iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged

Browse Source 
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.

Add 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.

Link: https://lkml.kernel.org/r/983fc33542db2f6b1e77b34ca23448d4640bbb9e.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrey Konovalov 2022-03-24 18:11:16 -07:00 committed by Linus Torvalds
parent 1d96320f8d
commit 01d92c7f35
3 changed files with 22 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm64/include/asm/vmalloc.h
View File

@ -25,4 +25,10 @@ static inline bool arch_vmap_pmd_supported(pgprot_t prot)
#endif #endif
#define arch_vmap_pgprot_tagged arch_vmap_pgprot_tagged
static inline pgprot_t arch_vmap_pgprot_tagged(pgprot_t prot)
{
return pgprot_tagged(prot);
}
#endif /* _ASM_ARM64_VMALLOC_H */ #endif /* _ASM_ARM64_VMALLOC_H */

7
include/linux/vmalloc.h
View File

@ -115,6 +115,13 @@ static inline int arch_vmap_pte_supported_shift(unsigned long size)
} }
#endif #endif
#ifndef arch_vmap_pgprot_tagged
static inline pgprot_t arch_vmap_pgprot_tagged(pgprot_t prot)
{
return prot;
}
#endif
/* /*
* Highlevel APIs for driver use * Highlevel APIs for driver use
*/ */

9
mm/vmalloc.c
View File

@ -3128,6 +3128,15 @@ again:
goto fail; goto fail;
} }
/*
* Modify protection bits to allow tagging.
* This must be done before mapping by __vmalloc_area_node().
*/
if (kasan_hw_tags_enabled() &&
pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
prot = arch_vmap_pgprot_tagged(prot);
/* Allocate physical pages and map them into vmalloc space. */
addr = __vmalloc_area_node(area, gfp_mask, prot, shift, node); addr = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
if (!addr) if (!addr)
goto fail; goto fail;