Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- Limit the linear region to 51-bit when KVM is running in nVHE mode.
Otherwise, depending on the placement of the ID map, kernel-VA to
hyp-VA translations may produce addresses that either conflict with
other HYP mappings or generate addresses outside of the 52-bit
addressable range.
- Instruct kmemleak not to scan the memory reserved for kdump as this
range is removed from the kernel linear map and therefore not
accessible.
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: kdump: Skip kmemleak scan reserved memory for kdump
arm64: mm: limit linear region to 51 bits for KVM in nVHE mode
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index b16be52..37a8175 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -30,6 +30,7 @@
#include <linux/crash_dump.h>
#include <linux/hugetlb.h>
#include <linux/acpi_iort.h>
+#include <linux/kmemleak.h>
#include <asm/boot.h>
#include <asm/fixmap.h>
@@ -101,6 +102,11 @@ static void __init reserve_crashkernel(void)
pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
crash_base, crash_base + crash_size, crash_size >> 20);
+ /*
+ * The crashkernel memory will be removed from the kernel linear
+ * map. Inform kmemleak so that it won't try to access it.
+ */
+ kmemleak_ignore_phys(crash_base);
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
}
@@ -222,7 +228,21 @@ early_param("mem", early_mem);
void __init arm64_memblock_init(void)
{
- const s64 linear_region_size = PAGE_END - _PAGE_OFFSET(vabits_actual);
+ s64 linear_region_size = PAGE_END - _PAGE_OFFSET(vabits_actual);
+
+ /*
+ * Corner case: 52-bit VA capable systems running KVM in nVHE mode may
+ * be limited in their ability to support a linear map that exceeds 51
+ * bits of VA space, depending on the placement of the ID map. Given
+ * that the placement of the ID map may be randomized, let's simply
+ * limit the kernel's linear map to 51 bits as well if we detect this
+ * configuration.
+ */
+ if (IS_ENABLED(CONFIG_KVM) && vabits_actual == 52 &&
+ is_hyp_mode_available() && !is_kernel_in_hyp_mode()) {
+ pr_info("Capping linear region to 51 bits for KVM in nVHE mode on LVA capable hardware.\n");
+ linear_region_size = min_t(u64, linear_region_size, BIT(51));
+ }
/* Remove memory above our supported physical address size */
memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX);
