The use of mem= could leave part or all of the initrd outside of
the kernel linear map. This will lead to an error when unpacking
the initrd and a probable failure to boot. This patch catches that
situation and relocates the initrd to be fully within the linear
map.
Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
---
arch/arm64/kernel/setup.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index f3067d4..96339b5 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -359,6 +359,60 @@ static void __init request_standard_resources(void)
}
}
+/*
+ * Relocate initrd if it is not completely within the linear mapping.
+ * This would be the case if mem= cuts out all or part of it.
+ */
+static void __init relocate_initrd(void)
+{
+#ifdef CONFIG_BLK_DEV_INITRD
+ phys_addr_t orig_start = __virt_to_phys(initrd_start);
+ phys_addr_t orig_end = __virt_to_phys(initrd_end);
+ phys_addr_t ram_end = memblock_end_of_DRAM();
+ phys_addr_t new_start;
+ unsigned long size, to_free = 0;
+ void *dest;
+
+ if (orig_end <= ram_end)
+ return;
+
+ /* Note if any of original initrd will freeing below */
+ if (orig_start < ram_end)
+ to_free = ram_end - orig_start;
+
+ size = orig_end - orig_start;
+
+ /* initrd needs to be relocated completely inside linear mapping */
+ new_start = memblock_find_in_range(0, PFN_PHYS(max_pfn),
+ size, PAGE_SIZE);
+ if (!new_start)
+ panic("Cannot relocate initrd of size %ld\n", size);
+ memblock_reserve(new_start, size);
+
+ initrd_start = __phys_to_virt(new_start);
+ initrd_end = initrd_start + size;
+
+ pr_info("Moving initrd from [%llx-%llx] to [%llx-%llx]\n",
+ orig_start, orig_start + size - 1,
+ new_start, new_start + size - 1);
+
+ dest = (void *)initrd_start;
+
+ if (to_free) {
+ memcpy(dest, (void *)__phys_to_virt(orig_start), to_free);
+ dest += to_free;
+ }
+
+ copy_from_early_mem(dest, orig_start + to_free, size - to_free);
+
+ if (to_free) {
+ pr_info("Freeing original RAMDISK from [%llx-%llx]\n",
+ orig_start, orig_start + to_free - 1);
+ memblock_free(orig_start, to_free);
+ }
+#endif
+}
+
u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
void __init setup_arch(char **cmdline_p)
@@ -392,6 +446,7 @@ void __init setup_arch(char **cmdline_p)
acpi_boot_table_init();
paging_init();
+ relocate_initrd();
request_standard_resources();
early_ioremap_reset();
--
2.4.3
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