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[PATCH] sys_pselect7 vs compat_sys_pselect7 uaccess error handling

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758333458a fixes the not checked copy_to_user
return value of compat_sys_pselect7.  I ran into this too because of an old
source tree, but my fix would look quite a bit different to Andi's fix.

The reason is that the compat function IMHO should behave the very same as
the non-compat function if possible.  Since sys_pselect7 does not return
-EFAULT in this specific case, change the compat code so it behaves like
sys_pselect7.

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Heiko Carstens 2006-11-02 22:06:58 -08:00 committed by Linus Torvalds
parent 7870db4c7f
commit 87c2b7c045
1 changed files with 17 additions and 3 deletions
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20
fs/compat.c
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@ -1835,9 +1835,12 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,
} while (!ret && !timeout && tsp && (ts.tv_sec || ts.tv_nsec));
if (ret == 0 && tsp && !(current->personality & STICKY_TIMEOUTS)) {
if (tsp) {
struct compat_timespec rts;
if (current->personality & STICKY_TIMEOUTS)
goto sticky;
rts.tv_sec = timeout / HZ;
rts.tv_nsec = (timeout % HZ) * (NSEC_PER_SEC/HZ);
if (rts.tv_nsec >= NSEC_PER_SEC) {
@ -1846,8 +1849,19 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,
}
if (compat_timespec_compare(&rts, &ts) >= 0)
rts = ts;
if (copy_to_user(tsp, &rts, sizeof(rts)))
ret = -EFAULT;
if (copy_to_user(tsp, &rts, sizeof(rts))) {
sticky:
/*
* If an application puts its timeval in read-only
* memory, we don't want the Linux-specific update to
* the timeval to cause a fault after the select has
* completed successfully. However, because we're not
* updating the timeval, we can't restart the system
* call.
*/
if (ret == -ERESTARTNOHAND)
ret = -EINTR;
}
}
if (ret == -ERESTARTNOHAND) {