On Thu, Jan 11, 2018 at 06:59:32PM -0600, Eric W. Biederman wrote: > 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.
Thanks, this looks good to me. Acked-by: Stafford Horne <[email protected]> I see you have a series of related issues, so I guess you want to get them merged together. Let me know if I should put this patch onto my queue seperately. Trivia: this looks to have been copied from the mm page fault handling code, hence the strange comment. $ grep -r "info.si_code has been set above" arch/ arch/cris/mm/fault.c: /* info.si_code has been set above */ arch/m32r/mm/fault.c: /* info.si_code has been set above */ arch/mn10300/mm/fault.c: /* info.si_code has been set above */ arch/openrisc/mm/fault.c: /* info.si_code has been set above */ arch/openrisc/kernel/traps.c: /* info.si_code has been set above */ arch/arc/mm/fault.c: /* info.si_code has been set above */ arch/xtensa/mm/fault.c: /* info.si_code has been set above */ arch/mips/mm/fault.c: /* info.si_code has been set above */ arch/score/mm/fault.c: /* info.si_code has been set above */ arch/frv/mm/fault.c: /* info.si_code has been set above */ -Stafford > Cc: [email protected] > Fixes: 769a8a96229e ("OpenRISC: Traps") > Cc: Jonas Bonn <[email protected]> > Cc: Stefan Kristiansson <[email protected]> > Cc: Stafford Horne <[email protected]> > Cc: Arnd Bergmann <[email protected]> > Cc: [email protected] > Signed-off-by: "Eric W. Biederman" <[email protected]> > --- > arch/openrisc/kernel/traps.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c > index 4085d72fa5ae..9e38dc66c9e4 100644 > --- a/arch/openrisc/kernel/traps.c > +++ b/arch/openrisc/kernel/traps.c > @@ -266,12 +266,12 @@ asmlinkage void do_unaligned_access(struct pt_regs > *regs, unsigned long address) > 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); > -- > 2.14.1 >
