[PATCH] Common compat_sys_sysinfo

I noticed that almost all architectures implemented exactly the same
sys32_sysinfo...  except parisc, where a bug was to be found in handling of
the uptime.  So let's remove a whole whack of code for fun and profit.
Cribbed compat_sys_sysinfo from x86_64's implementation, since I figured it
would be the best tested.

This patch incorporates Arnd's suggestion of not using set_fs/get_fs, but
instead extracting out the common code from sys_sysinfo.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

18 files changed, 112 insertions, 453 deletions

diff --git a/arch/ia64/ia32/ia32_entry.S b/arch/ia64/ia32/ia32_entry.S
index a32cd59b81ed..687e5fdc9683 100644
--- a/arch/ia64/ia32/ia32_entry.S
+++ b/arch/ia64/ia32/ia32_entry.S
@@ -326,7 +326,7 @@ ia32_syscall_table:
         data8 sys_ni_syscall
         data8 compat_sys_wait4
         data8 sys_swapoff         /* 115 */
-        data8 sys32_sysinfo
+        data8 compat_sys_sysinfo
         data8 sys32_ipc
         data8 sys_fsync
         data8 sys32_sigreturn
diff --git a/arch/ia64/ia32/sys_ia32.c b/arch/ia64/ia32/sys_ia32.c
index 957681c39ad9..d430d36ae49d 100644
--- a/arch/ia64/ia32/sys_ia32.c
+++ b/arch/ia64/ia32/sys_ia32.c
@@ -2209,74 +2209,6 @@ sys32_fstat64 (unsigned int fd, struct stat64 __user *statbuf)
         return ret;
 }
 
-struct sysinfo32 {
-        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[8];
-};
-
-asmlinkage long
-sys32_sysinfo (struct sysinfo32 __user *info)
-{
-        struct sysinfo s;
-        long ret, err;
-        int bitcount = 0;
-        mm_segment_t old_fs = get_fs();
-
-        set_fs(KERNEL_DS);
-        ret = sys_sysinfo((struct sysinfo __user *) &s);
-        set_fs(old_fs);
-        /* 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)) {
-                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(*info)))
-                return -EFAULT;
-
-        err  = __put_user(s.uptime, &info->uptime);
-        err |= __put_user(s.loads[0], &info->loads[0]);
-        err |= __put_user(s.loads[1], &info->loads[1]);
-        err |= __put_user(s.loads[2], &info->loads[2]);
-        err |= __put_user(s.totalram, &info->totalram);
-        err |= __put_user(s.freeram, &info->freeram);
-        err |= __put_user(s.sharedram, &info->sharedram);
-        err |= __put_user(s.bufferram, &info->bufferram);
-        err |= __put_user(s.totalswap, &info->totalswap);
-        err |= __put_user(s.freeswap, &info->freeswap);
-        err |= __put_user(s.procs, &info->procs);
-        err |= __put_user (s.totalhigh, &info->totalhigh);
-        err |= __put_user (s.freehigh, &info->freehigh);
-        err |= __put_user (s.mem_unit, &info->mem_unit);
-        if (err)
-                return -EFAULT;
-        return ret;
-}
-
 asmlinkage long
 sys32_sched_rr_get_interval (pid_t pid, struct compat_timespec __user *interval)
 {
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 0b8ce59429a8..ca7ad78f4def 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -193,50 +193,6 @@ sysn32_waitid(int which, compat_pid_t pid,
         return ret;
 }
 
-struct sysinfo32 {
-        s32 uptime;
-        u32 loads[3];
-        u32 totalram;
-        u32 freeram;
-        u32 sharedram;
-        u32 bufferram;
-        u32 totalswap;
-        u32 freeswap;
-        u16 procs;
-        u32 totalhigh;
-        u32 freehigh;
-        u32 mem_unit;
-        char _f[8];
-};
-
-asmlinkage int sys32_sysinfo(struct sysinfo32 __user *info)
-{
-        struct sysinfo s;
-        int ret, err;
-        mm_segment_t old_fs = get_fs ();
-
-        set_fs (KERNEL_DS);
-        ret = sys_sysinfo((struct sysinfo __user *)&s);
-        set_fs (old_fs);
-        err = put_user (s.uptime, &info->uptime);
-        err |= __put_user (s.loads[0], &info->loads[0]);
-        err |= __put_user (s.loads[1], &info->loads[1]);
-        err |= __put_user (s.loads[2], &info->loads[2]);
-        err |= __put_user (s.totalram, &info->totalram);
-        err |= __put_user (s.freeram, &info->freeram);
-        err |= __put_user (s.sharedram, &info->sharedram);
-        err |= __put_user (s.bufferram, &info->bufferram);
-        err |= __put_user (s.totalswap, &info->totalswap);
-        err |= __put_user (s.freeswap, &info->freeswap);
-        err |= __put_user (s.procs, &info->procs);
-        err |= __put_user (s.totalhigh, &info->totalhigh);
-        err |= __put_user (s.freehigh, &info->freehigh);
-        err |= __put_user (s.mem_unit, &info->mem_unit);
-        if (err)
-                return -EFAULT;
-        return ret;
-}
-
 #define RLIM_INFINITY32 0x7fffffff
 #define RESOURCE32(x) ((x > RLIM_INFINITY32) ? RLIM_INFINITY32 : x)
 
diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
index 39add2341aa2..ee8802b59758 100644
--- a/arch/mips/kernel/scall64-n32.S
+++ b/arch/mips/kernel/scall64-n32.S
@@ -217,7 +217,7 @@ EXPORT(sysn32_call_table)
         PTR     sys32_gettimeofday
         PTR     compat_sys_getrlimit            /* 6095 */
         PTR     compat_sys_getrusage
-        PTR     sys32_sysinfo
+        PTR     compat_sys_sysinfo
         PTR     compat_sys_times
         PTR     sys32_ptrace
         PTR     sys_getuid                      /* 6100 */
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index c58b8e0105ea..c5f590ca99b0 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -321,7 +321,7 @@ sys_call_table: