Messages in this thread | | | Date | Tue, 25 Jan 2022 17:10:41 +0100 | Subject | Re: [PATCH] riscv: mm: remove the BUG_ON check of mapping the last 4K bytes of memory | From | Alexandre Ghiti <> |
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On 1/25/22 16:55, Jisheng Zhang wrote: > remove the BUG_ON check of mapping the last 4K bytes of the addressable > memory since "this is true for every kernel actually" as pointed out > by Alexandre. > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > Reviewed-by: Alexandre Ghiti <alex@ghiti.fr> > --- > arch/riscv/mm/init.c | 8 -------- > 1 file changed, 8 deletions(-) > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index cf4d018b7d66..8347d0fda8cd 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -811,14 +811,6 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); > BUG_ON((kernel_map.phys_addr % PMD_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
This BUG_ON seems pretty legit to me: I re-read the exchanges we had, and I see that I didn't notice that in your v2, you actually removed the BUG_ON. So that's my bad, what I meant in the first place was that the BUG_ON is true for 32-bit and 64-bit kernels actually.
Sorry my RB was not right on this one :(
Alex
> - > pt_ops_set_early(); > > /* Setup early PGD for fixmap */
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