Messages in this thread Patch in this message | | | From | Amanieu d'Antras <> | Subject | [RESEND PATCH v4 5/8] arm64: mm: Use HAVE_ARCH_COMPAT_MMAP_BASES | Date | Tue, 18 May 2021 10:06:55 +0100 |
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This patch switches arm64 to use separate mmap_base for 32-bit and 64-bit mmaps. This is needed to ensure that compat syscalls invoked by 64-bit tasks perform VM allocations in the low 4G of the address space.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Co-developed-by: Ryan Houdek <Houdek.Ryan@fex-emu.org> Signed-off-by: Ryan Houdek <Houdek.Ryan@fex-emu.org> --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/elf.h | 8 +++++--- arch/arm64/include/asm/processor.h | 33 ++++++++++++++++++------------ arch/arm64/mm/mmap.c | 33 ++++++++++++++++++++++++++++++ 4 files changed, 59 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index dfdc3e0af5e1..d57b7bcbd758 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -133,6 +133,7 @@ config ARM64 select HAVE_ALIGNED_STRUCT_PAGE if SLUB select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_BITREVERSE + select HAVE_ARCH_COMPAT_MMAP_BASES if COMPAT select HAVE_ARCH_COMPILER_H select HAVE_ARCH_HUGE_VMAP select HAVE_ARCH_JUMP_LABEL diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 8d1c8dcb87fd..e21964898d06 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -187,12 +187,14 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp); /* 1GB of VA */ +#define STACK_RND_MASK_64 (0x3ffff >> (PAGE_SHIFT - 12)) #ifdef CONFIG_COMPAT +#define STACK_RND_MASK_32 (0x7ff >> (PAGE_SHIFT - 12)) #define STACK_RND_MASK (test_thread_flag(TIF_32BIT) ? \ - 0x7ff >> (PAGE_SHIFT - 12) : \ - 0x3ffff >> (PAGE_SHIFT - 12)) + STACK_RND_MASK_32 : \ + STACK_RND_MASK_64) #else -#define STACK_RND_MASK (0x3ffff >> (PAGE_SHIFT - 12)) +#define STACK_RND_MASK STACK_RND_MASK_64 #endif #ifdef __AARCH64EB__ diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index f47528aae321..f8309f8d0ece 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -70,29 +70,36 @@ #ifdef CONFIG_ARM64_FORCE_52BIT #define STACK_TOP_MAX TASK_SIZE_64 -#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4)) +#define TASK_UNMAPPED_BASE_64 (PAGE_ALIGN(TASK_SIZE_64 / 4)) #else #define STACK_TOP_MAX DEFAULT_MAP_WINDOW_64 -#define TASK_UNMAPPED_BASE (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4)) +#define TASK_UNMAPPED_BASE_64 (PAGE_ALIGN(DEFAULT_MAP_WINDOW_64 / 4)) #endif /* CONFIG_ARM64_FORCE_52BIT */ +#ifdef CONFIG_COMPAT +#define TASK_UNMAPPED_BASE_32 (PAGE_ALIGN(TASK_SIZE_32 / 4)) +#define TASK_UNMAPPED_BASE (test_thread_flag(TIF_32BIT) ? \ + TASK_UNMAPPED_BASE_32 : TASK_UNMAPPED_BASE_64) +#else +#define TASK_UNMAPPED_BASE TASK_UNMAPPED_BASE_64 +#endif /* CONFIG_COMPAT */ + +#define STACK_TOP_64 STACK_TOP_MAX #ifdef CONFIG_COMPAT #define AARCH32_VECTORS_BASE 0xffff0000 +#define STACK_TOP_32 AARCH32_VECTORS_BASE #define STACK_TOP (test_thread_flag(TIF_32BIT) ? \ - AARCH32_VECTORS_BASE : STACK_TOP_MAX) + STACK_TOP_32 : STACK_TOP_64) #else -#define STACK_TOP STACK_TOP_MAX +#define STACK_TOP STACK_TOP_64 #endif /* CONFIG_COMPAT */ -#ifndef CONFIG_ARM64_FORCE_52BIT -#define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\ - DEFAULT_MAP_WINDOW) - -#define arch_get_mmap_base_topdown(addr) \ - ((addr > DEFAULT_MAP_WINDOW) ? \ - current->mm->mmap_base + TASK_SIZE - DEFAULT_MAP_WINDOW :\ - current->mm->mmap_base) -#endif /* CONFIG_ARM64_FORCE_52BIT */ +#define arch_get_mmap_end arch_get_mmap_end +#define arch_get_mmap_base arch_get_mmap_base +#define arch_get_mmap_base_topdown arch_get_mmap_base_topdown +unsigned long arch_get_mmap_end(unsigned long addr); +unsigned long arch_get_mmap_base(unsigned long addr); +unsigned long arch_get_mmap_base_topdown(unsigned long addr); extern phys_addr_t arm64_dma_phys_limit; #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1) diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index a38f54cd638c..956cab3ade11 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -38,3 +38,36 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) { return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK); } + +unsigned long arch_get_mmap_end(unsigned long addr) +{ +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + return TASK_SIZE_32; +#endif /* CONFIG_COMPAT */ +#ifndef CONFIG_ARM64_FORCE_52BIT + if (addr > DEFAULT_MAP_WINDOW_64) + return TASK_SIZE_64; +#endif /* CONFIG_ARM64_FORCE_52BIT */ + return DEFAULT_MAP_WINDOW_64; +} +unsigned long arch_get_mmap_base(unsigned long addr) +{ +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + return current->mm->mmap_compat_base; +#endif /* CONFIG_COMPAT */ + return current->mm->mmap_base; +} +unsigned long arch_get_mmap_base_topdown(unsigned long addr) +{ +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) + return current->mm->mmap_compat_base; +#endif /* CONFIG_COMPAT */ +#ifndef CONFIG_ARM64_FORCE_52BIT + if (addr > DEFAULT_MAP_WINDOW_64) + return current->mm->mmap_base + TASK_SIZE - DEFAULT_MAP_WINDOW_64; +#endif /* CONFIG_ARM64_FORCE_52BIT */ + return current->mm->mmap_base; +} -- 2.31.1
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