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In r218101 I have not changed properly the futex syscall definition.

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Some Linux futex ops atomically verifies that the futex address uaddr
(uval) contains the value val. Comparing signed uval and unsigned val
may lead to an unexpected result, mostly to a deadlock.

So copyin uaddr to an unsigned int to compare the parameters correctly.

While here change ktr records to print parameters in more readable format.

Tested by	eadler@

MFC after:	3 days
This commit is contained in:
Dmitry Chagin 2014-05-28 05:57:35 +00:00
parent 5930251a9d
commit 32fd44657c
1 changed files with 16 additions and 13 deletions
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29
sys/compat/linux/linux_futex.c
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@ -679,12 +679,12 @@ futex_atomic_op(struct thread *td, int encoded_op, uint32_t *uaddr)
int
linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
{
int clockrt, nrwake, op_ret, ret, val;
int clockrt, nrwake, op_ret, ret;
struct linux_emuldata *em;
struct waiting_proc *wp;
struct futex *f, *f2;
int error;
uint32_t flags;
uint32_t flags, val;
LIN_SDT_PROBE2(futex, linux_sys_futex, entry, td, args);
@ -721,7 +721,7 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
case LINUX_FUTEX_WAIT_BITSET:
LIN_SDT_PROBE3(futex, linux_sys_futex, debug_wait, args->uaddr,
args->val, args->val3);
LINUX_CTR3(sys_futex, "WAIT uaddr %p val %d val3 %d",
LINUX_CTR3(sys_futex, "WAIT uaddr %p val 0x%x bitset 0x%x",
args->uaddr, args->val, args->val3);
error = futex_get(args->uaddr, &wp, &f,
@ -746,9 +746,9 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
LIN_SDT_PROBE4(futex, linux_sys_futex,
debug_wait_value_neq, args->uaddr, args->val, val,
args->val3);
LINUX_CTR4(sys_futex,
"WAIT uaddr %p val %d != uval %d val3 %d",
args->uaddr, args->val, val, args->val3);
LINUX_CTR3(sys_futex,
"WAIT uaddr %p val 0x%x != uval 0x%x",
args->uaddr, args->val, val);
futex_put(f, wp);
LIN_SDT_PROBE1(futex, linux_sys_futex, return,
@ -766,7 +766,7 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
case LINUX_FUTEX_WAKE_BITSET:
LIN_SDT_PROBE3(futex, linux_sys_futex, debug_wake, args->uaddr,
args->val, args->val3);
LINUX_CTR3(sys_futex, "WAKE uaddr %p val % d val3 %d",
LINUX_CTR3(sys_futex, "WAKE uaddr %p nrwake 0x%x bitset 0x%x",
args->uaddr, args->val, args->val3);
error = futex_get(args->uaddr, NULL, &f,
@ -791,9 +791,9 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
args->uaddr, args->val, args->val3, args->uaddr2,
args->timeout);
LINUX_CTR5(sys_futex, "CMP_REQUEUE uaddr %p "
"val %d val3 %d uaddr2 %p val2 %d",
"nrwake 0x%x uval 0x%x uaddr2 %p nrequeue 0x%x",
args->uaddr, args->val, args->val3, args->uaddr2,
(int)(unsigned long)args->timeout);
args->timeout);
/*
* Linux allows this, we would not, it is an incorrect
@ -842,7 +842,7 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
if (val != args->val3) {
LIN_SDT_PROBE2(futex, linux_sys_futex,
debug_cmp_requeue_value_neq, args->val, val);
LINUX_CTR2(sys_futex, "CMP_REQUEUE val %d != uval %d",
LINUX_CTR2(sys_futex, "CMP_REQUEUE val 0x%x != uval 0x%x",
args->val, val);
futex_put(f2, NULL);
futex_put(f, NULL);
@ -861,9 +861,9 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
LIN_SDT_PROBE5(futex, linux_sys_futex, debug_wake_op,
args->uaddr, args->op, args->val, args->uaddr2, args->val3);
LINUX_CTR5(sys_futex, "WAKE_OP "
"uaddr %p op %d val %x uaddr2 %p val3 %x",
args->uaddr, args->op, args->val,
args->uaddr2, args->val3);
"uaddr %p nrwake 0x%x uaddr2 %p op 0x%x nrwake2 0x%x",
args->uaddr, args->val, args->uaddr2, args->val3,
args->timeout);
error = futex_get(args->uaddr, NULL, &f, flags);
if (error) {
@ -886,6 +886,9 @@ linux_sys_futex(struct thread *td, struct linux_sys_futex_args *args)
*/
op_ret = futex_atomic_op(td, args->val3, args->uaddr2);
LINUX_CTR2(sys_futex, "WAKE_OP atomic_op uaddr %p ret 0x%x",
args->uaddr, op_ret);
if (op_ret < 0) {
/* XXX: We don't handle the EFAULT yet. */
if (op_ret != -EFAULT) {