This is a note to let you know that I've just added the patch titled
signal/openrisc: Fix do_unaligned_access to send the proper signal
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
signal-openrisc-fix-do_unaligned_access-to-send-the-proper-signal.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 500d58300571b6602341b041f97c082a461ef994 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Date: Tue, 1 Aug 2017 04:16:47 -0500
Subject: signal/openrisc: Fix do_unaligned_access to send the proper signal
From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
commit 500d58300571b6602341b041f97c082a461ef994 upstream.
While reviewing the signal sending on openrisc the do_unaligned_access
function stood out because it is obviously wrong. A comment about an
si_code set above when actually si_code is never set. Leading to a
random si_code being sent to userspace in the event of an unaligned
access.
Looking further SIGBUS BUS_ADRALN is the proper pair of signal and
si_code to send for an unaligned access. That is what other
architectures do and what is required by posix.
Given that do_unaligned_access is broken in a way that no one can be
relying on it on openrisc fix the code to just do the right thing.
Fixes: 769a8a96229e ("OpenRISC: Traps")
Cc: Jonas Bonn <jonas@xxxxxxxxxxxx>
Cc: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx>
Cc: Stafford Horne <shorne@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: openrisc@xxxxxxxxxxxxxxxxxxxx
Acked-by: Stafford Horne <shorne@xxxxxxxxx>
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/openrisc/kernel/traps.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/arch/openrisc/kernel/traps.c
+++ b/arch/openrisc/kernel/traps.c
@@ -302,12 +302,12 @@ asmlinkage void do_unaligned_access(stru
siginfo_t info;
if (user_mode(regs)) {
- /* Send a SIGSEGV */
- info.si_signo = SIGSEGV;
+ /* Send a SIGBUS */
+ info.si_signo = SIGBUS;
info.si_errno = 0;
- /* info.si_code has been set above */
- info.si_addr = (void *)address;
- force_sig_info(SIGSEGV, &info, current);
+ info.si_code = BUS_ADRALN;
+ info.si_addr = (void __user *)address;
+ force_sig_info(SIGBUS, &info, current);
} else {
printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
show_registers(regs);
Patches currently in stable-queue which might be from ebiederm@xxxxxxxxxxxx are
queue-4.4/netfilter-nf_queue-make-the-queue_handler-pernet.patch
queue-4.4/signal-openrisc-fix-do_unaligned_access-to-send-the-proper-signal.patch
queue-4.4/signal-sh-ensure-si_signo-is-initialized-in-do_divide_error.patch