kernel/compat.c: make do_sysinfo() static

The only use outside of kernel/timer.c was in kernel/compat.c, so move
compat_sys_sysinfo() next to sys_sysinfo() in kernel/timer.c.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 69 insertions, 1 deletions

diff --git a/kernel/timer.c b/kernel/timer.c
index dbf7a78a1ef..06b3245624e 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -41,6 +41,7 @@
 #include <linux/sched.h>
 #include <linux/sched/sysctl.h>
 #include <linux/slab.h>
+#include <linux/compat.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -1567,7 +1568,7 @@ SYSCALL_DEFINE0(gettid)
  * do_sysinfo - fill in sysinfo struct
  * @info: pointer to buffer to fill
  */
-int do_sysinfo(struct sysinfo *info)
+static int do_sysinfo(struct sysinfo *info)
 {
 	unsigned long mem_total, sav_total;
 	unsigned int mem_unit, bitcount;
@@ -1642,6 +1643,73 @@ SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
 	return 0;
 }
 
+#ifdef CONFIG_COMPAT
+struct compat_sysinfo {
+	s32 uptime;
+	u32 loads[3];
+	u32 totalram;
+	u32 freeram;
+	u32 sharedram;
+	u32 bufferram;
+	u32 totalswap;
+	u32 freeswap;
+	u16 procs;
+	u16 pad;
+	u32 totalhigh;
+	u32 freehigh;
+	u32 mem_unit;
+	char _f[20-2*sizeof(u32)-sizeof(int)];
+};
+
+asmlinkage long
+compat_sys_sysinfo(struct compat_sysinfo __user *info)
+{
+	struct sysinfo s;
+
+	do_sysinfo(&s);
+
+	/* Check to see if any memory value is too large for 32-bit and scale
+	 *  down if needed
+	 */
+	if ((s.totalram >> 32) || (s.totalswap >> 32)) {
+		int bitcount = 0;
+
+		while (s.mem_unit < PAGE_SIZE) {
+			s.mem_unit <<= 1;
+			bitcount++;
+		}
+
+		s.totalram >>= bitcount;
+		s.freeram >>= bitcount;
+		s.sharedram >>= bitcount;
+		s.bufferram >>= bitcount;
+		s.totalswap >>= bitcount;
+		s.freeswap >>= bitcount;
+		s.totalhigh >>= bitcount;
+		s.freehigh >>= bitcount;
+	}
+
+	if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
+	    __put_user (s.uptime, &info->uptime) ||
+	    __put_user (s.loads[0], &info->loads[0]) ||
+	    __put_user (s.loads[1], &info->loads[1]) ||
+	    __put_user (s.loads[2], &info->loads[2]) ||
+	    __put_user (s.totalram, &info->totalram) ||
+	    __put_user (s.freeram, &info->freeram) ||
+	    __put_user (s.sharedram, &info->sharedram) ||
+	    __put_user (s.bufferram, &info->bufferram) ||
+	    __put_user (s.totalswap, &info->totalswap) ||
+	    __put_user (s.freeswap, &info->freeswap) ||
+	    __put_user (s.procs, &info->procs) ||
+	    __put_user (s.totalhigh, &info->totalhigh) ||
+	    __put_user (s.freehigh, &info->freehigh) ||
+	    __put_user (s.mem_unit, &info->mem_unit))
+		return -EFAULT;
+
+	return 0;
+}
+#endif /* CONFIG_COMPAT */
+
 static int __cpuinit init_timers_cpu(int cpu)
 {
 	int j;