Re: [PATCH -tip v2 0/7] kprobes: Fix %p in kprobes

Masami Hiramatsu
2018-04-26T08:13:52Z

On Thu, 26 Apr 2018 17:08:00 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:

> Hi,
>
> This 2nd version of the series which fixes %p uses in kprobes.
> Some by replacing with %pS, some by replacing with %px but
> masking with kallsyms_show_value().

Oops, I missed to porting this on tip tree, but since this is
including some other archs, it can go directly to each trees
or linus tree.

Anyway, those should be cleanly applicable for the latest
linus tree too.

Thanks,

>
> V1 series is here:
> https://lkml.org/lkml/2018/1/25/1
>
> I've read the thread about %pK and if I understand correctly
> we shouldn't print kernel addresses. However, kprobes debugfs
> interface can not stop to show the actual probe address because
> it should be compared with addresses in kallsyms for debugging.
> So, it depends on that kallsyms_show_value() allows to show
> address to user, because if it returns true, anyway that user
> can dump /proc/kallsyms.
>
> Other error messages are replaced it with %pS, and one critical
> function uses %px which is called right before BUG().
>
> Also, I tried to fix this issue on each arch port. I searched
> it by
>
> # find arch/* | grep -e 'kprobe.*c' | xargs grep -w %p
>
> And fixed all %p uses in those files.
>
> Changes in this version;
> - [1/7] is newly added.
> - patches for MN10300(deleted) and s390(merged) are removed.
>
> Thank you,
>
> ---
>
> Masami Hiramatsu (7):
> kprobes: Make blacklist root user read only
> kprobes: Show blacklist addresses as same as kallsyms does
> kprobes: Show address of kprobes if kallsyms does
> kprobes: Replace %p with other pointer types
> kprobes/x86: Fix %p uses in error messages
> kprobes/arm: Fix %p uses in error messages
> kprobes/arm64: Fix %p uses in error messages
>
>
> arch/arm/probes/kprobes/core.c | 10 ++++----
> arch/arm/probes/kprobes/test-core.c | 1 -
> arch/arm64/kernel/probes/kprobes.c | 4 ++-
> arch/x86/kernel/kprobes/core.c | 12 +++------
> kernel/kprobes.c | 46 ++++++++++++++++++++++-------------
> 5 files changed, 40 insertions(+), 33 deletions(-)
>
> --
> Masami Hiramatsu (Linaro) <mhiramat@kernel.org>

--
Masami Hiramatsu <mhiramat@kernel.org>