[Stable-8.1.3 19/55] target/arm: Fix syndrome for FGT traps on ERET

[Michael Tokarev]

From: Peter Maydell <peter.maydell@linaro.org>

In commit 442c9d682c94fc2 when we converted the ERET, ERETAA, ERETAB
instructions to decodetree, the conversion accidentally lost the
correct setting of the syndrome register when taking a trap because
of the FEAT_FGT HFGITR_EL1.ERET bit.  Instead of reporting a correct
full syndrome value with the EC and IL bits, we only reported the low
two bits of the syndrome, because the call to syn_erettrap() got
dropped.

Fix the syndrome values for these traps by reinstating the
syn_erettrap() calls.

Fixes: 442c9d682c94fc2 ("target/arm: Convert ERET, ERETAA, ERETAB to 
decodetree")
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20231024172438.2990945-1-peter.maydell@linaro.org
(cherry picked from commit 307521d6e29e559c89afa9dbd337ae75fe3c436d)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 5fa1257d32..58787ee8a7 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -1627,7 +1627,7 @@ static bool trans_ERET(DisasContext *s, arg_ERET *a)
         return false;
     }
     if (s->fgt_eret) {
-        gen_exception_insn_el(s, 0, EXCP_UDEF, 0, 2);
+        gen_exception_insn_el(s, 0, EXCP_UDEF, syn_erettrap(0), 2);
         return true;
     }
     dst = tcg_temp_new_i64();
@@ -1654,7 +1654,7 @@ static bool trans_ERETA(DisasContext *s, arg_reta *a)
     }
     /* The FGT trap takes precedence over an auth trap. */
     if (s->fgt_eret) {
-        gen_exception_insn_el(s, 0, EXCP_UDEF, a->m ? 3 : 2, 2);
+        gen_exception_insn_el(s, 0, EXCP_UDEF, syn_erettrap(a->m ? 3 : 2), 2);
         return true;
     }
     dst = tcg_temp_new_i64();
-- 
2.39.2