From f7ae2c44a8762daed4b49f3d13cb8b42128ba3ef Mon Sep 17 00:00:00 2001
From: Thiago Macieira <thiago.macieira@intel.com>
Date: Fri, 14 Oct 2022 08:57:07 -0700
Subject: [PATCH] IPC: move the removal of the file and shm to cleanHandle()

It makes far more sense here, because we can also avoid the need to save
the old key file name.

Change-Id: I12a088d1ae424825abd3fffd171dfaa5dca8a36e
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
---
 src/corelib/ipc/qsharedmemory_systemv.cpp | 61 ++++++++++-------------
 1 file changed, 26 insertions(+), 35 deletions(-)

diff --git a/src/corelib/ipc/qsharedmemory_systemv.cpp b/src/corelib/ipc/qsharedmemory_systemv.cpp
index ddda5cc6f4..b14f5db39f 100644
--- a/src/corelib/ipc/qsharedmemory_systemv.cpp
+++ b/src/corelib/ipc/qsharedmemory_systemv.cpp
@@ -89,11 +89,33 @@ key_t QSharedMemorySystemV::handle(QSharedMemoryPrivate *self)
     return unix_key;
 }
 
-bool QSharedMemorySystemV::cleanHandle(QSharedMemoryPrivate *)
+bool QSharedMemorySystemV::cleanHandle(QSharedMemoryPrivate *self)
 {
+    if (unix_key == 0)
+        return true;
+
+    // Get the number of current attachments
+    struct shmid_ds shmid_ds;
+    QByteArray keyfile = std::exchange(nativeKeyFile, QByteArray());
+
+    int id = shmget(unix_key, 0, 0400);
     unix_key = 0;
-    nativeKeyFile.clear();
-    return true;
+    if (shmctl(id, IPC_STAT, &shmid_ds))
+        return errno != EINVAL;
+
+    // If there are still attachments, keep the keep file and shm
+    if (shmid_ds.shm_nattch != 0)
+        return true;
+
+    if (shmctl(id, IPC_RMID, &shmid_ds) < 0) {
+        if (errno != EINVAL) {
+            self->setUnixErrorString("QSharedMemory::remove"_L1);
+            return false;
+        }
+    };
+
+    // remove file
+    return unlink(keyfile) == 0;
 }
 
 bool QSharedMemorySystemV::create(QSharedMemoryPrivate *self, qsizetype size)
@@ -186,38 +208,7 @@ bool QSharedMemorySystemV::detach(QSharedMemoryPrivate *self)
     self->memory = nullptr;
     self->size = 0;
 
-    // Get the number of current attachments
-    int id = shmget(unix_key, 0, 0400);
-    QByteArray oldNativeKeyFile = nativeKeyFile;
-    cleanHandle(self);
-
-    struct shmid_ds shmid_ds;
-    if (0 != shmctl(id, IPC_STAT, &shmid_ds)) {
-        switch (errno) {
-        case EINVAL:
-            return true;
-        default:
-            return false;
-        }
-    }
-    // If there are no attachments then remove it.
-    if (shmid_ds.shm_nattch == 0) {
-        // mark for removal
-        if (-1 == shmctl(id, IPC_RMID, &shmid_ds)) {
-            self->setUnixErrorString("QSharedMemory::remove"_L1);
-            switch (errno) {
-            case EINVAL:
-                return true;
-            default:
-                return false;
-            }
-        }
-
-        // remove file
-        if (unlink(oldNativeKeyFile) < 0)
-            return false;
-    }
-    return true;
+    return cleanHandle(self);
 }
 
 QT_END_NAMESPACE