target/riscv: Fix PC sync in trans_sspopchk for CFI exception handling

Move gen_update_pc call before conditional logic to ensure consistent
PC state regardless of execution path.

Previously, the host instructions generated to update the cpu_pc were
only executed in the failure path when shadow stack validation failed.
This created inconsistent PC synchronization.

This inconsistency caused issues in CF_PCREL mode where subsequent
instructions calculated wrong relative offsets from stale pc_save
values, and could lead to incorrect exception return addresses.

This fix ensures PC is always synchronized before any helper that
might raise an exception, maintaining consistent translator state
across all execution paths.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/4118
Signed-off-by: Max Chou <max.chou@sifive.com>
[ahshehab: rebased on current master; file moved to
 target/riscv/tcg/insn_trans/ and the ssp load is now 64-bit wide]
Tested-by: A-Shehab <ahshehab24@gmail.com>
Signed-off-by: A-Shehab <ahshehab24@gmail.com>
Reviewed-by: Daniel Henrique Barboza <daniel.barboza@oss.qualcomm.com>
Message-ID: <20260730181852.1622-1-ahshehab24@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
(cherry picked from commit 4a884ba94b43f5b2a640f4ea882655503f9ae954)
(Mjt: back-port the changes back to 11.0.x, to the original patch state)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

1 files changed, 1 insertions, 1 deletions

diff --git a/target/riscv/insn_trans/trans_rvzicfiss.c.inc b/target/riscv/insn_trans/trans_rvzicfiss.c.inc
index f4a1c12ca0..4cf14d2a37 100644
--- a/target/riscv/insn_trans/trans_rvzicfiss.c.inc
+++ b/target/riscv/insn_trans/trans_rvzicfiss.c.inc
@@ -32,6 +32,7 @@ static bool trans_sspopchk(DisasContext *ctx, arg_sspopchk *a)
     TCGLabel *skip = gen_new_label();
     uint32_t tmp = (get_xl(ctx) == MXL_RV64) ? 8 : 4;
     TCGv data = tcg_temp_new();
+    gen_update_pc(ctx, 0);
     tcg_gen_ld_tl(addr, tcg_env, offsetof(CPURISCVState, ssp));
     decode_save_opc(ctx, RISCV_UW2_ALWAYS_STORE_AMO);
     tcg_gen_qemu_ld_tl(data, addr, SS_MMU_INDEX(ctx),
@@ -40,7 +41,6 @@ static bool trans_sspopchk(DisasContext *ctx, arg_sspopchk *a)
     tcg_gen_brcond_tl(TCG_COND_EQ, data, rs1, skip);
     tcg_gen_st_tl(tcg_constant_tl(RISCV_EXCP_SW_CHECK_BCFI_TVAL),
                   tcg_env, offsetof(CPURISCVState, sw_check_code));
-    gen_update_pc(ctx, 0);
     gen_helper_raise_exception(tcg_env,
                   tcg_constant_i32(RISCV_EXCP_SW_CHECK));
     gen_set_label(skip);