[Qemu-devel] [PATCH] syscall getgroups() optimization

["Kirill A. Shutemov" <k.shutemov@velesys.com>]

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On success, getgroups() returns the number of supplementary group IDs. So, 
we can swap real number group IDs.

Patch in the attachment.

-- 
Regards,  Kirill A. Shutemov
 + Belarus, Minsk
 + Velesys LLC, http://www.velesys.com/
 + ALT Linux Team, http://www.altlinux.com/

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--- qemu/linux-user/syscall.c	2007-05-08 12:42:50 +0300
+++ qemu-0.9.0.cvs20070420/linux-user/syscall.c	2007-05-20 21:13:06 +0300
@@ -3741,7 +4144,7 @@
             ret = get_errno(getgroups(gidsetsize, grouplist));
             if (!is_error(ret)) {
                 target_grouplist = lock_user(arg2, gidsetsize * 2, 0);
-                for(i = 0;i < gidsetsize; i++)
+                for(i = 0;i < ret; i++)
                     target_grouplist[i] = tswap16(grouplist[i]);
                 unlock_user(target_grouplist, arg2, gidsetsize * 2);
             }
@@ -3873,7 +4276,7 @@
             ret = get_errno(getgroups(gidsetsize, grouplist));
             if (!is_error(ret)) {
                 target_grouplist = lock_user(arg2, gidsetsize * 4, 0);
-                for(i = 0;i < gidsetsize; i++)
+                for(i = 0;i < ret; i++)
                     target_grouplist[i] = tswap32(grouplist[i]);
                 unlock_user(target_grouplist, arg2, gidsetsize * 4);
             }

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