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path: root/src/VBox/Runtime/r3/linux/sysfs.cpp
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Diffstat (limited to 'src/VBox/Runtime/r3/linux/sysfs.cpp')
-rw-r--r--src/VBox/Runtime/r3/linux/sysfs.cpp164
1 files changed, 80 insertions, 84 deletions
diff --git a/src/VBox/Runtime/r3/linux/sysfs.cpp b/src/VBox/Runtime/r3/linux/sysfs.cpp
index f5dfc6a57..15309330f 100644
--- a/src/VBox/Runtime/r3/linux/sysfs.cpp
+++ b/src/VBox/Runtime/r3/linux/sysfs.cpp
@@ -53,8 +53,7 @@
* Constructs the path of a sysfs file from the format parameters passed,
* prepending a prefix if the path is relative.
*
- * @returns The number of characters returned, or -1 and errno set to ERANGE on
- * failure.
+ * @returns The number of characters returned, or an iprt error code on failure.
*
* @param pszPrefix The prefix to prepend if the path is relative. Must end
* in '/'.
@@ -70,8 +69,8 @@ static ssize_t rtLinuxConstructPathV(char *pszBuf, size_t cchBuf,
const char *pszFormat, va_list va)
{
size_t cchPrefix = strlen(pszPrefix);
- AssertReturnStmt(pszPrefix[cchPrefix - 1] == '/', errno = ERANGE, -1);
- AssertReturnStmt(cchBuf > cchPrefix + 1, errno = ERANGE, -1);
+ AssertReturn(pszPrefix[cchPrefix - 1] == '/', VERR_INVALID_PARAMETER);
+ AssertReturn(cchBuf > cchPrefix + 1, VERR_INVALID_PARAMETER);
/** @todo While RTStrPrintfV prevents overflows, it doesn't make it easy to
* check for truncations. RTPath should provide some formatters and
@@ -80,7 +79,7 @@ static ssize_t rtLinuxConstructPathV(char *pszBuf, size_t cchBuf,
size_t cch = RTStrPrintfV(pszBuf, cchBuf, pszFormat, va);
if (*pszBuf != '/')
{
- AssertReturnStmt(cchBuf >= cch + cchPrefix + 1, errno = ERANGE, -1);
+ AssertReturn(cchBuf >= cch + cchPrefix + 1, VERR_BUFFER_OVERFLOW);
memmove(pszBuf + cchPrefix, pszBuf, cch + 1);
memcpy(pszBuf, pszPrefix, cchPrefix);
cch += cchPrefix;
@@ -93,8 +92,8 @@ static ssize_t rtLinuxConstructPathV(char *pszBuf, size_t cchBuf,
* Constructs the path of a sysfs file from the format parameters passed,
* prepending a prefix if the path is relative.
*
- * @returns The number of characters returned, or -1 and errno set to ERANGE on
- * failure.
+ * @returns The number of characters returned, or an iprt error code on failure.
+ * @note Unused.
*
* @param pszPrefix The prefix to prepend if the path is relative. Must end
* in '/'.
@@ -131,7 +130,11 @@ static ssize_t rtLinuxConstructPath(char *pszBuf, size_t cchBuf,
*/
static ssize_t rtLinuxSysFsConstructPath(char *pszBuf, size_t cchBuf, const char *pszFormat, va_list va)
{
- return rtLinuxConstructPathV(pszBuf, cchBuf, "/sys/", pszFormat, va);
+ ssize_t rc = rtLinuxConstructPathV(pszBuf, cchBuf, "/sys/", pszFormat, va);
+ if (rc >= 0)
+ return rc;
+ errno = ERANGE;
+ return -1;
}
@@ -409,125 +412,118 @@ RTDECL(ssize_t) RTLinuxSysFsGetLinkDest(char *pszBuf, size_t cchBuf, const char
}
-static ssize_t rtLinuxFindDevicePathRecursive(dev_t DevNum, RTFMODE fMode, const char *pszBasePath,
- char *pszBuf, size_t cchBuf)
+/** Search for a device node with the number @a DevNum and the type (character
+ * or block) @a fMode below the path @a pszPath. @a pszPath MUST point to a
+ * buffer of size at least RTPATH_MAX which will be modified during the function
+ * execution. On successful return it will contain the path to the device node
+ * found. */
+/** @note This function previously used a local stack buffer of size RTPATH_MAX
+ * to construct the path passed to the next recursive call, which used up 4K
+ * of stack space per iteration and caused a stack overflow on a path with
+ * too many components. */
+static int rtLinuxFindDevicePathRecursive(dev_t DevNum, RTFMODE fMode,
+ char *pszPath)
{
+ int rc;
+ PRTDIR pDir;
+ size_t const cchPath = strlen(pszPath);
+
/*
* Check assumptions made by the code below.
*/
- size_t const cchBasePath = strlen(pszBasePath);
- AssertReturnStmt(cchBasePath < RTPATH_MAX - 10U, errno = ENAMETOOLONG, -1);
-
- ssize_t rcRet;
- PRTDIR pDir;
- int rc = RTDirOpen(&pDir, pszBasePath);
+ AssertReturn(cchPath < RTPATH_MAX - 10U, VERR_BUFFER_OVERFLOW);
+ rc = RTDirOpen(&pDir, pszPath);
if (RT_SUCCESS(rc))
{
- char szPath[RTPATH_MAX]; /** @todo 4K per recursion - can easily be optimized away by passing it along pszBasePath
- and only remember the length. */
- memcpy(szPath, pszBasePath, cchBasePath + 1);
-
for (;;)
{
RTDIRENTRYEX Entry;
- rc = RTDirReadEx(pDir, &Entry, NULL, RTFSOBJATTRADD_UNIX, RTPATH_F_ON_LINK);
+ rc = RTDirReadEx(pDir, &Entry, NULL, RTFSOBJATTRADD_UNIX,
+ RTPATH_F_ON_LINK);
if (RT_FAILURE(rc))
- {
- errno = rc == VERR_NO_MORE_FILES
- ? ENOENT
- : rc == VERR_BUFFER_OVERFLOW
- ? EOVERFLOW
- : EIO;
- rcRet = -1;
break;
- }
if (RTFS_IS_SYMLINK(Entry.Info.Attr.fMode))
continue;
-
+ pszPath[cchPath] = '\0';
+ rc = RTPathAppend(pszPath, RTPATH_MAX, Entry.szName);
+ if (RT_FAILURE(rc))
+ break;
/* Do the matching. */
if ( Entry.Info.Attr.u.Unix.Device == DevNum
&& (Entry.Info.Attr.fMode & RTFS_TYPE_MASK) == fMode)
- {
- rcRet = rtLinuxConstructPath(pszBuf, cchBuf, pszBasePath, "%s", Entry.szName);
break;
- }
-
/* Recurse into subdirectories. */
if (!RTFS_IS_DIRECTORY(Entry.Info.Attr.fMode))
continue;
if (Entry.szName[0] == '.')
continue;
-
- szPath[cchBasePath] = '\0';
- rc = RTPathAppend(szPath, sizeof(szPath) - 1, Entry.szName); /* -1: for slash */
- if (RT_FAILURE(rc))
- {
- errno = ENAMETOOLONG;
- rcRet = -1;
- break;
- }
- strcat(&szPath[cchBasePath], "/");
- rcRet = rtLinuxFindDevicePathRecursive(DevNum, fMode, szPath, pszBuf, cchBuf);
- if (rcRet >= 0 || errno != ENOENT)
+ rc = rtLinuxFindDevicePathRecursive(DevNum, fMode, pszPath);
+ if (RT_SUCCESS(rc) || rc != VERR_NO_MORE_FILES)
break;
}
RTDirClose(pDir);
}
- else
- {
- rcRet = -1;
- errno = RTErrConvertToErrno(rc);
- }
- return rcRet;
+ return rc;
}
-RTDECL(ssize_t) RTLinuxFindDevicePathV(dev_t DevNum, RTFMODE fMode, char *pszBuf, size_t cchBuf,
- const char *pszSuggestion, va_list va)
+RTDECL(ssize_t) RTLinuxFindDevicePathV(dev_t DevNum, RTFMODE fMode, char *pszBuf,
+ size_t cchBuf, const char *pszSuggestion,
+ va_list va)
{
- AssertReturnStmt(cchBuf >= 2, errno = EINVAL, -1);
- AssertReturnStmt( fMode == RTFS_TYPE_DEV_CHAR
- || fMode == RTFS_TYPE_DEV_BLOCK,
- errno = EINVAL, -1);
+ char szFilename[RTPATH_MAX];
+ int rc = VINF_TRY_AGAIN;
+ AssertReturn(cchBuf >= 2, VERR_INVALID_PARAMETER);
+ AssertReturn( fMode == RTFS_TYPE_DEV_CHAR
+ || fMode == RTFS_TYPE_DEV_BLOCK,
+ VERR_INVALID_PARAMETER);
if (pszSuggestion)
{
/*
* Construct the filename and read the link.
*/
- char szFilename[RTPATH_MAX];
- int rc = rtLinuxConstructPathV(szFilename, sizeof(szFilename), "/dev/", pszSuggestion, va);
- if (rc == -1)
- return -1;
-
- /*
- * Check whether the caller's suggestion was right.
- */
- RTFSOBJINFO Info;
- rc = RTPathQueryInfo(szFilename, &Info, RTFSOBJATTRADD_UNIX);
- if ( RT_SUCCESS(rc)
- && Info.Attr.u.Unix.Device == DevNum
- && (Info.Attr.fMode & RTFS_TYPE_MASK) == fMode)
+ rc = rtLinuxConstructPathV(szFilename, sizeof(szFilename), "/dev/",
+ pszSuggestion, va);
+ if (rc > 0)
{
- size_t cchPath = strlen(szFilename);
- if (cchPath >= cchBuf)
- {
- errno = EOVERFLOW;
- return -1;
- }
- memcpy(pszBuf, szFilename, cchPath + 1);
- return cchPath;
+ /*
+ * Check whether the caller's suggestion was right.
+ */
+ RTFSOBJINFO Info;
+ rc = RTPathQueryInfo(szFilename, &Info, RTFSOBJATTRADD_UNIX);
+ if ( rc == VERR_PATH_NOT_FOUND
+ || rc == VERR_FILE_NOT_FOUND
+ || ( RT_SUCCESS(rc)
+ && ( Info.Attr.u.Unix.Device != DevNum
+ || (Info.Attr.fMode & RTFS_TYPE_MASK) != fMode)))
+ /* The suggestion was wrong, fall back on the brute force attack. */
+ rc = VINF_TRY_AGAIN;
}
-
- /* The suggestion was wrong, fall back on the brute force attack. */
}
- return rtLinuxFindDevicePathRecursive(DevNum, fMode, "/dev/", pszBuf, cchBuf);
+ if (rc == VINF_TRY_AGAIN)
+ {
+ RTStrCopy(szFilename, sizeof(szFilename), "/dev/");
+ rc = rtLinuxFindDevicePathRecursive(DevNum, fMode, szFilename);
+ }
+ if (RT_SUCCESS(rc))
+ {
+ size_t cchPath = strlen(szFilename);
+ if (cchPath >= cchBuf)
+ return VERR_BUFFER_OVERFLOW;
+ memcpy(pszBuf, szFilename, cchPath + 1);
+ return cchPath;
+ }
+ return rc;
}
-RTDECL(ssize_t) RTLinuxFindDevicePath(dev_t DevNum, RTFMODE fMode, char *pszBuf, size_t cchBuf,
- const char *pszSuggestion, ...)
+/** @todo Do we really need to return the string length? If the caller is
+ * interested (the current ones aren't) they can check themselves. */
+RTDECL(ssize_t) RTLinuxFindDevicePath(dev_t DevNum, RTFMODE fMode, char *pszBuf,
+ size_t cchBuf, const char *pszSuggestion,
+ ...)
{
va_list va;
va_start(va, pszSuggestion);
generated by cgit v1.2.3 (git 2.39.1) at 2025-06-29 16:37:01 +0000