Merge tag 'linux_kselftest-nolibc-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull nolibc updates from Shuah Khan:

 - add support for uname(2)

 - remove open-coded strnlen()

 - export strlen()

 - add tests for strlcat() and strlcpy()

 - fix memory error in realloc()

 - fix strlcat() and strlcpy() return code and size usage

* tag 'linux_kselftest-nolibc-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  tools/nolibc: add support for uname(2)
  tools/nolibc/string: remove open-coded strnlen()
  selftests/nolibc: Add tests for strlcat() and strlcpy()
  tools/nolibc: Fix strlcpy() return code and size usage
  tools/nolibc: Fix strlcat() return code and size usage
  tools/nolibc/string: export strlen()
  tools/nolibc/stdlib: fix memory error in realloc()

3 files changed, 54 insertions, 21 deletions

diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h
index bacfd35c5156..5be9d3c7435a 100644
--- a/tools/include/nolibc/stdlib.h
+++ b/tools/include/nolibc/stdlib.h
@@ -185,7 +185,7 @@ void *realloc(void *old_ptr, size_t new_size)
 	if (__builtin_expect(!ret, 0))
 		return NULL;
 
-	memcpy(ret, heap->user_p, heap->len);
+	memcpy(ret, heap->user_p, user_p_len);
 	munmap(heap, heap->len);
 	return ret;
 }
diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index a01c69dd495f..f9ab28421e6d 100644
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -123,7 +123,7 @@ char *strcpy(char *dst, const char *src)
  * thus itself, hence the asm() statement below that's meant to disable this
  * confusing practice.
  */
-static __attribute__((unused))
+__attribute__((weak,unused,section(".text.nolibc_strlen")))
 size_t strlen(const char *str)
 {
 	size_t len;
@@ -187,22 +187,26 @@ char *strndup(const char *str, size_t maxlen)
 static __attribute__((unused))
 size_t strlcat(char *dst, const char *src, size_t size)
 {
-	size_t len;
-	char c;
-
-	for (len = 0; dst[len];	len++)
-		;
-
-	for (;;) {
-		c = *src;
-		if (len < size)
-			dst[len] = c;
-		if (!c)
+	size_t len = strnlen(dst, size);
+
+	/*
+	 * We want len < size-1. But as size is unsigned and can wrap
+	 * around, we use len + 1 instead.
+	 */
+	while (len + 1 < size) {
+		dst[len] = *src;
+		if (*src == '\0')
 			break;
 		len++;
 		src++;
 	}
 
+	if (len < size)
+		dst[len] = '\0';
+
+	while (*src++)
+		len++;
+
 	return len;
 }
 
@@ -210,16 +214,18 @@ static __attribute__((unused))
 size_t strlcpy(char *dst, const char *src, size_t size)
 {
 	size_t len;
-	char c;
 
-	for (len = 0;;) {
-		c = src[len];
-		if (len < size)
-			dst[len] = c;
-		if (!c)
-			break;
-		len++;
+	for (len = 0; len < size; len++) {
+		dst[len] = src[len];
+		if (!dst[len])
+			return len;
 	}
+	if (size)
+		dst[size-1] = '\0';
+
+	while (src[len])
+		len++;
+
 	return len;
 }
 
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index dda9dffd1d74..7b82bc3cf107 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -22,6 +22,7 @@
 #include <linux/stat.h>  /* for statx() */
 #include <linux/prctl.h>
 #include <linux/resource.h>
+#include <linux/utsname.h>
 
 #include "arch.h"
 #include "errno.h"
@@ -1140,6 +1141,32 @@ int umount2(const char *path, int flags)
 
 
 /*
+ * int uname(struct utsname *buf);
+ */
+
+struct utsname {
+	char sysname[65];
+	char nodename[65];
+	char release[65];
+	char version[65];
+	char machine[65];
+	char domainname[65];
+};
+
+static __attribute__((unused))
+int sys_uname(struct utsname *buf)
+{
+	return my_syscall1(__NR_uname, buf);
+}
+
+static __attribute__((unused))
+int uname(struct utsname *buf)
+{
+	return __sysret(sys_uname(buf));
+}
+
+
+/*
  * int unlink(const char *path);
  */