There are a huge list of functions in POSIX which are not
safe to use from multiple threads currently. I generated
the list by looking at all libc symbol exports for variants
which have a parallel _r symbol.
nm -D --defined-only /lib/libc.so.6 \
| grep '_r$' \
| awk '{print $3}' \
| grep -v __ \
| grep -v qsort \
| grep -v readdir \
| sort \
| uniq \
| sed -e 's/_r//'
The qsort one is a red herring, since you only need qsort_r if
you need to pass a extra 'void * opaque' data blob to your sort
function - we don't, so don't need qsort_r.
The readdir one is also unneccessary, since reading from a single
DIR* is safe from a single thread. readdir_r is also horrific
http://womble.decadentplace.org.uk/readdir_r-advisory.html
This patch adds a 'make sc_prohibit_nonrentrant' rule to the
'syntax-check' for these forbidden functions.
.x-sc_prohibit_nonreentrant | 8 ++++
Makefile.am | 2 +
Makefile.maint | 11 +++++
Makefile.nonreentrant | 85 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 106 insertions(+)
Daniel
diff --git a/.x-sc_prohibit_nonreentrant b/.x-sc_prohibit_nonreentrant
new file mode 100644
--- /dev/null
+++ b/.x-sc_prohibit_nonreentrant
@@ -0,0 +1,8 @@
+^gnulib/
+^po/
+ChangeLog
+^Makefile*
+^docs/
+^tests/
+^src/virsh.c
+^build-aux/
diff --git a/Makefile.am b/Makefile.am
--- a/Makefile.am
+++ b/Makefile.am
@@ -17,6 +17,8 @@ EXTRA_DIST = \
.x-sc_require_config_h_first \
.x-sc_prohibit_strcmp \
.x-sc_require_config_h \
+ .x-sc_prohibit_nonreentrant \
+ Makefile.nonreentrant \
autogen.sh
man_MANS = virsh.1
diff --git a/Makefile.maint b/Makefile.maint
--- a/Makefile.maint
+++ b/Makefile.maint
@@ -12,6 +12,8 @@ VC_LIST = $(srcdir)/build-aux/vc-list-fi
VC_LIST_EXCEPT = \
$(VC_LIST) | if test -f .x-$@; then grep -vEf .x-$@; else grep -v ChangeLog; fi
+
+include Makefile.nonreentrant
# Prevent programs like 'sort' from considering distinct strings to be equal.
# Doing it here saves us from having to set LC_ALL elsewhere in this file.
@@ -110,6 +112,15 @@ sc_prohibit_asprintf:
sc_prohibit_asprintf:
@grep -nE '\<[a]sprintf\>' $$($(VC_LIST_EXCEPT)) && \
{ echo '$(ME): use virAsprintf, not a'sprintf 1>&2; exit 1; } || :
+
+sc_prohibit_nonreentrant:
+ @fail=0 ; \
+ for i in $(NON_REENTRANT) ; \
+ do \
+ grep -nE "\<$$i\>[:space:]*\(" $$($(VC_LIST_EXCEPT)) && \
+ fail=1 && echo "$(ME): use $${i}_r, not $${i}" || : ; \
+ done ; \
+ exit $$fail
# Using EXIT_SUCCESS as the first argument to error is misleading,
# since when that parameter is 0, error does not exit. Use `0' instead.
diff --git a/Makefile.nonreentrant b/Makefile.nonreentrant
new file mode 100644
--- /dev/null
+++ b/Makefile.nonreentrant
@@ -0,0 +1,85 @@
+
+#
+# Generated by running the following on Fedora 9:
+#
+# nm -D --defined-only /lib/libc.so.6 \
+# | grep '_r$' \
+# | awk '{print $3}' \
+# | grep -v __ \
+# | grep -v qsort \ # Red herring since we don't need to pass extra args to qsort comparator
+# | grep -v readdir \ # This is safe as long as each DIR * instance is only used by one thread
+# | sort \
+# | uniq \
+# | sed -e 's/_r//'
+#
+
+NON_REENTRANT =
+NON_REENTRANT += asctime
+NON_REENTRANT += ctime
+NON_REENTRANT += drand48
+NON_REENTRANT += ecvt
+NON_REENTRANT += erand48
+NON_REENTRANT += ether_aton
+NON_REENTRANT += ether_ntoa
+NON_REENTRANT += fcvt
+NON_REENTRANT += fgetgrent
+NON_REENTRANT += fgetpwent
+NON_REENTRANT += fgetspent
+NON_REENTRANT += getaliasbyname
+NON_REENTRANT += getaliasent
+NON_REENTRANT += getdate
+NON_REENTRANT += getgrent
+NON_REENTRANT += getgrgid
+NON_REENTRANT += getgrnam
+NON_REENTRANT += gethostbyaddr
+NON_REENTRANT += gethostbyname2
+NON_REENTRANT += gethostbyname
+NON_REENTRANT += gethostent
+NON_REENTRANT += getlogin
+NON_REENTRANT += getmntent
+NON_REENTRANT += getnetbyaddr
+NON_REENTRANT += getnetbyname
+NON_REENTRANT += getnetent
+NON_REENTRANT += getnetgrent
+NON_REENTRANT += getprotobyname
+NON_REENTRANT += getprotobynumber
+NON_REENTRANT += getprotoent
+NON_REENTRANT += getpwent
+NON_REENTRANT += getpwnam
+NON_REENTRANT += getpwuid
+NON_REENTRANT += getrpcbyname
+NON_REENTRANT += getrpcbynumber
+NON_REENTRANT += getrpcent
+NON_REENTRANT += getservbyname
+NON_REENTRANT += getservbyport
+NON_REENTRANT += getservent
+NON_REENTRANT += getspent
+NON_REENTRANT += getspnam
+NON_REENTRANT += getutent
+NON_REENTRANT += getutid
+NON_REENTRANT += getutline
+NON_REENTRANT += gmtime
+NON_REENTRANT += hcreate
+NON_REENTRANT += hdestroy
+NON_REENTRANT += hsearch
+NON_REENTRANT += initstate
+NON_REENTRANT += jrand48
+NON_REENTRANT += lcong48
+NON_REENTRANT += localtime
+NON_REENTRANT += lrand48
+NON_REENTRANT += mrand48
+NON_REENTRANT += nrand48
+NON_REENTRANT += ptsname
+NON_REENTRANT += qecvt
+NON_REENTRANT += qfcvt
+NON_REENTRANT += random
+NON_REENTRANT += rand
+NON_REENTRANT += seed48
+NON_REENTRANT += setstate
+NON_REENTRANT += sgetspent
+NON_REENTRANT += srand48
+NON_REENTRANT += srandom
+NON_REENTRANT += strerror
+NON_REENTRANT += strtok
+NON_REENTRANT += tmpnam
+NON_REENTRANT += ttyname
--
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