Hi David,
On Tue, Jun 16, 2015 at 6:15 AM, David Ahern <david.ahern@xxxxxxxxxx> wrote:
> Processes are getting killed (sigbus or segv) while walking userspace
> callchains when using perf. In some instances I have seen ufp = 0x7ff
> which does not seem like a proper stack address.
>
> This patch adds a function to run validity checks against the address
> before attempting the copy_from_user. The checks are copied from the
> x86 version as a start point with the addition of a 4-byte alignment
> check.
>
> Signed-off-by: David Ahern <david.ahern@xxxxxxxxxx>
> ---
> arch/sparc/include/asm/uaccess_64.h | 22 ++++++++++++++++++++++
> arch/sparc/kernel/perf_event.c | 13 +++++++++++++
> 2 files changed, 35 insertions(+)
>
> diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
> index a35194b7dba0..ea6e9a20f3ff 100644
> --- a/arch/sparc/include/asm/uaccess_64.h
> +++ b/arch/sparc/include/asm/uaccess_64.h
> @@ -49,6 +49,28 @@ do { \
> __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \
> } while(0)
>
> +/*
> + * Test whether a block of memory is a valid user space address.
> + * Returns 0 if the range is valid, nonzero otherwise.
Do you mean true / false here?
Thanks,
--
Julian Calaby
Email: julian.calaby@xxxxxxxxx
Profile: http://www.google.com/profiles/julian.calaby/
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