errors: be more robust in handling unexpected fatal errors

Introduce a new error level, ERR_CRITICAL, beyond which we will
minimize the amount of code that will be executed before we die; in
particular don't execute any memory allocations, and if we somehow end
up recursing, abort() immediately.

Basically, "less than panic, more than fatal."

At this point this level is used by nasm_alloc_failed().

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/rdoff/rdoff.c b/rdoff/rdoff.c
index 3fd2a0e9..bdba82ae 100644
--- a/rdoff/rdoff.c
+++ b/rdoff/rdoff.c
@@ -228,12 +228,18 @@ int rdf_errno = 0;
 /* ========================================================================
  * Hook for nasm_error() to work
  * ======================================================================== */
-static void rdoff_verror(errflags severity, const char *fmt, va_list val)
+fatal_func nasm_verror_critical(errflags severity, const char *fmt, va_list val)
 {
     vfprintf(stderr, fmt, val);
+    exit((severity & ERR_MASK) - ERR_FATAL + 2);
+}
 
+static void rdoff_verror(errflags severity, const char *fmt, va_list val)
+{
     if ((severity & ERR_MASK) >= ERR_FATAL)
-        exit(1);
+        nasm_verror_critical(severity, fmt, val);
+    else
+        vfprintf(stderr, fmt, val);
 }
 
 void rdoff_init(void)