Module: xenomai-jki
Branch: for-upstream
Commit: 86cf68e6f8d0dcee7c4dfaa9e25e5db5a9200d76
URL:
http://git.xenomai.org/?p=xenomai-jki.git;a=commit;h=86cf68e6f8d0dcee7c4dfaa9e25e5db5a9200d76
Author: Jan Kiszka <jan.kis...@siemens.com>
Date: Tue Mar 2 13:17:35 2010 +0100
Native: Ensure to re-acquire the mutex on cond_wait return
Always try to reacquire the mutex if the prologue released it. The only
exception is user space return on interruption.
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
ksrc/skins/native/cond.c | 17 +++++++++++------
ksrc/skins/native/syscall.c | 6 ++++--
2 files changed, 15 insertions(+), 8 deletions(-)
diff --git a/ksrc/skins/native/cond.c b/ksrc/skins/native/cond.c
index d6c8546..6076472 100644
--- a/ksrc/skins/native/cond.c
+++ b/ksrc/skins/native/cond.c
@@ -380,6 +380,8 @@ int rt_cond_wait_prologue(RT_COND *cond, RT_MUTEX *mutex,
unsigned *plockcnt,
spl_t s;
int err;
+ *plockcnt = 0;
+
if (timeout == TM_NONBLOCK)
return -EWOULDBLOCK;
@@ -467,15 +469,18 @@ static int rt_cond_wait_inner(RT_COND *cond, RT_MUTEX
*mutex,
xntmode_t timeout_mode, RTIME timeout)
{
unsigned lockcnt;
- int err, epilogue_err = 0;
+ int err, epilogue_err;
- err = rt_cond_wait_prologue(cond, mutex, &lockcnt,
+ err = rt_cond_wait_prologue(cond, mutex, &lockcnt,
timeout_mode, timeout);
- if(!err || err == -ETIMEDOUT || err == -EINTR)
- do {
- epilogue_err = rt_cond_wait_epilogue(mutex, lockcnt);
- } while (epilogue_err == -EINTR);
+ if (!lockcnt)
+ return err;
+
+ /* Reacquire the mutex if it was unlocked in the prologue. */
+ do {
+ epilogue_err = rt_cond_wait_epilogue(mutex, lockcnt);
+ } while (epilogue_err == -EINTR);
return err ? err : epilogue_err;
}
diff --git a/ksrc/skins/native/syscall.c b/ksrc/skins/native/syscall.c
index 40e5cfd..462ee7e 100644
--- a/ksrc/skins/native/syscall.c
+++ b/ksrc/skins/native/syscall.c
@@ -1869,9 +1869,11 @@ static int __rt_cond_wait_prologue(struct pt_regs *regs)
err = rt_cond_wait_prologue(cond, mutex, &lockcnt, timeout_mode,
timeout);
- if (err == 0 || err == -ETIMEDOUT)
+ /* Reacquire the mutex if it was unlocked in the prologue and we were
+ not interrupted. */
+ if (lockcnt && err != -EINTR)
err = rt_cond_wait_epilogue(mutex, lockcnt);
-
+
if (err == -EINTR && __xn_reg_arg3(regs)
&& __xn_safe_copy_to_user((void __user *)__xn_reg_arg3(regs),
&lockcnt, sizeof(lockcnt)))
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