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authorIngo Molnar <mingo@elte.hu>2008-01-30 13:34:09 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:34:09 +0100
commitee01f1122ceb02a2c9b7142c5dd17b49e59ba774 (patch)
tree82f4d23f6857e2cc8e623295d3b06ab70c05fa10
parent1a4872529e13265d05ffae75b8d09697540016d2 (diff)
x86: init memory debugging
debug incorrect/late access to init memory, by permanently unmapping the init memory ranges. Depends on CONFIG_DEBUG_PAGEALLOC=y. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--arch/x86/mm/init_32.c11
-rw-r--r--arch/x86/mm/init_64.c11
2 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index a72737c0574..8d7f723cfc2 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -783,6 +783,16 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
unsigned long addr;
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ /*
+ * If debugging page accesses then do not free this memory but
+ * mark them not present - any buggy init-section access will
+ * create a kernel page fault:
+ */
+ printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
+ begin, PAGE_ALIGN(end));
+ set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
+#else
/*
* We just marked the kernel text read only above, now that
* we are going to free part of that, we need to make that
@@ -798,6 +808,7 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
totalram_pages++;
}
printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
+#endif
}
void free_initmem(void)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index f51180c02b8..e0c1e98ad1b 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -550,6 +550,16 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
if (begin >= end)
return;
+ /*
+ * If debugging page accesses then do not free this memory but
+ * mark them not present - any buggy init-section access will
+ * create a kernel page fault:
+ */
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
+ begin, PAGE_ALIGN(end));
+ set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
+#else
printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
for (addr = begin; addr < end; addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
@@ -575,6 +585,7 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
set_memory_nx(begin, (end - begin)/PAGE_SIZE);
}
#endif
+#endif
}
void free_initmem(void)