[PATCH v2 05/74] semihosting: Add target_strlen for softmmu-uaccess.h

[Richard Henderson]

Mirror the user-only function of the same name.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/semihosting/softmmu-uaccess.h |  3 +++
 semihosting/uaccess.c                 | 29 +++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/include/semihosting/softmmu-uaccess.h 
b/include/semihosting/softmmu-uaccess.h
index 03300376d3..4f08dfc098 100644
--- a/include/semihosting/softmmu-uaccess.h
+++ b/include/semihosting/softmmu-uaccess.h
@@ -53,4 +53,7 @@ void softmmu_unlock_user(CPUArchState *env, void *p,
                          target_ulong addr, target_ulong len);
 #define unlock_user(s, args, len) softmmu_unlock_user(env, s, args, len)
 
+ssize_t softmmu_strlen_user(CPUArchState *env, target_ulong addr);
+#define target_strlen(p) softmmu_strlen_user(env, p)
+
 #endif /* SEMIHOSTING_SOFTMMU_UACCESS_H */
diff --git a/semihosting/uaccess.c b/semihosting/uaccess.c
index 0d3b32b75d..3cd809122c 100644
--- a/semihosting/uaccess.c
+++ b/semihosting/uaccess.c
@@ -23,6 +23,35 @@ void *softmmu_lock_user(CPUArchState *env, target_ulong addr,
     return p;
 }
 
+ssize_t softmmu_strlen_user(CPUArchState *env, target_ulong addr)
+{
+    char buf[256];
+    size_t len = 0;
+
+    while (1) {
+        size_t chunk;
+        char *p;
+
+        chunk = -(addr | TARGET_PAGE_MASK);
+        chunk = MIN(chunk, sizeof(buf));
+
+        if (cpu_memory_rw_debug(env_cpu(env), addr, buf, chunk, 0)) {
+            return -1;
+        }
+        p = memchr(buf, 0, chunk);
+        if (p) {
+            len += p - buf;
+            return len <= INT32_MAX ? (ssize_t)len : -1;
+        }
+
+        len += chunk;
+        addr += chunk;
+        if (len > INT32_MAX) {
+            return -1;
+        }
+    }
+}
+
 char *softmmu_lock_user_string(CPUArchState *env, target_ulong addr)
 {
     /* TODO: Make this something that isn't fixed size.  */
-- 
2.34.1