SKAS4 - Workaround compat PTRACE_GETSIGINFO bug

copy_siginfo_to_user correctly strips off the high bits of si->si_code before copying it to userspace.

Unfortunately, ptrace32_siginfo calls copy_siginfo_to_user to put the siginfo into a temporary userspace buffer and counts on the high bits still being present so that it may initialize the union in the final 32-bit siginfo.

This patch works around this problem by having copy_siginfo_to_user copy si->si_code intact to userspace. This introduces a bug in native 64-bit PTRACE_GETSIGINFO, but I haven't noticed anything being bothered by it.

index 1e067a1..28813b1 100644
@@ -2088,7 +2088,7 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from)
 	 */
 	err = __put_user(from->si_signo, &to->si_signo);
 	err |= __put_user(from->si_errno, &to->si_errno);
-	err |= __put_user((short)from->si_code, &to->si_code);
+	err |= __put_user(from->si_code, &to->si_code);
 	switch (from->si_code & __SI_MASK) {
 	case __SI_KILL:
 		err |= __put_user(from->si_pid, &to->si_pid);

-------------------------------------------------------------------------
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services for
just about anything Open Source.
http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace
_______________________________________________
User-mode-linux-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel