From: Andrei Vagin <avagin@gmail.com> To: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Andrei Vagin <avagin@gmail.com>, Thomas Gleixner <tglx@linutronix.de>, Dmitry Safonov <dima@arista.com> Subject: [PATCH v2 5/6] arm64/vdso: Restrict splitting VVAR VMA Date: Mon, 24 Feb 2020 23:37:30 -0800 [thread overview] Message-ID: <20200225073731.465270-6-avagin@gmail.com> (raw) In-Reply-To: <20200225073731.465270-1-avagin@gmail.com> Forbid splitting VVAR VMA resulting in a stricter ABI and reducing the amount of corner-cases to consider while working further on VDSO time namespace support. As the offset from timens to VVAR page is computed compile-time, the pages in VVAR should stay together and not being partically mremap()'ed. Signed-off-by: Andrei Vagin <avagin@gmail.com> --- arch/arm64/kernel/vdso.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index fb32c6f76078..c003f7ee383a 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -235,6 +235,17 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, return vmf_insert_pfn(vma, vmf->address, pfn); } +static int vvar_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + unsigned long new_size = new_vma->vm_end - new_vma->vm_start; + + if (new_size != VVAR_NR_PAGES * PAGE_SIZE) + return -EINVAL; + + return 0; +} + static int __setup_additional_pages(enum arch_vdso_type arch_index, struct mm_struct *mm, struct linux_binprm *bprm, @@ -315,6 +326,7 @@ static struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }, { .name = "[vdso]", @@ -497,6 +509,7 @@ static struct vm_special_mapping vdso_spec[A_PAGES] __ro_after_init = { { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }, { .name = "[vdso]", -- 2.24.1
WARNING: multiple messages have this Message-ID (diff)
From: Andrei Vagin <avagin@gmail.com> To: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de>, Andrei Vagin <avagin@gmail.com>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Dmitry Safonov <dima@arista.com> Subject: [PATCH v2 5/6] arm64/vdso: Restrict splitting VVAR VMA Date: Mon, 24 Feb 2020 23:37:30 -0800 [thread overview] Message-ID: <20200225073731.465270-6-avagin@gmail.com> (raw) In-Reply-To: <20200225073731.465270-1-avagin@gmail.com> Forbid splitting VVAR VMA resulting in a stricter ABI and reducing the amount of corner-cases to consider while working further on VDSO time namespace support. As the offset from timens to VVAR page is computed compile-time, the pages in VVAR should stay together and not being partically mremap()'ed. Signed-off-by: Andrei Vagin <avagin@gmail.com> --- arch/arm64/kernel/vdso.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index fb32c6f76078..c003f7ee383a 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -235,6 +235,17 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, return vmf_insert_pfn(vma, vmf->address, pfn); } +static int vvar_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + unsigned long new_size = new_vma->vm_end - new_vma->vm_start; + + if (new_size != VVAR_NR_PAGES * PAGE_SIZE) + return -EINVAL; + + return 0; +} + static int __setup_additional_pages(enum arch_vdso_type arch_index, struct mm_struct *mm, struct linux_binprm *bprm, @@ -315,6 +326,7 @@ static struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }, { .name = "[vdso]", @@ -497,6 +509,7 @@ static struct vm_special_mapping vdso_spec[A_PAGES] __ro_after_init = { { .name = "[vvar]", .fault = vvar_fault, + .mremap = vvar_mremap, }, { .name = "[vdso]", -- 2.24.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-02-25 7:37 UTC|newest] Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-25 7:37 [PATCH v2 0/6] arm64: add the time namespace support Andrei Vagin 2020-02-25 7:37 ` Andrei Vagin 2020-02-25 7:37 ` [PATCH v2 1/6] arm64/vdso: use the fault callback to map vvar pages Andrei Vagin 2020-02-25 7:37 ` Andrei Vagin 2020-04-09 12:01 ` Vincenzo Frascino 2020-04-09 12:01 ` Vincenzo Frascino 2020-02-25 7:37 ` [PATCH v2 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace Andrei Vagin 2020-02-25 7:37 ` Andrei Vagin 2020-04-09 12:01 ` Vincenzo Frascino 2020-04-09 12:01 ` Vincenzo Frascino 2020-02-25 7:37 ` [PATCH v2 3/6] arm64/vdso: Add time napespace page Andrei Vagin 2020-02-25 7:37 ` Andrei Vagin 2020-04-09 12:03 ` Vincenzo Frascino 2020-04-09 12:03 ` Vincenzo Frascino 2020-04-14 17:20 ` Mark Rutland 2020-04-14 17:20 ` Mark Rutland 2020-04-15 2:34 ` Andrei Vagin 2020-04-15 2:34 ` Andrei Vagin 2020-04-15 10:05 ` Mark Rutland 2020-04-15 10:05 ` Mark Rutland 2020-04-15 10:16 ` Vincenzo Frascino 2020-04-15 10:16 ` Vincenzo Frascino 2020-04-15 12:27 ` Mark Rutland 2020-04-15 12:27 ` Mark Rutland 2020-02-25 7:37 ` [PATCH v2 4/6] arm64/vdso: Handle faults on timens page Andrei Vagin 2020-02-25 7:37 ` Andrei Vagin 2020-04-09 12:04 ` Vincenzo Frascino 2020-04-09 12:04 ` Vincenzo Frascino 2020-02-25 7:37 ` Andrei Vagin [this message] 2020-02-25 7:37 ` [PATCH v2 5/6] arm64/vdso: Restrict splitting VVAR VMA Andrei Vagin 2020-04-09 12:05 ` Vincenzo Frascino 2020-04-09 12:05 ` Vincenzo Frascino 2020-02-25 7:37 ` [PATCH v2 6/6] arm64: enable time namespace support Andrei Vagin 2020-02-25 7:37 ` Andrei Vagin 2020-04-09 12:06 ` Vincenzo Frascino 2020-04-09 12:06 ` Vincenzo Frascino 2020-04-01 6:50 ` [PATCH v2 0/6] arm64: add the " Andrei Vagin 2020-04-01 6:50 ` Andrei Vagin 2020-04-01 9:02 ` Vincenzo Frascino 2020-04-01 9:02 ` Vincenzo Frascino 2020-04-09 13:24 ` Vincenzo Frascino 2020-04-09 13:24 ` Vincenzo Frascino 2020-04-11 7:33 ` Andrei Vagin 2020-04-11 7:33 ` Andrei Vagin 2020-04-14 9:02 ` Vincenzo Frascino 2020-04-14 9:02 ` Vincenzo Frascino 2020-04-15 16:14 ` Andrei Vagin 2020-04-15 16:14 ` Andrei Vagin 2020-04-15 16:35 ` Vincenzo Frascino 2020-04-15 16:35 ` Vincenzo Frascino
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