From 3b935595859e0232b74594c5aca6da88a31f90b3 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 6 Feb 2019 16:26:39 +0100 Subject: support: Use dlerror to detect NULL symbols in xdlsym --- ChangeLog | 5 +++++ support/xdlfcn.c | 20 ++++++++++---------- 2 files changed, 15 insertions(+), 10 deletions(-) diff --git a/ChangeLog b/ChangeLog index f2444576f2..66fa654f70 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2019-02-06 Florian Weimer + + * support/xdlfcn.c (xdlopen, xdlclose): Do not call dlerror. + (xdlsym): Use dlerror to detect a NULL symbol. + 2019-02-06 Florian Weimer * sysdeps/unix/sysv/linux/i386/lowlevellock.h: Do not include diff --git a/support/xdlfcn.c b/support/xdlfcn.c index 2f2ac76003..b2e5c21134 100644 --- a/support/xdlfcn.c +++ b/support/xdlfcn.c @@ -28,22 +28,25 @@ xdlopen (const char *filename, int flags) if (dso == NULL) FAIL_EXIT1 ("error: dlopen: %s\n", dlerror ()); - /* Clear any errors. */ - dlerror (); - return dso; } void * xdlsym (void *handle, const char *symbol) { + /* Clear any pending errors. */ + dlerror (); + void *sym = dlsym (handle, symbol); if (sym == NULL) - FAIL_EXIT1 ("error: dlsym: %s\n", dlerror ()); - - /* Clear any errors. */ - dlerror (); + { + const char *error = dlerror (); + if (error != NULL) + FAIL_EXIT1 ("error: dlsym: %s\n", error); + /* If there was no error, we found a NULL symbol. Return the + NULL value in this case. */ + } return sym; } @@ -53,7 +56,4 @@ xdlclose (void *handle) { if (dlclose (handle) != 0) FAIL_EXIT1 ("error: dlclose: %s\n", dlerror ()); - - /* Clear any errors. */ - dlerror (); } -- cgit 1.4.1