mn10300/misalignment: Use SIGSEGV SEGV_MAPERR to report a failed user…

… copy

Setting si_code to 0 is the same a setting si_code to SI_USER which is definitely
not correct.  With si_code set to SI_USER si_pid and si_uid will be copied to
userspace instead of si_addr.  Which is very wrong.

So fix this by using a sensible si_code (SEGV_MAPERR) for this failure.

Cc: [email protected]
Fixes: b920de1 ("mn10300: add the MN10300/AM33 architecture to the kernel")
Cc: David Howells <[email protected]>
Cc: Masakazu Urade <[email protected]>
Cc: Koichi Yasutake <[email protected]>
Signed-off-by: "Eric W. Biederman" <[email protected]>

arch/mn10300/mm/misalignment.c

@@ -437,7 +437,7 @@ asmlinkage void misalignment(struct pt_regs *regs, enum exception_code code)
 
 	info.si_signo	= SIGSEGV;
 	info.si_errno	= 0;
-	info.si_code	= 0;
+	info.si_code	= SEGV_MAPERR;
 	info.si_addr	= (void *) regs->pc;
 	force_sig_info(SIGSEGV, &info, current);
 	return;