[PATCH v2 1/5] nolibc: fix fd_set type

Sven Schnelle
2023-01-02T10:52:30Z

The kernel uses unsigned long for the fd_set bitmap,
but nolibc use u32. This works fine on little endian
machines, but fails on big endian. Convert to unsigned
long to fix this.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
---
tools/include/nolibc/types.h | 53 ++++++++++++++++++++----------------
1 file changed, 30 insertions(+), 23 deletions(-)

diff --git a/tools/include/nolibc/types.h b/tools/include/nolibc/types.h
index 959997034e55..300e0ff1cd58 100644
--- a/tools/include/nolibc/types.h
+++ b/tools/include/nolibc/types.h
@@ -89,39 +89,46 @@
#define EXIT_SUCCESS 0
#define EXIT_FAILURE 1

+#define FD_SETIDXMASK (8 * sizeof(unsigned long))
+#define FD_SETBITMASK (8 * sizeof(unsigned long)-1)
+
/* for select() */
typedef struct {
- uint32_t fd32[(FD_SETSIZE + 31) / 32];
+ unsigned long fds[(FD_SETSIZE + FD_SETBITMASK) / FD_SETIDXMASK];
} fd_set;

-#define FD_CLR(fd, set) do { \
- fd_set *__set = (set); \
- int __fd = (fd); \
- if (__fd >= 0) \
- __set->fd32[__fd / 32] &= ~(1U << (__fd & 31)); \
+#define FD_CLR(fd, set) do { \
+ fd_set *__set = (set); \
+ int __fd = (fd); \
+ if (__fd >= 0) \
+ __set->fds[__fd / FD_SETIDXMASK] &= \
+ ~(1U << (__fd & FX_SETBITMASK)); \
} while (0)

-#define FD_SET(fd, set) do { \
- fd_set *__set = (set); \
- int __fd = (fd); \
- if (__fd >= 0) \
- __set->fd32[__fd / 32] |= 1U << (__fd & 31); \
+#define FD_SET(fd, set) do { \
+ fd_set *__set = (set); \
+ int __fd = (fd); \
+ if (__fd >= 0) \
+ __set->fds[__fd / FD_SETIDXMASK] |= \
+ 1 << (__fd & FD_SETBITMASK); \
} while (0)

-#define FD_ISSET(fd, set) ({ \
- fd_set *__set = (set); \
- int __fd = (fd); \
- int __r = 0; \
- if (__fd >= 0) \
- __r = !!(__set->fd32[__fd / 32] & 1U << (__fd & 31)); \
- __r; \
+#define FD_ISSET(fd, set) ({ \
+ fd_set *__set = (set); \
+ int __fd = (fd); \
+ int __r = 0; \
+ if (__fd >= 0) \
+ __r = !!(__set->fds[__fd / FD_SETIDXMASK] & \
+1U << (__fd & FD_SET_BITMASK)); \
+ __r; \
})

-#define FD_ZERO(set) do { \
- fd_set *__set = (set); \
- int __idx; \
- for (__idx = 0; __idx < (FD_SETSIZE+31) / 32; __idx ++) \
- __set->fd32[__idx] = 0; \
+#define FD_ZERO(set) do { \
+ fd_set *__set = (set); \
+ int __idx; \
+ int __size = (FD_SETSIZE+FD_SETBITMASK) / FD_SETIDXMASK;\
+ for (__idx = 0; __idx < __size; __idx++) \
+ __set->fds[__idx] = 0; \
} while (0)

/* for poll() */
--
2.34.1