Rename is_addr_reserved to find_preload_reserved_area, with the following changes:
- Accept second argument "size" which specifies the size of the address range to test. - Return the index of the matching entry, or -1 if none found.
Signed-off-by: Jinoh Kang jinoh.kang.kr@gmail.com ---
Notes: v1 -> v2: handle overflows
v3 -> v4: - add comments and documentation
loader/preloader.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/loader/preloader.c b/loader/preloader.c index c23f1f087b5..94f5a264420 100644 --- a/loader/preloader.c +++ b/loader/preloader.c @@ -1469,18 +1469,29 @@ error: fatal_error( "invalid WINEPRELOADRESERVE value '%s'\n", str ); }
-/* check if address is in one of the reserved ranges */ -static int is_addr_reserved( const void *addr ) +/* + * find_preload_reserved_area + * + * Check if the given address range overlaps with one of the reserved ranges. + */ +static int find_preload_reserved_area( const void *addr, size_t size ) { + /* Make the interval inclusive to avoid integer overflow. */ + unsigned long start = (unsigned long)addr; + unsigned long end = (unsigned long)addr + size - 1; int i;
+ /* Handle size == 0 specifically since "end" may overflow otherwise. */ + if (!size) + return -1; + for (i = 0; preload_info[i].size; i++) { - if ((const char *)addr >= (const char *)preload_info[i].addr && - (const char *)addr < (const char *)preload_info[i].addr + preload_info[i].size) - return 1; + if (end >= (unsigned long)preload_info[i].addr && + start <= (unsigned long)preload_info[i].addr + preload_info[i].size - 1) + return i; } - return 0; + return -1; }
/* remove a range from the preload list */ @@ -1503,7 +1514,7 @@ static int is_in_preload_range( const struct wld_auxv *av, int type ) { while (av->a_type != AT_NULL) { - if (av->a_type == type) return is_addr_reserved( (const void *)av->a_un.a_val ); + if (av->a_type == type) return find_preload_reserved_area( (const void *)av->a_un.a_val, 1 ) >= 0; av++; } return 0; @@ -1591,7 +1602,7 @@ void* wld_start( void **stack )
/* add an executable page at the top of the address space to defeat * broken no-exec protections that play with the code selector limit */ - if (is_addr_reserved( (char *)0x80000000 - page_size )) + if (find_preload_reserved_area( (char *)0x80000000 - page_size, page_size ) >= 0) wld_mprotect( (char *)0x80000000 - page_size, page_size, PROT_EXEC | PROT_READ );
/* load the main binary */