posix_types.h: Cleanup stale __NFDBITS and related definitions

Recently, glibc made a change to suppress sign-conversion warnings in
FD_SET (glibc commit ceb9e56b3d1).  This uncovered an issue with the
kernel's definition of __NFDBITS if applications #include
<linux/types.h> after including <sys/select.h>.  A build failure would
be seen when passing the -Werror=sign-compare and -D_FORTIFY_SOURCE=2
flags to gcc.

It was suggested that the kernel should either match the glibc
definition of __NFDBITS or remove that entirely.  The current in-kernel
uses of __NFDBITS can be replaced with BITS_PER_LONG, and there are no
uses of the related __FDELT and __FDMASK defines.  Given that, we'll
continue the cleanup that was started with commit 8b3d1cda4f5f
("posix_types: Remove fd_set macros") and drop the remaining unused
macros.

Additionally, linux/time.h has similar macros defined that expand to
nothing so we'll remove those at the same time.

Reported-by: Jeff Law <law@redhat.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
CC: <stable@vger.kernel.org>
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
[ .. and fix up whitespace as per akpm ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/mips/kernel/kspd.c b/arch/mips/kernel/kspd.c
index 84d0639e4580230c78fc93207943700bc35ac007..b77f56bbb477eca591052bf87d5fe8bf6bc62f5a 100644 (file)
--- a/arch/mips/kernel/kspd.c
+++ b/arch/mips/kernel/kspd.c
@@ -323,7 +323,7 @@ static void sp_cleanup(void)
        fdt = files_fdtable(files);
        for (;;) {
                unsigned long set;
-               i = j * __NFDBITS;
+               i = j * BITS_PER_LONG;
                if (i >= fdt->max_fds)
                        break;
                set = fdt->open_fds[j++];

diff --git a/fs/exec.c b/fs/exec.c
index da27b91ff1e8cbe87d0fe42aa5d39513e6a9deeb..e95aeeddd25c4038ad1656621bd9af56b7a0868e 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1020,7 +1020,7 @@ static void flush_old_files(struct files_struct * files)
                unsigned long set, i;
 
                j++;
-               i = j * __NFDBITS;
+               i = j * BITS_PER_LONG;
                fdt = files_fdtable(files);
                if (i >= fdt->max_fds)
                        break;

diff --git a/fs/select.c b/fs/select.c
index bae321569dfa7283b290a2e2d65c99bb10b622f4..db14c781335e32c16d0d773c5ca7da53e5f771a4 100644 (file)
--- a/fs/select.c
+++ b/fs/select.c
@@ -345,8 +345,8 @@ static int max_select_fd(unsigned long n, fd_set_bits *fds)
        struct fdtable *fdt;
 
        /* handle last in-complete long-word first */
-       set = ~(~0UL << (n & (__NFDBITS-1)));
-       n /= __NFDBITS;
+       set = ~(~0UL << (n & (BITS_PER_LONG-1)));
+       n /= BITS_PER_LONG;
        fdt = files_fdtable(current->files);
        open_fds = fdt->open_fds + n;
        max = 0;
@@ -373,7 +373,7 @@ get_max:
                        max++;
                        set >>= 1;
                } while (set);
-               max += n * __NFDBITS;
+               max += n * BITS_PER_LONG;
        }
 
        return max;
@@ -435,11 +435,11 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
                        in = *inp++; out = *outp++; ex = *exp++;
                        all_bits = in | out | ex;
                        if (all_bits == 0) {
-                               i += __NFDBITS;
+                               i += BITS_PER_LONG;
                                continue;
                        }
 
-                       for (j = 0; j < __NFDBITS; ++j, ++i, bit <<= 1) {
+                       for (j = 0; j < BITS_PER_LONG; ++j, ++i, bit <<= 1) {
                                int fput_needed;
                                if (i >= n)
                                        break;

diff --git a/include/linux/posix_types.h b/include/linux/posix_types.h
index f04c98cf44f36376321d507d1fcd3352b26c4852..988f76e636e36912052b4d951173b304a07f476a 100644 (file)
--- a/include/linux/posix_types.h
+++ b/include/linux/posix_types.h
@@ -15,26 +15,14 @@
  */
 
 /*
- * Those macros may have been defined in <gnu/types.h>. But we always
- * use the ones here. 
+ * This macro may have been defined in <gnu/types.h>. But we always
+ * use the one here.
  */
-#undef __NFDBITS
-#define __NFDBITS      (8 * sizeof(unsigned long))
-
 #undef __FD_SETSIZE
 #define __FD_SETSIZE   1024
 
-#undef __FDSET_LONGS
-#define __FDSET_LONGS  (__FD_SETSIZE/__NFDBITS)
-
-#undef __FDELT
-#define        __FDELT(d)      ((d) / __NFDBITS)
-
-#undef __FDMASK
-#define        __FDMASK(d)     (1UL << ((d) % __NFDBITS))
-
 typedef struct {
-       unsigned long fds_bits [__FDSET_LONGS];
+       unsigned long fds_bits[__FD_SETSIZE / (8 * sizeof(long))];
 } __kernel_fd_set;
 
 /* Type of a signal handler.  */

diff --git a/include/linux/time.h b/include/linux/time.h
index 179f4d6755fc6f3b9e3c99f67e424b8c1e52bef2..c81c5e40fcb512dda61255ac7399fb818bcb0cec 100644 (file)
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -257,14 +257,6 @@ static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 
 #endif /* __KERNEL__ */
 
-#define NFDBITS                        __NFDBITS
-
-#define FD_SETSIZE             __FD_SETSIZE
-#define FD_SET(fd,fdsetp)      __FD_SET(fd,fdsetp)
-#define FD_CLR(fd,fdsetp)      __FD_CLR(fd,fdsetp)
-#define FD_ISSET(fd,fdsetp)    __FD_ISSET(fd,fdsetp)
-#define FD_ZERO(fdsetp)                __FD_ZERO(fdsetp)
-
 /*
  * Names of the interval timers, and structure
  * defining a timer setting:

diff --git a/kernel/exit.c b/kernel/exit.c
index d17f6c4ddfa9755f4318413805f9b64417b34d47..f65345f9e5bbe2aa06b69db5b91b1c4002857c0f 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -483,7 +483,7 @@ static void close_files(struct files_struct * files)
        rcu_read_unlock();
        for (;;) {
                unsigned long set;
-               i = j * __NFDBITS;
+               i = j * BITS_PER_LONG;
                if (i >= fdt->max_fds)
                        break;
                set = fdt->open_fds[j++];

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 689fe2d2216569aea465076ff7d219c9a8ea9216..94c45a1531a4c1199535b38a5eb0041075b29ce4 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2129,7 +2129,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
                int fd;
 
                j++;
-               i = j * __NFDBITS;
+               i = j * BITS_PER_LONG;
                fdt = files_fdtable(files);
                if (i >= fdt->max_fds)
                        break;