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| author |   Alexandre Ghiti <alex@ghiti.fr> | 2021-06-29 11:13:48 +0200 |
|---|---|---|
| committer |   Palmer Dabbelt <palmerdabbelt@google.com> | 2021-07-22 21:34:36 -0700 |
| commit | db6b84a368b495cb7e41be9cb9e73d4d0537d027 (patch) | |
| tree | eba21fdeb9b9b8238fb0cb08ef76226f5eec7e74 /arch | |
| parent | riscv: Make sure the linear mapping does not use the kernel mapping (diff) | |
| download | linux-dev-db6b84a368b495cb7e41be9cb9e73d4d0537d027.tar.xz linux-dev-db6b84a368b495cb7e41be9cb9e73d4d0537d027.zip | |
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')
| -rw-r--r-- | arch/riscv/mm/init.c | 18 |
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 |