On 09.04.2024 13:45, Luca Fancellu wrote:
> --- a/xen/arch/x86/extable.c
> +++ b/xen/arch/x86/extable.c
> @@ -23,7 +23,8 @@ static inline unsigned long ex_cont(const struct
> exception_table_entry *x)
> return EX_FIELD(x, cont);
> }
>
> -static int init_or_livepatch cf_check cmp_ex(const void *a, const void *b)
> +static int init_or_livepatch cf_check cmp_ex(const void *a, const void *b,
> + const void *data)
> {
> const struct exception_table_entry *l = a, *r = b;
> unsigned long lip = ex_addr(l);
> @@ -53,7 +54,7 @@ void init_or_livepatch sort_exception_table(struct
> exception_table_entry *start,
> const struct exception_table_entry *stop)
> {
> sort(start, stop - start,
> - sizeof(struct exception_table_entry), cmp_ex, swap_ex);
> + sizeof(struct exception_table_entry), cmp_ex, swap_ex, NULL);
> }
Not the least because of this addition of an entirely useless parameter /
argument
I'm not in favor of ...
> --- a/xen/include/xen/sort.h
> +++ b/xen/include/xen/sort.h
> @@ -23,8 +23,8 @@
> extern gnu_inline
> #endif
> void sort(void *base, size_t num, size_t size,
> - int (*cmp)(const void *a, const void *b),
> - void (*swap)(void *a, void *b, size_t size))
> + int (*cmp)(const void *a, const void *b, const void *data),
> + void (*swap)(void *a, void *b, size_t size), const void *cmp_data)
> {
... this change. Consider you were doing this on a C library you cannot change.
You'd have to find a different solution anyway. And the way we have sort()
right now is matching the C spec. The change to do renders things unexpected to
anyone wanting to use this function in a spec-compliant way. One approach may
be to make an adjustment to data representation, such that the extra reference
data is accessible through the pointers already being passed.
Jan
