diff options
| author | Anton Blanchard <anton@samba.org> | 2004-09-13 00:05:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-09-13 00:05:30 -0700 |
| commit | 7d783796ed8e974fc82bed4ce4aec3dfa1f6a9b6 (patch) | |
| tree | 14f8e113d7305f778b95c93386deee75096bf6ae | |
| parent | 2d3399ab54c9763fcba314d0b33ab82e1580d7aa (diff) | |
[PATCH] Backward compatibility for compat sched_getaffinity
The follow patch special cases the NR_CPUS <= BITS_PER_COMPAT_LONG case.
Without this patch, a 32bit task would be required to have a 64bit
cpumask no matter what value of NR_CPUS are used.
With this patch a compat long sized bitmask is allowed if NR_CPUS is
small enough to fit within it.
Of course applications should be using the glibc wrappers that use an
opaque cpu_mask_t type, but there could be older applications using the
syscalls directly.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | kernel/compat.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/kernel/compat.c b/kernel/compat.c index 9f3f23fd2788..33880d224077 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -446,8 +446,12 @@ asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len, int ret; cpumask_t mask; unsigned long *k; + unsigned int min_length = sizeof(cpumask_t); - if (len < sizeof(cpumask_t)) + if (NR_CPUS <= BITS_PER_COMPAT_LONG) + min_length = sizeof(compat_ulong_t); + + if (len < min_length) return -EINVAL; ret = sched_getaffinity(pid, &mask); @@ -455,11 +459,11 @@ asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len, return ret; k = cpus_addr(mask); - ret = compat_put_bitmap(user_mask_ptr, k, sizeof(cpumask_t) * 8); + ret = compat_put_bitmap(user_mask_ptr, k, min_length * 8); if (ret) return ret; - return sizeof(cpumask_t); + return min_length; } static int get_compat_itimerspec(struct itimerspec *dst, |