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alpha: separate thread-synchronous flags

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... and fix the race in updating unaligned control ones

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Al Viro
2012-10-20 15:52:23 +01:00
committed by Linus Torvalds
parent 3d0ceac129
commit 3185bd2618
4 changed files with 68 additions and 45 deletions
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25
arch/alpha/kernel/osf_sys.c
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@@ -793,8 +793,7 @@ SYSCALL_DEFINE5(osf_getsysinfo, unsigned long, op, void __user *, buffer,
case GSI_UACPROC:
if (nbytes < sizeof(unsigned int))
return -EINVAL;
w = (current_thread_info()->flags >> ALPHA_UAC_SHIFT) &
UAC_BITMASK;
w = current_thread_info()->status & UAC_BITMASK;
if (put_user(w, (unsigned int __user *)buffer))
return -EFAULT;
return 1;
@@ -904,24 +903,20 @@ SYSCALL_DEFINE5(osf_setsysinfo, unsigned long, op, void __user *, buffer,
break;
case SSI_NVPAIRS: {
unsigned long v, w, i;
unsigned int old, new;
unsigned __user *p = buffer;
unsigned i;
for (i = 0; i < nbytes; ++i) {
for (i = 0, p = buffer; i < nbytes; ++i, p += 2) {
unsigned v, w, status;
if (get_user(v, 2*i + (unsigned int __user *)buffer))
return -EFAULT;
if (get_user(w, 2*i + 1 + (unsigned int __user *)buffer))
if (get_user(v, p) || get_user(w, p + 1))
return -EFAULT;
switch (v) {
case SSIN_UACPROC:
again:
old = current_thread_info()->flags;
new = old & ~(UAC_BITMASK << ALPHA_UAC_SHIFT);
new = new | (w & UAC_BITMASK) << ALPHA_UAC_SHIFT;
if (cmpxchg(&current_thread_info()->flags,
old, new) != old)
goto again;
w &= UAC_BITMASK;
status = current_thread_info()->status;
status = (status & ~UAC_BITMASK) | w;
current_thread_info()->status = status;
break;
default: