Re: [Qemu-devel] [PATCH V5 1/6] oslib-posix: add helpers for stack alloc and free

[Eric Blake <eblake@redhat.com>]

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On 07/12/2016 10:23 AM, Peter Lieven wrote:
> the allocated stack will be adjusted to the minimum supported stack size
> by the OS and rounded up to be a multiple of the system pagesize.
> Additionally an architecture dependent guard page is added to the stack
> to catch stack overflows.
> 
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  include/sysemu/os-posix.h | 23 +++++++++++++++++++++++
>  util/oslib-posix.c        | 46 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 69 insertions(+)
> 

> +static size_t adjust_stack_size(size_t sz)
> +{
> +#ifdef _SC_THREAD_STACK_MIN
> +    /* avoid stacks smaller than _SC_THREAD_STACK_MIN */
> +    sz = MAX(MAX(sysconf(_SC_THREAD_STACK_MIN), 0), sz);

MAX(MAX(int, int), unsigned)

is not transitive, but does the job. I won't request a rewrite.

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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