Hi,
Sorry - it seem that I forgot to retest the patch without sysctl() after
converting from direct if/else to max().
On 4/12/19 8:43 PM, kbuild test robot wrote:
[...]
ipc/util.c: In function 'ipc_idr_alloc':
include/linux/kernel.h:828:29: warning: comparison of distinct pointer types lacks a cast
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
^
include/linux/kernel.h:842:4: note: in expansion of macro '__typecheck'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~
include/linux/kernel.h:852:24: note: in expansion of macro '__safe_cmp'
__builtin_choose_expr(__safe_cmp(x, y), \
^~~~~~~~~~
include/linux/kernel.h:868:19: note: in expansion of macro '__careful_cmp'
#define max(x, y) __careful_cmp(x, y, >)
^~~~~~~~~~~~~
ipc/util.c:226:13: note: in expansion of macro 'max'
max_idx = max(ids->in_use*3/2, ipc_min_cycle);
^~~
223 if (next_id < 0) { /* !CHECKPOINT_RESTORE or next_id is unset */
224 int max_idx;
225
> 226 max_idx = max(ids->in_use*3/2, ipc_min_cycle);
With sysctl disabled, ipc_min_cycle is RADIX_TREE_MAP_SIZE, and this is
> include/linux/radix-tree.h:#define RADIX_TREE_MAP_SIZE (1UL <<
RADIX_TREE_MAP_SHIFT)
The checker behind max() is not smart enough to notice that
RADIX_TREE_MAP_SIZE can be represented as int without an overflow.
What is the right approach?
> #define ipc_min_cycle ({ int tmp; tmp = RADIX_TREE_MAP_SIZE; tmp;})
--
Manfred
