diff mbox series

[v2,24/34] kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged

Message ID a1f0413493eb7db125c3f8086f5d8635b627fd2c.1638825394.git.andreyknvl@google.com (mailing list archive)
State New
Headers show
Series kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS | expand

Commit Message

andrey.konovalov@linux.dev Dec. 6, 2021, 9:44 p.m. UTC
From: Andrey Konovalov <andreyknvl@google.com>

HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE). With MTE,
a memory region must be mapped as MT_NORMAL_TAGGED to allow setting
memory tags via MTE-specific instructions.

This change adds proper protection bits to vmalloc() allocations.
These allocations are always backed by page_alloc pages, so the tags
will actually be getting set on the corresponding physical memory.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/arm64/include/asm/vmalloc.h | 10 ++++++++++
 include/linux/vmalloc.h          |  7 +++++++
 mm/vmalloc.c                     |  2 ++
 3 files changed, 19 insertions(+)

Comments

Andrey Konovalov Dec. 6, 2021, 9:48 p.m. UTC | #1
On Mon, Dec 6, 2021 at 10:46 PM <andrey.konovalov@linux.dev> wrote:
>
> From: Andrey Konovalov <andreyknvl@google.com>
>
> HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE). With MTE,
> a memory region must be mapped as MT_NORMAL_TAGGED to allow setting
> memory tags via MTE-specific instructions.
>
> This change adds proper protection bits to vmalloc() allocations.
> These allocations are always backed by page_alloc pages, so the tags
> will actually be getting set on the corresponding physical memory.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> ---
>  arch/arm64/include/asm/vmalloc.h | 10 ++++++++++
>  include/linux/vmalloc.h          |  7 +++++++
>  mm/vmalloc.c                     |  2 ++
>  3 files changed, 19 insertions(+)
>
> diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h
> index b9185503feae..3d35adf365bf 100644
> --- a/arch/arm64/include/asm/vmalloc.h
> +++ b/arch/arm64/include/asm/vmalloc.h
> @@ -25,4 +25,14 @@ static inline bool arch_vmap_pmd_supported(pgprot_t prot)
>
>  #endif
>
> +#define arch_vmalloc_pgprot_modify arch_vmalloc_pgprot_modify
> +static inline pgprot_t arch_vmalloc_pgprot_modify(pgprot_t prot)
> +{
> +       if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&
> +                       (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)))
> +               prot = pgprot_tagged(prot);
> +
> +       return prot;
> +}
> +
>  #endif /* _ASM_ARM64_VMALLOC_H */
> diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> index b22369f540eb..965c4bf475f1 100644
> --- a/include/linux/vmalloc.h
> +++ b/include/linux/vmalloc.h
> @@ -108,6 +108,13 @@ static inline int arch_vmap_pte_supported_shift(unsigned long size)
>  }
>  #endif
>
> +#ifndef arch_vmalloc_pgprot_modify
> +static inline pgprot_t arch_vmalloc_pgprot_modify(pgprot_t prot)
> +{
> +       return prot;
> +}
> +#endif
> +
>  /*
>   *     Highlevel APIs for driver use
>   */
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 7be18b292679..f37d0ed99bf9 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -3033,6 +3033,8 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
>                 return NULL;
>         }
>
> +       prot = arch_vmalloc_pgprot_modify(prot);
> +
>         if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
>                 unsigned long size_per_node;
>
> --
> 2.25.1
>

Hi Vincenzo,

This patch is based on an early version of the HW_TAGS series you had.
Could you PTAL and give your sign-off?

Thanks!
Vincenzo Frascino Dec. 13, 2021, 3:17 p.m. UTC | #2
Hi Andrey,

On 12/6/21 9:44 PM, andrey.konovalov@linux.dev wrote:
> From: Andrey Konovalov <andreyknvl@google.com>
> 
> HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE). With MTE,
> a memory region must be mapped as MT_NORMAL_TAGGED to allow setting
> memory tags via MTE-specific instructions.
> 
> This change adds proper protection bits to vmalloc() allocations.

Please avoid "this patch/this change" in patch description and use imperative
mode as if you are giving a command to the code base ([1] paragraph 2).

> These allocations are always backed by page_alloc pages, so the tags
> will actually be getting set on the corresponding physical memory.
> 
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

With the change to the commit message:

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
>  arch/arm64/include/asm/vmalloc.h | 10 ++++++++++
>  include/linux/vmalloc.h          |  7 +++++++
>  mm/vmalloc.c                     |  2 ++
>  3 files changed, 19 insertions(+)
> 
> diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h
> index b9185503feae..3d35adf365bf 100644
> --- a/arch/arm64/include/asm/vmalloc.h
> +++ b/arch/arm64/include/asm/vmalloc.h
> @@ -25,4 +25,14 @@ static inline bool arch_vmap_pmd_supported(pgprot_t prot)
>  
>  #endif
>  
> +#define arch_vmalloc_pgprot_modify arch_vmalloc_pgprot_modify
> +static inline pgprot_t arch_vmalloc_pgprot_modify(pgprot_t prot)
> +{
> +	if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&
> +			(pgprot_val(prot) == pgprot_val(PAGE_KERNEL)))
> +		prot = pgprot_tagged(prot);
> +
> +	return prot;
> +}
> +
>  #endif /* _ASM_ARM64_VMALLOC_H */
> diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> index b22369f540eb..965c4bf475f1 100644
> --- a/include/linux/vmalloc.h
> +++ b/include/linux/vmalloc.h
> @@ -108,6 +108,13 @@ static inline int arch_vmap_pte_supported_shift(unsigned long size)
>  }
>  #endif
>  
> +#ifndef arch_vmalloc_pgprot_modify
> +static inline pgprot_t arch_vmalloc_pgprot_modify(pgprot_t prot)
> +{
> +	return prot;
> +}
> +#endif
> +
>  /*
>   *	Highlevel APIs for driver use
>   */
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 7be18b292679..f37d0ed99bf9 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -3033,6 +3033,8 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
>  		return NULL;
>  	}
>  
> +	prot = arch_vmalloc_pgprot_modify(prot);
> +
>  	if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
>  		unsigned long size_per_node;
>  
>
Andrey Konovalov Dec. 13, 2021, 9:57 p.m. UTC | #3
On Mon, Dec 13, 2021 at 4:17 PM Vincenzo Frascino
<vincenzo.frascino@arm.com> wrote:
>
> Hi Andrey,
>
> On 12/6/21 9:44 PM, andrey.konovalov@linux.dev wrote:
> > From: Andrey Konovalov <andreyknvl@google.com>
> >
> > HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE). With MTE,
> > a memory region must be mapped as MT_NORMAL_TAGGED to allow setting
> > memory tags via MTE-specific instructions.
> >
> > This change adds proper protection bits to vmalloc() allocations.
>
> Please avoid "this patch/this change" in patch description and use imperative
> mode as if you are giving a command to the code base ([1] paragraph 2).

Hi Vincenzo,

Done in v3.

> > These allocations are always backed by page_alloc pages, so the tags
> > will actually be getting set on the corresponding physical memory.
> >
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
>
> With the change to the commit message:
>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

Thanks!
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h
index b9185503feae..3d35adf365bf 100644
--- a/arch/arm64/include/asm/vmalloc.h
+++ b/arch/arm64/include/asm/vmalloc.h
@@ -25,4 +25,14 @@  static inline bool arch_vmap_pmd_supported(pgprot_t prot)
 
 #endif
 
+#define arch_vmalloc_pgprot_modify arch_vmalloc_pgprot_modify
+static inline pgprot_t arch_vmalloc_pgprot_modify(pgprot_t prot)
+{
+	if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&
+			(pgprot_val(prot) == pgprot_val(PAGE_KERNEL)))
+		prot = pgprot_tagged(prot);
+
+	return prot;
+}
+
 #endif /* _ASM_ARM64_VMALLOC_H */
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index b22369f540eb..965c4bf475f1 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -108,6 +108,13 @@  static inline int arch_vmap_pte_supported_shift(unsigned long size)
 }
 #endif
 
+#ifndef arch_vmalloc_pgprot_modify
+static inline pgprot_t arch_vmalloc_pgprot_modify(pgprot_t prot)
+{
+	return prot;
+}
+#endif
+
 /*
  *	Highlevel APIs for driver use
  */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 7be18b292679..f37d0ed99bf9 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3033,6 +3033,8 @@  void *__vmalloc_node_range(unsigned long size, unsigned long align,
 		return NULL;
 	}
 
+	prot = arch_vmalloc_pgprot_modify(prot);
+
 	if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
 		unsigned long size_per_node;