In the likely case that XIP_BASE is above PAGE_OFFSET, we
want to discard any early identity mappings. So rather than
keeping every PMD above PAGE_OFFSET, only copy the ones from
PAGE_OFFSET to the last PMD of _end. At this point, the linear
address space should look normal.
Signed-off-by: Jim Kukunas <james.t.kuku...@linux.intel.com>
---
arch/x86/include/asm/pgtable.h | 7 +++++++
arch/x86/kernel/setup.c | 2 +-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index a0c35bf..5eaba7d 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -660,6 +660,13 @@ static inline int pgd_none(pgd_t pgd)
#define KERNEL_PGD_BOUNDARY pgd_index(PAGE_OFFSET)
#define KERNEL_PGD_PTRS (PTRS_PER_PGD - KERNEL_PGD_BOUNDARY)
+#ifdef CONFIG_XIP_KERNEL
+#define BOOT_PGD_COPY_PTRS \
+ ((pgd_index((unsigned long)_end) - pgd_index(PAGE_OFFSET)) + 4)
+#else
+#define BOOT_PGD_COPY_PTRS KERNEL_PGD_PTRS
+#endif
+
#ifndef __ASSEMBLY__
extern int direct_gbpages;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index e2d85c4..d276ebf 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -894,7 +894,7 @@ void __init setup_arch(char **cmdline_p)
*/
clone_pgd_range(swapper_pg_dir + KERNEL_PGD_BOUNDARY,
initial_page_table + KERNEL_PGD_BOUNDARY,
- KERNEL_PGD_PTRS);
+ BOOT_PGD_COPY_PTRS);
load_cr3(swapper_pg_dir);
/*
--
2.1.0
--
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