linux/arch/s390
Linus Torvalds faf309009e sys_poll: fix incorrect type for 'timeout' parameter
The 'poll()' system call timeout parameter is supposed to be 'int', not
'long'.

Now, the reason this matters is that right now 32-bit compat mode is
broken on at least x86-64, because the 32-bit code just calls
'sys_poll()' directly on x86-64, and the 32-bit argument will have been
zero-extended, turning a signed 'int' into a large unsigned 'long'
value.

We could just introduce a 'compat_sys_poll()' function for this, and
that may eventually be what we have to do, but since the actual standard
poll() semantics is *supposed* to be 'int', and since at least on x86-64
glibc sign-extends the argument before invocing the system call (so
nobody can actually use a 64-bit timeout value in user space _anyway_,
even in 64-bit binaries), the simpler solution would seem to be to just
fix the definition of the system call to match what it should have been
from the very start.

If it turns out that somebody somehow circumvents the user-level libc
64-bit sign extension and actually uses a large unsigned 64-bit timeout
despite that not being how poll() is supposed to work, we will need to
do the compat_sys_poll() approach.

Reported-by: Thomas Meyer <thomas@m3y3r.de>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-21 17:24:20 -08:00
..
appldata sched/accounting: Change cpustat fields to an array 2011-12-06 09:06:38 +01:00
boot [S390] Remove Kerntypes leftovers 2011-12-27 11:27:12 +01:00
crypto [S390] crypto: avoid MSA3 and MSA4 instructions in ESA mode 2011-11-14 11:19:09 +01:00
hypfs vfs: switch ->show_options() to struct dentry * 2012-01-06 23:19:54 -05:00
include/asm kdump: define KEXEC_NOTE_BYTES arch specific for s390x 2012-01-23 08:38:48 -08:00
kernel sys_poll: fix incorrect type for 'timeout' parameter 2012-02-21 17:24:20 -08:00
kvm KVM: s390: announce SYNC_MMU 2011-11-17 16:25:52 +02:00
lib [S390] sparse: fix sparse warnings with __user pointers 2011-10-30 15:16:46 +01:00
math-emu s390: change to new flag variable 2011-03-17 14:02:57 +01:00
mm [S390] incorrect PageTables counter for kvm page tables 2012-02-17 10:29:33 +01:00
oprofile Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-01-06 08:02:58 -08:00
defconfig [S390] defconfig: switch on CONFIG_DEVTMPFS 2011-10-30 15:16:42 +01:00
Kbuild [S390] make arch/s390 subdirectories depend on config option 2011-12-27 11:27:12 +01:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2012-01-09 08:11:13 -08:00
Kconfig.debug [S390] Write protect module text and RO data 2011-03-15 17:08:23 +01:00
Makefile [S390] cleanup entry point definition 2012-01-18 18:03:41 +01:00