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linux
RISC-V: mm: Restrict address space for sv39,sv48,sv57
Make sv48 the default address space for mmap as some applications
currently depend on this assumption. A hint address passed to mmap will
cause the largest address space that fits entirely into the hint to be
used. If the hint is less than or equal to 1<<38, an sv39 address will
be used. An exception is that if the hint address is 0, then a sv48
address will be used. After an address space is completely full, the next
smallest address space will be used.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20230809232218.849726-2-charlie@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
authored by
Charlie Jenkins
and committed by
Palmer Dabbelt
add2cc6b
06c2afb8
+70
-9
+1
-1
arch/riscv/include/asm/elf.h
+1
-1
arch/riscv/include/asm/elf.h
···
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* the loader. We need to make sure that it is out of the way of the program
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* that it will "exec", and that there is sufficient room for the brk.
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*/
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#define ELF_ET_DYN_BASE ((TASK_SIZE / 3) * 2)
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#define ELF_ET_DYN_BASE ((DEFAULT_MAP_WINDOW / 3) * 2)
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#ifdef CONFIG_64BIT
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#ifdef CONFIG_COMPAT
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-2
arch/riscv/include/asm/pgtable.h
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-2
arch/riscv/include/asm/pgtable.h
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* struct pages to map half the virtual address space. Then
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* position vmemmap directly below the VMALLOC region.
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*/
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#define VA_BITS_SV32 32
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#ifdef CONFIG_64BIT
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#define VA_BITS_SV39 39
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#define VA_BITS_SV48 48
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#define VA_BITS_SV57 57
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+
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#define VA_BITS (pgtable_l5_enabled ? \
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57 : (pgtable_l4_enabled ? 48 : 39))
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VA_BITS_SV57 : (pgtable_l4_enabled ? VA_BITS_SV48 : VA_BITS_SV39))
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#else
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#define VA_BITS 32
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#define VA_BITS VA_BITS_SV32
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#endif
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#define VMEMMAP_SHIFT \
···
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#include <asm/page.h>
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#include <asm/tlbflush.h>
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#include <linux/mm_types.h>
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#include <asm/compat.h>
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#define __page_val_to_pfn(_val) (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT)
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#ifdef CONFIG_64BIT
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#include <asm/pgtable-64.h>
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#define VA_USER_SV39 (UL(1) << (VA_BITS_SV39 - 1))
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#define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1))
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#define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1))
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#ifdef CONFIG_COMPAT
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#define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
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#define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
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#define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
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#define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
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#else
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#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
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#define MMAP_MIN_VA_BITS (VA_BITS_SV39)
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#endif /* CONFIG_COMPAT */
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#else
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#include <asm/pgtable-32.h>
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#endif /* CONFIG_64BIT */
+46
-6
arch/riscv/include/asm/processor.h
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-6
arch/riscv/include/asm/processor.h
···
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#include <asm/ptrace.h>
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#ifdef CONFIG_64BIT
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#define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1))
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#define STACK_TOP_MAX TASK_SIZE_64
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#define arch_get_mmap_end(addr, len, flags) \
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({ \
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unsigned long mmap_end; \
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typeof(addr) _addr = (addr); \
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if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
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mmap_end = STACK_TOP_MAX; \
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else if ((_addr) >= VA_USER_SV57) \
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mmap_end = STACK_TOP_MAX; \
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else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \
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mmap_end = VA_USER_SV48; \
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else \
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mmap_end = VA_USER_SV39; \
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mmap_end; \
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})
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#define arch_get_mmap_base(addr, base) \
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({ \
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unsigned long mmap_base; \
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typeof(addr) _addr = (addr); \
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typeof(base) _base = (base); \
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unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \
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if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
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mmap_base = (_base); \
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else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
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mmap_base = VA_USER_SV57 - rnd_gap; \
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else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \
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mmap_base = VA_USER_SV48 - rnd_gap; \
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else \
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mmap_base = VA_USER_SV39 - rnd_gap; \
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mmap_base; \
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})
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#else
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#define DEFAULT_MAP_WINDOW TASK_SIZE
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#define STACK_TOP_MAX TASK_SIZE
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#endif
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#define STACK_ALIGN 16
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#define STACK_TOP DEFAULT_MAP_WINDOW
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/*
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* This decides where the kernel will search for a free chunk of vm
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* space during mmap's.
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*/
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#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
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#define STACK_TOP TASK_SIZE
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#ifdef CONFIG_64BIT
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#define STACK_TOP_MAX TASK_SIZE_64
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#define TASK_UNMAPPED_BASE PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3)
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#else
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#define STACK_TOP_MAX TASK_SIZE
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#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
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#endif
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#define STACK_ALIGN 16
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#ifndef __ASSEMBLY__
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