On Tue,  9 Dec 2025 14:40:24 -0800
Ian Rogers <[email protected]> wrote:

> 64-bit truncation to 32-bit can result in the sign of the truncated
> value changing. The cmp_mod_entry is used in bsearch and so the
> truncation could result in an invalid search order. This would only
> happen were the addresses more than 2GB apart and so unlikely, but
> let's fix the potentially broken compare anyway.

I'm fine with fixing this but I believe if the addresses are more than
2GB apart there could be other issues elsewhere ;-)

> 
> Signed-off-by: Ian Rogers <[email protected]>
> ---
>  kernel/trace/trace.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index d1e527cf2aae..e6a80cbe9326 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -6057,8 +6057,10 @@ static int cmp_mod_entry(const void *key, const void 
> *pivot)
>  
>       if (addr >= ent[0].mod_addr && addr < ent[1].mod_addr)
>               return 0;
> +     else if (addr > ent->mod_addr)
> +             return 1;
>       else
> -             return addr - ent->mod_addr;
> +             return -1;

Could we still keep this down to a single if check?

        if (addr < ent->mod_addr)
                return -1;

        return addr >= ent[1].mod_addr;

-- Steve




>  }
>  
>  /**


Reply via email to