Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/aarch64/cpu_loop.c |  3 +++
 linux-user/aarch64/signal.c   | 34 +++++++++++++++++++++++++++++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/linux-user/aarch64/cpu_loop.c b/linux-user/aarch64/cpu_loop.c
index 7ad26316de..6060572eed 100644
--- a/linux-user/aarch64/cpu_loop.c
+++ b/linux-user/aarch64/cpu_loop.c
@@ -33,6 +33,9 @@ static void signal_for_exception(CPUARMState *env, vaddr addr)
     uint32_t syn = env->exception.syndrome;
     int si_code, si_signo;
 
+    /* Let signal delivery see that ESR is live. */
+    env->cp15.esr_el[1] = syn;
+
     switch (syn_get_ec(syn)) {
     case EC_DATAABORT:
     case EC_INSNABORT:
diff --git a/linux-user/aarch64/signal.c b/linux-user/aarch64/signal.c
index 668353bbda..ef97be3ac7 100644
--- a/linux-user/aarch64/signal.c
+++ b/linux-user/aarch64/signal.c
@@ -65,6 +65,13 @@ struct target_fpsimd_context {
     uint64_t vregs[32 * 2]; /* really uint128_t vregs[32] */
 };
 
+#define TARGET_ESR_MAGIC    0x45535201
+
+struct target_esr_context {
+    struct target_aarch64_ctx head;
+    uint64_t esr;
+};
+
 #define TARGET_EXTRA_MAGIC  0x45585401
 
 struct target_extra_context {
@@ -201,6 +208,14 @@ static void target_setup_fpsimd_record(struct target_fpsimd_context *fpsimd,
     }
 }
 
+static void target_setup_esr_record(struct target_esr_context *ctx,
+                                    CPUARMState *env)
+{
+    __put_user(TARGET_ESR_MAGIC, &ctx->head.magic);
+    __put_user(sizeof(*ctx), &ctx->head.size);
+    __put_user(env->cp15.esr_el[1], &ctx->esr);
+}
+
 static void target_setup_extra_record(struct target_extra_context *extra,
                                       uint64_t datap, uint32_t extra_size)
 {
@@ -531,6 +546,9 @@ static int target_restore_sigframe(CPUARMState *env,
             fpsimd = (struct target_fpsimd_context *)ctx;
             break;
 
+        case TARGET_ESR_MAGIC:
+            break; /* ignore */
+
         case TARGET_SVE_MAGIC:
             if (sve || size < sizeof(struct target_sve_context)) {
                 goto err;
@@ -683,7 +701,7 @@ static void target_setup_frame(int usig, struct target_sigaction *ka,
                                uc.tuc_mcontext.__reserved),
     };
     int fpsimd_ofs, fr_ofs, sve_ofs = 0, za_ofs = 0, tpidr2_ofs = 0;
-    int zt_ofs = 0;
+    int zt_ofs = 0, esr_ofs = 0;
     int sve_size = 0, za_size = 0, tpidr2_size = 0, zt_size = 0;
     struct target_rt_sigframe *frame;
     struct target_rt_frame_record *fr;
@@ -693,6 +711,15 @@ static void target_setup_frame(int usig, struct target_sigaction *ka,
     fpsimd_ofs = alloc_sigframe_space(sizeof(struct target_fpsimd_context),
                                       &layout);
 
+    /*
+     * In user mode, ESR_EL1 is only set by cpu_loop while queueing the
+     * signal, and it's only valid for the one sync insn.
+     */
+    if (env->cp15.esr_el[1]) {
+        esr_ofs = alloc_sigframe_space(sizeof(struct target_esr_context),
+                                       &layout);
+    }
+
     /* SVE state needs saving only if it exists.  */
     if (cpu_isar_feature(aa64_sve, env_archcpu(env)) ||
         cpu_isar_feature(aa64_sme, env_archcpu(env))) {
@@ -754,6 +781,11 @@ static void target_setup_frame(int usig, struct target_sigaction *ka,
 
     target_setup_general_frame(frame, env, set);
     target_setup_fpsimd_record((void *)frame + fpsimd_ofs, env);
+    if (esr_ofs) {
+        target_setup_esr_record((void *)frame + esr_ofs, env);
+        /* Leave ESR_EL1 clear while it's not relevant. */
+        env->cp15.esr_el[1] = 0;
+    }
     target_setup_end_record((void *)frame + layout.std_end_ofs);
     if (layout.extra_ofs) {
         target_setup_extra_record((void *)frame + layout.extra_ofs,
-- 
2.43.0