The switch from target_ulong to uint64_t broke the mechanism of passing -1
(0xffffffff) in arg2 to signal validate_strlen() to compute the string
length automatically. For 32‑bit semihosting, detect when arg2 is
0xffffffff and replace it with 0xffffffffffffffff. This causes an overflow
to zero, restoring the original behavior of automatic length calculation.
Fixes: 6dfbf9b6cfe ("semihosting/arm-compat-semi: replace target_ulong")
Signed-off-by: Nikita Shubin <[email protected]>
---
semihosting/arm-compat-semi.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c
index 5e5f181b90..682349bd51 100644
--- a/semihosting/arm-compat-semi.c
+++ b/semihosting/arm-compat-semi.c
@@ -442,6 +442,17 @@ void do_common_semihosting(CPUState *cs)
}
} else {
unlock_user(s, arg0, 0);
+ /*
+ * Due to the switch from target_ulong to uint64_t, passing -1
+ * as arg2 is no longer possible.
+ * For 32‑bit targets, if arg2 == 0xffffffff, set it
+ * to 0xffffffffffffffff to trigger overflow so zero strlen
+ * is passed to validate_strlen().
+ */
+ if (!is_64bit_semihosting(env) && arg2 == (uint32_t)-1) {
+ arg2 = -1;
+ }
+
semihost_sys_open(cs, common_semi_cb, arg0, arg2 + 1,
gdb_open_modeflags[arg1], 0644);
break;
--
2.52.0
