| Message ID | 20230203075232.274282-4-alexghiti@rivosinc.com |
|---|---|
| State | Accepted |
| Commit | 401e84488800d05e8ed6db2a687eaa94415f4ec8 |
| Headers | show |
| Series | RISC-V kasan rework | expand |
Alexandre Ghiti <alexghiti@rivosinc.com> writes: > The early virtual address should lie in the kernel address space for > inline kasan instrumentation to succeed, otherwise kasan tries to > dereference an address that does not exist in the address space (since > kasan only maps *kernel* address space, not the userspace). > > Simply use the very first address of the kernel address space for the > early fdt mapping. > > It allowed an Ubuntu kernel to boot successfully with inline > instrumentation. > > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 478d6763a01a..87f6a5d475a6 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -57,7 +57,7 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] EXPORT_SYMBOL(empty_zero_page); extern char _start[]; -#define DTB_EARLY_BASE_VA PGDIR_SIZE +#define DTB_EARLY_BASE_VA (ADDRESS_SPACE_END - (PTRS_PER_PGD / 2 * PGDIR_SIZE) + 1) void *_dtb_early_va __initdata; uintptr_t _dtb_early_pa __initdata;
The early virtual address should lie in the kernel address space for inline kasan instrumentation to succeed, otherwise kasan tries to dereference an address that does not exist in the address space (since kasan only maps *kernel* address space, not the userspace). Simply use the very first address of the kernel address space for the early fdt mapping. It allowed an Ubuntu kernel to boot successfully with inline instrumentation. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> --- arch/riscv/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)