From: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
To: Dave Hansen <dave@sr71.net>, linux-kernel@vger.kernel.org
Cc: mtk.manpages@gmail.com, linux-mm@kvack.org, x86@kernel.org,
dave.hansen@linux.intel.com, linux-api@vger.kernel.org
Subject: Re: [PATCH 26/34] mm: implement new mprotect_key() system call
Date: Sat, 05 Dec 2015 07:50:51 +0100 [thread overview]
Message-ID: <5662894B.7090903@gmail.com> (raw)
In-Reply-To: <20151204011500.69487A6C@viggo.jf.intel.com>
Dave,
On 12/04/2015 02:15 AM, Dave Hansen wrote:
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> mprotect_key() is just like mprotect, except it also takes a
> protection key as an argument. On systems that do not support
> protection keys, it still works, but requires that key=0.
> Otherwise it does exactly what mprotect does.
Is there a man page for this API?
Thanks,
Michael
> I expect it to get used like this, if you want to guarantee that
> any mapping you create can *never* be accessed without the right
> protection keys set up.
>
> pkey_deny_access(11); // random pkey
> int real_prot = PROT_READ|PROT_WRITE;
> ptr = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
> ret = mprotect_key(ptr, PAGE_SIZE, real_prot, 11);
>
> This way, there is *no* window where the mapping is accessible
> since it was always either PROT_NONE or had a protection key set.
>
> We settled on 'unsigned long' for the type of the key here. We
> only need 4 bits on x86 today, but I figured that other
> architectures might need some more space.
>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: linux-api@vger.kernel.org
> ---
>
> b/arch/x86/include/asm/mmu_context.h | 10 +++++++--
> b/include/linux/pkeys.h | 7 +++++-
> b/mm/Kconfig | 7 ++++++
> b/mm/mprotect.c | 36 +++++++++++++++++++++++++++++------
> 4 files changed, 51 insertions(+), 9 deletions(-)
>
> diff -puN arch/x86/include/asm/mmu_context.h~pkeys-85-mprotect_pkey arch/x86/include/asm/mmu_context.h
> --- a/arch/x86/include/asm/mmu_context.h~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.181877894 -0800
> +++ b/arch/x86/include/asm/mmu_context.h 2015-12-03 16:21:30.190878302 -0800
> @@ -4,6 +4,7 @@
> #include <asm/desc.h>
> #include <linux/atomic.h>
> #include <linux/mm_types.h>
> +#include <linux/pkeys.h>
>
> #include <trace/events/tlb.h>
>
> @@ -243,10 +244,14 @@ static inline void arch_unmap(struct mm_
> mpx_notify_unmap(mm, vma, start, end);
> }
>
> +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> +/*
> + * If the config option is off, we get the generic version from
> + * include/linux/pkeys.h.
> + */
> static inline int vma_pkey(struct vm_area_struct *vma)
> {
> u16 pkey = 0;
> -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 |
> VM_PKEY_BIT2 | VM_PKEY_BIT3;
> /*
> @@ -259,9 +264,10 @@ static inline int vma_pkey(struct vm_are
> */
> pkey = (vma->vm_flags >> vm_pkey_shift) &
> (vma_pkey_mask >> vm_pkey_shift);
> -#endif
> +
> return pkey;
> }
> +#endif
>
> static inline bool __pkru_allows_pkey(u16 pkey, bool write)
> {
> diff -puN include/linux/pkeys.h~pkeys-85-mprotect_pkey include/linux/pkeys.h
> --- a/include/linux/pkeys.h~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.183877985 -0800
> +++ b/include/linux/pkeys.h 2015-12-03 16:21:30.190878302 -0800
> @@ -2,10 +2,10 @@
> #define _LINUX_PKEYS_H
>
> #include <linux/mm_types.h>
> -#include <asm/mmu_context.h>
>
> #ifdef CONFIG_ARCH_HAS_PKEYS
> #include <asm/pkeys.h>
> +#include <asm/mmu_context.h>
> #else /* ! CONFIG_ARCH_HAS_PKEYS */
>
> /*
> @@ -17,6 +17,11 @@ static inline bool arch_validate_pkey(in
> {
> return true;
> }
> +
> +static inline int vma_pkey(struct vm_area_struct *vma)
> +{
> + return 0;
> +}
> #endif /* ! CONFIG_ARCH_HAS_PKEYS */
>
> #endif /* _LINUX_PKEYS_H */
> diff -puN mm/Kconfig~pkeys-85-mprotect_pkey mm/Kconfig
> --- a/mm/Kconfig~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.185878075 -0800
> +++ b/mm/Kconfig 2015-12-03 16:21:30.190878302 -0800
> @@ -673,3 +673,10 @@ config ARCH_USES_HIGH_VMA_FLAGS
> bool
> config ARCH_HAS_PKEYS
> bool
> +
> +config NR_PROTECTION_KEYS
> + int
> + # Everything supports a _single_ key, so allow folks to
> + # at least call APIs that take keys, but require that the
> + # key be 0.
> + default 1
> diff -puN mm/mprotect.c~pkeys-85-mprotect_pkey mm/mprotect.c
> --- a/mm/mprotect.c~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.186878121 -0800
> +++ b/mm/mprotect.c 2015-12-03 16:21:30.191878347 -0800
> @@ -24,6 +24,7 @@
> #include <linux/migrate.h>
> #include <linux/perf_event.h>
> #include <linux/ksm.h>
> +#include <linux/pkeys.h>
> #include <asm/uaccess.h>
> #include <asm/pgtable.h>
> #include <asm/cacheflush.h>
> @@ -344,10 +345,13 @@ fail:
> return error;
> }
>
> -SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
> - unsigned long, prot)
> +/*
> + * pkey=-1 when doing a legacy mprotect()
> + */
> +static int do_mprotect_pkey(unsigned long start, size_t len,
> + unsigned long prot, int pkey)
> {
> - unsigned long vm_flags, nstart, end, tmp, reqprot;
> + unsigned long nstart, end, tmp, reqprot;
> struct vm_area_struct *vma, *prev;
> int error = -EINVAL;
> const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
> @@ -373,8 +377,6 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
> if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
> prot |= PROT_EXEC;
>
> - vm_flags = calc_vm_prot_bits(prot, 0);
> -
> down_write(¤t->mm->mmap_sem);
>
> vma = find_vma(current->mm, start);
> @@ -407,7 +409,14 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
>
> /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
>
> - newflags = vm_flags;
> + /*
> + * If this is a vanilla, non-pkey mprotect, inherit the
> + * pkey from the VMA we are working on.
> + */
> + if (pkey == -1)
> + newflags = calc_vm_prot_bits(prot, vma_pkey(vma));
> + else
> + newflags = calc_vm_prot_bits(prot, pkey);
> newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
>
> /* newflags >> 4 shift VM_MAY% in place of VM_% */
> @@ -443,3 +452,18 @@ out:
> up_write(¤t->mm->mmap_sem);
> return error;
> }
> +
> +SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
> + unsigned long, prot)
> +{
> + return do_mprotect_pkey(start, len, prot, -1);
> +}
> +
> +SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len,
> + unsigned long, prot, int, pkey)
> +{
> + if (!arch_validate_pkey(pkey))
> + return -EINVAL;
> +
> + return do_mprotect_pkey(start, len, prot, pkey);
> +}
> _
> --
> To unsubscribe from this list: send the line "unsubscribe linux-api" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
WARNING: multiple messages have this Message-ID (diff)
From: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
To: Dave Hansen <dave@sr71.net>, linux-kernel@vger.kernel.org
Cc: mtk.manpages@gmail.com, linux-mm@kvack.org, x86@kernel.org,
dave.hansen@linux.intel.com, linux-api@vger.kernel.org
Subject: Re: [PATCH 26/34] mm: implement new mprotect_key() system call
Date: Sat, 05 Dec 2015 07:50:51 +0100 [thread overview]
Message-ID: <5662894B.7090903@gmail.com> (raw)
In-Reply-To: <20151204011500.69487A6C@viggo.jf.intel.com>
Dave,
On 12/04/2015 02:15 AM, Dave Hansen wrote:
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> mprotect_key() is just like mprotect, except it also takes a
> protection key as an argument. On systems that do not support
> protection keys, it still works, but requires that key=0.
> Otherwise it does exactly what mprotect does.
Is there a man page for this API?
Thanks,
Michael
> I expect it to get used like this, if you want to guarantee that
> any mapping you create can *never* be accessed without the right
> protection keys set up.
>
> pkey_deny_access(11); // random pkey
> int real_prot = PROT_READ|PROT_WRITE;
> ptr = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
> ret = mprotect_key(ptr, PAGE_SIZE, real_prot, 11);
>
> This way, there is *no* window where the mapping is accessible
> since it was always either PROT_NONE or had a protection key set.
>
> We settled on 'unsigned long' for the type of the key here. We
> only need 4 bits on x86 today, but I figured that other
> architectures might need some more space.
>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: linux-api@vger.kernel.org
> ---
>
> b/arch/x86/include/asm/mmu_context.h | 10 +++++++--
> b/include/linux/pkeys.h | 7 +++++-
> b/mm/Kconfig | 7 ++++++
> b/mm/mprotect.c | 36 +++++++++++++++++++++++++++++------
> 4 files changed, 51 insertions(+), 9 deletions(-)
>
> diff -puN arch/x86/include/asm/mmu_context.h~pkeys-85-mprotect_pkey arch/x86/include/asm/mmu_context.h
> --- a/arch/x86/include/asm/mmu_context.h~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.181877894 -0800
> +++ b/arch/x86/include/asm/mmu_context.h 2015-12-03 16:21:30.190878302 -0800
> @@ -4,6 +4,7 @@
> #include <asm/desc.h>
> #include <linux/atomic.h>
> #include <linux/mm_types.h>
> +#include <linux/pkeys.h>
>
> #include <trace/events/tlb.h>
>
> @@ -243,10 +244,14 @@ static inline void arch_unmap(struct mm_
> mpx_notify_unmap(mm, vma, start, end);
> }
>
> +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> +/*
> + * If the config option is off, we get the generic version from
> + * include/linux/pkeys.h.
> + */
> static inline int vma_pkey(struct vm_area_struct *vma)
> {
> u16 pkey = 0;
> -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 |
> VM_PKEY_BIT2 | VM_PKEY_BIT3;
> /*
> @@ -259,9 +264,10 @@ static inline int vma_pkey(struct vm_are
> */
> pkey = (vma->vm_flags >> vm_pkey_shift) &
> (vma_pkey_mask >> vm_pkey_shift);
> -#endif
> +
> return pkey;
> }
> +#endif
>
> static inline bool __pkru_allows_pkey(u16 pkey, bool write)
> {
> diff -puN include/linux/pkeys.h~pkeys-85-mprotect_pkey include/linux/pkeys.h
> --- a/include/linux/pkeys.h~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.183877985 -0800
> +++ b/include/linux/pkeys.h 2015-12-03 16:21:30.190878302 -0800
> @@ -2,10 +2,10 @@
> #define _LINUX_PKEYS_H
>
> #include <linux/mm_types.h>
> -#include <asm/mmu_context.h>
>
> #ifdef CONFIG_ARCH_HAS_PKEYS
> #include <asm/pkeys.h>
> +#include <asm/mmu_context.h>
> #else /* ! CONFIG_ARCH_HAS_PKEYS */
>
> /*
> @@ -17,6 +17,11 @@ static inline bool arch_validate_pkey(in
> {
> return true;
> }
> +
> +static inline int vma_pkey(struct vm_area_struct *vma)
> +{
> + return 0;
> +}
> #endif /* ! CONFIG_ARCH_HAS_PKEYS */
>
> #endif /* _LINUX_PKEYS_H */
> diff -puN mm/Kconfig~pkeys-85-mprotect_pkey mm/Kconfig
> --- a/mm/Kconfig~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.185878075 -0800
> +++ b/mm/Kconfig 2015-12-03 16:21:30.190878302 -0800
> @@ -673,3 +673,10 @@ config ARCH_USES_HIGH_VMA_FLAGS
> bool
> config ARCH_HAS_PKEYS
> bool
> +
> +config NR_PROTECTION_KEYS
> + int
> + # Everything supports a _single_ key, so allow folks to
> + # at least call APIs that take keys, but require that the
> + # key be 0.
> + default 1
> diff -puN mm/mprotect.c~pkeys-85-mprotect_pkey mm/mprotect.c
> --- a/mm/mprotect.c~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.186878121 -0800
> +++ b/mm/mprotect.c 2015-12-03 16:21:30.191878347 -0800
> @@ -24,6 +24,7 @@
> #include <linux/migrate.h>
> #include <linux/perf_event.h>
> #include <linux/ksm.h>
> +#include <linux/pkeys.h>
> #include <asm/uaccess.h>
> #include <asm/pgtable.h>
> #include <asm/cacheflush.h>
> @@ -344,10 +345,13 @@ fail:
> return error;
> }
>
> -SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
> - unsigned long, prot)
> +/*
> + * pkey=-1 when doing a legacy mprotect()
> + */
> +static int do_mprotect_pkey(unsigned long start, size_t len,
> + unsigned long prot, int pkey)
> {
> - unsigned long vm_flags, nstart, end, tmp, reqprot;
> + unsigned long nstart, end, tmp, reqprot;
> struct vm_area_struct *vma, *prev;
> int error = -EINVAL;
> const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
> @@ -373,8 +377,6 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
> if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
> prot |= PROT_EXEC;
>
> - vm_flags = calc_vm_prot_bits(prot, 0);
> -
> down_write(¤t->mm->mmap_sem);
>
> vma = find_vma(current->mm, start);
> @@ -407,7 +409,14 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
>
> /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
>
> - newflags = vm_flags;
> + /*
> + * If this is a vanilla, non-pkey mprotect, inherit the
> + * pkey from the VMA we are working on.
> + */
> + if (pkey == -1)
> + newflags = calc_vm_prot_bits(prot, vma_pkey(vma));
> + else
> + newflags = calc_vm_prot_bits(prot, pkey);
> newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
>
> /* newflags >> 4 shift VM_MAY% in place of VM_% */
> @@ -443,3 +452,18 @@ out:
> up_write(¤t->mm->mmap_sem);
> return error;
> }
> +
> +SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
> + unsigned long, prot)
> +{
> + return do_mprotect_pkey(start, len, prot, -1);
> +}
> +
> +SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len,
> + unsigned long, prot, int, pkey)
> +{
> + if (!arch_validate_pkey(pkey))
> + return -EINVAL;
> +
> + return do_mprotect_pkey(start, len, prot, pkey);
> +}
> _
> --
> To unsubscribe from this list: send the line "unsubscribe linux-api" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: "Michael Kerrisk (man-pages)" <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Dave Hansen <dave-gkUM19QKKo4@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
dave.hansen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 26/34] mm: implement new mprotect_key() system call
Date: Sat, 05 Dec 2015 07:50:51 +0100 [thread overview]
Message-ID: <5662894B.7090903@gmail.com> (raw)
In-Reply-To: <20151204011500.69487A6C-LXbPSdftPKxrdx17CPfAsdBPR1lH4CV8@public.gmane.org>
Dave,
On 12/04/2015 02:15 AM, Dave Hansen wrote:
> From: Dave Hansen <dave.hansen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
>
> mprotect_key() is just like mprotect, except it also takes a
> protection key as an argument. On systems that do not support
> protection keys, it still works, but requires that key=0.
> Otherwise it does exactly what mprotect does.
Is there a man page for this API?
Thanks,
Michael
> I expect it to get used like this, if you want to guarantee that
> any mapping you create can *never* be accessed without the right
> protection keys set up.
>
> pkey_deny_access(11); // random pkey
> int real_prot = PROT_READ|PROT_WRITE;
> ptr = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
> ret = mprotect_key(ptr, PAGE_SIZE, real_prot, 11);
>
> This way, there is *no* window where the mapping is accessible
> since it was always either PROT_NONE or had a protection key set.
>
> We settled on 'unsigned long' for the type of the key here. We
> only need 4 bits on x86 today, but I figured that other
> architectures might need some more space.
>
> Signed-off-by: Dave Hansen <dave.hansen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Cc: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> ---
>
> b/arch/x86/include/asm/mmu_context.h | 10 +++++++--
> b/include/linux/pkeys.h | 7 +++++-
> b/mm/Kconfig | 7 ++++++
> b/mm/mprotect.c | 36 +++++++++++++++++++++++++++++------
> 4 files changed, 51 insertions(+), 9 deletions(-)
>
> diff -puN arch/x86/include/asm/mmu_context.h~pkeys-85-mprotect_pkey arch/x86/include/asm/mmu_context.h
> --- a/arch/x86/include/asm/mmu_context.h~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.181877894 -0800
> +++ b/arch/x86/include/asm/mmu_context.h 2015-12-03 16:21:30.190878302 -0800
> @@ -4,6 +4,7 @@
> #include <asm/desc.h>
> #include <linux/atomic.h>
> #include <linux/mm_types.h>
> +#include <linux/pkeys.h>
>
> #include <trace/events/tlb.h>
>
> @@ -243,10 +244,14 @@ static inline void arch_unmap(struct mm_
> mpx_notify_unmap(mm, vma, start, end);
> }
>
> +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> +/*
> + * If the config option is off, we get the generic version from
> + * include/linux/pkeys.h.
> + */
> static inline int vma_pkey(struct vm_area_struct *vma)
> {
> u16 pkey = 0;
> -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 |
> VM_PKEY_BIT2 | VM_PKEY_BIT3;
> /*
> @@ -259,9 +264,10 @@ static inline int vma_pkey(struct vm_are
> */
> pkey = (vma->vm_flags >> vm_pkey_shift) &
> (vma_pkey_mask >> vm_pkey_shift);
> -#endif
> +
> return pkey;
> }
> +#endif
>
> static inline bool __pkru_allows_pkey(u16 pkey, bool write)
> {
> diff -puN include/linux/pkeys.h~pkeys-85-mprotect_pkey include/linux/pkeys.h
> --- a/include/linux/pkeys.h~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.183877985 -0800
> +++ b/include/linux/pkeys.h 2015-12-03 16:21:30.190878302 -0800
> @@ -2,10 +2,10 @@
> #define _LINUX_PKEYS_H
>
> #include <linux/mm_types.h>
> -#include <asm/mmu_context.h>
>
> #ifdef CONFIG_ARCH_HAS_PKEYS
> #include <asm/pkeys.h>
> +#include <asm/mmu_context.h>
> #else /* ! CONFIG_ARCH_HAS_PKEYS */
>
> /*
> @@ -17,6 +17,11 @@ static inline bool arch_validate_pkey(in
> {
> return true;
> }
> +
> +static inline int vma_pkey(struct vm_area_struct *vma)
> +{
> + return 0;
> +}
> #endif /* ! CONFIG_ARCH_HAS_PKEYS */
>
> #endif /* _LINUX_PKEYS_H */
> diff -puN mm/Kconfig~pkeys-85-mprotect_pkey mm/Kconfig
> --- a/mm/Kconfig~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.185878075 -0800
> +++ b/mm/Kconfig 2015-12-03 16:21:30.190878302 -0800
> @@ -673,3 +673,10 @@ config ARCH_USES_HIGH_VMA_FLAGS
> bool
> config ARCH_HAS_PKEYS
> bool
> +
> +config NR_PROTECTION_KEYS
> + int
> + # Everything supports a _single_ key, so allow folks to
> + # at least call APIs that take keys, but require that the
> + # key be 0.
> + default 1
> diff -puN mm/mprotect.c~pkeys-85-mprotect_pkey mm/mprotect.c
> --- a/mm/mprotect.c~pkeys-85-mprotect_pkey 2015-12-03 16:21:30.186878121 -0800
> +++ b/mm/mprotect.c 2015-12-03 16:21:30.191878347 -0800
> @@ -24,6 +24,7 @@
> #include <linux/migrate.h>
> #include <linux/perf_event.h>
> #include <linux/ksm.h>
> +#include <linux/pkeys.h>
> #include <asm/uaccess.h>
> #include <asm/pgtable.h>
> #include <asm/cacheflush.h>
> @@ -344,10 +345,13 @@ fail:
> return error;
> }
>
> -SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
> - unsigned long, prot)
> +/*
> + * pkey=-1 when doing a legacy mprotect()
> + */
> +static int do_mprotect_pkey(unsigned long start, size_t len,
> + unsigned long prot, int pkey)
> {
> - unsigned long vm_flags, nstart, end, tmp, reqprot;
> + unsigned long nstart, end, tmp, reqprot;
> struct vm_area_struct *vma, *prev;
> int error = -EINVAL;
> const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
> @@ -373,8 +377,6 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
> if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
> prot |= PROT_EXEC;
>
> - vm_flags = calc_vm_prot_bits(prot, 0);
> -
> down_write(¤t->mm->mmap_sem);
>
> vma = find_vma(current->mm, start);
> @@ -407,7 +409,14 @@ SYSCALL_DEFINE3(mprotect, unsigned long,
>
> /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
>
> - newflags = vm_flags;
> + /*
> + * If this is a vanilla, non-pkey mprotect, inherit the
> + * pkey from the VMA we are working on.
> + */
> + if (pkey == -1)
> + newflags = calc_vm_prot_bits(prot, vma_pkey(vma));
> + else
> + newflags = calc_vm_prot_bits(prot, pkey);
> newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
>
> /* newflags >> 4 shift VM_MAY% in place of VM_% */
> @@ -443,3 +452,18 @@ out:
> up_write(¤t->mm->mmap_sem);
> return error;
> }
> +
> +SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
> + unsigned long, prot)
> +{
> + return do_mprotect_pkey(start, len, prot, -1);
> +}
> +
> +SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len,
> + unsigned long, prot, int, pkey)
> +{
> + if (!arch_validate_pkey(pkey))
> + return -EINVAL;
> +
> + return do_mprotect_pkey(start, len, prot, pkey);
> +}
> _
> --
> To unsubscribe from this list: send the line "unsubscribe linux-api" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
next prev parent reply other threads:[~2015-12-05 6:50 UTC|newest]
Thread overview: 145+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-04 1:14 [PATCH 00/34] x86: Memory Protection Keys (v5) Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 01/34] mm, gup: introduce concept of "foreign" get_user_pages() Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 02/34] x86, fpu: add placeholder for Processor Trace XSAVE state Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 03/34] x86, pkeys: Add Kconfig option Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 04/34] x86, pkeys: cpuid bit definition Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 05/34] x86, pkeys: define new CR4 bit Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 06/34] x86, pkeys: add PKRU xsave fields and data structure(s) Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 07/34] x86, pkeys: PTE bits for storing protection key Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 08/34] x86, pkeys: new page fault error code bit: PF_PK Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 09/34] x86, pkeys: store protection in high VMA flags Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 14:17 ` Thomas Gleixner
2015-12-08 14:17 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 10/34] x86, pkeys: arch-specific protection bits Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 15:15 ` [PATCH 10/34] x86, pkeys: arch-specific protection bitsy Thomas Gleixner
2015-12-08 15:15 ` Thomas Gleixner
2015-12-08 16:34 ` Dave Hansen
2015-12-08 16:34 ` Dave Hansen
2015-12-08 17:24 ` Thomas Gleixner
2015-12-08 17:24 ` Thomas Gleixner
2015-12-08 18:06 ` Dave Hansen
2015-12-08 18:29 ` Thomas Gleixner
2015-12-08 18:29 ` Thomas Gleixner
2015-12-08 18:35 ` Thomas Gleixner
2015-12-08 18:35 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 11/34] x86, pkeys: pass VMA down in to fault signal generation code Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 12/34] signals, pkeys: notify userspace about protection key faults Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 13/34] x86, pkeys: fill in pkey field in siginfo Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 14/34] x86, pkeys: add functions to fetch PKRU Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 15:18 ` Thomas Gleixner
2015-12-08 15:18 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 15/34] mm: factor out VMA fault permission checking Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 17:26 ` Thomas Gleixner
2015-12-08 17:26 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 16/34] x86, mm: simplify get_user_pages() PTE bit handling Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 18:01 ` Thomas Gleixner
2015-12-08 18:01 ` Thomas Gleixner
2015-12-08 18:30 ` Dave Hansen
2015-12-08 18:30 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 17/34] x86, pkeys: check VMAs and PTEs for protection keys Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 18:11 ` Thomas Gleixner
2015-12-08 18:11 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 18/34] mm: add gup flag to indicate "foreign" mm access Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 19/34] x86, pkeys: optimize fault handling in access_error() Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 18:14 ` Thomas Gleixner
2015-12-08 18:14 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 20/34] x86, pkeys: differentiate instruction fetches Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 18:17 ` Thomas Gleixner
2015-12-08 18:17 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 21/34] x86, pkeys: dump PKRU with other kernel registers Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 18:19 ` Thomas Gleixner
2015-12-08 18:19 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 22/34] x86, pkeys: dump PTE pkey in /proc/pid/smaps Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 18:20 ` Thomas Gleixner
2015-12-08 18:20 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 23/34] x86, pkeys: add Kconfig prompt to existing config option Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 18:21 ` Thomas Gleixner
2015-12-08 18:21 ` Thomas Gleixner
2015-12-04 1:14 ` [PATCH 24/34] mm, multi-arch: pass a protection key in to calc_vm_flag_bits() Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-04 1:14 ` [PATCH 25/34] x86, pkeys: add arch_validate_pkey() Dave Hansen
2015-12-04 1:14 ` Dave Hansen
2015-12-08 18:39 ` Thomas Gleixner
2015-12-08 18:39 ` Thomas Gleixner
2015-12-04 1:15 ` [PATCH 26/34] mm: implement new mprotect_key() system call Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-05 6:50 ` Michael Kerrisk (man-pages) [this message]
2015-12-05 6:50 ` Michael Kerrisk (man-pages)
2015-12-05 6:50 ` Michael Kerrisk (man-pages)
2015-12-07 16:44 ` Dave Hansen
2015-12-07 16:44 ` Dave Hansen
2015-12-09 11:08 ` Michael Kerrisk (man-pages)
2015-12-09 11:08 ` Michael Kerrisk (man-pages)
2015-12-09 15:48 ` Dave Hansen
2015-12-09 15:48 ` Dave Hansen
2015-12-09 16:45 ` Michael Kerrisk (man-pages)
2015-12-09 16:45 ` Michael Kerrisk (man-pages)
2015-12-09 16:45 ` Michael Kerrisk (man-pages)
2015-12-09 17:05 ` Dave Hansen
2015-12-09 17:05 ` Dave Hansen
2015-12-09 17:05 ` Dave Hansen
2015-12-11 20:13 ` Michael Kerrisk (man-pages)
2015-12-11 20:13 ` Michael Kerrisk (man-pages)
2015-12-04 1:15 ` [PATCH 27/34] x86, pkeys: make mprotect_key() mask off additional vm_flags Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-08 18:41 ` Thomas Gleixner
2015-12-08 18:41 ` Thomas Gleixner
2015-12-04 1:15 ` [PATCH 28/34] x86: wire up mprotect_key() system call Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-08 18:44 ` Thomas Gleixner
2015-12-08 18:44 ` Thomas Gleixner
2015-12-08 18:44 ` Thomas Gleixner
2015-12-08 19:06 ` Dave Hansen
2015-12-08 19:06 ` Dave Hansen
2015-12-08 20:38 ` Thomas Gleixner
2015-12-08 20:38 ` Thomas Gleixner
2015-12-08 20:38 ` Thomas Gleixner
2015-12-04 1:15 ` [PATCH 29/34] x86: separate out LDT init from context init Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-08 18:45 ` Thomas Gleixner
2015-12-08 18:45 ` Thomas Gleixner
2015-12-04 1:15 ` [PATCH 30/34] x86, fpu: allow setting of XSAVE state Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-08 18:48 ` Thomas Gleixner
2015-12-08 18:48 ` Thomas Gleixner
2015-12-04 1:15 ` [PATCH 31/34] x86, pkeys: allocation/free syscalls Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-04 1:15 ` [PATCH 32/34] x86, pkeys: add pkey set/get syscalls Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-04 1:15 ` [PATCH 33/34] x86, pkeys: actually enable Memory Protection Keys in CPU Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-04 1:15 ` [PATCH 34/34] x86, pkeys: Documentation Dave Hansen
2015-12-04 1:15 ` Dave Hansen
2015-12-04 23:31 ` [PATCH 00/34] x86: Memory Protection Keys (v5) Andy Lutomirski
2015-12-04 23:31 ` Andy Lutomirski
2015-12-04 23:38 ` Dave Hansen
2015-12-04 23:38 ` Dave Hansen
2015-12-04 23:38 ` Dave Hansen
2015-12-11 20:16 ` Andy Lutomirski
2015-12-11 20:16 ` Andy Lutomirski
2015-12-11 20:16 ` Andy Lutomirski
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5662894B.7090903@gmail.com \
--to=mtk.manpages@gmail.com \
--cc=dave.hansen@linux.intel.com \
--cc=dave@sr71.net \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.