X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=share%2Fusterr.h;h=1819f973069b99f670fd5411f6d7809c35daffee;hb=79e36890013903cb83326ee0d411eede31888949;hp=93333e557ca6edca06d4975ad9694aeeacf1495b;hpb=d61bfa72a22d7faf64c1babe1bc663aeb280717b;p=ust.git

diff --git a/share/usterr.h b/share/usterr.h
index 93333e5..1819f97 100644
--- a/share/usterr.h
+++ b/share/usterr.h
@@ -2,6 +2,12 @@
 #define USTERR_H
 
 #include <string.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <errno.h>
+#include <stdarg.h>
+
+#include "share.h"
 
 #ifndef UST_COMPONENT
 //#error UST_COMPONENT is undefined
@@ -12,24 +18,51 @@
 #define XSTR(d) STR(d)
 #define STR(s) #s
 
+/* We sometimes print in the tracing path, and tracing can occur in
+ * signal handlers, so we must use a print method which is signal safe.
+ */
+
+#define sigsafe_print_err(fmt, args...) \
+{ \
+	/* Can't use dynamic allocation. Limit ourselves to 250 chars. */ \
+	char ____buf[250]; \
+	int ____saved_errno; \
+\
+	/* Save the errno. */ \
+	____saved_errno = errno; \
+\
+	snprintf(____buf, sizeof(____buf), fmt, ## args); \
+\
+	/* Add end of string in case of buffer overflow. */ \
+	____buf[sizeof(____buf)-1] = 0; \
+\
+	patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
+	/* Can't print errors because we are in the error printing code path. */ \
+\
+	/* Restore errno, in order to be async-signal safe. */ \
+	errno = ____saved_errno; \
+}
+
 #define UST_STR_COMPONENT XSTR(UST_COMPONENT)
 
+#define ERRMSG(fmt, args...) do { sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (" __FILE__ ":" XSTR(__LINE__) ")\n", (long) getpid(), (long) syscall(SYS_gettid), ## args); fflush(stderr); } while(0)
+
 #define DEBUG
 #ifdef DEBUG
-# define DBG(fmt, args...) do { fprintf(stderr, UST_STR_COMPONENT ": " fmt " (" __FILE__ ":" XSTR(__LINE__) ")\n", ## args); fflush(stderr); } while(0)
+# define DBG(fmt, args...) ERRMSG(fmt, ## args)
 #else
 # define DBG(fmt, args...) do {} while(0)
 #endif
-#define WARN(fmt, args...) fprintf(stderr, UST_STR_COMPONENT ": Warning: " fmt "\n", ## args); fflush(stderr)
-#define ERR(fmt, args...) fprintf(stderr, UST_STR_COMPONENT ": Error: " fmt "\n", ## args); fflush(stderr)
-#define BUG(fmt, args...) fprintf(stderr, UST_STR_COMPONENT ": BUG: " fmt "\n", ## args); fflush(stderr)
+#define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
+#define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
+#define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
 
 #if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
 #define PERROR(call, args...)\
 	do { \
 		char buf[200] = "Error in strerror_r()"; \
 		strerror_r(errno, buf, sizeof(buf)); \
-		fprintf(stderr, UST_STR_COMPONENT ": Error: " call ": %s\n", ## args, buf); fflush(stderr); \
+		ERRMSG("Error: " call ": %s", ## args, buf); \
 	} while(0);
 #else
 #define PERROR(call, args...)\
@@ -37,7 +70,7 @@
 		char *buf; \
 		char tmp[200]; \
 		buf = strerror_r(errno, tmp, sizeof(tmp)); \
-		fprintf(stderr, UST_STR_COMPONENT ": Error: " call ": %s\n", ## args, buf); fflush(stderr); \
+		ERRMSG("Error: " call ": %s", ## args, buf); \
 	} while(0);
 #endif