Merge tag 'linux_kselftest-nolibc-6.10-rc1' of...

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()

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;
 }

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;
+	size_t len = strnlen(dst, size);
 
-	for (len = 0; dst[len];	len++)
-		;
-
-	for (;;) {
-		c = *src;
-		if (len < size)
-			dst[len] = c;
-		if (!c)
+	/*
+	 * 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;
 }
 

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"
@@ -1139,6 +1140,32 @@ 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);
  */

tools/testing/selftests/nolibc/nolibc-test.c

@@ -27,6 +27,7 @@
 #include <sys/syscall.h>
 #include <sys/sysmacros.h>
 #include <sys/time.h>
+#include <sys/utsname.h>
 #include <sys/wait.h>
 #include <dirent.h>
 #include <errno.h>
@@ -600,6 +601,25 @@ int expect_strne(const char *expr, int llen, const char *cmp)
 	return ret;
 }
 
+#define EXPECT_STRBUFEQ(cond, expr, buf, val, cmp)				\
+	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_str_buf_eq(expr, buf, val, llen, cmp); } while (0)
+
+static __attribute__((unused))
+int expect_str_buf_eq(size_t expr, const char *buf, size_t val, int llen, const char *cmp)
+{
+	llen += printf(" = %lu <%s> ", expr, buf);
+	if (strcmp(buf, cmp) != 0) {
+		result(llen, FAIL);
+		return 1;
+	}
+	if (expr != val) {
+		result(llen, FAIL);
+		return 1;
+	}
+
+	result(llen, OK);
+	return 0;
+}
 
 /* declare tests based on line numbers. There must be exactly one test per line. */
 #define CASE_TEST(name) \
@@ -761,6 +781,45 @@ int test_stat_timestamps(void)
 	return 0;
 }
 
+int test_uname(void)
+{
+	struct utsname buf;
+	char osrelease[sizeof(buf.release)];
+	ssize_t r;
+	int fd;
+
+	memset(&buf.domainname, 'P', sizeof(buf.domainname));
+
+	if (uname(&buf))
+		return 1;
+
+	if (strncmp("Linux", buf.sysname, sizeof(buf.sysname)))
+		return 1;
+
+	fd = open("/proc/sys/kernel/osrelease", O_RDONLY);
+	if (fd == -1)
+		return 1;
+
+	r = read(fd, osrelease, sizeof(osrelease));
+	if (r == -1)
+		return 1;
+
+	close(fd);
+
+	if (osrelease[r - 1] == '\n')
+		r--;
+
+	/* Validate one of the later fields to ensure field sizes are correct */
+	if (strncmp(osrelease, buf.release, r))
+		return 1;
+
+	/* Ensure the field domainname is set, it is missing from struct old_utsname */
+	if (strnlen(buf.domainname, sizeof(buf.domainname)) == sizeof(buf.domainname))
+		return 1;
+
+	return 0;
+}
+
 int test_mmap_munmap(void)
 {
 	int ret, fd, i, page_size;
@@ -966,6 +1025,8 @@ int run_syscall(int min, int max)
 		CASE_TEST(stat_fault);        EXPECT_SYSER(1, stat(NULL, &stat_buf), -1, EFAULT); break;
 		CASE_TEST(stat_timestamps);   EXPECT_SYSZR(1, test_stat_timestamps()); break;
 		CASE_TEST(symlink_root);      EXPECT_SYSER(1, symlink("/", "/"), -1, EEXIST); break;
+		CASE_TEST(uname);             EXPECT_SYSZR(proc, test_uname()); break;
+		CASE_TEST(uname_fault);       EXPECT_SYSER(1, uname(NULL), -1, EFAULT); break;
 		CASE_TEST(unlink_root);       EXPECT_SYSER(1, unlink("/"), -1, EISDIR); break;
 		CASE_TEST(unlink_blah);       EXPECT_SYSER(1, unlink("/proc/self/blah"), -1, ENOENT); break;
 		CASE_TEST(wait_child);        EXPECT_SYSER(1, wait(&tmp), -1, ECHILD); break;
@@ -991,6 +1052,14 @@ int run_stdlib(int min, int max)
 	for (test = min; test >= 0 && test <= max; test++) {
 		int llen = 0; /* line length */
 
+		/* For functions that take a long buffer, like strlcat()
+		 * Add some more chars after the \0, to test functions that overwrite the buffer set
+		 * the \0 at the exact right position.
+		 */
+		char buf[10] = "test123456";
+		buf[4] = '\0';
+
+
 		/* avoid leaving empty lines below, this will insert holes into
 		 * test numbers.
 		 */
@@ -1007,6 +1076,19 @@ int run_stdlib(int min, int max)
 		CASE_TEST(strchr_foobar_z);    EXPECT_STRZR(1, strchr("foobar", 'z')); break;
 		CASE_TEST(strrchr_foobar_o);   EXPECT_STREQ(1, strrchr("foobar", 'o'), "obar"); break;
 		CASE_TEST(strrchr_foobar_z);   EXPECT_STRZR(1, strrchr("foobar", 'z')); break;
+#ifdef NOLIBC
+		CASE_TEST(strlcat_0);          EXPECT_STRBUFEQ(1, strlcat(buf, "bar", 0), buf, 3, "test"); break;
+		CASE_TEST(strlcat_1);          EXPECT_STRBUFEQ(1, strlcat(buf, "bar", 1), buf, 4, "test"); break;
+		CASE_TEST(strlcat_5);          EXPECT_STRBUFEQ(1, strlcat(buf, "bar", 5), buf, 7, "test"); break;
+		CASE_TEST(strlcat_6);          EXPECT_STRBUFEQ(1, strlcat(buf, "bar", 6), buf, 7, "testb"); break;
+		CASE_TEST(strlcat_7);          EXPECT_STRBUFEQ(1, strlcat(buf, "bar", 7), buf, 7, "testba"); break;
+		CASE_TEST(strlcat_8);          EXPECT_STRBUFEQ(1, strlcat(buf, "bar", 8), buf, 7, "testbar"); break;
+		CASE_TEST(strlcpy_0);          EXPECT_STRBUFEQ(1, strlcpy(buf, "bar", 0), buf, 3, "test"); break;
+		CASE_TEST(strlcpy_1);          EXPECT_STRBUFEQ(1, strlcpy(buf, "bar", 1), buf, 3, ""); break;
+		CASE_TEST(strlcpy_2);          EXPECT_STRBUFEQ(1, strlcpy(buf, "bar", 2), buf, 3, "b"); break;
+		CASE_TEST(strlcpy_3);          EXPECT_STRBUFEQ(1, strlcpy(buf, "bar", 3), buf, 3, "ba"); break;
+		CASE_TEST(strlcpy_4);          EXPECT_STRBUFEQ(1, strlcpy(buf, "bar", 4), buf, 3, "bar"); break;
+#endif
 		CASE_TEST(memcmp_20_20);       EXPECT_EQ(1, memcmp("aaa\x20", "aaa\x20", 4), 0); break;
 		CASE_TEST(memcmp_20_60);       EXPECT_LT(1, memcmp("aaa\x20", "aaa\x60", 4), 0); break;
 		CASE_TEST(memcmp_60_20);       EXPECT_GT(1, memcmp("aaa\x60", "aaa\x20", 4), 0); break;