Le 03/04/2020 à 11:35, Nicholas Piggin a écrit :
There is no need to allow user accesses when probing kernel addresses.
I just discovered the following commit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=75a1a607bb7e6d918be3aca11ec2214a275392f4
This commit adds probe_kernel_read_strict() and probe_kernel_write_strict().
When reading the commit log, I understand that probe_kernel_read() may
be used to access some user memory. Which will not work anymore with
your patch.
Isn't it probe_kernel_read_strict() and probe_kernel_write_strict() that
you want to add ?
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
v2:
- Enable for all powerpc (suggested by Christophe)
- Fold helper function together (Christophe)
- Rename uaccess.c to maccess.c to match kernel/maccess.c.
arch/powerpc/include/asm/uaccess.h | 25 +++++++++++++++-------
arch/powerpc/lib/Makefile | 2 +-
arch/powerpc/lib/maccess.c | 34 ++++++++++++++++++++++++++++++
x86 does it in mm/maccess.c
3 files changed, 52 insertions(+), 9 deletions(-)
create mode 100644 arch/powerpc/lib/maccess.c
Christophe
