From: Krzysztof Wilczyński <kwilczynski@kernel.org>
Date: Fri, 8 May 2026 04:35:34 +0000 (+0000)
Subject: alpha/PCI: Remove WARN from __pci_mmap_fits() and __legacy_mmap_fits()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=29840080f5a68de131ae5bf89138d6ae11c591d8;p=thirdparty%2Flinux.git

alpha/PCI: Remove WARN from __pci_mmap_fits() and __legacy_mmap_fits()

Remove the WARN() that fires when userspace attempts to mmap beyond the BAR
bounds.  The check still returns 0 to reject the mapping, but the warning
is excessive for normal operation.

A similar warning was removed from the PCI core in the commit 3b519e4ea618
("PCI: fix size checks for mmap() on /proc/bus/pci files").

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: squash https://lore.kernel.org/all/20260508045824.GA3160093@rocinante]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Tested-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Magnus Lindholm <linmag7@gmail.com>
Link: https://patch.msgid.link/20260508043543.217179-16-kwilczynski@kernel.org
---

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 8802f955256e..6cf688621ea9 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -48,13 +48,7 @@ static int __pci_mmap_fits(struct pci_dev *pdev, int num,
 	start = vma->vm_pgoff;
 	size = ((len - 1) >> (PAGE_SHIFT - shift)) + 1;
 
-	if (start < size && size - start >= nr)
-		return 1;
-	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on %s BAR %d "
-		"(size 0x%08lx)\n",
-		current->comm, sparse ? " sparse" : "", start, start + nr,
-		pci_name(pdev), num, size);
-	return 0;
+	return start < size && size - start >= nr;
 }
 
 /**
@@ -257,9 +251,8 @@ int pci_create_resource_files(struct pci_dev *pdev)
 
 /* Legacy I/O bus mapping stuff. */
 
-static int __legacy_mmap_fits(struct pci_controller *hose,
-			      struct vm_area_struct *vma,
-			      unsigned long res_size, int sparse)
+static int __legacy_mmap_fits(struct vm_area_struct *vma,
+			      unsigned long res_size)
 {
 	unsigned long nr, start, size;
 
@@ -267,13 +260,7 @@ static int __legacy_mmap_fits(struct pci_controller *hose,
 	start = vma->vm_pgoff;
 	size = ((res_size - 1) >> PAGE_SHIFT) + 1;
 
-	if (start < size && size - start >= nr)
-		return 1;
-	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on hose %d "
-		"(size 0x%08lx)\n",
-		current->comm, sparse ? " sparse" : "", start, start + nr,
-		hose->index, size);
-	return 0;
+	return start < size && size - start >= nr;
 }
 
 static inline int has_sparse(struct pci_controller *hose,
@@ -296,7 +283,7 @@ int pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,
 
 	res_size = (mmap_type == pci_mmap_mem) ? bus->legacy_mem->size :
 						 bus->legacy_io->size;
-	if (!__legacy_mmap_fits(hose, vma, res_size, sparse))
+	if (!__legacy_mmap_fits(vma, res_size))
 		return -EINVAL;
 
 	return hose_mmap_page_range(hose, vma, mmap_type, sparse);