[PATCH 0/2] arm64: fix crash when reading /proc/kcore

On 06/08/2017 12:41 PM, Ard Biesheuvel wrote:

This is a follow-up to patches from zhonjiang [0] and myself [1] that aim
to solve a problem in the kcore code, which gets confused by the presence
of block mappings in the vmalloc region.

While fixing the crash is quite straight forward [2], we need to tweak
the kcore code itself to ensure that it operates correctly on arm64.
Fortunately, we can achieve this with two very simple changes:

- replace a call to is_vmalloc_or_module_addr() in read_kcore() with a
  comparison of the kclist type field (#1)
- enable CONFIG_ARCH_PROC_KCORE_TEXT for arm64 (#2)

[0] http://marc.info/?l=linux-mm&m=149632393629295&w=2
[1] http://marc.info/?l=linux-mm&m=149685966530180&w=2
[2] http://marc.info/?l=linux-mm&m=149694975123959&w=2

Ard Biesheuvel (2):
  fs/proc: kcore: use kcore_list type to check for vmalloc/module
    address
  arm64: mm: select CONFIG_ARCH_PROC_KCORE_TEXT

 arch/arm64/Kconfig | 3 +++
 fs/proc/kcore.c    | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

Reviewed-by: Laura Abbott <redacted>

I wish there was actual Kconfig help text for CONFIG_ARCH_PROC_KCORE_TEXT
instead of having to go into kcore.c to read about how it was used but
that can be fixed up separately.

Thanks,
Laura