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sh: add working futex atomic ops on userspace addresses for smp

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The version of futex.h in asm-generic should really be adapted to do
the same thing so that this hideous code does not have to be
duplicated per-arch.

Signed-off-by: Rich Felker <dalias@libc.org>
This commit is contained in:
Rich Felker
2016-04-25 21:58:03 +00:00
parent 2b47d54ed4
commit 00b73d8d1b
4 changed files with 151 additions and 141 deletions
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131
arch/sh/include/asm/futex.h
View File

@@ -7,62 +7,15 @@
#include <linux/uaccess.h>
#include <asm/errno.h>
/* XXX: UP variants, fix for SH-4A and SMP.. */
#if !defined(CONFIG_SMP)
#include <asm/futex-irq.h>
static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
{
int op = (encoded_op >> 28) & 7;
int cmp = (encoded_op >> 24) & 15;
int oparg = (encoded_op << 8) >> 20;
int cmparg = (encoded_op << 20) >> 20;
int oldval = 0, ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
ret = atomic_futex_op_xchg_set(oparg, uaddr, &oldval);
break;
case FUTEX_OP_ADD:
ret = atomic_futex_op_xchg_add(oparg, uaddr, &oldval);
break;
case FUTEX_OP_OR:
ret = atomic_futex_op_xchg_or(oparg, uaddr, &oldval);
break;
case FUTEX_OP_ANDN:
ret = atomic_futex_op_xchg_and(~oparg, uaddr, &oldval);
break;
case FUTEX_OP_XOR:
ret = atomic_futex_op_xchg_xor(oparg, uaddr, &oldval);
break;
default:
ret = -ENOSYS;
break;
}
pagefault_enable();
if (!ret) {
switch (cmp) {
case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
default: ret = -ENOSYS;
}
}
return ret;
}
#elif defined(CONFIG_CPU_J2)
#include <asm/futex-cas.h>
#elif defined(CONFIG_CPU_SH4A)
#include <asm/futex-llsc.h>
#else
#error SMP not supported on this configuration.
#endif
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
@@ -74,5 +27,73 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
return atomic_futex_op_cmpxchg_inatomic(uval, uaddr, oldval, newval);
}
static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
{
int op = (encoded_op >> 28) & 7;
int cmp = (encoded_op >> 24) & 15;
u32 oparg = (encoded_op << 8) >> 20;
u32 cmparg = (encoded_op << 20) >> 20;
u32 oldval, newval, prev;
int ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
pagefault_disable();
do {
if (op == FUTEX_OP_SET)
ret = oldval = 0;
else
ret = get_user(oldval, uaddr);
if (ret) break;
switch (op) {
case FUTEX_OP_SET:
newval = oparg;
break;
case FUTEX_OP_ADD:
newval = oldval + oparg;
break;
case FUTEX_OP_OR:
newval = oldval | oparg;
break;
case FUTEX_OP_ANDN:
newval = oldval & ~oparg;
break;
case FUTEX_OP_XOR:
newval = oldval ^ oparg;
break;
default:
ret = -ENOSYS;
break;
}
if (ret) break;
ret = futex_atomic_cmpxchg_inatomic(&prev, uaddr, oldval, newval);
} while (!ret && prev != oldval);
pagefault_enable();
if (!ret) {
switch (cmp) {
case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
case FUTEX_OP_CMP_LT: ret = ((int)oldval < (int)cmparg); break;
case FUTEX_OP_CMP_GE: ret = ((int)oldval >= (int)cmparg); break;
case FUTEX_OP_CMP_LE: ret = ((int)oldval <= (int)cmparg); break;
case FUTEX_OP_CMP_GT: ret = ((int)oldval > (int)cmparg); break;
default: ret = -ENOSYS;
}
}
return ret;
}
#endif /* __KERNEL__ */
#endif /* __ASM_SH_FUTEX_H */