util/cutils: drop qemu_strnlen() in favor of strnlen()
There are only three call sites, and strnlen() is available on all supported platforms (POSIX.1-2008, Windows via UCRT, MinGW). Remove the hand-rolled wrapper and use the standard function directly. While here, align bsd-user/uaccess.c to use size_t for max_len/len, matching linux-user/uaccess.c and eliminating a signed/unsigned mismatch. Also remove the stale qemu_strnlen() entry from docs/devel/style.rst. Suggested-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Bin Guo <guobin@linux.alibaba.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Warner Losh <imp@bsdimp.com> Message-ID: <20260530062816.59206-1-guobin@linux.alibaba.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Bin Guo committed
May 30, 2026 at 14:28 UTC
66ac993bdacf4d30e96db4dc82f9644913d5f7b7
5 files changed
+5
-34
bsd-user/uaccess.c
+2
-2
@@ -43,7 +43,7 @@ abi_long target_strlen(abi_ulong guest_addr1)
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{
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uint8_t *ptr;
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abi_ulong guest_addr;
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- int max_len, len;
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+ size_t max_len, len;
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guest_addr = guest_addr1;
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for (;;) {
@@ -51,7 +51,7 @@ abi_long target_strlen(abi_ulong guest_addr1)
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ptr = lock_user(VERIFY_READ, guest_addr, max_len, 1);
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if (!ptr)
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return -TARGET_EFAULT;
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- len = qemu_strnlen((const char *)ptr, max_len);
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+ len = strnlen((const char *)ptr, max_len);
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unlock_user(ptr, guest_addr, 0);
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guest_addr += len;
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/* we don't allow wrapping or integer overflow */
docs/devel/style.rst
-1
@@ -519,7 +519,6 @@ QEMU provides other useful string functions:
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int strstart(const char *str, const char *val, const char **ptr)
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int stristart(const char *str, const char *val, const char **ptr)
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- int qemu_strnlen(const char *s, int max_len)
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There are also replacement character processing macros for isxyz and toxyz,
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so instead of e.g. isalnum you should use qemu_isalnum.
include/qemu/cutils.h
+1
-16
@@ -101,22 +101,7 @@ int strstart(const char *str, const char *val, const char **ptr);
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* false otherwise.
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*/
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int stristart(const char *str, const char *val, const char **ptr);
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-/**
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- * qemu_strnlen:
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- * @s: string
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- * @max_len: maximum number of bytes in @s to scan
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- *
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- * Return the length of the string @s, like strlen(), but do not
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- * examine more than @max_len bytes of the memory pointed to by @s.
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- * If no NUL terminator is found within @max_len bytes, then return
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- * @max_len instead.
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- *
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- * This function has the same behaviour as the POSIX strnlen()
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- * function.
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- *
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- * Returns: length of @s in bytes, or @max_len, whichever is smaller.
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- */
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-int qemu_strnlen(const char *s, int max_len);
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+
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/**
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* qemu_strsep:
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* @input: pointer to string to parse
linux-user/uaccess.c
+1
-1
@@ -99,7 +99,7 @@ ssize_t target_strlen(abi_ulong guest_addr1)
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ptr = lock_user(VERIFY_READ, guest_addr, max_len, 1);
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if (!ptr)
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return -TARGET_EFAULT;
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- len = qemu_strnlen((const char *)ptr, max_len);
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+ len = strnlen((const char *)ptr, max_len);
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unlock_user(ptr, guest_addr, 0);
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guest_addr += len;
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/* we don't allow wrapping or integer overflow */
util/cutils.c
+1
-14
@@ -54,7 +54,7 @@
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void strpadcpy(char *buf, int buf_size, const char *str, char pad)
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{
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- int len = qemu_strnlen(str, buf_size);
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+ size_t len = strnlen(str, buf_size);
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memcpy(buf, str, len);
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memset(buf + len, pad, buf_size - len);
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}
@@ -118,19 +118,6 @@ int stristart(const char *str, const char *val, const char **ptr)
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return 1;
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}
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-/* XXX: use host strnlen if available ? */
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-int qemu_strnlen(const char *s, int max_len)
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-{
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- int i;
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-
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- for(i = 0; i < max_len; i++) {
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- if (s[i] == '\0') {
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- break;
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- }
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- }
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- return i;
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-}
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-
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char *qemu_strsep(char **input, const char *delim)
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{
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char *result = *input;