[PATCH] Ensure different messages in STRICT_DEVMEM and PAT cases

[Pavel Machek <pavel@ucw.cz>]

commit 823a62aebddaec01fd776a8dd4f8f4a5b419e3f9
Author: Pavel <pavel@ucw.cz>
Date:   Sun Dec 28 17:04:02 2014 +0100

STRICT_DEVMEM and PAT produce same failure accessing /dev/mem, which
is quite confusing to the user. Make printk messages different to
lessen confusion.
    
Signed-off-by: Pavel Machek <pavel@ucw.cz>

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 6574388..2b6f5d8 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -488,7 +488,7 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 }
 
 #ifdef CONFIG_STRICT_DEVMEM
-/* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM*/
+/* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM */
 static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 {
 	return 1;
@@ -506,7 +506,7 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 
 	while (cursor < to) {
 		if (!devmem_is_allowed(pfn)) {
pp-			printk(KERN_INFO "Program %s tried to access /dev/mem between [mem %#010Lx-%#010Lx]\n",
+			printk(KERN_INFO "Program %s tried to access /dev/mem between [mem %#010Lx-%#010Lx], PAT prevents it\n",
 				current->comm, from, to - 1);
 			return 0;
 		}

-- 
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