arch/tile: fix up some minor trap handling issues

We now respond to MEM_ERROR traps (e.g. an atomic instruction to
non-cacheable memory) with a SIGBUS.

We also no longer generate a console crash message if a user
process die due to a SIGTRAP.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S
index 2c181c864ef7..005535d108c1 100644
--- a/arch/tile/kernel/intvec_64.S
+++ b/arch/tile/kernel/intvec_64.S
@@ -1178,7 +1178,7 @@ STD_ENTRY(fill_ra_stack)
 #define do_hardwall_trap bad_intr
 #endif
 
-        int_hand     INT_MEM_ERROR, MEM_ERROR, bad_intr
+        int_hand     INT_MEM_ERROR, MEM_ERROR, do_trap
         int_hand     INT_SINGLE_STEP_3, SINGLE_STEP_3, bad_intr
 #if CONFIG_KERNEL_PL == 2
         int_hand     INT_SINGLE_STEP_2, SINGLE_STEP_2, gx_singlestep_handle
diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c
index 32acfd9e23d0..73cff814ac57 100644
--- a/arch/tile/kernel/traps.c
+++ b/arch/tile/kernel/traps.c
@@ -200,7 +200,7 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 {
         siginfo_t info = { 0 };
         int signo, code;
-        unsigned long address;
+        unsigned long address = 0;
         bundle_bits instr;
 
         /* Re-enable interrupts. */
@@ -223,6 +223,10 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
         }
 
         switch (fault_num) {
+        case INT_MEM_ERROR:
+                signo = SIGBUS;
+                code = BUS_OBJERR;
+                break;
         case INT_ILL:
                 if (copy_from_user(&instr, (void __user *)regs->pc,
                                    sizeof(instr))) {
@@ -312,7 +316,8 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
         info.si_addr = (void __user *)address;
         if (signo == SIGILL)
                 info.si_trapno = fault_num;
-        trace_unhandled_signal("trap", regs, address, signo);
+        if (signo != SIGTRAP)
+                trace_unhandled_signal("trap", regs, address, signo);
         force_sig_info(signo, &info, current);
 }