From: jsg <jsg@openbsd.org>
Date: Fri, 11 Oct 2024 02:33:11 +0000 (+0000)
Subject: drm/printer: Allow NULL data in devcoredump printer
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=68bd9ea94afe6dbbb156de4d07c52acd541d70e1;p=openbsd

drm/printer: Allow NULL data in devcoredump printer

From Matthew Brost
4ee08b4a7201ba0f7f3d52e3840fee92f415b6c5 in linux-6.6.y/6.6.55
53369581dc0c68a5700ed51e1660f44c4b2bb524 in mainline linux
---

diff --git a/sys/dev/pci/drm/drm_print.c b/sys/dev/pci/drm/drm_print.c
index 68c810e2d7b..da63a054a0d 100644
--- a/sys/dev/pci/drm/drm_print.c
+++ b/sys/dev/pci/drm/drm_print.c
@@ -104,8 +104,9 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str)
 			copy = iterator->remain;
 
 		/* Copy out the bit of the string that we need */
-		memcpy(iterator->data,
-			str + (iterator->start - iterator->offset), copy);
+		if (iterator->data)
+			memcpy(iterator->data,
+			       str + (iterator->start - iterator->offset), copy);
 
 		iterator->offset = iterator->start + copy;
 		iterator->remain -= copy;
@@ -114,7 +115,8 @@ void __drm_puts_coredump(struct drm_printer *p, const char *str)
 
 		len = min_t(ssize_t, strlen(str), iterator->remain);
 
-		memcpy(iterator->data + pos, str, len);
+		if (iterator->data)
+			memcpy(iterator->data + pos, str, len);
 
 		iterator->offset += len;
 		iterator->remain -= len;
@@ -144,8 +146,9 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf)
 	if ((iterator->offset >= iterator->start) && (len < iterator->remain)) {
 		ssize_t pos = iterator->offset - iterator->start;
 
-		snprintf(((char *) iterator->data) + pos,
-			iterator->remain, "%pV", vaf);
+		if (iterator->data)
+			snprintf(((char *) iterator->data) + pos,
+				 iterator->remain, "%pV", vaf);
 
 		iterator->offset += len;
 		iterator->remain -= len;