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usercopy: Cast pointer to an integer once
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Get rid of a lot of annoying casts by setting 'addr' once at the top
of the function.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Tested-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220612213227.3881769-3-willy@infradead.org
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Matthew Wilcox (Oracle) authored and Kees Cook committed Jun 13, 2022
1 parent 993d0b2 commit 35fb9ae
Showing 1 changed file with 6 additions and 5 deletions.
11 changes: 6 additions & 5 deletions mm/usercopy.c
Original file line number Diff line number Diff line change
Expand Up @@ -161,26 +161,27 @@ static inline void check_bogus_address(const unsigned long ptr, unsigned long n,
static inline void check_heap_object(const void *ptr, unsigned long n,
bool to_user)
{
uintptr_t addr = (uintptr_t)ptr;
struct folio *folio;

if (is_kmap_addr(ptr)) {
unsigned long page_end = (unsigned long)ptr | (PAGE_SIZE - 1);
unsigned long page_end = addr | (PAGE_SIZE - 1);

if ((unsigned long)ptr + n - 1 > page_end)
if (addr + n - 1 > page_end)
usercopy_abort("kmap", NULL, to_user,
offset_in_page(ptr), n);
return;
}

if (is_vmalloc_addr(ptr)) {
struct vmap_area *area = find_vmap_area((unsigned long)ptr);
struct vmap_area *area = find_vmap_area(addr);
unsigned long offset;

if (!area)
usercopy_abort("vmalloc", "no area", to_user, 0, n);

offset = (unsigned long)ptr - area->va_start;
if ((unsigned long)ptr + n > area->va_end)
offset = addr - area->va_start;
if (addr + n > area->va_end)
usercopy_abort("vmalloc", NULL, to_user, offset, n);
return;
}
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