arm64: dump: De-constify VA_START and KASAN_SHADOW_START

The kernel page table dumper assumes that the placement of VA regions is
constant and determined at compile time. As we are about to introduce
variable VA logic, we need to be able to determine certain regions at
boot time.

Specifically the VA_START and KASAN_SHADOW_START will depend on whether
or not the system is booted with 52-bit kernel VAs.

This patch adds logic to the kernel page table dumper s.t. these regions
can be computed at boot time.

Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index beec87488e979c355961e0a7db26d2a4ae92567b..6ec75305828e0c8c161d434a8565d96a42656363 100644 (file)
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -25,11 +25,20 @@
 #include <asm/pgtable-hwdef.h>
 #include <asm/ptdump.h>
 
-static const struct addr_marker address_markers[] = {
+
+enum address_markers_idx {
+       PAGE_OFFSET_NR = 0,
+       VA_START_NR,
+#ifdef CONFIG_KASAN
+       KASAN_START_NR,
+#endif
+};
+
+static struct addr_marker address_markers[] = {
        { PAGE_OFFSET,                  "Linear Mapping start" },
-       { VA_START,                     "Linear Mapping end" },
+       { 0 /* VA_START */,             "Linear Mapping end" },
 #ifdef CONFIG_KASAN
-       { KASAN_SHADOW_START,           "Kasan shadow start" },
+       { 0 /* KASAN_SHADOW_START */,   "Kasan shadow start" },
        { KASAN_SHADOW_END,             "Kasan shadow end" },
 #endif
        { MODULES_VADDR,                "Modules start" },
@@ -402,6 +411,10 @@ void ptdump_check_wx(void)
 
 static int ptdump_init(void)
 {
+       address_markers[VA_START_NR].start_address = VA_START;
+#ifdef CONFIG_KASAN
+       address_markers[KASAN_START_NR].start_address = KASAN_SHADOW_START;
+#endif
        ptdump_initialize();
        ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables");
        return 0;