[qemu-xen staging] target/xtensa: work around missing SR definitions

[patchbot@xxxxxxx]

commit 59afd43daedabe672c289326a5f268f737d35252
Author:     Max Filippov <jcmvbkbc@xxxxxxxxx>
AuthorDate: Tue Apr 28 15:59:08 2020 -0700
Commit:     Max Filippov <jcmvbkbc@xxxxxxxxx>
CommitDate: Thu Apr 30 04:37:36 2020 -0700

    target/xtensa: work around missing SR definitions
    
    Xtensa configuration overlays for recent releases may have special
    registers for which [rwx]sr opcodes are defined, but they are not listed
    as SR in xtensa_sysreg_name and associated functions. As a result
    generic translate_[rwx]sr* functions generate access to uninitialized
    cpu_SR causing segfault at runtime.
    Don't try to access cpu_SR for such registers, ignore writes and return
    0 for reads.
    
    Cc: qemu-stable@xxxxxxxxxx
    Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
---
 target/xtensa/translate.c | 48 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 14 deletions(-)

diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c
index e0beaf7abb..546d2fa2fa 100644
--- a/target/xtensa/translate.c
+++ b/target/xtensa/translate.c
@@ -2191,7 +2191,11 @@ static void translate_rsil(DisasContext *dc, const 
OpcodeArg arg[],
 static void translate_rsr(DisasContext *dc, const OpcodeArg arg[],
                           const uint32_t par[])
 {
-    tcg_gen_mov_i32(arg[0].out, cpu_SR[par[0]]);
+    if (sr_name[par[0]]) {
+        tcg_gen_mov_i32(arg[0].out, cpu_SR[par[0]]);
+    } else {
+        tcg_gen_movi_i32(arg[0].out, 0);
+    }
 }
 
 static void translate_rsr_ccount(DisasContext *dc, const OpcodeArg arg[],
@@ -2563,13 +2567,17 @@ static void translate_wrmsk_expstate(DisasContext *dc, 
const OpcodeArg arg[],
 static void translate_wsr(DisasContext *dc, const OpcodeArg arg[],
                           const uint32_t par[])
 {
-    tcg_gen_mov_i32(cpu_SR[par[0]], arg[0].in);
+    if (sr_name[par[0]]) {
+        tcg_gen_mov_i32(cpu_SR[par[0]], arg[0].in);
+    }
 }
 
 static void translate_wsr_mask(DisasContext *dc, const OpcodeArg arg[],
                                const uint32_t par[])
 {
-    tcg_gen_andi_i32(cpu_SR[par[0]], arg[0].in, par[2]);
+    if (sr_name[par[0]]) {
+        tcg_gen_andi_i32(cpu_SR[par[0]], arg[0].in, par[2]);
+    }
 }
 
 static void translate_wsr_acchi(DisasContext *dc, const OpcodeArg arg[],
@@ -2775,23 +2783,31 @@ static void translate_xor(DisasContext *dc, const 
OpcodeArg arg[],
 static void translate_xsr(DisasContext *dc, const OpcodeArg arg[],
                           const uint32_t par[])
 {
-    TCGv_i32 tmp = tcg_temp_new_i32();
+    if (sr_name[par[0]]) {
+        TCGv_i32 tmp = tcg_temp_new_i32();
 
-    tcg_gen_mov_i32(tmp, arg[0].in);
-    tcg_gen_mov_i32(arg[0].out, cpu_SR[par[0]]);
-    tcg_gen_mov_i32(cpu_SR[par[0]], tmp);
-    tcg_temp_free(tmp);
+        tcg_gen_mov_i32(tmp, arg[0].in);
+        tcg_gen_mov_i32(arg[0].out, cpu_SR[par[0]]);
+        tcg_gen_mov_i32(cpu_SR[par[0]], tmp);
+        tcg_temp_free(tmp);
+    } else {
+        tcg_gen_movi_i32(arg[0].out, 0);
+    }
 }
 
 static void translate_xsr_mask(DisasContext *dc, const OpcodeArg arg[],
                                const uint32_t par[])
 {
-    TCGv_i32 tmp = tcg_temp_new_i32();
+    if (sr_name[par[0]]) {
+        TCGv_i32 tmp = tcg_temp_new_i32();
 
-    tcg_gen_mov_i32(tmp, arg[0].in);
-    tcg_gen_mov_i32(arg[0].out, cpu_SR[par[0]]);
-    tcg_gen_andi_i32(cpu_SR[par[0]], tmp, par[2]);
-    tcg_temp_free(tmp);
+        tcg_gen_mov_i32(tmp, arg[0].in);
+        tcg_gen_mov_i32(arg[0].out, cpu_SR[par[0]]);
+        tcg_gen_andi_i32(cpu_SR[par[0]], tmp, par[2]);
+        tcg_temp_free(tmp);
+    } else {
+        tcg_gen_movi_i32(arg[0].out, 0);
+    }
 }
 
 static void translate_xsr_ccount(DisasContext *dc, const OpcodeArg arg[],
@@ -2819,7 +2835,11 @@ static void translate_xsr_ccount(DisasContext *dc, const 
OpcodeArg arg[],
 { \
     TCGv_i32 tmp = tcg_temp_new_i32(); \
  \
-    tcg_gen_mov_i32(tmp, cpu_SR[par[0]]); \
+    if (sr_name[par[0]]) { \
+        tcg_gen_mov_i32(tmp, cpu_SR[par[0]]); \
+    } else { \
+        tcg_gen_movi_i32(tmp, 0); \
+    } \
     translate_wsr_##name(dc, arg, par); \
     tcg_gen_mov_i32(arg[0].out, tmp); \
     tcg_temp_free(tmp); \
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#staging