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 --- arch/riscv/include/asm/elf.h | 2 +- arch/riscv/include/asm/pgtable.h | 25 ++++++++++++-- arch/riscv/include/asm/processor.h | 52 ++++++++++++++++++++++++++---- 3 files changed, 70 insertions(+), 9 deletions(-)
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index c24280774caf..5d3368d5585c 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -49,7 +49,7 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr); * the loader. We need to make sure that it is out of the way of the program * that it will "exec", and that there is sufficient room for the brk. */ -#define ELF_ET_DYN_BASE ((TASK_SIZE / 3) * 2) +#define ELF_ET_DYN_BASE ((DEFAULT_MAP_WINDOW / 3) * 2)
#ifdef CONFIG_64BIT #ifdef CONFIG_COMPAT diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 75970ee2bda2..bb0b9ac7b581 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -62,11 +62,16 @@ * struct pages to map half the virtual address space. Then * position vmemmap directly below the VMALLOC region. */ +#define VA_BITS_SV32 32 #ifdef CONFIG_64BIT +#define VA_BITS_SV39 39 +#define VA_BITS_SV48 48 +#define VA_BITS_SV57 57 + #define VA_BITS (pgtable_l5_enabled ? \ - 57 : (pgtable_l4_enabled ? 48 : 39)) + VA_BITS_SV57 : (pgtable_l4_enabled ? VA_BITS_SV48 : VA_BITS_SV39)) #else -#define VA_BITS 32 +#define VA_BITS VA_BITS_SV32 #endif
#define VMEMMAP_SHIFT \ @@ -111,11 +116,27 @@ #include <asm/page.h> #include <asm/tlbflush.h> #include <linux/mm_types.h> +#include <asm/compat.h>
#define __page_val_to_pfn(_val) (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT)
#ifdef CONFIG_64BIT #include <asm/pgtable-64.h> + +#define VA_USER_SV39 (UL(1) << (VA_BITS_SV39 - 1)) +#define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1)) +#define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1)) + +#ifdef CONFIG_COMPAT +#define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS) +#define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39) +#define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64) +#define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64) +#else +#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS) +#define MMAP_MIN_VA_BITS (VA_BITS_SV39) +#endif /* CONFIG_COMPAT */ + #else #include <asm/pgtable-32.h> #endif /* CONFIG_64BIT */ diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index c950a8d9edef..3e23e1786d05 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -13,19 +13,59 @@
#include <asm/ptrace.h>
+#ifdef CONFIG_64BIT +#define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1)) +#define STACK_TOP_MAX TASK_SIZE_64 + +#define arch_get_mmap_end(addr, len, flags) \ +({ \ + unsigned long mmap_end; \ + typeof(addr) _addr = (addr); \ + if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \ + mmap_end = STACK_TOP_MAX; \ + else if ((_addr) >= VA_USER_SV57) \ + mmap_end = STACK_TOP_MAX; \ + else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \ + mmap_end = VA_USER_SV48; \ + else \ + mmap_end = VA_USER_SV39; \ + mmap_end; \ +}) + +#define arch_get_mmap_base(addr, base) \ +({ \ + unsigned long mmap_base; \ + typeof(addr) _addr = (addr); \ + typeof(base) _base = (base); \ + unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \ + if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \ + mmap_base = (_base); \ + else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \ + mmap_base = VA_USER_SV57 - rnd_gap; \ + else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \ + mmap_base = VA_USER_SV48 - rnd_gap; \ + else \ + mmap_base = VA_USER_SV39 - rnd_gap; \ + mmap_base; \ +}) + +#else +#define DEFAULT_MAP_WINDOW TASK_SIZE +#define STACK_TOP_MAX TASK_SIZE +#endif +#define STACK_ALIGN 16 + +#define STACK_TOP DEFAULT_MAP_WINDOW + /* * This decides where the kernel will search for a free chunk of vm * space during mmap's. */ -#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3) - -#define STACK_TOP TASK_SIZE #ifdef CONFIG_64BIT -#define STACK_TOP_MAX TASK_SIZE_64 +#define TASK_UNMAPPED_BASE PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3) #else -#define STACK_TOP_MAX TASK_SIZE +#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3) #endif -#define STACK_ALIGN 16
#ifndef __ASSEMBLY__