diff options
Diffstat (limited to 'meta-oe/recipes-extended/rsyslog/rsyslog/0001-remove-memleak-introduced-by-GenerateLocalHostName-H.patch')
| -rw-r--r-- | meta-oe/recipes-extended/rsyslog/rsyslog/0001-remove-memleak-introduced-by-GenerateLocalHostName-H.patch | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/meta-oe/recipes-extended/rsyslog/rsyslog/0001-remove-memleak-introduced-by-GenerateLocalHostName-H.patch b/meta-oe/recipes-extended/rsyslog/rsyslog/0001-remove-memleak-introduced-by-GenerateLocalHostName-H.patch new file mode 100644 index 0000000000..fcc5d8ebfb --- /dev/null +++ b/meta-oe/recipes-extended/rsyslog/rsyslog/0001-remove-memleak-introduced-by-GenerateLocalHostName-H.patch @@ -0,0 +1,103 @@ +From 17e1ee2539cea6bac16832b488afd52b20a348ac Mon Sep 17 00:00:00 2001 +From: Rainer Gerhards <rgerhards@adiscon.com> +Date: Mon, 28 Oct 2013 14:17:56 +0100 +Subject: [PATCH] remove memleak introduced by GenerateLocalHostName HUP + bugfix + +Upstream-Status: backport + +Signed-off-by: Li Zhou <li.zhou@windriver.com> +--- + runtime/glbl.c | 45 ++++++++++++++++++++++++++++++++------------- + 1 file changed, 32 insertions(+), 13 deletions(-) + +diff --git a/runtime/glbl.c b/runtime/glbl.c +index bcb3795..41d56c2 100644 +--- a/runtime/glbl.c ++++ b/runtime/glbl.c +@@ -72,6 +72,7 @@ static int option_DisallowWarning = 1; /* complain if message from disallowed se + static int bDisableDNS = 0; /* don't look up IP addresses of remote messages */ + static prop_t *propLocalIPIF = NULL;/* IP address to report for the local host (default is 127.0.0.1) */ + static prop_t *propLocalHostName = NULL;/* our hostname as FQDN - read-only after startup */ ++static prop_t *propLocalHostNameToDelete = NULL;/* see GenerateLocalHostName function hdr comment! */ + static uchar *LocalHostName = NULL;/* our hostname - read-only after startup, except HUP */ + static uchar *LocalHostNameOverride = NULL;/* user-overridden hostname - read-only after startup */ + static uchar *LocalFQDNName = NULL;/* our hostname as FQDN - read-only after startup, except HUP */ +@@ -380,24 +381,31 @@ GetLocalDomain(void) + /* generate the local hostname property. This must be done after the hostname info + * has been set as well as PreserveFQDN. + * rgerhards, 2009-06-30 +- * NOTE: This function DELIBERATELY introduces a small memory leak in order to gain +- * speed. Each time it is called when a property name already exists, a new one is +- * allocated but the previous one is NOT freed. This is so that current readers can +- * continue to use the previous name. Otherwise, we would need to use read/write locks +- * to protect the update process. As this function is called extremely infrequently and +- * the memory leak is very small, this is totally accessible. Think that otherwise we +- * would need to place a read look each time the property is read, which is much more +- * frequent (once per message for the modules that use this local hostname!). ++ * NOTE: This function tries to avoid locking by not destructing the previous value ++ * immediately. This is so that current readers can continue to use the previous name. ++ * Otherwise, we would need to use read/write locks to protect the update process. ++ * In order to do so, we save the previous value and delete it when we are called again ++ * the next time. Note that this in theory is racy and can lead to a double-free. ++ * In practice, however, the window of exposure to trigger this is extremely short ++ * and as this functions is very infrequently being called (on HUP), the trigger ++ * condition for this bug is so highly unlikely that it never occurs in practice. ++ * Probably if you HUP rsyslog every few milliseconds, but who does that... ++ * To further reduce risk potential, we do only update the property when there ++ * actually is a hostname change, which makes it even less likely. + * rgerhards, 2013-10-28 + */ + static rsRetVal + GenerateLocalHostNameProperty(void) + { ++ uchar *pszPrev; ++ int lenPrev; + prop_t *hostnameNew; + uchar *pszName; + DEFiRet; + +- CHKiRet(prop.Construct(&hostnameNew)); ++ if(propLocalHostNameToDelete != NULL) ++ prop.Destruct(&propLocalHostNameToDelete); ++ + if(LocalHostNameOverride == NULL) { + if(LocalHostName == NULL) + pszName = (uchar*) "[localhost]"; +@@ -411,11 +419,20 @@ GenerateLocalHostNameProperty(void) + pszName = LocalHostNameOverride; + } + DBGPRINTF("GenerateLocalHostName uses '%s'\n", pszName); +- CHKiRet(prop.SetString(hostnameNew, pszName, ustrlen(pszName))); +- CHKiRet(prop.ConstructFinalize(hostnameNew)); + +- propLocalHostName = hostnameNew; +- /* inititional MEM LEAK for old value -- see function hdr comment! */ ++ if(propLocalHostName == NULL) ++ pszPrev = (uchar*)""; /* make sure strcmp() below does not match */ ++ else ++ prop.GetString(propLocalHostName, &pszPrev, &lenPrev); ++ ++ if(ustrcmp(pszPrev, pszName)) { ++ /* we need to update */ ++ CHKiRet(prop.Construct(&hostnameNew)); ++ CHKiRet(prop.SetString(hostnameNew, pszName, ustrlen(pszName))); ++ CHKiRet(prop.ConstructFinalize(hostnameNew)); ++ propLocalHostNameToDelete = propLocalHostName; ++ propLocalHostName = hostnameNew; ++ } + + finalize_it: + RETiRet; +@@ -678,6 +695,8 @@ BEGINObjClassExit(glbl, OBJ_IS_CORE_MODULE) /* class, version */ + free(LocalHostNameOverride); + free(LocalFQDNName); + objRelease(prop, CORE_COMPONENT); ++ if(propLocalHostNameToDelete != NULL) ++ prop.Destruct(&propLocalHostNameToDelete); + DESTROY_ATOMIC_HELPER_MUT(mutTerminateInputs); + ENDObjClassExit(glbl) + +-- +1.7.9.5 + |