[PATCH 0/2] MR7809: server: Do not call setpriority() if it cannot be used safely.

[Conor McCarthy (＠cmccarthy)]

Not checking nice_limit here can result in some calls to setpriority()
succeeding while others fail, which can result in relative priorities
being incorrect. For example, buffer underflows can occur in
winepulse.drv because the priority is too low in pulse_timer_loop().

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/7809

[PATCH 1/2] server: Emit an error message if setpriority() fails.

[Conor McCarthy]

From: Conor McCarthy <cmccarthy(a)codeweavers.com>

---
 server/thread.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/server/thread.c b/server/thread.c
index 27a40ce38ad..603bf2bd0a5 100644
--- a/server/thread.c
+++ b/server/thread.c
@@ -256,7 +256,8 @@ static void apply_thread_priority( struct thread *thread, int effective_priority
     if (effective_priority >= LOW_REALTIME_PRIORITY) effective_priority = LOW_REALTIME_PRIORITY - 1;
     /* map an NT application band [1,15] priority to [-nice_limit, nice_limit] */
     niceness = (min + (effective_priority - 1) * range / 14);
-    setpriority( PRIO_PROCESS, thread->unix_tid, niceness );
+    if (setpriority( PRIO_PROCESS, thread->unix_tid, niceness ) != 0)
+        fprintf( stderr, "wine: setpriority %d for pid %d failed: %d\n", niceness, thread->unix_tid, errno );
 }
 
 #elif defined(__APPLE__)
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/7809

[PATCH 2/2] server: Do not call setpriority() if it cannot be used safely.

[Conor McCarthy]

From: Conor McCarthy <cmccarthy(a)codeweavers.com>

Not checking nice_limit here can result in some calls to setpriority()
succeeding while others fail, which can result in relative priorities
being incorrect. For example, buffer underflows can occur in
winepulse.drv because the priority is too low in pulse_timer_loop().
---
 server/thread.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/server/thread.c b/server/thread.c
index 603bf2bd0a5..addb0292e5f 100644
--- a/server/thread.c
+++ b/server/thread.c
@@ -252,6 +252,9 @@ static void apply_thread_priority( struct thread *thread, int effective_priority
 {
     int min = -nice_limit, max = nice_limit, range = max - min, niceness;
 
+    if (nice_limit >= 0)
+        return;
+
     /* FIXME: handle realtime priorities using SCHED_RR if possible */
     if (effective_priority >= LOW_REALTIME_PRIORITY) effective_priority = LOW_REALTIME_PRIORITY - 1;
     /* map an NT application band [1,15] priority to [-nice_limit, nice_limit] */
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/7809

[Alexandre Julliard (＠julliard)]

Printing errors from the server should be avoided. If there's really a need for it, the error should be propagated to the client and printed there.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/7809#note_100747