4.15-stable review patch. If anyone has any objections, please let me know.
------------------
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
@@ -266,12 +266,12 @@ 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);