write in 30M

hc

2024-02-20 ea08eeccae9297f7aabd2ef7f0c2517ac4549acc

 kernel/net/sunrpc/sysctl.c
..
..
@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /*
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  * linux/net/sunrpc/sysctl.c
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  *
..
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@@ -59,25 +60,32 @@
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 }
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 static int proc_do_xprt(struct ctl_table *table, int write,
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-			void __user *buffer, size_t *lenp, loff_t *ppos)
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+			void *buffer, size_t *lenp, loff_t *ppos)
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 {
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 	char tmpbuf[256];
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-	size_t len;
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+	ssize_t len;
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-	if ((*ppos && !write) || !*lenp) {
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+	if (write || *ppos) {
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 		*lenp = 0;
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 		return 0;
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 	}
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 	len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
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-	return simple_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
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+	len = memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
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+
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+	if (len < 0) {
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+		*lenp = 0;
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+		return -EINVAL;
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+	}
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+	*lenp = len;
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+	return 0;
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 }
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 static int
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-proc_dodebug(struct ctl_table *table, int write,
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-				void __user *buffer, size_t *lenp, loff_t *ppos)
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+proc_dodebug(struct ctl_table *table, int write, void *buffer, size_t *lenp,
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+	     loff_t *ppos)
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 {
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-	char		tmpbuf[20], c, *s = NULL;
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-	char __user *p;
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+	char		tmpbuf[20], *s = NULL;
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+	char *p;
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 	unsigned int	value;
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 	size_t		left, len;
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@@ -89,18 +97,17 @@
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 	left = *lenp;
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 	if (write) {
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-		if (!access_ok(VERIFY_READ, buffer, left))
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-			return -EFAULT;
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 		p = buffer;
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-		while (left && __get_user(c, p) >= 0 && isspace(c))
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-			left--, p++;
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+		while (left && isspace(*p)) {
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+			left--;
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+			p++;
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+		}
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 		if (!left)
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 			goto done;
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 		if (left > sizeof(tmpbuf) - 1)
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 			return -EINVAL;
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-		if (copy_from_user(tmpbuf, p, left))
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-			return -EFAULT;
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+		memcpy(tmpbuf, p, left);
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 		tmpbuf[left] = '\0';
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 		value = simple_strtol(tmpbuf, &s, 0);
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@@ -108,8 +115,10 @@
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 			left -= (s - tmpbuf);
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 			if (left && !isspace(*s))
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 				return -EINVAL;
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-			while (left && isspace(*s))
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-				left--, s++;
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+			while (left && isspace(*s)) {
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+				left--;
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+				s++;
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+			}
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 		} else
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 			left = 0;
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 		*(unsigned int *) table->data = value;
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@@ -120,11 +129,9 @@
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 		len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
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 		if (len > left)
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 			len = left;
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-		if (copy_to_user(buffer, tmpbuf, len))
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-			return -EFAULT;
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+		memcpy(buffer, tmpbuf, len);
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 		if ((left -= len) > 0) {
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-			if (put_user('\n', (char __user *)buffer + len))
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-				return -EFAULT;
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+			*((char *)buffer + len) = '\n';
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 			left--;
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 		}
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 	}