[PATCH] ARM: mmu: fix access to illegal address when using earlycon & memblock=debug

Victor Hassan victor at allwinnertech.com
Tue Mar 15 19:33:56 PDT 2022


earlycon uses fixmap to create a memory map,
So we need to close earlycon before closing fixmap,
otherwise printk will access illegal addresses.
After creating a new memory map, we open earlycon again.

Signed-off-by: Victor Hassan <victor at allwinnertech.com>
---
 arch/arm/mm/mmu.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 274e4f73fd33..f3511f07a7d0 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -14,6 +14,7 @@
 #include <linux/fs.h>
 #include <linux/vmalloc.h>
 #include <linux/sizes.h>
+#include <linux/console.h>
 
 #include <asm/cp15.h>
 #include <asm/cputype.h>
@@ -1695,6 +1696,9 @@ static void __init early_fixmap_shutdown(void)
 	pmd_clear(fixmap_pmd(va));
 	local_flush_tlb_kernel_page(va);
 
+#ifdef CONFIG_FIX_EARLYCON_MEM
+	console_stop(console_drivers);
+#endif
 	for (i = 0; i < __end_of_permanent_fixed_addresses; i++) {
 		pte_t *pte;
 		struct map_desc map;
@@ -1713,6 +1717,9 @@ static void __init early_fixmap_shutdown(void)
 
 		create_mapping(&map);
 	}
+#ifdef CONFIG_FIX_EARLYCON_MEM
+	console_start(console_drivers);
+#endif
 }
 
 /*
-- 
2.29.0




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