
+
+int __x32_sysinfo(struct sysinfo *info)
+{
+	struct kernel_sysinfo tmp;
+	int ret = syscall(SYS_sysinfo, &tmp);
+	if(ret == -1) return ret;
+	info->uptime = tmp.uptime;
+	info->loads[0] = tmp.loads[0];
+	info->loads[1] = tmp.loads[1];
+	info->loads[2] = tmp.loads[2];
+	kulong shifts;
+	kulong max = tmp.totalram | tmp.totalswap;
+	__asm__("bsr %1,%0" : "=r"(shifts) : "r"(max));
+	shifts = shifts >= 32 ? shifts - 31 : 0;
+	info->totalram = tmp.totalram >> shifts;
+	info->freeram = tmp.freeram >> shifts;
+	info->sharedram = tmp.sharedram >> shifts;
+	info->bufferram = tmp.bufferram >> shifts;
+	info->totalswap = tmp.totalswap >> shifts;
+	info->freeswap = tmp.freeswap >> shifts;
+	info->procs = tmp.procs ;
+	info->totalhigh = tmp.totalhigh >> shifts;
+	info->freehigh = tmp.freehigh >> shifts;
+	info->mem_unit = (tmp.mem_unit ? tmp.mem_unit : 1) << shifts;
+	return ret;
+}

src/linux/x32/sysinfo.s

@@ -0,0 +1,5 @@
+.text
+.global sysinfo
+.type   sysinfo,@function
+sysinfo:
+	jmp __x32_sysinfo