Changeset 98073 in vbox for trunk

Timestamp:

Jan 13, 2023 11:24:01 AM (2 years ago)

Author:

vboxsync

Message:

Main/HostHardwareLinux.cpp: We don't need to dynamically resolve inotify functions, we can assume we're on a Linux verion that has it and is more than recent enough for inotify_init1 and pipe2 (see also dns monitoring code).

File:

• trunk/src/VBox/Main/src-server/linux/HostHardwareLinux.cpp (modified) (15 diffs)

trunk/src/VBox/Main/src-server/linux/HostHardwareLinux.cpp

@@ -56 +56 @@
 #ifdef VBOX_USB_WITH_SYSFS
 # ifdef VBOX_USB_WITH_INOTIFY
-#  include <dlfcn.h>
-#  include <fcntl.h>
+#  include <fcntl.h>        /* O_CLOEXEC */
 #  include <poll.h>
 #  include <signal.h>
 #  include <unistd.h>
+#  include <sys/inotify.h>
 # endif
 #endif
 
-#include <vector>
+//#include <vector>
 
 #include <errno.h>
@@ -116 +116 @@
 
 
-/** Find the length of a string, ignoring trailing non-ascii or control
+/**
+ * Find the length of a string, ignoring trailing non-ascii or control
  * characters
- * @note Code duplicated in HostHardwareFreeBSD.cpp  */
+ *
+ * @note Code duplicated in HostHardwareFreeBSD.cpp
+ */
 static size_t strLenStripped(const char *pcsz) RT_NOTHROW_DEF
 {
@@ -131 +134 @@
 /**
  * Get the name of a floppy drive according to the Linux floppy driver.
+ *
  * @returns true on success, false if the name was not available (i.e. the
  *          device was not readable, or the file name wasn't a PC floppy
@@ -159 +163 @@
 /**
  * Create a UDI and a description for a floppy drive based on a number and the
- * driver's name for it.  We deliberately return an ugly sequence of
- * characters as the description rather than an English language string to
- * avoid translation issues.
+ * driver's name for it.
+ *
+ * We deliberately return an ugly sequence of characters as the description
+ * rather than an English language string to avoid translation issues.
  *
  * @returns true if we know the device to be valid, false otherwise
@@ -350 +355 @@
  * Initialise the device strings (description and UDI) for a DVD drive based on
  * vendor and model name strings.
+ *
  * @param pcszVendor  the vendor ID string
  * @param pcszModel   the product ID string
@@ -1018 +1024 @@
 typedef struct inotifyWatch
 {
-    /** Pointer to the inotify_add_watch() glibc function/Linux API */
-    int (*inotify_add_watch)(int, const char *, uint32_t);
     /** The native handle of the inotify fd. */
     int mhInotify;
@@ -1026 +1030 @@
 /** The flags we pass to inotify - modify, create, delete, change permissions
  */
-#define IN_FLAGS 0x306
+#define MY_IN_FLAGS (IN_CREATE | IN_DELETE | IN_MODIFY | IN_ATTRIB)
+AssertCompile(MY_IN_FLAGS == 0x306);
 
 static int iwAddWatch(inotifyWatch *pSelf, const char *pcszPath)
 {
     errno = 0;
-    if (  pSelf->inotify_add_watch(pSelf->mhInotify, pcszPath, IN_FLAGS) >= 0
-        || (errno == EACCES))
+    if (   inotify_add_watch(pSelf->mhInotify, pcszPath, MY_IN_FLAGS) >= 0
+        || errno == EACCES)
         return VINF_SUCCESS;
     /* Other errors listed in the manpage can be treated as fatal */
@@ -1041 +1046 @@
 static int iwInit(inotifyWatch *pSelf)
 {
-    int (*inotify_init)(void);
-    int fd, flags;
-    int rc = VINF_SUCCESS;
-
     AssertPtr(pSelf);
     pSelf->mhInotify = -1;
-    errno = 0;
-    *(void **)(&inotify_init) = dlsym(RTLD_DEFAULT, "inotify_init");
-    if (!inotify_init)
-        return VERR_LDR_IMPORTED_SYMBOL_NOT_FOUND;
-    *(void **)(&pSelf->inotify_add_watch)
-                    = dlsym(RTLD_DEFAULT, "inotify_add_watch");
-    if (!pSelf->inotify_add_watch)
-        return VERR_LDR_IMPORTED_SYMBOL_NOT_FOUND;
-    fd = inotify_init();
-    if (fd < 0)
-    {
-        Assert(errno > 0);
-        return RTErrConvertFromErrno(errno);
-    }
-    Assert(errno == 0);
-
-    flags = fcntl(fd, F_GETFL, NULL);
-    if (   flags < 0
-        || fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0
-        || fcntl(fd, F_SETFD, FD_CLOEXEC) < 0 /* race here */)
-    {
-        Assert(errno > 0);
-        rc = RTErrConvertFromErrno(errno);
-    }
-    if (RT_FAILURE(rc))
-        close(fd);
-    else
-    {
-        Assert(errno == 0);
+    int fd = inotify_init1(IN_CLOEXEC | IN_NONBLOCK);
+    if (fd >= 0)
+    {
         pSelf->mhInotify = fd;
-    }
-    return rc;
+        return VINF_SUCCESS;
+    }
+    Assert(errno > 0);
+    return RTErrConvertFromErrno(errno);
 }
 
@@ -1147 +1124 @@
     /** Is inotify available and working on this system?  If so we expect that
      * this implementation will be usable. */
-    /** @todo test the "inotify in glibc but not in the kernel" case. */
     static bool Available(void)
     {
-        int (*inotify_init)(void);
-
-        *(void **)(&inotify_init) = dlsym(RTLD_DEFAULT, "inotify_init");
-        if (!inotify_init)
-            return false;
-        int fd = inotify_init();
-        if (fd == -1)
-            return false;
-        close(fd);
-        return true;
+        int const fd = inotify_init1(IN_CLOEXEC | IN_NONBLOCK);
+        if (fd >= 0)
+            close(fd);
+        return fd >= 0;
     }
 
@@ -1181 +1151 @@
     /*
      * Create the pipe and set the close-on-exec flag.
+     * ASSUMES we're building and running on Linux 2.6.27 or later (pipe2).
      */
     int aFds[2] = {-1, -1};
-    if (pipe(aFds))
+    if (pipe2(aFds, O_CLOEXEC))
         return RTErrConvertFromErrno(errno);
-    if (   fcntl(aFds[0], F_SETFD, FD_CLOEXEC) < 0
-        || fcntl(aFds[1], F_SETFD, FD_CLOEXEC) < 0)
-    {
-        int rc = RTErrConvertFromErrno(errno);
-        close(aFds[0]);
-        close(aFds[1]);
-        return rc;
-    }
 
     *phPipeRead  = aFds[0];
@@ -1204 +1167 @@
 }
 
-hotplugInotifyImpl::hotplugInotifyImpl(const char *pcszDevicesRoot) :
-    mhWakeupPipeR(-1), mhWakeupPipeW(-1), mfWaiting(0),
-    mpcszDevicesRoot(pcszDevicesRoot), mStatus(VERR_WRONG_ORDER)
+hotplugInotifyImpl::hotplugInotifyImpl(const char *pcszDevicesRoot)
+    : mhWakeupPipeR(-1), mhWakeupPipeW(-1), mfWaiting(0)
+    , mpcszDevicesRoot(pcszDevicesRoot), mStatus(VERR_WRONG_ORDER)
 {
 #  ifdef DEBUG
@@ -1217 +1180 @@
      * available */
 #  endif
-    int rc;
-    do {
-        if (RT_FAILURE(rc = iwInit(&mWatches)))
-            break;
-        if (RT_FAILURE(rc = iwAddWatch(&mWatches, mpcszDevicesRoot)))
-            break;
-        if (RT_FAILURE(rc = pipeCreateSimple(&mhWakeupPipeR, &mhWakeupPipeW)))
-            break;
-    } while (0);
+
+    int rc = iwInit(&mWatches);
+    if (RT_SUCCESS(rc))
+    {
+        rc = iwAddWatch(&mWatches, mpcszDevicesRoot);
+        if (RT_SUCCESS(rc))
+            rc = pipeCreateSimple(&mhWakeupPipeR, &mhWakeupPipeW);
+    }
     mStatus = rc;
     if (RT_FAILURE(rc))
@@ -1255 +1217 @@
     AssertRCReturn(mStatus, VERR_WRONG_ORDER);
     errno = 0;
-    do {
+    do
         cchRead = read(iwGetFD(&mWatches), chBuf, sizeof(chBuf));
-    } while (cchRead > 0);
+    while (cchRead > 0);
     if (cchRead == 0)
         return VINF_SUCCESS;
@@ -1286 +1248 @@
 {
     int rc;
-    char **ppszEntry;
-    VECTOR_PTR(char *) vecpchDevs;
 
     AssertRCReturn(mStatus, VERR_WRONG_ORDER);
     bool fEntered = ASMAtomicCmpXchgU32(&mfWaiting, 1, 0);
     AssertReturn(fEntered, VERR_WRONG_ORDER);
+
+    VECTOR_PTR(char *) vecpchDevs;
     VEC_INIT_PTR(&vecpchDevs, char *, RTStrFree);
-    do {
-        struct pollfd pollFD[MAX_POLLID];
-
+    for (;;)
+    {
         rc = readFilePaths(mpcszDevicesRoot, &vecpchDevs, false);
         if (RT_SUCCESS(rc))
+        {
+            char **ppszEntry;
             VEC_FOR_EACH(&vecpchDevs, char *, ppszEntry)
                 if (RT_FAILURE(rc = iwAddWatch(&mWatches, *ppszEntry)))
                     break;
+        }
         if (RT_FAILURE(rc))
             break;
+
+        struct pollfd pollFD[MAX_POLLID];
         pollFD[RPIPE_ID].fd = mhWakeupPipeR;
         pollFD[RPIPE_ID].events = POLLIN;
@@ -1332 +1298 @@
         if (RT_FAILURE(rc = drainInotify()))
             break;
-    } while (false);
+    }
+
     mfWaiting = 0;
     VEC_CLEANUP_PTR(&vecpchDevs);