diff options
| -rw-r--r-- | Documentation/riscv/vm-layout.rst | 22 | ||||
| -rw-r--r-- | arch/riscv/include/asm/elf.h | 2 | ||||
| -rw-r--r-- | arch/riscv/include/asm/pgtable.h | 33 | ||||
| -rw-r--r-- | arch/riscv/include/asm/processor.h | 52 | ||||
| -rw-r--r-- | tools/testing/selftests/riscv/Makefile | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/riscv/mm/.gitignore | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/riscv/mm/Makefile | 15 | ||||
| -rw-r--r-- | tools/testing/selftests/riscv/mm/testcases/mmap_bottomup.c | 35 | ||||
| -rw-r--r-- | tools/testing/selftests/riscv/mm/testcases/mmap_default.c | 35 | ||||
| -rw-r--r-- | tools/testing/selftests/riscv/mm/testcases/mmap_test.h | 64 | ||||
| -rwxr-xr-x | tools/testing/selftests/riscv/mm/testcases/run_mmap.sh | 12 |
11 files changed, 261 insertions, 13 deletions
diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst index 5462c84f4723..69ff6da1dbf8 100644 --- a/Documentation/riscv/vm-layout.rst +++ b/Documentation/riscv/vm-layout.rst @@ -133,3 +133,25 @@ RISC-V Linux Kernel SV57 ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel __________________|____________|__________________|_________|____________________________________________________________ + + +Userspace VAs +-------------------- +To maintain compatibility with software that relies on the VA space with a +maximum of 48 bits the kernel will, by default, return virtual addresses to +userspace from a 48-bit range (sv48). This default behavior is achieved by +passing 0 into the hint address parameter of mmap. On CPUs with an address space +smaller than sv48, the CPU maximum supported address space will be the default. + +Software can "opt-in" to receiving VAs from another VA space by providing +a hint address to mmap. A hint address passed to mmap will cause the largest +address space that fits entirely into the hint to be used, unless there is no +space left in the address space. If there is no space available in the requested +address space, an address in the next smallest available address space will be +returned. + +For example, in order to obtain 48-bit VA space, a hint address greater than +:code:`1 << 47` must be provided. Note that this is 47 due to sv48 userspace +ending at :code:`1 << 47` and the addresses beyond this are reserved for the +kernel. Similarly, to obtain 57-bit VA space addresses, a hint address greater +than or equal to :code:`1 << 56` must be provided. diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index c33fe923ef6d..b3b2dfbdf945 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -50,7 +50,7 @@ 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..2c5f6c8edc8a 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 */ @@ -830,14 +851,16 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32. * Note that PGDIR_SIZE must evenly divide TASK_SIZE. * Task size is: - * - 0x9fc00000 (~2.5GB) for RV32. - * - 0x4000000000 ( 256GB) for RV64 using SV39 mmu - * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu + * - 0x9fc00000 (~2.5GB) for RV32. + * - 0x4000000000 ( 256GB) for RV64 using SV39 mmu + * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu + * - 0x100000000000000 ( 64PB) for RV64 using SV57 mmu * * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V * Instruction Set Manual Volume II: Privileged Architecture" states that * "load and store effective addresses, which are 64bits, must have bits * 63–48 all equal to bit 47, or else a page-fault exception will occur." + * Similarly for SV57, bits 63–57 must be equal to bit 56. */ #ifdef CONFIG_64BIT #define TASK_SIZE_64 (PGDIR_SIZE * PTRS_PER_PGD / 2) 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__ diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile index 9dd629cc86aa..1b79da90396e 100644 --- a/tools/testing/selftests/riscv/Makefile +++ b/tools/testing/selftests/riscv/Makefile @@ -5,7 +5,7 @@ ARCH ?= $(shell uname -m 2>/dev/null || echo not) ifneq (,$(filter $(ARCH),riscv)) -RISCV_SUBTARGETS ?= hwprobe vector +RISCV_SUBTARGETS ?= hwprobe vector mm else RISCV_SUBTARGETS := endif diff --git a/tools/testing/selftests/riscv/mm/.gitignore b/tools/testing/selftests/riscv/mm/.gitignore new file mode 100644 index 000000000000..5c2c57cb950c --- /dev/null +++ b/tools/testing/selftests/riscv/mm/.gitignore @@ -0,0 +1,2 @@ +mmap_bottomup +mmap_default diff --git a/tools/testing/selftests/riscv/mm/Makefile b/tools/testing/selftests/riscv/mm/Makefile new file mode 100644 index 000000000000..11e0f0568923 --- /dev/null +++ b/tools/testing/selftests/riscv/mm/Makefile @@ -0,0 +1,15 @@ +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2021 ARM Limited +# Originally tools/testing/arm64/abi/Makefile + +# Additional include paths needed by kselftest.h and local headers +CFLAGS += -D_GNU_SOURCE -std=gnu99 -I. + +TEST_GEN_FILES := testcases/mmap_default testcases/mmap_bottomup + +TEST_PROGS := testcases/run_mmap.sh + +include ../../lib.mk + +$(OUTPUT)/mm: testcases/mmap_default.c testcases/mmap_bottomup.c testcases/mmap_tests.h + $(CC) -o$@ $(CFLAGS) $(LDFLAGS) $^ diff --git a/tools/testing/selftests/riscv/mm/testcases/mmap_bottomup.c b/tools/testing/selftests/riscv/mm/testcases/mmap_bottomup.c new file mode 100644 index 000000000000..b29379f7e478 --- /dev/null +++ b/tools/testing/selftests/riscv/mm/testcases/mmap_bottomup.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <sys/mman.h> +#include <testcases/mmap_test.h> + +#include "../../kselftest_harness.h" + +TEST(infinite_rlimit) +{ +// Only works on 64 bit +#if __riscv_xlen == 64 + struct addresses mmap_addresses; + + EXPECT_EQ(BOTTOM_UP, memory_layout()); + + do_mmaps(&mmap_addresses); + + EXPECT_NE(MAP_FAILED, mmap_addresses.no_hint); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_37_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_38_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_46_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_47_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_55_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_56_addr); + + EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.no_hint); + EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_37_addr); + EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_38_addr); + EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_46_addr); + EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.on_47_addr); + EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.on_55_addr); + EXPECT_GT(1UL << 56, (unsigned long)mmap_addresses.on_56_addr); +#endif +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/riscv/mm/testcases/mmap_default.c b/tools/testing/selftests/riscv/mm/testcases/mmap_default.c new file mode 100644 index 000000000000..d1accb91b726 --- /dev/null +++ b/tools/testing/selftests/riscv/mm/testcases/mmap_default.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <sys/mman.h> +#include <testcases/mmap_test.h> + +#include "../../kselftest_harness.h" + +TEST(default_rlimit) +{ +// Only works on 64 bit +#if __riscv_xlen == 64 + struct addresses mmap_addresses; + + EXPECT_EQ(TOP_DOWN, memory_layout()); + + do_mmaps(&mmap_addresses); + + EXPECT_NE(MAP_FAILED, mmap_addresses.no_hint); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_37_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_38_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_46_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_47_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_55_addr); + EXPECT_NE(MAP_FAILED, mmap_addresses.on_56_addr); + + EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.no_hint); + EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_37_addr); + EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_38_addr); + EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_46_addr); + EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.on_47_addr); + EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.on_55_addr); + EXPECT_GT(1UL << 56, (unsigned long)mmap_addresses.on_56_addr); +#endif +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/riscv/mm/testcases/mmap_test.h b/tools/testing/selftests/riscv/mm/testcases/mmap_test.h new file mode 100644 index 000000000000..9b8434f62f57 --- /dev/null +++ b/tools/testing/selftests/riscv/mm/testcases/mmap_test.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _TESTCASES_MMAP_TEST_H +#define _TESTCASES_MMAP_TEST_H +#include <sys/mman.h> +#include <sys/resource.h> +#include <stddef.h> + +#define TOP_DOWN 0 +#define BOTTOM_UP 1 + +struct addresses { + int *no_hint; + int *on_37_addr; + int *on_38_addr; + int *on_46_addr; + int *on_47_addr; + int *on_55_addr; + int *on_56_addr; +}; + +static inline void do_mmaps(struct addresses *mmap_addresses) +{ + /* + * Place all of the hint addresses on the boundaries of mmap + * sv39, sv48, sv57 + * User addresses end at 1<<38, 1<<47, 1<<56 respectively + */ + void *on_37_bits = (void *)(1UL << 37); + void *on_38_bits = (void *)(1UL << 38); + void *on_46_bits = (void *)(1UL << 46); + void *on_47_bits = (void *)(1UL << 47); + void *on_55_bits = (void *)(1UL << 55); + void *on_56_bits = (void *)(1UL << 56); + + int prot = PROT_READ | PROT_WRITE; + int flags = MAP_PRIVATE | MAP_ANONYMOUS; + + mmap_addresses->no_hint = + mmap(NULL, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_37_addr = + mmap(on_37_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_38_addr = + mmap(on_38_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_46_addr = + mmap(on_46_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_47_addr = + mmap(on_47_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_55_addr = + mmap(on_55_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_56_addr = + mmap(on_56_bits, 5 * sizeof(int), prot, flags, 0, 0); +} + +static inline int memory_layout(void) +{ + int prot = PROT_READ | PROT_WRITE; + int flags = MAP_PRIVATE | MAP_ANONYMOUS; + + void *value1 = mmap(NULL, sizeof(int), prot, flags, 0, 0); + void *value2 = mmap(NULL, sizeof(int), prot, flags, 0, 0); + + return value2 > value1; +} +#endif /* _TESTCASES_MMAP_TEST_H */ diff --git a/tools/testing/selftests/riscv/mm/testcases/run_mmap.sh b/tools/testing/selftests/riscv/mm/testcases/run_mmap.sh new file mode 100755 index 000000000000..ca5ad7c48bad --- /dev/null +++ b/tools/testing/selftests/riscv/mm/testcases/run_mmap.sh @@ -0,0 +1,12 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +original_stack_limit=$(ulimit -s) + +./mmap_default + +# Force mmap_bottomup to be ran with bottomup memory due to +# the unlimited stack +ulimit -s unlimited +./mmap_bottomup +ulimit -s $original_stack_limit |