Commit Graph

3 Commits

Author SHA1 Message Date
Alex Sverdlin
3680442cba ARM: 9242/1: kasan: Only map modules if CONFIG_KASAN_VMALLOC=n
[ Upstream commit 823f606ab6b4759a1faf0388abcf4fb0776710d2 ]

In case CONFIG_KASAN_VMALLOC=y kasan_populate_vmalloc() allocates the
shadow pages dynamically. But even worse is that kasan_release_vmalloc()
releases them, which is not compatible with create_mapping() of
MODULES_VADDR..MODULES_END range:

BUG: Bad page state in process kworker/9:1  pfn:2068b
page:e5e06160 refcount:0 mapcount:0 mapping:00000000 index:0x0
flags: 0x1000(reserved)
raw: 00001000 e5e06164 e5e06164 00000000 00000000 00000000 ffffffff 00000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
bad because of flags: 0x1000(reserved)
Modules linked in: ip_tables
CPU: 9 PID: 154 Comm: kworker/9:1 Not tainted 5.4.188-... #1
Hardware name: LSI Axxia AXM55XX
Workqueue: events do_free_init
unwind_backtrace
show_stack
dump_stack
bad_page
free_pcp_prepare
free_unref_page
kasan_depopulate_vmalloc_pte
__apply_to_page_range
apply_to_existing_page_range
kasan_release_vmalloc
__purge_vmap_area_lazy
_vm_unmap_aliases.part.0
__vunmap
do_free_init
process_one_work
worker_thread
kthread

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 12:35:45 +02:00
Arnd Bergmann
a521a0ddd5 ARM: 9142/1: kasan: work around LPAE build warning
[ Upstream commit c2e6df3eaaf120cde5e7c3a70590dd82e427458a ]

pgd_page_vaddr() returns an 'unsigned long' address, causing a warning
with the memcpy() call in kasan_init():

arch/arm/mm/kasan_init.c: In function 'kasan_init':
include/asm-generic/pgtable-nop4d.h:44:50: error: passing argument 2 of '__memcpy' makes pointer from integer without a cast [-Werror=int-conversion]
   44 | #define pgd_page_vaddr(pgd)                     ((unsigned long)(p4d_pgtable((p4d_t){ pgd })))
      |                                                 ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |                                                  |
      |                                                  long unsigned int
arch/arm/include/asm/string.h:58:45: note: in definition of macro 'memcpy'
   58 | #define memcpy(dst, src, len) __memcpy(dst, src, len)
      |                                             ^~~
arch/arm/mm/kasan_init.c:229:16: note: in expansion of macro 'pgd_page_vaddr'
  229 |                pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_START)),
      |                ^~~~~~~~~~~~~~
arch/arm/include/asm/string.h:21:47: note: expected 'const void *' but argument is of type 'long unsigned int'
   21 | extern void *__memcpy(void *dest, const void *src, __kernel_size_t n);
      |                                   ~~~~~~~~~~~~^~~

Avoid this by adding an explicit typecast.

Link: https://lore.kernel.org/all/CACRpkdb3DMvof3-xdtss0Pc6KM36pJA-iy=WhvtNVnsDpeJ24Q@mail.gmail.com/

Fixes: 5615f69bc2 ("ARM: 9016/2: Initialize the mapping of KASan shadow memory")
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 19:16:41 +01:00
Linus Walleij
5615f69bc2 ARM: 9016/2: Initialize the mapping of KASan shadow memory
This patch initializes KASan shadow region's page table and memory.
There are two stage for KASan initializing:

1. At early boot stage the whole shadow region is mapped to just
   one physical page (kasan_zero_page). It is finished by the function
   kasan_early_init which is called by __mmap_switched(arch/arm/kernel/
   head-common.S)

2. After the calling of paging_init, we use kasan_zero_page as zero
   shadow for some memory that KASan does not need to track, and we
   allocate a new shadow space for the other memory that KASan need to
   track. These issues are finished by the function kasan_init which is
   call by setup_arch.

When using KASan we also need to increase the THREAD_SIZE_ORDER
from 1 to 2 as the extra calls for shadow memory uses quite a bit
of stack.

As we need to make a temporary copy of the PGD when setting up
shadow memory we create a helpful PGD_SIZE definition for both
LPAE and non-LPAE setups.

The KASan core code unconditionally calls pud_populate() so this
needs to be changed from BUG() to do {} while (0) when building
with KASan enabled.

After the initial development by Andre Ryabinin several modifications
have been made to this code:

Abbott Liu <liuwenliang@huawei.com>
- Add support ARM LPAE: If LPAE is enabled, KASan shadow region's
  mapping table need be copied in the pgd_alloc() function.
- Change kasan_pte_populate,kasan_pmd_populate,kasan_pud_populate,
  kasan_pgd_populate from .meminit.text section to .init.text section.
  Reported by Florian Fainelli <f.fainelli@gmail.com>

Linus Walleij <linus.walleij@linaro.org>:
- Drop the custom mainpulation of TTBR0 and just use
  cpu_switch_mm() to switch the pgd table.
- Adopt to handle 4th level page tabel folding.
- Rewrite the entire page directory and page entry initialization
  sequence to be recursive based on ARM64:s kasan_init.c.

Ard Biesheuvel <ardb@kernel.org>:
- Necessary underlying fixes.
- Crucial bug fixes to the memory set-up code.

Co-developed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Co-developed-by: Abbott Liu <liuwenliang@huawei.com>
Co-developed-by: Ard Biesheuvel <ardb@kernel.org>

Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Ard Biesheuvel <ardb@kernel.org> # QEMU/KVM/mach-virt/LPAE/8G
Tested-by: Florian Fainelli <f.fainelli@gmail.com> # Brahma SoCs
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # i.MX6Q
Reported-by: Russell King - ARM Linux <rmk+kernel@armlinux.org.uk>
Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Abbott Liu <liuwenliang@huawei.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2020-10-27 12:11:10 +00:00