Re: [RFC v2 1/7] mm: Provide generic VDSO unmap and remap functions
On November 1, 2016 11:23:54 AM MDT, Dmitry Safonov <0x7f454...@gmail.com> wrote: >Hi Christopher, > > by this moment I got another patch for this. I hope, you don't mind >if I send it concurrently. I haven't sent it yet as I was testing it in > qemu. Please do, that'd be great. Thanks, Cov -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. Sent from my Snapdragon powered Android device with K-9 Mail. Please excuse my brevity.
Re: [RFC v2 1/7] mm: Provide generic VDSO unmap and remap functions
On November 1, 2016 11:23:54 AM MDT, Dmitry Safonov <0x7f454...@gmail.com> wrote: >Hi Christopher, > > by this moment I got another patch for this. I hope, you don't mind >if I send it concurrently. I haven't sent it yet as I was testing it in > qemu. Please do, that'd be great. Thanks, Cov -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. Sent from my Snapdragon powered Android device with K-9 Mail. Please excuse my brevity.
Re: [RFC v2 1/7] mm: Provide generic VDSO unmap and remap functions
Hi Christopher, by this moment I got another patch for this. I hope, you don't mind if I send it concurrently. I haven't sent it yet as I was testing it in qemu. Thanks, Dmitry
Re: [RFC v2 1/7] mm: Provide generic VDSO unmap and remap functions
Hi Christopher, by this moment I got another patch for this. I hope, you don't mind if I send it concurrently. I haven't sent it yet as I was testing it in qemu. Thanks, Dmitry
[RFC v2 1/7] mm: Provide generic VDSO unmap and remap functions
When Address Space Layout Randomization (ASLR, randmaps) is enabled, the address of the VDSO fluctuates from one process to the next. If Checkpoint/Restore In Userspace (CRIU) is to fully replicate the memory map of a previous process, it must be able to remap the VDSO of a new process to the address used by the previous process. Historically this has been implemented in architecture-specific code for PowerPC and x86. In order to support 32-bit and 64-bit ARM without further duplication of code, copy Laurent Dufour's implementation for PowerPC with slight modifications to a generic location. This is hopefully the beginning of a long process of VDSO code de-duplication between architectures. Signed-off-by: Christopher Covington--- include/asm-generic/mm_hooks.h | 35 --- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/include/asm-generic/mm_hooks.h b/include/asm-generic/mm_hooks.h index cc5d9a1..73f09f1 100644 --- a/include/asm-generic/mm_hooks.h +++ b/include/asm-generic/mm_hooks.h @@ -1,7 +1,17 @@ /* - * Define generic no-op hooks for arch_dup_mmap, arch_exit_mmap - * and arch_unmap to be included in asm-FOO/mmu_context.h for any - * arch FOO which doesn't need to hook these. + * Define generic hooks for arch_dup_mmap, arch_exit_mmap and arch_unmap to be + * included in asm-FOO/mmu_context.h for any arch FOO which doesn't need to + * specially hook these. + * + * arch_remap originally from include/linux-mm-arch-hooks.h + * arch_unmap originally from arch/powerpc/include/asm/mmu_context.h + * Copyright (C) 2015, IBM Corporation + * Author: Laurent Dufour + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * */ #ifndef _ASM_GENERIC_MM_HOOKS_H #define _ASM_GENERIC_MM_HOOKS_H @@ -19,6 +29,25 @@ static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long start, unsigned long end) { +#ifdef CONFIG_GENERIC_VDSO + if (start <= mm->context.vdso && mm->context.vdso < end) + mm->context.vdso = 0; +#endif /* CONFIG_GENERIC_VDSO */ +} + +static inline void arch_remap(struct mm_struct *mm, + unsigned long old_start, unsigned long old_end, + unsigned long new_start, unsigned long new_end) +{ +#ifdef CONFIG_GENERIC_VDSO + /* +* mremap() doesn't allow moving multiple vmas so we can limit the +* check to old_addr == vdso. +*/ + if (old_addr == mm->context.vdso) + mm->context.vdso = new_addr; + +#endif /* CONFIG_GENERIC_VDSO */ } static inline void arch_bprm_mm_init(struct mm_struct *mm, -- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
[RFC v2 1/7] mm: Provide generic VDSO unmap and remap functions
When Address Space Layout Randomization (ASLR, randmaps) is enabled, the address of the VDSO fluctuates from one process to the next. If Checkpoint/Restore In Userspace (CRIU) is to fully replicate the memory map of a previous process, it must be able to remap the VDSO of a new process to the address used by the previous process. Historically this has been implemented in architecture-specific code for PowerPC and x86. In order to support 32-bit and 64-bit ARM without further duplication of code, copy Laurent Dufour's implementation for PowerPC with slight modifications to a generic location. This is hopefully the beginning of a long process of VDSO code de-duplication between architectures. Signed-off-by: Christopher Covington --- include/asm-generic/mm_hooks.h | 35 --- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/include/asm-generic/mm_hooks.h b/include/asm-generic/mm_hooks.h index cc5d9a1..73f09f1 100644 --- a/include/asm-generic/mm_hooks.h +++ b/include/asm-generic/mm_hooks.h @@ -1,7 +1,17 @@ /* - * Define generic no-op hooks for arch_dup_mmap, arch_exit_mmap - * and arch_unmap to be included in asm-FOO/mmu_context.h for any - * arch FOO which doesn't need to hook these. + * Define generic hooks for arch_dup_mmap, arch_exit_mmap and arch_unmap to be + * included in asm-FOO/mmu_context.h for any arch FOO which doesn't need to + * specially hook these. + * + * arch_remap originally from include/linux-mm-arch-hooks.h + * arch_unmap originally from arch/powerpc/include/asm/mmu_context.h + * Copyright (C) 2015, IBM Corporation + * Author: Laurent Dufour + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * */ #ifndef _ASM_GENERIC_MM_HOOKS_H #define _ASM_GENERIC_MM_HOOKS_H @@ -19,6 +29,25 @@ static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long start, unsigned long end) { +#ifdef CONFIG_GENERIC_VDSO + if (start <= mm->context.vdso && mm->context.vdso < end) + mm->context.vdso = 0; +#endif /* CONFIG_GENERIC_VDSO */ +} + +static inline void arch_remap(struct mm_struct *mm, + unsigned long old_start, unsigned long old_end, + unsigned long new_start, unsigned long new_end) +{ +#ifdef CONFIG_GENERIC_VDSO + /* +* mremap() doesn't allow moving multiple vmas so we can limit the +* check to old_addr == vdso. +*/ + if (old_addr == mm->context.vdso) + mm->context.vdso = new_addr; + +#endif /* CONFIG_GENERIC_VDSO */ } static inline void arch_bprm_mm_init(struct mm_struct *mm, -- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.