From f4c0f888817ee7c593b56a5fe47b4acfbc83c7d3 Mon Sep 17 00:00:00 2001 From: Janne Blomqvist Date: Fri, 23 Nov 2018 22:42:03 +0200 Subject: [PATCH] Make recursion_check work for multiple threads With multiple threads, using an unprotected static variable to check whether recursion has occured isn't valid, as one thread might have modified the variable, thus causing another thread to incorrectly conclude that recursion has occured. This patch avoids this problem by using a thread-specific variable for the recursion check. Regtested on x86_64-pc-linux-gnu. libgfortran/ChangeLog: 2018-11-23 Janne Blomqvist * runtime/error.c (MAGIC): Remove. (recursion_key): New variable. (recursion_check): Use thread-specific variable for recursion check if threads are active. (constructor_recursion_check): New function. (destructor_recursion_check): New funcion. From-SVN: r266419 --- libgfortran/ChangeLog | 9 +++++++ libgfortran/runtime/error.c | 47 ++++++++++++++++++++++++++++++------- 2 files changed, 47 insertions(+), 9 deletions(-) diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog index 59c16f35072..d9397623ee1 100644 --- a/libgfortran/ChangeLog +++ b/libgfortran/ChangeLog @@ -1,3 +1,12 @@ +2018-11-23 Janne Blomqvist + + * runtime/error.c (MAGIC): Remove. + (recursion_key): New variable. + (recursion_check): Use thread-specific variable for recursion + check if threads are active. + (constructor_recursion_check): New function. + (destructor_recursion_check): New funcion. + 2018-11-22 Janne Blomqvist * acinclude.m4 (LIBGFOR_CHECK_ATOMIC_FETCH_ADD): Rename and test diff --git a/libgfortran/runtime/error.c b/libgfortran/runtime/error.c index b07a4c0b12a..7c52733c19c 100644 --- a/libgfortran/runtime/error.c +++ b/libgfortran/runtime/error.c @@ -332,22 +332,51 @@ show_locus (st_parameter_common *cmp) /* recursion_check()-- It's possible for additional errors to occur * during fatal error processing. We detect this condition here and - * exit with code 4 immediately. */ + * abort immediately. */ -#define MAGIC 0x20DE8101 +static __gthread_key_t recursion_key; static void recursion_check (void) { - static int magic = 0; - - /* Don't even try to print something at this point */ - if (magic == MAGIC) - sys_abort (); - - magic = MAGIC; + if (__gthread_active_p ()) + { + bool* p = __gthread_getspecific (recursion_key); + if (!p) + { + p = xcalloc (1, sizeof (bool)); + __gthread_setspecific (recursion_key, p); + } + if (*p) + sys_abort (); + *p = true; + } + else + { + static bool recur; + if (recur) + sys_abort (); + recur = true; + } } +#ifdef __GTHREADS +static void __attribute__((constructor)) +constructor_recursion_check (void) +{ + if (__gthread_active_p ()) + __gthread_key_create (&recursion_key, &free); +} + +static void __attribute__((destructor)) +destructor_recursion_check (void) +{ + if (__gthread_active_p ()) + __gthread_key_delete (recursion_key); +} +#endif + + #define STRERR_MAXSZ 256