[PATCH v2 4/8] linux-user/arm: Report SIGBUS and SIGSEGV correctly

[Richard Henderson]

Pull the fault information from where we placed it, in
arm_cpu_tlb_fill and arm_cpu_do_unaligned_access.

Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
Pulled out from the larger unaligned data patch set.
For short-form FSC, pc misalignment is reported in the same way.
---
 linux-user/arm/cpu_loop.c | 39 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c
index d4b4f0c71f..5731d3c937 100644
--- a/linux-user/arm/cpu_loop.c
+++ b/linux-user/arm/cpu_loop.c
@@ -24,6 +24,7 @@
 #include "cpu_loop-common.h"
 #include "signal-common.h"
 #include "semihosting/common-semi.h"
+#include "target/arm/syndrome.h"
 
 #define get_user_code_u32(x, gaddr, env)                \
     ({ abi_long __r = get_user_u32((x), (gaddr));       \
@@ -279,8 +280,8 @@ static bool emulate_arm_fpa11(CPUARMState *env, uint32_t 
opcode)
 void cpu_loop(CPUARMState *env)
 {
     CPUState *cs = env_cpu(env);
-    int trapnr;
-    unsigned int n, insn;
+    int trapnr, si_signo, si_code;
+    unsigned int n, insn, ec, fsc;
     abi_ulong ret;
 
     for(;;) {
@@ -422,9 +423,37 @@ void cpu_loop(CPUARMState *env)
             break;
         case EXCP_PREFETCH_ABORT:
         case EXCP_DATA_ABORT:
-            /* XXX: check env->error_code */
-            force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR,
-                            env->exception.vaddress);
+            /*
+             * For user-only we don't set TTBCR_EAE, so we always get
+             * short-form FSC, which then tells us to look at the FSR.
+             */
+            ec = syn_get_ec(env->exception.syndrome);
+            assert(ec == EC_DATAABORT || ec == EC_INSNABORT);
+            fsc = extract32(env->exception.syndrome, 0, 6);
+            assert(fsc == 0x3f);
+            switch (env->exception.fsr & 0x1f) {
+            case 0x1: /* Alignment */
+                si_signo = TARGET_SIGBUS;
+                si_code = TARGET_BUS_ADRALN;
+                break;
+            case 0x3: /* Access flag fault, level 1 */
+            case 0x6: /* Access flag fault, level 2 */
+            case 0x9: /* Domain fault, level 1 */
+            case 0xb: /* Domain fault, level 2 */
+            case 0xd: /* Permision fault, level 1 */
+            case 0xf: /* Permision fault, level 2 */
+                si_signo = TARGET_SIGSEGV;
+                si_code = TARGET_SEGV_ACCERR;
+                break;
+            case 0x5: /* Translation fault, level 1 */
+            case 0x7: /* Translation fault, level 2 */
+                si_signo = TARGET_SIGSEGV;
+                si_code = TARGET_SEGV_MAPERR;
+                break;
+            default:
+                g_assert_not_reached();
+            }
+            force_sig_fault(si_signo, si_code, env->exception.vaddress);
             break;
         case EXCP_DEBUG:
         case EXCP_BKPT:
-- 
2.25.1