From: Hou Wenlong <houwenlong.hwl@antgroup.com>
Date: Mon, 12 Jan 2026 12:24:29 +0000 (+0800)
Subject: mm/early_ioremap: clean up the use of WARN() for debugging
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5fd8391cb71982152785edc1e6f48a5c7dcadabc;p=thirdparty%2Fkernel%2Fstable.git

mm/early_ioremap: clean up the use of WARN() for debugging

Using WARN() for debugging is strange when nothing is wrong, so replace
WARN(early_ioremap_debug) with pr_warn() + dump_stack().

Link: https://lkml.kernel.org/r/d4470531ce0c03fd80f9a1be7e8d8ae1bc60fcd1.1768220636.git.houwenlong.hwl@antgroup.com
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Suggested-by: Mike Rapoport <rppt@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hou Wenlong <houwenlong.hwl@antgroup.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c
index 3fdde074c9da..96c29b9dc85d 100644
--- a/mm/early_ioremap.c
+++ b/mm/early_ioremap.c
@@ -30,6 +30,14 @@ static int __init early_ioremap_debug_setup(char *str)
 }
 early_param("early_ioremap_debug", early_ioremap_debug_setup);
 
+#define early_ioremap_dbg(fmt, args...)			\
+	do {						\
+		if (unlikely(early_ioremap_debug)) {	\
+			pr_warn(fmt, ##args);		\
+			dump_stack();			\
+		}					\
+	} while (0)
+
 static int after_paging_init __initdata;
 
 pgprot_t __init __weak early_memremap_pgprot_adjust(resource_size_t phys_addr,
@@ -139,8 +147,8 @@ __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
 	if (WARN_ON(nrpages > NR_FIX_BTMAPS))
 		return NULL;
 
-	WARN(early_ioremap_debug, "%s(%pa, %08lx) [%d] => %08lx + %08lx\n",
-	     __func__, &phys_addr, size, slot, slot_virt[slot], offset);
+	early_ioremap_dbg("%s(%pa, %08lx) [%d] => %08lx + %08lx\n",
+			  __func__, &phys_addr, size, slot, slot_virt[slot], offset);
 
 	/*
 	 * Ok, go for it..
@@ -185,8 +193,7 @@ void __init early_iounmap(void __iomem *addr, unsigned long size)
 		  __func__, addr, size, slot, prev_size[slot]))
 		return;
 
-	WARN(early_ioremap_debug, "%s(%p, %08lx) [%d]\n",
-	      __func__, addr, size, slot);
+	early_ioremap_dbg("%s(%p, %08lx) [%d]\n", __func__, addr, size, slot);
 
 	virt_addr = (unsigned long)addr;
 	if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)))