On 10/12/2020 2:56 PM, Linus Walleij wrote:

This is the 15th iteration of KASan for ARM/Aarch32.

I dropped my fix in the beginning of the series for
Ard's more elaborate and thorough fix moving the DTB
out of the kernel linear mapped region and into its own
part of the memory.

This fixes my particular issue on the Qualcomm APQ8060
and I hope it may also solve Florian's issue and what
Ard has been seeing. KASan should be working with
pretty much everything you throw on it, unless you
do what I did and ran it on a 64MB system, where
under some load it can run into the OOM killer for
obvious reasons.

You are encouraged to test this patch set to find memory out
of bounds bugs with ARM32 platforms and drivers.

There is a git branch you can pull in:
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git/log/?h=kasan

This branch includes Ard's two patches.

As Ard's patches are in Russell's patch tracker I will
put these there as well if it now works for everyone.

Tested-by: Florian Fainelli <f.fainelli@gmail.com>

On Brahma-B15 (ARMv7 LPAE) and Brahma-B53 (ARMv8 in AArch32, also with 
LPAE). The 3 Cortex-A72 devices that I have access to all fail with the 
following (not related to the CPU type, more to the memory map) which I 
am hoping to track down later this week, I would not consider those 
failures to be a blocker at this point.

Thanks a lot for your persistence working on this Linus, and Ard!


[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 5.9.0-gdf4dd84a3f7d 
(fainelli@fainelli-desktop) (arm-linux-gcc (GCC) 8.3.0, GNU ld (GNU 
Binutils) 2.32) #16 SMP Mon Oct 12 20:01:43 PDT 2020
[    0.000000] CPU: ARMv7 Processor [410fd083] revision 3 (ARMv7), 
cr=30c5383d
[    0.000000] CPU: div instructions available: patching division code
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction 
cache
[    0.000000] OF: fdt: Machine model: BCM972112SV
[    0.000000] earlycon: pl11 at MMIO 0x000000047e201000 (options '115200')
[    0.000000] printk: bootconsole [pl11] enabled
[    0.000000] Memory policy: Data cache writealloc
[    0.000000] cma: Reserved 16 MiB at 0x000000007f000000
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000000000000-0x000000002fffffff]
[    0.000000]   Normal   empty
[    0.000000]   HighMem  [mem 0x0000000030000000-0x000000007fffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000000000-0x00000000063fdfff]
[    0.000000]   node   0: [mem 0x0000000006400000-0x000000000fffffff]
[    0.000000]   node   0: [mem 0x0000000010400000-0x000000007fffffff]
[    0.000000] Zeroed struct page in unavailable ranges: 2 pages
[    0.000000] Initmem setup node 0 [mem 
0x0000000000000000-0x000000007fffffff]
[    0.000000] kasan: Mapping kernel virtual memory block: 
c0000000-c63fe000 at shadow: b7000000-b7c7fc00
[    0.000000] Kernel panic - not syncing: kasan_pte_populate failed to 
alloc pte for address 0xe2806000
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 
5.9.0-gdf4dd84a3f7d #16
[    0.000000] Hardware name: Broadcom STB (Flattened Device Tree)
[    0.000000] Backtrace:
[    0.000000] [<c02120b4>] (dump_backtrace) from [<c02123d8>] 
(show_stack+0x20/0x24)
[    0.000000]  r9:ffffffff r8:00000080 r7:c298e3c0 r6:600000d3 
r5:00000000 r4:c298e3c0
[    0.000000] [<c02123b8>] (show_stack) from [<c08852a0>] 
(dump_stack+0xbc/0xe0)
[    0.000000] [<c08851e4>] (dump_stack) from [<c022fbec>] 
(panic+0x19c/0x3e4)
[    0.000000]  r10:e2806000 r9:c2b790e0 r8:c166b410 r7:c2803d80 
r6:00000000 r5:c2b7de80
[    0.000000]  r4:c2b78e20 r3:00000001
[    0.000000] [<c022fa50>] (panic) from [<c180b960>] 
(kasan_pgd_populate+0x1ac/0x26c)
[    0.000000]  r3:00000000 r2:e2806000 r1:c12126d4 r0:c166b410
[    0.000000]  r7:b7c7fc00
[    0.000000] [<c180b7b4>] (kasan_pgd_populate) from [<c180ba78>] 
(create_mapping+0x58/0x64)
[    0.000000]  r10:c166b4e4 r9:00000000 r8:063fe000 r7:c2ba0a40 
r6:c28a24e0 r5:b7000000
[    0.000000]  r4:b7c7fc00
[    0.000000] [<c180ba20>] (create_mapping) from [<c180bd58>] 
(kasan_init+0x26c/0x390)
[    0.000000]  r5:00000000 r4:c0000000
[    0.000000] [<c180baec>] (kasan_init) from [<c1805728>] 
(setup_arch+0x288/0xa28)
[    0.000000]  r10:c1861238 r9:410fd083 r8:c0008000 r7:c1873a40 
r6:c2803fbc r5:c2fdcf60
[    0.000000]  r4:c28a2280
[    0.000000] [<c18054a0>] (setup_arch) from [<c1801010>] 
(start_kernel+0x88/0x3e4)
[    0.000000]  r10:c2806d40 r9:410fd083 r8:0e415000 r7:ffffffff 
r6:30c0387d r5:c2806d48
[    0.000000]  r4:00007000
[    0.000000] [<c1800f88>] (start_kernel) from [<00000000>] (0x0)
[    0.000000]  r10:30c5387d r9:410fd083 r8:0e415000 r7:ffffffff 
r6:30c0387d r5:00000000
[    0.000000]  r4:c1800334
[    0.000000] ---[ end Kernel panic - not syncing: kasan_pte_populate 
failed to alloc pte for address 0xe2806000 ]---

Abbott Liu (1):
   ARM: Define the virtual space of KASan's shadow region

Andrey Ryabinin (3):
   ARM: Disable KASan instrumentation for some code
   ARM: Replace string mem* functions for KASan
   ARM: Enable KASan for ARM

Linus Walleij (1):
   ARM: Initialize the mapping of KASan shadow memory

  Documentation/arm/memory.rst                  |   5 +
  Documentation/dev-tools/kasan.rst             |   4 +-
  .../features/debug/KASAN/arch-support.txt     |   2 +-
  arch/arm/Kconfig                              |  10 +
  arch/arm/boot/compressed/Makefile             |   1 +
  arch/arm/boot/compressed/string.c             |  19 ++
  arch/arm/include/asm/kasan.h                  |  33 ++
  arch/arm/include/asm/kasan_def.h              |  81 +++++
  arch/arm/include/asm/memory.h                 |   5 +
  arch/arm/include/asm/pgalloc.h                |   8 +-
  arch/arm/include/asm/string.h                 |  21 ++
  arch/arm/include/asm/thread_info.h            |   8 +
  arch/arm/include/asm/uaccess-asm.h            |   2 +-
  arch/arm/kernel/entry-armv.S                  |   3 +-
  arch/arm/kernel/entry-common.S                |   9 +-
  arch/arm/kernel/head-common.S                 |   7 +-
  arch/arm/kernel/setup.c                       |   2 +
  arch/arm/kernel/unwind.c                      |   6 +-
  arch/arm/lib/memcpy.S                         |   3 +
  arch/arm/lib/memmove.S                        |   5 +-
  arch/arm/lib/memset.S                         |   3 +
  arch/arm/mm/Makefile                          |   5 +
  arch/arm/mm/kasan_init.c                      | 284 ++++++++++++++++++
  arch/arm/mm/mmu.c                             |  18 ++
  arch/arm/mm/pgd.c                             |  16 +-
  arch/arm/vdso/Makefile                        |   2 +
  26 files changed, 548 insertions(+), 14 deletions(-)
  create mode 100644 arch/arm/include/asm/kasan.h
  create mode 100644 arch/arm/include/asm/kasan_def.h
  create mode 100644 arch/arm/mm/kasan_init.c

-- 
Florian

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel