Re: [PATCH v2] exec: flush the whole TLB if a watchpoint crosses a page boundary

[Richard Henderson <richard.henderson@linaro.org>]

On 6/3/20 4:24 AM, Alex Bennée wrote:
> There is no particular reason why you can't have a watchpoint in TCG
> that covers a large chunk of the address space. We could be clever
> about it but these cases are pretty rare and we can assume the user
> will expect a little performance degradation.
> 
> NB: In my testing gdb will silently squash a watchpoint like:
> 
>   watch (char[0x7fffffffff]) *0x0
> 
> to a 4 byte watchpoint. Practically it will limit the maximum size
> based on max-value-size. However given enough of a tweak the sky is
> the limit.
> 
> Reported-by: Alexander Bulekov <alxndr@bu.edu>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> 
> ---
> v2
>   - use cleaner in_page = -(addr | TARGET_PAGE_MASK) logic per rth
> ---
>  exec.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Queued to tcg-next.


r~