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authorAlexandre Ghiti <alex@ghiti.fr>2021-06-29 11:13:48 +0200
committerPalmer Dabbelt <palmerdabbelt@google.com>2021-07-22 21:34:36 -0700
commitdb6b84a368b495cb7e41be9cb9e73d4d0537d027 (patch)
treeeba21fdeb9b9b8238fb0cb08ef76226f5eec7e74 /arch/riscv/mm
parentc99127c452484ac89c75af39c3c865174ce2de99 (diff)
downloadlinux-db6b84a368b495cb7e41be9cb9e73d4d0537d027.tar.bz2
riscv: Make sure the kernel mapping does not overlap with IS_ERR_VALUE
The check that is done in setup_bootmem currently only works for 32-bit kernel since the kernel mapping has been moved outside of the linear mapping for 64-bit kernel. So make sure that for 64-bit kernel, the kernel mapping does not overlap with the last 4K of the addressable memory. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Fixes: 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear mapping") Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv/mm')
-rw-r--r--arch/riscv/mm/init.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 644a34b0d77d..a14bf3910eec 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -159,7 +159,7 @@ static void __init setup_bootmem(void)
{
phys_addr_t vmlinux_end = __pa_symbol(&_end);
phys_addr_t vmlinux_start = __pa_symbol(&_start);
- phys_addr_t max_mapped_addr = __pa(~(ulong)0);
+ phys_addr_t __maybe_unused max_mapped_addr;
phys_addr_t dram_end;
#ifdef CONFIG_XIP_KERNEL
@@ -183,14 +183,20 @@ static void __init setup_bootmem(void)
dram_end = memblock_end_of_DRAM();
+#ifndef CONFIG_64BIT
/*
* memblock allocator is not aware of the fact that last 4K bytes of
* the addressable memory can not be mapped because of IS_ERR_VALUE
* macro. Make sure that last 4k bytes are not usable by memblock
- * if end of dram is equal to maximum addressable memory.
+ * if end of dram is equal to maximum addressable memory. For 64-bit
+ * kernel, this problem can't happen here as the end of the virtual
+ * address space is occupied by the kernel mapping then this check must
+ * be done in create_kernel_page_table.
*/
+ max_mapped_addr = __pa(~(ulong)0);
if (max_mapped_addr == (dram_end - 1))
memblock_set_current_limit(max_mapped_addr - 4096);
+#endif
min_low_pfn = PFN_UP(memblock_start_of_DRAM());
max_low_pfn = max_pfn = PFN_DOWN(dram_end);
@@ -578,6 +584,14 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
BUG_ON((kernel_map.phys_addr % map_size) != 0);
+#ifdef CONFIG_64BIT
+ /*
+ * The last 4K bytes of the addressable memory can not be mapped because
+ * of IS_ERR_VALUE macro.
+ */
+ BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
+#endif
+
pt_ops.alloc_pte = alloc_pte_early;
pt_ops.get_pte_virt = get_pte_virt_early;
#ifndef __PAGETABLE_PMD_FOLDED