Block early_write during MMU pagetable initialization to avoid crashi…

…ng kernel
amery · Apr 2, 2012 · f7d7280 · f7d7280
1 parent 0001448
commit f7d7280
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Showing 2 changed files with 14 additions and 0 deletions.
diff --git a/arch/arm/kernel/early_printk.c b/arch/arm/kernel/early_printk.c
@@ -14,8 +14,12 @@
 
 extern void printch(int);
 
+int early_write_ok = 1;
+
 static void early_write(const char *s, unsigned n)
 {
+	if (!early_write_ok)
+		return;
 	while (n-- > 0) {
 		if (*s == '\n')
 			printch('\r');

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
@@ -993,16 +993,23 @@ void __init arm_mm_memblock_reserve(void)
  * called function.  This means you can't use any function or debugging
  * method which may touch any device, otherwise the kernel _will_ crash.
  */
+#define EARLY_WRITE_OK defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_ICEDCC)
 static void __init devicemaps_init(struct machine_desc *mdesc)
 {
 	struct map_desc map;
 	unsigned long addr;
+#if EARLY_WRITE_OK
+	extern int early_write_ok;
+#endif
 
 	/*
 	 * Allocate the vector page early.
 	 */
 	vectors_page = early_alloc(PAGE_SIZE);
 
+#if EARLY_WRITE_OK
+	early_write_ok = 0;
+#endif
 	for (addr = VMALLOC_START; addr; addr += PMD_SIZE)
 		pmd_clear(pmd_off_k(addr));
 
@@ -1067,6 +1074,9 @@ static void __init devicemaps_init(struct machine_desc *mdesc)
 	 */
 	local_flush_tlb_all();
 	flush_cache_all();
+#if EARLY_WRITE_OK
+	early_write_ok = 1;
+#endif
 }
 
 static void __init kmap_init(void)