From 65b3903ff576488eaabb51d3c4fbf9c73d867d7c Mon Sep 17 00:00:00 2001 From: Zbigniew Jędrzejewski-Szmek Date: Sat, 25 Jan 2014 23:35:28 -0500 Subject: journal: guarantee async-signal-safety in sd_journald_sendv signal(7) provides a list of functions which may be called from a signal handler. Other functions, which only call those functions and don't access global memory and are reentrant are also safe. sd_j_sendv was mostly OK, but would call mkostemp and writev in a fallback path, which are unsafe. Being able to call sd_j_sendv in a async-signal-safe way is important because it allows it be used in signal handlers. Safety is achieved by replacing mkostemp with open(O_TMPFILE) and an open-coded writev replacement which uses write. Unfortunately, O_TMPFILE is only available on kernels >= 3.11. When O_TMPFILE is unavailable, an open-coded mkostemp is used. https://bugzilla.gnome.org/show_bug.cgi?id=722889 --- src/shared/util.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/shared/util.h') diff --git a/src/shared/util.h b/src/shared/util.h index 630137a53a..1169864c3a 100644 --- a/src/shared/util.h +++ b/src/shared/util.h @@ -850,4 +850,7 @@ bool pid_valid(pid_t pid); int getpeercred(int fd, struct ucred *ucred); int getpeersec(int fd, char **ret); +int writev_safe(int fd, const struct iovec *w, int j); + +int mkostemp_safe(char *pattern, int flags); int open_tmpfile(const char *path, int flags); -- cgit v1.2.3-54-g00ecf