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| author | Harry Sintonen <sintonen@iki.fi> | 2023-04-25 09:22:26 +0200 |
|---|---|---|
| committer | Daniel Stenberg <daniel@haxx.se> | 2023-04-26 15:40:07 +0200 |
| commit | 13718030ad4b3209a7583b4f27f683cd3a6fa5f2 (patch) | |
| tree | d7899180a0bb5470f1ce9617c7ef299e122a8377 | |
| parent | 91b53efa4b6854dc3688f55bfb329b0cafcf5325 (diff) | |
| download | curl-13718030ad4b3209a7583b4f27f683cd3a6fa5f2.tar.gz | |
hostip: add locks around use of global buffer for alarm()
When building with the sync name resolver and timeout ability we now
require thread-safety to be present to enable it.
Closes #11030
| -rw-r--r-- | lib/hostip.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/lib/hostip.c b/lib/hostip.c index 2381290fd..e410cda69 100644 --- a/lib/hostip.c +++ b/lib/hostip.c @@ -70,12 +70,19 @@ #include <SystemConfiguration/SCDynamicStoreCopySpecific.h> #endif -#if defined(CURLRES_SYNCH) && \ - defined(HAVE_ALARM) && defined(SIGALRM) && defined(HAVE_SIGSETJMP) +#if defined(CURLRES_SYNCH) && \ + defined(HAVE_ALARM) && \ + defined(SIGALRM) && \ + defined(HAVE_SIGSETJMP) && \ + defined(GLOBAL_INIT_IS_THREADSAFE) /* alarm-based timeouts can only be used with all the dependencies satisfied */ #define USE_ALARM_TIMEOUT #endif +#ifdef USE_ALARM_TIMEOUT +#include "easy_lock.h" +#endif + #define MAX_HOSTCACHE_LEN (255 + 7) /* max FQDN + colon + port number + zero */ /* @@ -254,11 +261,12 @@ void Curl_hostcache_prune(struct Curl_easy *data) Curl_share_unlock(data, CURL_LOCK_DATA_DNS); } -#ifdef HAVE_SIGSETJMP +#ifdef USE_ALARM_TIMEOUT /* Beware this is a global and unique instance. This is used to store the return address that we can jump back to from inside a signal handler. This is not thread-safe stuff. */ sigjmp_buf curl_jmpenv; +curl_simple_lock curl_jmpenv_lock; #endif /* lookup address, returns entry if found and not stale */ @@ -832,7 +840,6 @@ enum resolve_t Curl_resolv(struct Curl_easy *data, static void alarmfunc(int sig) { - /* this is for "-ansi -Wall -pedantic" to stop complaining! (rabe) */ (void)sig; siglongjmp(curl_jmpenv, 1); } @@ -912,6 +919,8 @@ enum resolve_t Curl_resolv_timeout(struct Curl_easy *data, This should be the last thing we do before calling Curl_resolv(), as otherwise we'd have to worry about variables that get modified before we invoke Curl_resolv() (and thus use "volatile"). */ + curl_simple_lock_lock(&curl_jmpenv_lock); + if(sigsetjmp(curl_jmpenv, 1)) { /* this is coming from a siglongjmp() after an alarm signal */ failf(data, "name lookup timed out"); @@ -980,6 +989,8 @@ clean_up: #endif #endif /* HAVE_SIGACTION */ + curl_simple_lock_unlock(&curl_jmpenv_lock); + /* switch back the alarm() to either zero or to what it was before minus the time we spent until now! */ if(prev_alarm) { |