rpms/libqb
5
0
Fork 0
Code Issues Pull Requests Releases Activity

1.0.3-1 - Update to libqb-1.0.3

Browse Source 
...for list of changes see:
  https://github.com/ClusterLabs/libqb/releases/tag/v1.0.3

Signed-off-by: Jan Pokorný <jpokorny@redhat.com>
This commit is contained in:
Jan Pokorný 2017-12-21 22:26:44 +01:00
parent 93fffaf298
commit 09b32107fc
No known key found for this signature in database
GPG Key ID: 61BBB23A9E8F8DE2
8 changed files with 10 additions and 2897 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

120
01-Med-qblog.h-better-explanation-behaviour-of-QB_LOG_I.patch
View File

@ -1,120 +0,0 @@
From 5e5370134377bbec66060d9adb5673973239981b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Pokorn=C3=BD?= <jpokorny@redhat.com>
Date: Fri, 6 Oct 2017 17:17:26 +0200
Subject: [PATCH 1/6] Med: qblog.h: better explanation + behaviour of
QB_LOG_INIT_DATA
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Based on better understanding how link-time callsite collection works,
put a better description for the macro. Also based on poor user
experience in case that feature does not work well, say because
the linker deliberately changes the previously settled visibility
of the section boundary symbols (happened in ld from binutils-2.29,
fix is forthcoming), tweak the assertion message a bit, together
with an extension of the general intro to point that macro out.
Also play fair, include the <assert.h> header, which this macro
requires.
- use case:
/usr/sbin/pacemakerd --features
- before:
pacemakerd: utils.c:69: common:
Assertion `0' failed
- after:
pacemakerd: utils.c:69: common:
Assertion `"non-empty implicit callsite section" && QB_ATTR_SECTION_START != QB_ATTR_SECTION_STOP' failed.
Restructuring of the assertion inspired by the suggestion of Ferenc
Wágner (for the subsequent commit, actually).
And regarding:
> as a side effect, it can ensure the boundary-denoting symbols for
> the target collection area are kept alive with some otherwise unkind
> linkers
this was actually empirically discovered in one particular combination
with ld.bfd @ binutils 2.29, and extensively with 2.29.1 (placing here
a forward reference for the following commits that elaborate on the
libqb-target cross-combination matrix and the findings).
Signed-off-by: Jan Pokorný <jpokorny@redhat.com>
---
include/qb/qblog.h | 45 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 40 insertions(+), 5 deletions(-)
diff --git a/include/qb/qblog.h b/include/qb/qblog.h
index 3cb4eef..99ead1b 100644
--- a/include/qb/qblog.h
+++ b/include/qb/qblog.h
@@ -42,6 +42,10 @@ extern "C" {
#undef QB_HAVE_ATTRIBUTE_SECTION
#endif /* S_SPLINT_S */
+#ifdef QB_HAVE_ATTRIBUTE_SECTION
+#include <assert.h> /* possibly needed for QB_LOG_INIT_DATA */
+#endif
+
/**
* @file qblog.h
* The logging API provides four main parts (basics, filtering, threading & blackbox).
@@ -64,6 +68,17 @@ extern "C" {
* }
* @endcode
*
+ * @note
+ * In practice, such a minimalistic approach hardly caters real use cases.
+ * Following section discusses the customization. Moreover, it's quite
+ * vital to instrument the target user of this logging subsystem with
+ * @c QB_LOG_INIT_DATA() macro placed in the top file scope in an exactly
+ * one source file (preferably the main one) to be mixed into the resulting
+ * compilation unit. This is a self-defensive measure for when the
+ * linker-assisted collection of callsite data silently fails, which
+ * could otherwise go unnoticed, causing troubles down the road.
+ *
+ *
* @par Configuring log targets.
* A log target can be syslog, stderr, the blackbox, stdout, or a text file.
* By default only syslog is enabled.
@@ -268,11 +283,31 @@ typedef void (*qb_log_filter_fn)(struct qb_log_callsite * cs);
extern struct qb_log_callsite QB_ATTR_SECTION_START[];
extern struct qb_log_callsite QB_ATTR_SECTION_STOP[];
-/* mere linker sanity check, possible future extension for internal purposes */
-#define QB_LOG_INIT_DATA(name) \
- void name(void); \
- void name(void) \
- { if (QB_ATTR_SECTION_START == QB_ATTR_SECTION_STOP) assert(0); } \
+/* optional on-demand self-check of 1/ toolchain sanity (prerequisite for
+ the logging subsystem to work properly) and 2/ non-void active use of
+ logging (satisfied with a justifying existence of a logging callsite as
+ defined with a @c qb_logt invocation) at the target (but see below), which
+ is supposedly assured by it's author(!) as of relying on this very macro
+ [technically, the symbols that happen to be resolved under the respective
+ identifiers do not necessarily originate in the same compilation unit as
+ when it's not the end executable (or by induction, a library positioned
+ earlier in the symbol lookup order) but a shared library, the former takes
+ a precedence unless that site comes short of exercising the logging,
+ making its callsite section empty and, in turn, without such boundary
+ symbols, hence making the resolution continue further in the lookup order
+ -- despite fuzzily targeted attestation, the check remains reasonable];
+ only effective when link-time ("run-time amortizing") callsite collection
+ is; as a side effect, it can ensure the boundary-denoting symbols for the
+ target collection area are kept alive with some otherwise unkind linkers;
+ may be extended in future for more in-depth self-validation */
+#define QB_LOG_INIT_DATA(name) \
+ void name(void); \
+ void name(void) { \
+ /* our own (target's) sanity, or possibly that of higher priority \
+ symbol resolution site (unless target equals end executable) \
+ or even the lower one if no such predecessor defines these */ \
+ assert("implicit callsite section is populated" \
+ && QB_ATTR_SECTION_START != QB_ATTR_SECTION_STOP); } \
void __attribute__ ((constructor)) name(void);
#else
#define QB_LOG_INIT_DATA(name)
--
2.15.1

80
02-build-configure-check-section-boundary-symbols-prese.patch
View File

@ -1,80 +0,0 @@
From 9fadd438cbbabcde8fe3e19644bacc044279ebdb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Pokorn=C3=BD?= <jpokorny@redhat.com>
Date: Fri, 6 Oct 2017 17:17:26 +0200
Subject: [PATCH 2/6] build: configure: check section boundary symbols present
in the test
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
There was an idea to make apparently run-time test set to that effect,
but it would make cross-building harder. So arrange the test as if it
would be meant for AC_TRY_RUN, but achieve the same as with the first
assertion by the means of inspecting the linked result with, possibly
target-specific, nm utility.
While arranging the test for AC_TRY_RUN, based on feedback by Ferenc
Wágner, unify and increase usability of the run-time error signalling
through assertions.
Signed-off-by: Jan Pokorný <jpokorny@redhat.com>
---
configure.ac | 35 ++++++++++++++++++++++++++---------
1 file changed, 26 insertions(+), 9 deletions(-)
diff --git a/configure.ac b/configure.ac
index 22630ba..29bd569 100644
--- a/configure.ac
+++ b/configure.ac
@@ -77,6 +77,7 @@ AC_CHECK_PROGS([DOXYGEN], [doxygen])
AM_CONDITIONAL(HAVE_DOXYGEN, test -n "${DOXYGEN}")
AC_CHECK_PROGS([SPLINT], [splint])
AM_CONDITIONAL(HAVE_SPLINT, test -n "${SPLINT}")
+AC_CHECK_TOOLS([NM], [eu-nm nm], [:])
## local helper functions
@@ -620,15 +621,31 @@ AC_SUBST(HAVE_SLOW_TESTS)
if test "x${GCC}" = xyes; then
AC_MSG_CHECKING([whether GCC supports __attribute__((section()) + ld supports orphan sections])
if test "x${ac_cv_link_attribute_section}" = x ; then
- AC_TRY_LINK([#include <assert.h>
- extern void * __start___verbose, * __stop___verbose;],
- [static int my_var __attribute__((section("__verbose"))) = 5;
- if (__start___verbose == __stop___verbose) assert(0);
- if (my_var == 5) return 0;
- else return -1;
- ],
- [gcc_has_attribute_section=yes],
- [gcc_has_attribute_section=no])
+ dnl could be turned to AC_TRY_RUN (first assertion is equivalent to
+ dnl the further check in action-if-true), but that would prevent
+ dnl cross-building
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <assert.h>
+ extern void * __start___verbose, * __stop___verbose;]],
+ [[static int my_var __attribute__((section("__verbose"))) = 5;
+ assert("non-empty data section"
+ && __start___verbose != __stop___verbose);
+ assert("no data section value loss"
+ && my_var == 5);]]
+ )],
+ [# alternatively something like (but requires number parsing):
+ # readelf -SW "conftest${ac_exeext}" \
+ # | sed -n '/__verbose/s/^\s*//p' | tr -s ' ' | cut -d" " -f6
+ verbose_start_addr=$(${NM} -g --portability -- "conftest${ac_exeext}" \
+ | grep __start___verbose | cut -d" " -f 3)
+ verbose_stop_addr=$(${NM} -g --portability -- "conftest${ac_exeext}" \
+ | grep __stop___verbose | cut -d" " -f 3)
+ test "${verbose_start_addr}" = "${verbose_stop_addr}" \
+ && gcc_has_attribute_section=no \
+ || gcc_has_attribute_section=yes],
+ [gcc_has_attribute_section=no]
+ )
else
gcc_has_attribute_section=${ac_cv_link_attribute_section}
fi
--
2.15.0

1071
03-tests-new-sort-of-tests-dubbed-functional-cover-link.patch
View File

File diff suppressed because it is too large Load Diff

626
04-Med-add-extra-run-time-client-libqb-checks-that-logg.patch
View File

@ -1,626 +0,0 @@
From b36464c9487ec2b56caa1e99e58bc74c43774577 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Pokorn=C3=BD?= <jpokorny@redhat.com>
Date: Fri, 6 Oct 2017 17:17:26 +0200
Subject: [PATCH 4/6] Med: add extra run-time (client, libqb) checks that
logging will work
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Now that the previous commit provides a foundation for what exactly can
go wrong with ld.bfd = 2.29+ linker, let's start reconciling that with
some reasonable assurance that logging is not silently severed, because
realizing the logs are missing is otherwise bound to happen when the
logs are suddently pretty crucial analytical resource :-)
We'll proceed in two steps as detailed.
* * *
As a first step, the table below concludes how the test matrix overview
introduced with a message for the preceding commit (also introducing
log_test_mock.sh runner which got reused here) looks as of this
refreshed sanity check, once QB_LOG_INIT_DATA macro at hand gets applied
(meaning "for non-libqb logging participants" so as not complicate the
matrix further). That macro is nothing triggered directly, it will just
plant a constructor-like function (to be invoked automatically early in
the execution) that will run through the checks (one original and couple
of new ones as of this changeset).
Note that for libqb users, this implies a new link dependency on libdl,
because they may opt-in for refreshed QB_LOG_INIT_DATA sanity check that
calls out to dlopen/dlsym/dladdr directly in case of "attribute section"
being available for the particular platform, and hence immediately needs
those symbols resolved in link time. Hence, add this conditional link
dependency to libqb.pc pkg-config file under Libs variable -- we
actually restore the occurrence of "-ldl" there as it used to be present
until commit 56754d0. While doing so, also move immediate link
dependencies of libqb (if any, currently not but that may be
a regression arising from the cleanup related to the mentioned commit)
represented with the LIBS autoconf variable under Libs.private variable
in libqb.pc, where it belongs per pkg-config documentation.
The promised table follows, but first as a recap, "X(Y)" denotes
"X linked with linker Y":
X(a) .. ld.bfd < 2.29
X(b) .. ld.bfd = 2.29 (and only 2.29)
goes like this (values in <angle brackets> denote non-trivial change
[not mere rewording] introduced as of this commit, in comparison to
the table stated in the preceding commit):
+=========+=========+=========+=========+=========+=========+=========+
#client(x)# libqb(a) usage # libqb(b) usage #
# vvv #---------+---------+---------+---------+---------+---------+
# V # direct | libX(a) : libX(b) # direct | libX(a) : libX(b) #
+=========+=========+=========+=========+=========+=========+=========+
# x = a # OK | OK : BAD[*2] #<BAD[*E]>|<BAD[*F]>:<BAD[*G]>#
# x = b # BAD[*A] | BAD[*B] : BAD[*C] #<BAD[*E]>|<BAD[*F]>:<BAD[*G]>#
+=========+=========+=========+=========+=========+=========+=========+
Woefully, nothing changes if we swap binutils 2.29 for 2.29.1, i.e.,
X(b) .. ld.bfd = 2.29.1, compared to previous state, i.e., the second
table from the previous commit is still applicable for that situation.
The added sanity checks are useful nonetheless, consider for example,
that attribute-section-less libqb is what gets run-time linked to an
attribute-section-full target. The most precise check we could use
-- a custom logger function applied in a self-test scheme -- is not
available at the point the macro-defined function gets invoked, simply
because qb_log_init hasn't been invoked by the time that constructor
gets triggered. However, what we can do is to add a non-trapping
libqb-residing reverse-testing of the client space that (and once it)
voluntarily initiates qb_log_init (delivering abruption all of a sudden
at some unanticipated, as opposed to a well-timed like with
constructors, execution point, seems pretty bad idea + libqb as
a library is a mere helper, not an undertaker :) -- this check then
only announces, via syslog (the only pre-enabled logging target),
the target's logging may be severed.
* * *
Hence, as a promised second step, after incorporating the syslog
change (and extending log_test_mock.sh so as to capture syslog
stream within the container), not much changes with the table above,
i.e., X(b) .. ld.bfd = 2.29:
[*A] in addition, unless QB_LOG_INIT_DATA used on client side,
syslog carries this notice:
"(libqb) log module hasn't observed target chain supplied callsite
section, target's and/or libqb's build is at fault, preventing
reliable logging (unless qb_log_init invoked in no-custom-logging
context unexpectedly, or target chain built purposefully without
these sections)"
logged by libqb proper
[*C] in addition, unless QB_LOG_INIT_DATA used on interlib side,
syslog carries this notice:
"(libqb) log module hasn't observed target chain supplied callsite
section, target's and/or libqb's build is at fault, preventing
reliable logging (unless qb_log_init invoked in no-custom-logging
context unexpectedly, or target chain built purposefully without
these sections)"
logged by libqb proper
[*E] in addition, unless QB_LOG_INIT_DATA used on client side,
syslog carries this warning:
"(libqb) log module has observed target chain supplied section
unpopulated, target's and/or libqb's build is at fault, preventing
reliable logging (unless qb_log_init invoked in no-custom-logging
context unexpectedly)"
logged by libqb proper
[*F] in addition, unless QB_LOG_INIT_DATA used on interlib side,
syslog carries this warning:
"(libqb) log module has observed target chain supplied section
unpopulated, target's and/or libqb's build is at fault, preventing
reliable logging (unless qb_log_init invoked in no-custom-logging
context unexpectedly)"
logged by libqb proper
[*G] in addition, unless QB_LOG_INIT_DATA used on interlib side,
syslog carries this warning:
"(libqb) log module has observed target chain supplied section
unpopulated, target's and/or libqb's build is at fault, preventing
reliable logging (unless qb_log_init invoked in no-custom-logging
context unexpectedly)"
logged by libqb proper
but desirably changes with "X(b) .. ld.bfd = 2.29.1" one
(DEP ~ "depends"):
+=========+=========+=========+=========+=========+=========+=========+
#client(x)# libqb(a) usage # libqb(b) usage #
# vvv #---------+---------+---------+---------+---------+---------+
# V # direct | libX(a) : libX(b) # direct | libX(a) : libX(b) #
+=========+=========+=========+=========+=========+=========+=========+
# x = a # OK | OK : DEP[*J] #<BAD[*M]>|<BAD[*M]>:<BAD[*L]>#
# x = b #<DEP[*N]>| DEP[*I] :<DEP[*O]>#<BAD[*M]>|<BAD[*M]>:<BAD[*L]>#
+=========+=========+=========+=========+=========+=========+=========+
* * *
[*1] client logging not working
[*2] interlib logging not working
[*3] both client and interlib logging not working
[*A] boils down to [*1], unless QB_LOG_INIT_DATA used on client side,
which then fails on
"implicit callsite section is populated, otherwise target's build
is at fault, preventing reliable logging"
assertion
[*B] boils down to [*1], unless QB_LOG_INIT_DATA used on interlib side,
which then fails on
"implicit callsite section is populated, otherwise target's build
is at fault, preventing reliable logging"
assertion
[*C] boils down to [*3], unless QB_LOG_INIT_DATA used on interlib side,
which then fails on
"implicit callsite section is populated, otherwise target's build
is at fault, preventing reliable logging"
assertion
[*E] boils down to [*1], unless QB_LOG_INIT_DATA used on client side,
which then fails on
"implicit callsite section is self-observable, otherwise target's
and/or libqb's build is at fault, preventing reliable logging"
assertion
[*F] boils down to [*3], unless QB_LOG_INIT_DATA used on interlib side,
which then fails on
"libqb's callsite section is populated, otherwise libqb's build is
at fault, preventing reliable logging"
assertion
[*G] boils down to [*3], unless QB_LOG_INIT_DATA used on interlib side,
which then fails on
"implicit callsite section is self-observable, otherwise target's
and/or libqb's build is at fault, preventing reliable logging"
assertion
[*I] boils down to [*1], unless QB_LOG_INIT_DATA used on client side,
which makes it, likely through self-reference keepalive (see
below), work OK
[*J] boils down to [*2], unless QB_LOG_INIT_DATA used on interlib side,
which makes it, likely through self-reference keepalive (see
below), work OK
[*K] boils down to [*3]
in addition, syslog carries this notice:
"(libqb) log module hasn't observed target chain supplied callsite
section, target's and/or libqb's build is at fault, preventing
reliable logging (unless qb_log_init invoked in no-custom-logging
context unexpectedly, or target chain built purposefully without
these sections)"
logged by libqb proper
[*L] boils down to [*3], unless QB_LOG_INIT_DATA used on interlib side
(sufficient?), which makes it, likely through self-reference
keepalive (see below), boil down just to [*1];
in addition, syslog carries this notice:
"(libqb) log module hasn't observed target chain supplied callsite
section, target's and/or libqb's build is at fault, preventing
reliable logging (unless qb_log_init invoked in no-custom-logging
context unexpectedly, or target chain built purposefully without
these sections)"
logged by libqb proper
[*M] boils down to [*1];
in addition, syslog carries this notice:
"(libqb) log module hasn't observed target chain supplied callsite
section, target's and/or libqb's build is at fault, preventing
reliable logging (unless qb_log_init invoked in no-custom-logging
context unexpectedly, or target chain built purposefully without
these sections)"
logged by libqb proper
[*N] boils down to [*M], unless QB_LOG_INIT_DATA used on client side,
which makes it, likely through self-reference keepalive (see
below), work OK
[*O] boils down to [*K], unless QB_LOG_INIT_DATA used on both client
and interlib side, which makes it, likely through self-reference
keepalive (see below), work OK (it's expected that this a mere
composite of situations [*I] and [*J] with consequences as stated)
* * *
Note: the only problematic (i.e. not captured automatically by the
QB_LOG_INIT_DATA macro presumably utilized at every non-libqb logging
system participant in the form of a discrete compilation unit)
combination with 2.29 is the one intersecting at "BAD[*2]" pertaining
"everything but interlib compiled with ld.bfd < 2.29". It would, of
course, be solvable as well, but presumably not in an easy way, and
that use case should not be as frequent.
Takeway: whenever your target (library or client program) actively
utilizes logging (meaning it emits at least a single log message,
otherwise there's an imminent danger of possibly even run-terminating
false positive in the self-check mechanism!),
YOU ARE strongly ENCOURAGED TO USE QB_LOG_INIT_DATA macro function
at (exactly) one of the source code files (presumably the main one)
per respective target's compilation unit.
It will alleviate the hassles possibly caused by downgrading libqb
to the linker-vs-libqb incompatibly compiled one or in similar
circumstances arising merely from the linker behaviour change,
which the current build system/code shake is all about.
Signed-off-by: Jan Pokorný <jpokorny@redhat.com>
---
configure.ac | 1 +
include/qb/qblog.h | 108 ++++++++++++++++++++++--------
lib/libqb.pc.in | 3 +-
lib/log.c | 51 ++++++++++++++
tests/functional/Makefile.am | 3 +-
tests/functional/log.am | 2 +-
tests/functional/log_external/Makefile.am | 8 ++-
tests/functional/log_test_mock.sh | 13 +++-
tests/functional/syslog-stdout.py | 51 ++++++++++++++
9 files changed, 205 insertions(+), 35 deletions(-)
create mode 100755 tests/functional/syslog-stdout.py
diff --git a/configure.ac b/configure.ac
index 8c588cb..fdcd93c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -655,6 +655,7 @@ if test "x${GCC}" = xyes; then
AC_DEFINE([QB_HAVE_ATTRIBUTE_SECTION], 1,
[Enabling code using __attribute__((section))])
PACKAGE_FEATURES="$PACKAGE_FEATURES attribute-section"
+ AC_SUBST([client_dlopen_LIBS],[$dlopen_LIBS])
fi
fi
diff --git a/include/qb/qblog.h b/include/qb/qblog.h
index d09b21c..7be1390 100644
--- a/include/qb/qblog.h
+++ b/include/qb/qblog.h
@@ -1,9 +1,10 @@
/*
- * Copyright (C) 2010 Red Hat, Inc.
+ * Copyright 2017 Red Hat, Inc.
*
* All rights reserved.
*
* Author: Angus Salkeld <asalkeld@redhat.com>
+ * Jan Pokorny <jpokorny@redhat.com>
*
* libqb is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
@@ -44,6 +45,7 @@ extern "C" {
#ifdef QB_HAVE_ATTRIBUTE_SECTION
#include <assert.h> /* possibly needed for QB_LOG_INIT_DATA */
+#include <dlfcn.h> /* dynamic linking: dlopen, dlsym, dladdr, ... */
#endif
/**
@@ -70,14 +72,14 @@ extern "C" {
*
* @note
* In practice, such a minimalistic approach hardly caters real use cases.
- * Following section discusses the customization. Moreover, it's quite
- * vital to instrument the target user of this logging subsystem with
- * @c QB_LOG_INIT_DATA() macro placed in the top file scope in an exactly
- * one source file (preferably the main one) to be mixed into the resulting
- * compilation unit. This is a self-defensive measure for when the
- * linker-assisted collection of callsite data silently fails, which
- * could otherwise go unnoticed, causing troubles down the road.
- *
+ * Following section discusses the customization. Moreover when employing
+ * the log module is bound to its active use (some log messages are assuredly
+ * emitted within the target compilation unit), it's quite vital to instrument
+ * the target side with @c QB_LOG_INIT_DATA() macro placed in the top file
+ * scope in exactly one source file (preferably the main one) to be mixed into
+ * the resulting compilation unit. This is a self-defensive measure for when
+ * the linker-assisted collection of callsite data silently fails, which could
+ * otherwise go unnoticed, causing troubles down the road.
*
* @par Configuring log targets.
* A log target can be syslog, stderr, the blackbox, stdout, or a text file.
@@ -283,35 +285,85 @@ typedef void (*qb_log_filter_fn)(struct qb_log_callsite * cs);
extern struct qb_log_callsite QB_ATTR_SECTION_START[];
extern struct qb_log_callsite QB_ATTR_SECTION_STOP[];
-/* optional on-demand self-check of 1/ toolchain sanity (prerequisite for
- the logging subsystem to work properly) and 2/ non-void active use of
- logging (satisfied with a justifying existence of a logging callsite as
- defined with a @c qb_logt invocation) at the target (but see below), which
- is supposedly assured by it's author(!) as of relying on this very macro
- [technically, the symbols that happen to be resolved under the respective
- identifiers do not necessarily originate in the same compilation unit as
- when it's not the end executable (or by induction, a library positioned
- earlier in the symbol lookup order) but a shared library, the former takes
- a precedence unless that site comes short of exercising the logging,
- making its callsite section empty and, in turn, without such boundary
- symbols, hence making the resolution continue further in the lookup order
- -- despite fuzzily targeted attestation, the check remains reasonable];
- only effective when link-time ("run-time amortizing") callsite collection
- is; as a side effect, it can ensure the boundary-denoting symbols for the
- target collection area are kept alive with some otherwise unkind linkers;
- may be extended in future for more in-depth self-validation */
+/* Related to the next macro that is -- unlike this one -- a public API */
+#ifndef _GNU_SOURCE
+#define QB_NONAPI_LOG_INIT_DATA_EXTRA_ \
+ _Pragma(QB_PP_STRINGIFY(GCC warning QB_PP_STRINGIFY( \
+ without "_GNU_SOURCE" defined (directly or not) \
+ QB_LOG_INIT_DATA cannot check sanity of libqb proper)))
+#else
+#define QB_NONAPI_LOG_INIT_DATA_EXTRA_ \
+ { Dl_info work_dli; \
+ /* libqb sanity (locating libqb by it's relatively unique \
+ -- and currently only such per-linkage global one -- \
+ non-functional symbol, due to possible confusion otherwise) */ \
+ if (dladdr(dlsym(RTLD_DEFAULT, "facilitynames"), &work_dli) \
+ && (work_handle = dlopen(work_dli.dli_fname, \
+ RTLD_LOCAL|RTLD_LAZY)) != NULL) { \
+ work_s1 = (struct qb_log_callsite *) \
+ dlsym(work_handle, QB_ATTR_SECTION_START_STR); \
+ work_s2 = (struct qb_log_callsite *) \
+ dlsym(work_handle, QB_ATTR_SECTION_STOP_STR); \
+ assert("libqb's callsite section is observable, otherwise \
+libqb's build is at fault, preventing reliable logging" \
+ && work_s1 != NULL && work_s2 != NULL); \
+ assert("libqb's callsite section is populated, otherwise \
+libqb's build is at fault, preventing reliable logging" \
+ && work_s1 != work_s2); \
+ dlclose(work_handle); } }
+#endif /* _GNU_SOURCE */
+
+/**
+ * Optional on-demand self-check of 1/ toolchain sanity (prerequisite for
+ * the logging subsystem to work properly) and 2/ non-void active use of
+ * logging (satisfied with a justifying existence of a logging callsite as
+ * defined with a @c qb_logt invocation) at the target (but see below), which
+ * is supposedly assured by it's author(!) as of relying on this very macro
+ * [technically, the symbols that happen to be resolved under the respective
+ * identifiers do not necessarily originate in the same compilation unit as
+ * when it's not the end executable (or by induction, a library positioned
+ * earlier in the symbol lookup order) but a shared library, the former takes
+ * a precedence unless that site comes short of exercising the logging,
+ * making its callsite section empty and, in turn, without such boundary
+ * symbols, hence making the resolution continue further in the lookup order
+ * -- despite fuzzily targeted attestation, the check remains reasonable];
+ * only effective when link-time ("run-time amortizing") callsite collection
+ * is; as a side effect, it can ensure the boundary-denoting symbols for the
+ * target collection area are kept alive with some otherwise unkind linkers.
+ *
+ * Applying this macro in the target program/library is strongly recommended
+ * whenever the logging as framed by this header file is in use.
+ * Moreover, it's important to state that using this check while not ensuring
+ * @c _GNU_SOURCE macro definition is present at compile-time means only half
+ * of the available sanity checking will be performed, possibly resulting
+ * in libqb's own internally logged messages being lost without warning.
+ */
#define QB_LOG_INIT_DATA(name) \
void name(void); \
void name(void) { \
+ void *work_handle; struct qb_log_callsite *work_s1, *work_s2; \
/* our own (target's) sanity, or possibly that of higher priority \
symbol resolution site (unless target equals end executable) \
or even the lower one if no such predecessor defines these */ \
- assert("implicit callsite section is populated" \
+ if ((work_handle = dlopen(NULL, RTLD_LOCAL|RTLD_LAZY)) != NULL) { \
+ work_s1 = (struct qb_log_callsite *) \
+ dlsym(work_handle, QB_ATTR_SECTION_START_STR); \
+ work_s2 = (struct qb_log_callsite *) \
+ dlsym(work_handle, QB_ATTR_SECTION_STOP_STR); \
+ assert("implicit callsite section is observable, otherwise \
+target's and/or libqb's build is at fault, preventing reliable logging" \
+ && work_s1 != NULL && work_s2 != NULL); \
+ dlclose(work_handle); /* perhaps overly eager thing to do */ } \
+ /* better targeted attestations when available */ \
+ QB_NONAPI_LOG_INIT_DATA_EXTRA_; \
+ /* finally, original, straightforward check */ \
+ assert("implicit callsite section is populated, otherwise \
+target's build is at fault, preventing reliable logging" \
&& QB_ATTR_SECTION_START != QB_ATTR_SECTION_STOP); } \
void __attribute__ ((constructor)) name(void);
#else
#define QB_LOG_INIT_DATA(name)
-#endif
+#endif /* QB_HAVE_ATTRIBUTE_SECTION */
/**
* Internal function: use qb_log() or qb_logt()
diff --git a/lib/libqb.pc.in b/lib/libqb.pc.in
index 8a8d0ba..37d27b7 100644
--- a/lib/libqb.pc.in
+++ b/lib/libqb.pc.in
@@ -7,5 +7,6 @@ Name: libqb
Version: @PACKAGE_VERSION@
Description: libqb
Requires:
-Libs: -L${libdir} -lqb @LIBS@
+Libs: -L${libdir} -lqb @client_dlopen_LIBS@
+Libs.private: @LIBS@
Cflags: -I${includedir}
diff --git a/lib/log.c b/lib/log.c
index bfd218f..c5fecc5 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -853,6 +853,18 @@ qb_log_init(const char *name, int32_t facility, uint8_t priority)
{
int32_t l;
enum qb_log_target_slot i;
+#ifdef QB_HAVE_ATTRIBUTE_SECTION
+ void *work_handle; struct qb_log_callsite *work_s1, *work_s2;
+ Dl_info work_dli;
+#endif /* QB_HAVE_ATTRIBUTE_SECTION */
+ /* cannot reuse single qb_log invocation in various contexts
+ through the variables (when section attribute in use),
+ hence this indirection */
+ enum {
+ preinit_err_none,
+ preinit_err_target_sec,
+ preinit_err_target_empty,
+ } preinit_err = preinit_err_none;
l = pthread_rwlock_init(&_listlock, NULL);
assert(l == 0);
@@ -871,6 +883,26 @@ qb_log_init(const char *name, int32_t facility, uint8_t priority)
qb_log_dcs_init();
#ifdef QB_HAVE_ATTRIBUTE_SECTION
+ /* sanity check that target chain supplied QB_ATTR_SECTION_ST{ART,OP}
+ symbols and hence the local references to them are not referencing
+ the proper libqb's ones (locating libqb-self by it's relatively
+ unique -- and currently only such per-linkage global one --
+ non-functional symbol, due to possible confusion otherwise) */
+ if (dladdr(dlsym(RTLD_DEFAULT, "facilitynames"), &work_dli)
+ && (work_handle = dlopen(work_dli.dli_fname,
+ RTLD_LOCAL|RTLD_LAZY)) != NULL) {
+ work_s1 = (struct qb_log_callsite *)
+ dlsym(work_handle, QB_ATTR_SECTION_START_STR);
+ work_s2 = (struct qb_log_callsite *)
+ dlsym(work_handle, QB_ATTR_SECTION_STOP_STR);
+ if (work_s1 == QB_ATTR_SECTION_START
+ || work_s2 == QB_ATTR_SECTION_STOP) {
+ preinit_err = preinit_err_target_sec;
+ } else if (work_s1 == work_s2) {
+ preinit_err = preinit_err_target_empty;
+ }
+ dlclose(work_handle); /* perhaps overly eager thing to do */
+ }
qb_log_callsites_register(QB_ATTR_SECTION_START, QB_ATTR_SECTION_STOP);
dl_iterate_phdr(_log_so_walk_callback, NULL);
_log_so_walk_dlnames();
@@ -884,6 +916,25 @@ qb_log_init(const char *name, int32_t facility, uint8_t priority)
_log_target_state_set(&conf[QB_LOG_SYSLOG], QB_LOG_STATE_ENABLED);
(void)qb_log_filter_ctl(QB_LOG_SYSLOG, QB_LOG_FILTER_ADD,
QB_LOG_FILTER_FILE, "*", priority);
+
+ if (preinit_err == preinit_err_target_sec)
+ qb_util_log(LOG_NOTICE, "(libqb) log module hasn't observed"
+ " target chain supplied callsite"
+ " section, target's and/or libqb's"
+ " build is at fault, preventing"
+ " reliable logging (unless qb_log_init"
+ " invoked in no-custom-logging context"
+ " unexpectedly, or target chain built"
+ " purposefully without these sections)");
+ else if (preinit_err == preinit_err_target_empty) {
+ qb_util_log(LOG_WARNING, "(libqb) log module has observed"
+ " target chain supplied section"
+ " unpopulated, target's and/or libqb's"
+ " build is at fault, preventing"
+ " reliable logging (unless qb_log_init"
+ " invoked in no-custom-logging context"
+ " unexpectedly)");
+ }
}
void
diff --git a/tests/functional/Makefile.am b/tests/functional/Makefile.am
index 33dde48..4d9071f 100644
--- a/tests/functional/Makefile.am
+++ b/tests/functional/Makefile.am
@@ -19,5 +19,6 @@
MAINTAINERCLEANFILES = Makefile.in
EXTRA_DIST = GNUmakefile log_test_client.err log_test_interlib_client.err \
- log_test_client.sh log_test_interlib_client.sh log_test_mock.sh
+ log_test_client.sh log_test_interlib_client.sh \
+ log_test_mock.sh syslog-stdout.py
SUBDIRS = log_external log_internal
diff --git a/tests/functional/log.am b/tests/functional/log.am
index 8976b6c..f2c6fbc 100644
--- a/tests/functional/log.am
+++ b/tests/functional/log.am
@@ -21,6 +21,6 @@ MAINTAINERCLEANFILES = Makefile.in
CLEANFILES = log_test_client.err.real log_test_interlib_client.err.real
-AM_CPPFLAGS = -I$(top_builddir)/include -I$(top_srcdir)/include
+AM_CPPFLAGS = -D_GNU_SOURCE -I$(top_builddir)/include -I$(top_srcdir)/include
noinst_PROGRAMS = log_client log_interlib_client
# cannot use {check,noinst}_LTLIBRARIES because it leads to solely static lib
diff --git a/tests/functional/log_external/Makefile.am b/tests/functional/log_external/Makefile.am
index 018c836..b1b568a 100644
--- a/tests/functional/log_external/Makefile.am
+++ b/tests/functional/log_external/Makefile.am
@@ -19,5 +19,9 @@
include ../log.am
-log_client_LDFLAGS = -lqb
-liblog_inter_la_LIBADD = -lqb
+# while linking with system-wide version of libqb, we are still pursuing
+# local in-tree header file, hence we need to link with dynamic linking
+# library (which is a prerequisite for using QB_LOG_INIT_DATA defined
+# in qblog.h) explicitly
+log_client_LDFLAGS = -lqb @client_dlopen_LIBS@
+liblog_inter_la_LIBADD = -lqb @client_dlopen_LIBS@
diff --git a/tests/functional/log_test_mock.sh b/tests/functional/log_test_mock.sh
index 145b9f4..cdfce1f 100755
--- a/tests/functional/log_test_mock.sh
+++ b/tests/functional/log_test_mock.sh
@@ -166,10 +166,19 @@ do_compile_and_test_client () {
-exec rm -- {} \;"
;;
esac
+ mock ${mock_args} --copyin "syslog-stdout.py" "builddir"
mock ${mock_args} --shell "( cd \"builddir/build/BUILD/$1\"; ./configure )"
mock ${mock_args} --shell \
- "make -C \"builddir/build/BUILD/$1/tests/functional/log_external\" \
- check-TESTS \"TESTS=../${_logfile}.sh\" $5" \
+ "python3 builddir/syslog-stdout.py \
+ >\"builddir/build/BUILD/$1/tests/functional/log_external/.syslog\" & \
+ { sleep 2; make -C \"builddir/build/BUILD/$1/tests/functional/log_external\" \
+ check-TESTS \"TESTS=../${_logfile}.sh\" $5; } \
+ && ! test -s \"builddir/build/BUILD/$1/tests/functional/log_external/.syslog\"; \
+ ret_ec=\$?; \
+ ( cd \"builddir/build/BUILD/$1/tests/functional/log_external\"; \
+ cat .syslog >> test-suite.log; \
+ echo SYSLOG-begin; cat .syslog; echo SYSLOG-end ); \
+ ret () { return \$1; }; ret \${ret_ec}" \
&& _result="${_result}_good" \
|| _result="${_result}_bad"
mock ${mock_args} --copyout \
diff --git a/tests/functional/syslog-stdout.py b/tests/functional/syslog-stdout.py
new file mode 100755
index 0000000..64baf4c
--- /dev/null
+++ b/tests/functional/syslog-stdout.py
@@ -0,0 +1,51 @@
+#!/usr/bin/python3
+# Copyright 2017 Red Hat, Inc.
+#
+# Author: Jan Pokorny <jpokorny@redhat.com>
+#
+# This file is part of libqb.
+#
+# libqb is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 2.1 of the License, or
+# (at your option) any later version.
+#
+# libqb is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with libqb. If not, see <http://www.gnu.org/licenses/>.
+
+"""Simple /dev/log to stdout forwarding"""
+
+import socket
+from atexit import register
+from os import remove
+from sys import argv
+
+# no locking, but anyway
+try:
+ remove("/dev/log")
+except FileNotFoundError:
+ pass
+sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+sock.bind("/dev/log")
+
+def shutdown():
+ sock.close()
+ remove("/dev/log")
+
+def main(*argv):
+ register(shutdown)
+ while True:
+ try:
+ b = sock.recv(4096)
+ # flushing is crucial here
+ print(">>> " + str(b, 'ascii').split(' ', 3)[-1], flush=True)
+ except IOError:
+ pass
+
+if __name__ == '__main__':
+ main(*argv)
--
2.15.1

792
05-High-bare-fix-for-libqb-logging-not-working-with-ld..patch
View File

@ -1,792 +0,0 @@
From ae47b6941efa0565de5e1187585a2ee54132e653 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Pokorn=C3=BD?= <jpokorny@redhat.com>
Date: Fri, 6 Oct 2017 17:17:26 +0200
Subject: [PATCH 5/6] High: bare fix for libqb logging not working with
ld.bfd/binutils 2.29+
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
(or rather [read on]: "bare" fix, now that we established means to
analyse the impact of the linker-dependent misbehaviour and to detect
some of its symptoms in preceding two commits, respectively)
Initially with the help of the internal test suite and the failing log
test, it was eventually discovered[1] that these binutils commits going
to the recent 2.29 release affected the treatment of _start_SECNAME
and __stop_SECNAME symbols denoting the boundary start/stop addresses
of a SECNAME orphan section -- specifically in libqb context a custom
section (SECNAME=__verbose) used for link-time ("run-time amortizing")
callsite collection when there's a support in the toolchain[*]:
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cbd0eecf261c2447781f8c89b0d955ee66fae7e9
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=b27685f2016c510d03ac9a64f7b04ce8efcf95c4
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7dba9362c172f1073487536eb137feb2da30b0ff
The first one explicitly states:
> Also __start_SECNAME and __stop_SECNAME symbols are marked as hidden
> by ELF linker so that __start_SECNAME and __stop_SECNAME symbols for
> section SECNAME in different modules are unique.
The problem is that libqb silently depends on the previous status quo
ld.bfd linker behaviour of keeping those symbols externally visible,
which was apparently not granted as it has deliberately changed per
above.
And then for 2.29.1 release of binutils once again, as someone actually
noticed something went overboard with the 2.29 changes:
http://lists.gnu.org/archive/html/bug-binutils/2017-08/msg00195.html
(overview of the original bug discussion, rather than directly
https://sourceware.org/bugzilla/show_bug.cgi?id=21964, which is
a result of a conflct resolution when restoring bugzilla backup)
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=487b6440dad57440939fab7afdd84a218b612796
At least that change doesn't invalidate all the effort being put into
the original version of the changeset, only the configure script check
had to be refined so as not to miss the "orphan section magic not
working properly out of the box, without band aid" observation
(see the inline comment) -- the workaround arrangement needs
to be applied in that case as well.
* * *
So regarding the solution itself, the core of the fix was sketched at
the original Fedora targeted bug against binutils[2]. In short, we are
using a custom linker script that (re)describes the mentioned custom
orphan output section, or better yet, assuredly pushes that section, and
more importantly, it's own boundary denoting symbols, through into the
resulting executable when it's being linked (as in compile-time step).
This solution alone, while working for the non-libqb (more on that
below) logging participants, is not good enough, as it requires all
libqb targets to start using new incantation (namely "-Wl,foo.t" switch)
in the final link step during compilation, which might be solvable
with a tweak in libqb's pkg-config file under assumption that practice
of using "pkg-config --libs libqb" is rigidly followed. Which is likely
a false expectation, and furthermore only for the regular consumption
model, as it doesn't cover the least bit the developmental one (refer
to previous-but-one "tests" commit message), e.g. applied for internal
examples + tests (but no local sub-checkout tree usage can be excluded).
So further extensions were devised to cover both consumption models:
- a. regular:
courtesy of binutils maintainer[3], we follow an idea to make libqb.so
(i.e. what the targets link against) rather a linker script on its
own, which first include the version-specified (e.g. libqb.so.0) file
into the link, then lists, in situ, the content of the linker script
per above, hence -lqb linking has the same effect as having both
"-lqb -Wl,foo.t" explicitly in the link command prior to this trick
- b. developmental:
to eliminate any kind of race condition arising from the attempt
to post-modify libqb.la libtool archive file generated internally
by libtool, we sort of abuse "inherited_linker_flags" variable
within this file format, as it forms an accumulative value across
the whole transitive dependencies chain (if not impaired per the
note below), fitting exactly our purpose of injecting "-Wl,foo.t"
switch equivalent for those libtool-linking by L{D,IB}ADD'ing
libqb.la; it's then enough to craft a custom libtool archive file
declaring that value, and hook it into such dependency chain through
libqb_la_LIBADD, and with a little bit of further fiddling, it works
as desired (note that double occurrence of "-Wl,foo.t" equivalent
present at some stages of sorting this trick turned out to be,
surprisingly, counter-productive, which should now demistify the
very existence of effectively empty qblog_script_noop.ld file);
NOTE: some forms of libtool distribution (debian + derivatives ones
in particular) undermine natural transitive dependency propagation
with a deliberate cut off (https://bugs.debian.org/702737), so we
need to ensure the "impairment" is not happening by force (corosync
precedent: https://github.com/corosync/corosync/commit/0f1dc5c1)
^ something like this needs to be applied for any such "private
consumer" (although it hopefully goes without saying this way
of consuming libqb outside of it's own playground is hardly
the Right Thing) if portability is important, nonetheless!
* * *
On the address of linker script workaround, there are linkers out there
that do not support the trick, for instance:
- ld.gold from binutils (but it has hardly ever been working with
orphan sections, anyway:
https://sourceware.org/bugzilla/show_bug.cgi?id=22291)
- ancient versions of ld.bfd, e.g. 10+ years old one used as a native
system linker even in the most recent releases of FreeBSD, unless
GCC toolchain is used instead
If these are hit when (because) the compiler has already demonstrated it
supports "section" attribute, the build system configuration is forcibly
stopped, simply to stay conceptually compatible with the prior state in
which the affinity to leverage that feature hasn't been called off
under any circumstances. One is, however, able to achieve exactly
this behaviour with --enable-nosection-fallback switch, but if some
other participants in the logging, possibly linked with a more friendly
linker, do utilize this orphan section, logging may silently break
(another reason to require an explicit sign-off).
Another note, the particular self-check change slightly touched in the
previous commit but otherwise predating this whole effort by far needs
to be modified now once again, this time because linker-script-based
workaround for newer linkers as stated causes the section boundary
symbols to be present regardless if that section is utilized, leading
to a self-inflicted breakage due to these empty section symbols suddenly
winning in the symbol resolution mechanism (previously the empty section
would be dropped incl. the boundary symbols), causing problems down the
line. It also makes this very check self-contained in the same
compilation unit that trigggers it, whereas previously it used to be the
said "arbitrary" winner and things kept silently working just because
failure condition -- empty section -- would be implicitly isolated.
Last but not least, libqb itself needs to be linked with the mentioned
"-Wl,foo.t" equivalent for its own outgoing log messages to be honoured
under all circumstances, which is already achieved with the arrangement
for b. above, and by experiments, further redefinition of those boundary
denoting symbols as weak was necessary so as to make them truly global
within libqb.so proper (at least with binutils 2.29).
* * *
To provide a high-level prioritized overview of what drove the approach:
- PRESERVATION OF BINARY COMPATIBILITY (ABI), which is achieved except
for a single "ABI nongracefulness" I am aware of but that's more
a consequence of slightly incorrect assumptions in the logic of
QB_LOG_INIT_DATA macro function predating this whole affair by
a long shot and which the patchset finally rectifies:
if in the run-time dynamic link, following is combined:
(. libqb, arbitrary variant: pre-/post-fix, binutils < / >= 2.29)
. an "intermediate" library (something that the end executable links
with) triggering QB_LOG_INIT_DATA macro and being built with
pre-fix libqb (and perhaps only with binutils < 2.29)
. end executable using no libqb's logging at all, but being built
with post-fix libqb (and arbitrary binutils < / >= 2.29)
then, unlike when executable is built with pre-fix libqb, the
special callsite data containing section in the ELF structure
of the executable is created + its boundary denoting symbols
defined within, despite the section being empty (did not happen
with pre-fix libqb), and because the symbols defined within the
target program have priority over that of shared libraries in the
symbol resolution fallback scheme, the assertion of QB_LOG_INIT_DATA
of the mentioned intermediate library will actually be evaluating
the inequality of boundaries for the section of the executable(!)
rather than it's own (or whatever higher prio symbols are hit,
presumably only present if the section at that level is non-empty,
basically a generalization of the story so far);
the problem then manifests as unability to run said executable
as it will fail because of the intermediate library inflicted
assertion (sadly with very unhelpful "Assertion `0' failed"
message);
fortunately, there's enough flexibility so as how to fix
this, either should be fine:
. have everything in the executable's library dependency closure
that links against libqb assurably (compile-time) linked with one
variant of libqb only (either all pre-fix or post-fix, mind the
apparent limitation of binutils' versions with the former)
. have the end executable (that does not use logging at all as
discussed precondition) linked using substitution like this:
s/-lqb/-l:libqb.so.0/ (you may need to adapt the number later)
and you may also need to add this CPPFLAG for the executable:
-DQB_KILL_ATTRIBUTE_SECTION
- as high level of isolation of the client space from the linker
(respectively toolchain) subtleties as possible (no new compilation
flags and such required, plus there's no way to hook any dynamic
computational ad-hoc decision when the compilation is about to
happen, anyway), and in turn, versatility is preserved as much as
possible
* * *
Finally, let's have a look how the already well-known test matrix
overview changes as of this commit, but first as a recap,
"X(Y)" denotes "X linked with linker Y":
X(a) .. ld.bfd < 2.29
X(b) .. ld.bfd = 2.29 (+ 2.29.1 and hopefully on)
and here you are (values in <angle brackets> denote non-trivial change
[not mere rewording] introduced as of this commit, in comparison to the
table stated in the preceding commit):
+=========+=========+=========+=========+=========+=========+=========+
#client(x)# libqb(a) usage # libqb(b) usage #
# vvv #---------+---------+---------+---------+---------+---------+
# V # direct | libX(a) : libX(b) # direct | libX(a) : libX(b) #
+=========+=========+=========+=========+=========+=========+=========+
# x = a # OK | OK : <OK> # <OK> | <OK> : <OK> #
# x = b # <OK> | <OK> : <OK> # <OK> | <OK> : <OK> #
+=========+=========+=========+=========+=========+=========+=========+
Everything is green \o/
* * *
Note: as of this fix, it is assumed that the non-green counterpart of
this table in the message for the preceding commit (loosely though[!],
as the occurrence of empty callsite section can no longer be attributed
to something bad going on as of this fix that enforces its presence
unconditionally, whereas it would be suppressed when unused before
with kind linkers, hence some other conditions can be witnessed
especially when QB_LOG_INIT_DATA misused in no-logging context)
doubles as an indicator how will mixing the logging participants wrt.
linker+libqb version work out, when "X(Y)" becomes read as "X linked
with linker Y under additional restriction on libqb version when
compile-time link is performed of the particular part":
X(a) .. ld.bfd < 2.29 OR [arbitrary ld.bfd AND libqb after this fix)
X(b) .. ld.bfd = 2.29 (and likely on) AND libqb up to, but excluding
this fix
* * *
Let's also state some imperfections and loops kept open:
Deficiencies:
* whenever anything is compiled against our install-time-modified
libqb.so so as to force the visibility of the discussed symbols
(or when compiling [with] libqb internally):
> /usr/bin/ld: warning: ../lib/qblog_script.ld contains output sections; did you forget -T?
- not solvable as long as we use the linker script, and there's
hardly any other way not requiring the libqb consumers to adapt
in any aspect
* as already mentioned, lacking compatibility with ld.gold linker and
won't foreseeably be (cf. https://bugzilla.redhat.com/1500898#c7)
- please stick with ld.bfd (i.e. default ld linker), which you
had to do in the past anyway (at least for compiling libqb
itself)
Open questions:
* should we enable attribute((__section__)) for powerpc and other minor
platforms if the feature is proved to be working there as well?
and if/when that's going to happen, we need to figure out the
transition plan to be spread throughout an extended period to keep
the transition smooth -- notably when now-with-callsite-section
clients will get run-time linked with callsite-section-not-a-default
libqb (say upon it's downgrade), and for that, the libqb's support
alone should be enabled year(s) ahead of the actual client space...
* * *
[*] basically GCC's section("SECNAME") __attribute__ annotation of the
global variables + linker described behaviour previously mistakenly
taken for granted
References:
[1] http://oss.clusterlabs.org/pipermail/developers/2017-July/000503.html
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1477354#c2 + comment 8
[3] https://bugzilla.redhat.com/show_bug.cgi?id=1477354#c9
Signed-off-by: Jan Pokorný <jpokorny@redhat.com>
---
configure.ac | 156 +++++++++++++++++++++++++++++++++++++++++------
include/qb/qblog.h | 32 ++++++++--
lib/Makefile.am | 79 +++++++++++++++++++++++-
lib/libqb.pc.in | 11 ++++
lib/log.c | 7 +++
lib/qblog_script.la.in | 15 +++++
lib/qblog_script.ld.in | 30 +++++++++
lib/qblog_script_noop.ld | 1 +
8 files changed, 304 insertions(+), 27 deletions(-)
create mode 100644 lib/qblog_script.la.in
create mode 100644 lib/qblog_script.ld.in
create mode 100644 lib/qblog_script_noop.ld
diff --git a/configure.ac b/configure.ac
index fdcd93c..cc3d3c3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -78,6 +78,7 @@ AM_CONDITIONAL(HAVE_DOXYGEN, test -n "${DOXYGEN}")
AC_CHECK_PROGS([SPLINT], [splint])
AM_CONDITIONAL(HAVE_SPLINT, test -n "${SPLINT}")
AC_CHECK_TOOLS([NM], [eu-nm nm], [:])
+AC_CHECK_TOOLS([READELF], [eu-readelf readelf], [:])
## local helper functions
@@ -502,6 +503,14 @@ AC_ARG_ENABLE([debug],
AC_ARG_ENABLE([coverage],
[AS_HELP_STRING([--enable-coverage],[coverage analysis of the codebase])])
+AC_ARG_ENABLE([interlib-deps],
+ [AS_HELP_STRING([--disable-interlib-deps],
+ [disable inter-library dependencies (might break builds)])])
+
+AC_ARG_ENABLE([nosection-fallback],
+ [AS_HELP_STRING([--enable-nosection-fallback],
+ [allow (logging compat-breaking?) fallback when orphan section dead-ended])])
+
AC_ARG_ENABLE([slow-tests],
[AS_HELP_STRING([--enable-slow-tests],[build and run slow tests])])
@@ -610,6 +619,19 @@ else
COVERAGE_LDFLAGS=""
fi
+# --- inter-library dependencies ---
+# because of debian/ubuntu swimming against the stream
+# https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=702737,
+# override the libtool variable by force because the current
+# arrangement relies on transitive dependency propagation
+AC_MSG_NOTICE([Enabling inter-library dependencies: $enable_interlib_deps])
+if test "x${enable_interlib_deps}" = xno; then
+ link_all_deplibs=no
+else
+ link_all_deplibs=yes
+fi
+
+# --- slow tests ---
if test "x${enable_slow_tests}" = xyes ; then
AC_DEFINE([HAVE_SLOW_TESTS], 1,[have slow tests])
AC_MSG_NOTICE([Enabling Slow tests])
@@ -619,20 +641,60 @@ AC_SUBST(HAVE_SLOW_TESTS)
# --- callsite sections ---
if test "x${GCC}" = xyes; then
+ AX_SAVE_FLAGS
AC_MSG_CHECKING([whether GCC supports __attribute__((section()) + ld supports orphan sections])
if test "x${ac_cv_link_attribute_section}" = x ; then
+ LDFLAGS="${LDFLAGS_save} -shared -fPIC" # we are compiling shared lib
+ AC_LINK_IFELSE(
+ [AC_LANG_SOURCE(
+ [[#include <assert.h>
+ extern int __start___verbose[], __stop___verbose[];
+ int test(void) {
+ static int my_var __attribute__((section("__verbose"))) = 3;
+ assert("L:non-empty data section"
+ && __start___verbose != __stop___verbose);
+ assert("L:no data section value loss"
+ && my_var == 3 /* for 2.29.1+ */);
+ return *((int *) __start___verbose); }]]
+ )],
+ [gcc_has_attribute_section=yes; cp "conftest${ac_exeext}" "conftest.so"],
+ [gcc_has_attribute_section=no]
+ )
+ AX_RESTORE_FLAGS
+ else
+ gcc_has_attribute_section=${ac_cv_link_attribute_section}
+ fi
+ AC_MSG_RESULT($gcc_has_attribute_section)
+
+ # in the failing case (e.g. with ld from binutils 2.29), it's likely the
+ # following will fail readily in linkage (hidden symbol `__stop___verbose'
+ # in conftest is referenced by DSO), but keep the sensible test
+ # (in-executable symbol is expected to be propagated into the library,
+ # and to draw the full circle back to the executable through standard
+ # return value passing (respectively no-exec probing to spot the issue);
+ # -rpath passed because LD_LIBRARY_PATH exporting is unwieldy here);
+ # moreover, "my_var" == 3 assertion above (respectively checking if the
+ # boundary symbol visibility differs from DEFAULT in readelf output) is
+ # necessary so that binutils 2.29.1+ will not slip other parts of the
+ # overall is-workaround-needed harness, as it restored some (but not
+ # all) of the original behaviour, but the workaround is still provably
+ # needed
+ if test "x${gcc_has_attribute_section}" = xyes; then
+ AC_MSG_CHECKING([whether linker emits global boundary symbols for orphan sections])
+ LIBS="${LIBS} -L. -l:conftest${shrext_cmds} -Wl,-rpath=$(pwd)"
dnl could be turned to AC_TRY_RUN (first assertion is equivalent to
dnl the further check in action-if-true), but that would prevent
dnl cross-building
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#include <assert.h>
- extern void * __start___verbose, * __stop___verbose;]],
+ extern int __start___verbose[], __stop___verbose[];
+ int test(void);]],
[[static int my_var __attribute__((section("__verbose"))) = 5;
- assert("non-empty data section"
+ assert("E:non-empty data section"
&& __start___verbose != __stop___verbose);
- assert("no data section value loss"
- && my_var == 5);]]
+ assert("E:no data section value loss"
+ && my_var == test() /*5?*/);]]
)],
[# alternatively something like (but requires number parsing):
# readelf -SW "conftest${ac_exeext}" \
@@ -642,22 +704,78 @@ if test "x${GCC}" = xyes; then
verbose_stop_addr=$(${NM} -g --portability -- "conftest${ac_exeext}" \
| grep __stop___verbose | cut -d" " -f 3)
test "${verbose_start_addr}" = "${verbose_stop_addr}" \
- && gcc_has_attribute_section=no \
- || gcc_has_attribute_section=yes],
- [gcc_has_attribute_section=no]
+ && gcc_has_attribute_section_visible=no \
+ || { verbose_start_type=$(${READELF} -s backup \
+ | sed -n '/__start___verbose/{s/^\s*//p;q}' \
+ | tr -s ' ' \
+ | cut -d" " -f6)
+ test "${verbose_start_type}" = DEFAULT \
+ && gcc_has_attribute_section_visible=yes \
+ || gcc_has_attribute_section_visible=no; }],
+ [gcc_has_attribute_section_visible=no]
)
- else
- gcc_has_attribute_section=${ac_cv_link_attribute_section}
- fi
+ AX_RESTORE_FLAGS
+ AC_MSG_RESULT($gcc_has_attribute_section_visible)
+ rm -f "conftest${shrext_cmds}"
+
+ if test "x${gcc_has_attribute_section_visible}" = xno; then
+ # check if the linker script based workaround is
+ # feasible at all, otherwise fallback to using no
+ # section attribute while making some noise about it
+ # as combining with-without accustomed logging
+ # participants is currently uncharted waters
+ AC_MSG_CHECKING([whether linker workaround for orphan sections usable])
+ >conftest.ld cat <<-EOF
+ SECTIONS {
+ __verbose : {
+ __start___verbose = .;
+ *(__verbose);
+ __stop___verbose = .;
+ }
+ }
+ EOF
+ LDFLAGS="${LDFLAGS} -Wl,conftest.ld"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <assert.h>
+ extern int __start___verbose[], __stop___verbose[];
+ int test(void);]],
+ [[static int my_var __attribute__((section("__verbose"))) = 5;
+ assert("E:non-empty data section"
+ && __start___verbose != __stop___verbose);
+ assert("E:no data section value loss"
+ && my_var == 5);]]
+ )],
+ [],
+ [gcc_has_attribute_section=no]
+ )
+ AX_RESTORE_FLAGS
+ AC_MSG_RESULT([$gcc_has_attribute_section])
+ rm -f "conftest.ld"
+ fi
- AC_MSG_RESULT($gcc_has_attribute_section)
- if test $gcc_has_attribute_section = yes; then
- AC_DEFINE([QB_HAVE_ATTRIBUTE_SECTION], 1,
- [Enabling code using __attribute__((section))])
- PACKAGE_FEATURES="$PACKAGE_FEATURES attribute-section"
- AC_SUBST([client_dlopen_LIBS],[$dlopen_LIBS])
+ if test "x${gcc_has_attribute_section}" = xyes; then
+ AC_DEFINE([QB_HAVE_ATTRIBUTE_SECTION], 1,
+ [Enabling code using __attribute__((section))])
+ AC_SUBST([client_dlopen_LIBS],[$dlopen_LIBS])
+ if test "x${gcc_has_attribute_section_visible}" = xyes; then
+ PACKAGE_FEATURES="$PACKAGE_FEATURES attribute-section"
+ else
+ AC_DEFINE([QB_NEED_ATTRIBUTE_SECTION_WORKAROUND], 1,
+ [Enabling code using __attribute__((section))])
+ PACKAGE_FEATURES="$PACKAGE_FEATURES attribute-section-workaround"
+ fi
+ elif test "x${enable_nosection_fallback}" = xyes; then
+ AC_MSG_NOTICE([Falling back to not using orphan section])
+ else
+ AC_MSG_ERROR([Would use section attribute, cannot; see --enable-nosection-fallback])
+ fi
fi
fi
+AM_CONDITIONAL(HAVE_GCC_ATTRIBUTE_SECTION, [test "x${gcc_has_attribute_section}" = xyes])
+AM_CONDITIONAL(NEED_GCC_ATTRIBUTE_SECTION_WORKAROUND,
+ [test "x${gcc_has_attribute_section}" = xyes \
+ && test "x${gcc_has_attribute_section_visible}" != xyes])
# --- ansi ---
if test "x${enable_ansi}" = xyes && \
@@ -739,9 +857,11 @@ AC_CONFIG_FILES([Makefile
docs/Makefile
docs/common.dox
docs/html.dox
- docs/man.dox])
+ docs/man.dox
+ lib/qblog_script.la:lib/qblog_script.la.in])
-AC_CONFIG_LINKS([tests/functional/GNUmakefile:tests/functional/GNUmakefile])
+AC_CONFIG_LINKS([lib/qblog_script_noop.ld:lib/qblog_script_noop.ld
+ tests/functional/GNUmakefile:tests/functional/GNUmakefile])
AC_OUTPUT
diff --git a/include/qb/qblog.h b/include/qb/qblog.h
index a9a9ef2..00adb3a 100644
--- a/include/qb/qblog.h
+++ b/include/qb/qblog.h
@@ -79,7 +79,10 @@ extern "C" {
* scope in exactly one source file (preferably the main one) to be mixed into
* the resulting compilation unit. This is a self-defensive measure for when
* the linker-assisted collection of callsite data silently fails, which could
- * otherwise go unnoticed, causing troubles down the road.
+ * otherwise go unnoticed, causing troubles down the road, but alas it cannot
+ * discern misuse of @c QB_LOG_INIT_DATA() macro in no-logging context from
+ * broken callsite section handling assumptions owing to overboard fancy
+ * linker -- situation that the self-check aims to detect in the first place.
*
* @par Configuring log targets.
* A log target can be syslog, stderr, the blackbox, stdout, or a text file.
@@ -287,12 +290,13 @@ extern struct qb_log_callsite QB_ATTR_SECTION_STOP[];
/* Related to the next macro that is -- unlike this one -- a public API */
#ifndef _GNU_SOURCE
-#define QB_NONAPI_LOG_INIT_DATA_EXTRA_ \
+#define QB_NONAPI_LOG_INIT_DATA_EXTRA_(name) \
_Pragma(QB_PP_STRINGIFY(GCC warning QB_PP_STRINGIFY( \
without "_GNU_SOURCE" defined (directly or not) \
- QB_LOG_INIT_DATA cannot check sanity of libqb proper)))
+ QB_LOG_INIT_DATA cannot check sanity of libqb proper \
+ nor of the target site originating this check alone)))
#else
-#define QB_NONAPI_LOG_INIT_DATA_EXTRA_ \
+#define QB_NONAPI_LOG_INIT_DATA_EXTRA_(name) \
{ Dl_info work_dli; \
/* libqb sanity (locating libqb by it's relatively unique \
-- and currently only such per-linkage global one -- \
@@ -310,6 +314,23 @@ libqb's build is at fault, preventing reliable logging" \
assert("libqb's callsite section is populated, otherwise \
libqb's build is at fault, preventing reliable logging" \
&& work_s1 != work_s2); \
+ dlclose(work_handle); } \
+ /* sanity of the target site originating this check alone */ \
+ if (dladdr(dlsym(RTLD_DEFAULT, QB_PP_STRINGIFY(name)), &work_dli) \
+ && (work_handle = dlopen(work_dli.dli_fname, \
+ RTLD_LOCAL|RTLD_LAZY)) != NULL) { \
+ work_s1 = (struct qb_log_callsite *) \
+ dlsym(work_handle, QB_ATTR_SECTION_START_STR); \
+ work_s2 = (struct qb_log_callsite *) \
+ dlsym(work_handle, QB_ATTR_SECTION_STOP_STR); \
+ assert("target's own callsite section observable, otherwise \
+target's own linkage at fault and logging would not work reliably \
+(unless QB_LOG_INIT_DATA macro used unexpectedly in no-logging context)"\
+ && work_s1 != NULL && work_s2 != NULL); \
+ assert("target's own callsite section non-empty, otherwise \
+target's own linkage at fault and logging would not work reliably \
+(unless QB_LOG_INIT_DATA macro used unexpectedly in no-logging context)"\
+ && work_s1 != work_s2); \
dlclose(work_handle); } }
#endif /* _GNU_SOURCE */
@@ -354,8 +375,7 @@ libqb's build is at fault, preventing reliable logging" \
target's and/or libqb's build is at fault, preventing reliable logging" \
&& work_s1 != NULL && work_s2 != NULL); \
dlclose(work_handle); /* perhaps overly eager thing to do */ } \
- /* better targeted attestations when available */ \
- QB_NONAPI_LOG_INIT_DATA_EXTRA_; \
+ QB_NONAPI_LOG_INIT_DATA_EXTRA_(name); \
/* finally, original, straightforward check */ \
assert("implicit callsite section is populated, otherwise \
target's build is at fault, preventing reliable logging" \
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 0bebeb5..1572cff 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -19,6 +19,7 @@
# along with libqb. If not, see <http://www.gnu.org/licenses/>.
+CLEANFILES = qblog_script.ld
MAINTAINERCLEANFILES = Makefile.in
noinst_HEADERS = ipc_int.h util_int.h ringbuffer_int.h loop_int.h \
@@ -39,9 +40,48 @@ source_to_lint = util.c hdb.c ringbuffer.c ringbuffer_helper.c \
log_syslog.c log_dcs.c log_format.c \
map.c skiplist.c hashtable.c trie.c
+# Following two files related to linkage using classic ld from binutils 2.29+
+# with which we cannot afford to lose public access to section boundary symbols
+# (as the mentioned version started to scope them privately by default, see
+# the comment within the first of the files, ultimately leading to broken
+# logging functionality of libqb) deserve a bit of explanation:
+# * qblog_script.ld
+# - linker script that instructs the output section that those symbols should
+# be visible, i.e. supports the same behaviour regardless of ld version
+# - serves two purposes:
+# . local: libqb itself and its "private" (cf. examples) users need those
+# symbols visible, which is achieved with a help of the other file
+# . system-wide: whenever the non-private library users link against libqb
+# (it's development files), this linker script with
+# prepended INPUT command so as to refer to the actual
+# libqb library (it's numbered alias that is eventually
+# resolved to proper shared library) is masked as libqb.so,
+# this arrangement achieves the libqb's user will have
+# the discussed symbols visible alike
+# * qblog_script.la
+# - as mentioned earlier, this indirectly hooks into libtool machinery, with
+# the only true intention of injecting "-Wl,<path to qblog_script.ld>"
+# into "inherited_linker_flags" libtool archive variable, from where it's
+# subsequently spread into the build process of all the internal library
+# users, assuming they have their dep arranged as "user_LIBADD=libqb.la"
+# (this also alleviates the burden on getting things right if, e.g., any
+# libqb user consumes it directly like this from its own sub-checkout tree)
+# - it indirectly, once libtool prechew the original link command
+# originally referring to this file, it turns such reference into the
+# "real" library reference (here combining libdir and old_library
+# variables within the file), also ensures libqb itself will visibly
+# expose the discussed symbols, because such references point again to
+# the (not enriched) linker script file that will get interpreted just
+# like that during the last build step of the library
+EXTRA_libqb_la_DEPENDENCIES = qblog_script.ld qblog_script.la
+EXTRA_DIST = qblog_script.ld.in qblog_script.la.in qblog_script_noop.ld
+
libqb_la_SOURCES = $(source_to_lint) unix.c
libqb_la_CFLAGS = $(PTHREAD_CFLAGS)
libqb_la_LIBADD = $(LTLIBOBJS) $(dlopen_LIBS) $(PTHREAD_LIBS) $(socket_LIBS)
+if NEED_GCC_ATTRIBUTE_SECTION_WORKAROUND
+libqb_la_LIBADD += qblog_script.la
+endif
AM_LDFLAGS = $(LDFLAGS_COPY:-Bsymbolic-functions=)
@@ -60,9 +100,42 @@ else
endif
endif
-
-pkgconfigdir = $(libdir)/pkgconfig
-pkgconfig_DATA = libqb.pc
+qblog_script.ld: %.ld: %.ld.in
+ $(AM_V_GEN)$(CPP) -xc -I$(top_srcdir)/include -D_GNU_SOURCE -C -P $< \
+ | sed -n "/$$(sed -n '/^[^#]/{s/[*\/]/\\&/g;p;q;}' $<)/,$$ p" \
+ > $@
+
+# sadly, there's a distinction between "exec" and "data" install, and it's hard
+# to decouple install-exec-hook below (.pc file is platform-dependent, anyway)
+pkgconfigexecdir = $(libdir)/pkgconfig
+pkgconfigexec_DATA = libqb.pc
+
+# find the libqb.so symlink's target, if so, try to find out, iteratively,
+# its gradually shorter forms that likewise symlinks the same target as the
+# original libqb.so path, point to that file from the linker script using
+# qblog_script.ld as a template, storing result in place of original libqb.so
+# (e.g., libqb.so := "INPUT(libqb.so.0) " [...] "SECTIONS { " [...] "}")
+# NOTE: readlink nor realpath are POSIX; not chained links ready
+# NOTE: conservative check, i.e., not per NEED_GCC_ATTRIBUTE_SECTION_WORKAROUND
+if HAVE_GCC_ATTRIBUTE_SECTION
+install-exec-hook: qblog_script.ld
+ target=$$(ls -l "$(DESTDIR)$(libdir)/libqb.so" || :); \
+ target=$${target#* -> }; t1_bn=$$(basename "$${target}" || :); \
+ while test -n "$${t1_bn}"; do t2_bn=$${t1_bn%.*[0-9]*}; \
+ test "$${t2_bn}" != libqb.so || break; \
+ test -L "$${t2_bn}" || { t1_bn=$${t2_bn}; continue; }; \
+ t2_target=$$(ls -l "$${t2_bn}" || break); t2_target=$${t2_target#* -> }; \
+ test "$${t2_target}" = "$${target}" || break; \
+ t1_bn=$${t2_bn}; done; test -n "$${t1_bn}" || \
+ { echo "only applicable to SO symlink scheme"; exit 1; }; \
+ echo "$${t1_bn}" > "$(DESTDIR)$(libdir)/libqb.so-t"
+ so_ver=$$(cat "$(DESTDIR)$(libdir)/libqb.so-t"); \
+ echo "INPUT($${so_ver})" > "$(DESTDIR)$(libdir)/libqb.so-t"; \
+ cat $< >> "$(DESTDIR)$(libdir)/libqb.so-t"; \
+ sed -i -- "s/libqb.so.<digit>/$${so_ver}/" \
+ "$(DESTDIR)$(libdir)/libqb.so-t" "$(DESTDIR)$(pkgconfigexecdir)/libqb.pc"
+ mv -f "$(DESTDIR)$(libdir)/libqb.so-t" "$(DESTDIR)$(libdir)/libqb.so"
+endif
if HAVE_SPLINT
check_SCRIPTS = run_splint.sh
diff --git a/lib/libqb.pc.in b/lib/libqb.pc.in
index 37d27b7..d9839bf 100644
--- a/lib/libqb.pc.in
+++ b/lib/libqb.pc.in
@@ -8,5 +8,16 @@ Version: @PACKAGE_VERSION@
Description: libqb
Requires:
Libs: -L${libdir} -lqb @client_dlopen_LIBS@
+# NOTE: If -lqb not usable for linking (e.g. linker not compatible with
+# linker scripts ad-hoc modifying output sections), try recent
+# ld.bfd/binutils linker first when available, otherwise you can
+# try "-l:libqb.so.<digit>" link switch that bypasses said linker
+# script -- but beware, logging may be less efficient and may lack
+# possible future optimizations and extra features. Consequently,
+# logging issues (typically bound to QB_LOG_INIT_DATA macro) can be
+# mitigated with QB_KILL_ATTRIBUTE_SECTION macro defined for a build.
+# NOTE: when concerned about a warning coming from the build process like
+# warning: [...]libqb.so contains output sections; did you forget -T?
+# and the build finishes OK, take it merely as a harmless side-effect
Libs.private: @LIBS@
Cflags: -I${includedir}
diff --git a/lib/log.c b/lib/log.c
index eb35d6f..290f29f 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -40,6 +40,13 @@
#include "util_int.h"
#include <regex.h>
+#if defined(QB_NEED_ATTRIBUTE_SECTION_WORKAROUND) && !defined(S_SPLINT_S)
+/* following only needed to force these symbols be global
+ with ld 2.29: https://bugzilla.redhat.com/1477354 */
+struct qb_log_callsite __attribute__((weak)) QB_ATTR_SECTION_START[] = { 0 };
+struct qb_log_callsite __attribute__((weak)) QB_ATTR_SECTION_STOP[] = { 0 };
+#endif
+
static struct qb_log_target conf[QB_LOG_TARGET_MAX];
static uint32_t conf_active_max = 0;
static int32_t in_logger = QB_FALSE;
diff --git a/lib/qblog_script.la.in b/lib/qblog_script.la.in
new file mode 100644
index 0000000..f262df8
--- /dev/null
+++ b/lib/qblog_script.la.in
@@ -0,0 +1,15 @@
+# Generated by libtool
+# NOTE: above line is just to pass func_ltwrapper_script_p sanity check of
+# libtool script, as we are basically sort of abusing it so as to inject
+# our custom linker script to "private" (cf. examples) users of libqb.la
+
+# shall rather carry a location of old_library (possibly libdir or something
+# else, but installed=no needed to suppress 'library moved' warning then) as
+# it's together (with libtool implied prefix otherwise) used for linking libqb
+libdir=@abs_builddir@
+
+# avoids issues with library_names (spurious rpath emitting, relink-on-install)
+old_library=qblog_script_noop.ld
+
+# subject of our injection into libqb.la impacting build time for private users
+inherited_linker_flags=-Wl,@abs_builddir@/qblog_script.ld
diff --git a/lib/qblog_script.ld.in b/lib/qblog_script.ld.in
new file mode 100644
index 0000000..a188ac2
--- /dev/null
+++ b/lib/qblog_script.ld.in
@@ -0,0 +1,30 @@
+#include <qb/qblog.h>
+/* GNU ld script
+ This atypical arrangement enforces global visibility of boundary symbols
+ (QB_ATTR_SECTION_START, QB_ATTR_SECTION_STOP) for the custom section
+ QB_ATTR_SECTION used for compile-time offloading of the logging call sites
+ tracking. While libqb relies on these being global, default linker from
+ binutils change the visibility as of version 2.29, making the logging
+ unusable without artificial stimulus: https://bugzilla.redhat.com/1477354
+
+ NOTE: If -lqb not usable for linking (e.g. linker not compatible with
+ linker scripts ad-hoc modifying output sections), try recent
+ ld.bfd/binutils linker first when available, otherwise you can
+ try "-l:libqb.so.<digit>" link switch that bypasses said linker
+ script -- but beware, logging may be less efficient and may lack
+ possible future optimizations and extra features. Consequently,
+ logging issues (typically bound to QB_LOG_INIT_DATA macro) can be
+ mitigated with QB_KILL_ATTRIBUTE_SECTION macro defined for a build.
+ NOTE: When concerned about a warning coming from the build process like
+ warning: [...]libqb.so contains output sections; did you forget -T?
+ while it finishes OK, consider it merely a harmless side-effect.
+ */
+SECTIONS {
+#ifdef QB_HAVE_ATTRIBUTE_SECTION
+ QB_ATTR_SECTION : {
+ QB_ATTR_SECTION_START = .;
+ *(QB_ATTR_SECTION);
+ QB_ATTR_SECTION_STOP = .;
+ }
+#endif
+}
diff --git a/lib/qblog_script_noop.ld b/lib/qblog_script_noop.ld
new file mode 100644
index 0000000..f037fca
--- /dev/null
+++ b/lib/qblog_script_noop.ld
@@ -0,0 +1 @@
+/* this is an empty linker script having a role of a NO-OP link object */
--
2.15.1

197
06-Low-fix-internal-object-symbol-s-leak-expose-run-tim.patch
View File

@ -1,197 +0,0 @@
From 5ae933f0c3bf1685cf7251ee3db96fe401030be0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Pokorn=C3=BD?= <jpokorny@redhat.com>
Date: Fri, 6 Oct 2017 17:17:26 +0200
Subject: [PATCH 6/6] Low: fix internal object symbol's leak & expose run-time
lib version
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
The object in question has never been published through the header file,
hence it's presumably safe to make it static as it's meant to be.
On the other hand, QB_LOG_INIT_DATA macro from qblog.h has already
started to depend on that symbol so as to locate the library handle
for libqb itself correctly. This is trivially fixed by finally exposing
library versioning info in run-time ("online") as a structure with
members corresponding to compile-time ("offline") counterparts from
qbconfig.h header file, which are admittedly of very limited use
as opposed to the newly introduced dynamic info, plus lower-cased
equivalent of QB_VER_STR. Better than to roll out a futile data object
serving as an artificial anchor for the above purpose, and this was
due for a while, afterall.
In turn, also bump "current" and "age" of fields of the libtool's
"-version-info" versioning system.
Signed-off-by: Jan Pokorný <jpokorny@redhat.com>
---
include/qb/qbconfig.h.in | 7 ++++++-
include/qb/qblog.h | 8 +++++---
include/qb/qbutil.h | 11 +++++++++++
lib/Makefile.am | 2 +-
lib/log.c | 10 ++++++----
lib/log_format.c | 2 +-
lib/util.c | 10 ++++++++++
tests/functional/log_client.c | 5 +++++
tests/functional/log_test_client.err | 2 +-
9 files changed, 46 insertions(+), 11 deletions(-)
diff --git a/include/qb/qbconfig.h.in b/include/qb/qbconfig.h.in
index c1852e1..9094dc7 100644
--- a/include/qb/qbconfig.h.in
+++ b/include/qb/qbconfig.h.in
@@ -30,7 +30,12 @@
/* Enabling code using __attribute__((section)) */
#undef QB_HAVE_ATTRIBUTE_SECTION
-/* versioning info: MAJOR, MINOR, MICRO, and REST components */
+/* versioning info: MAJOR, MINOR, MICRO, and REST components;
+ note that static compile-time info is not that useful as consulting
+ the respectively named members of qb_version struct constant under
+ @c qb_ver identifier (or @c qb_ver_str equivalent of the local
+ upper-cased value) directly from libqb in run-time (see qbutil.h),
+ but that was only introduced after v1.0.2 */
#undef QB_VER_MAJOR
#undef QB_VER_MINOR
#undef QB_VER_MICRO
diff --git a/include/qb/qblog.h b/include/qb/qblog.h
index 00adb3a..059d633 100644
--- a/include/qb/qblog.h
+++ b/include/qb/qblog.h
@@ -299,9 +299,11 @@ extern struct qb_log_callsite QB_ATTR_SECTION_STOP[];
#define QB_NONAPI_LOG_INIT_DATA_EXTRA_(name) \
{ Dl_info work_dli; \
/* libqb sanity (locating libqb by it's relatively unique \
- -- and currently only such per-linkage global one -- \
- non-functional symbol, due to possible confusion otherwise) */ \
- if (dladdr(dlsym(RTLD_DEFAULT, "facilitynames"), &work_dli) \
+ non-functional symbols -- the two are mutually exclusive, the \
+ ordinarily latter was introduced by accident, the former is \
+ intentional -- due to possible confusion otherwise) */ \
+ if ((dladdr(dlsym(RTLD_DEFAULT, "qb_ver_str"), &work_dli) \
+ || dladdr(dlsym(RTLD_DEFAULT, "facilitynames"), &work_dli)) \
&& (work_handle = dlopen(work_dli.dli_fname, \
RTLD_LOCAL|RTLD_LAZY)) != NULL) { \
work_s1 = (struct qb_log_callsite *) \
diff --git a/include/qb/qbutil.h b/include/qb/qbutil.h
index bfce349..b02ce8d 100644
--- a/include/qb/qbutil.h
+++ b/include/qb/qbutil.h
@@ -289,6 +289,17 @@ uint64_t
qb_util_stopwatch_time_split_get(qb_util_stopwatch_t *sw,
uint32_t receint, uint32_t older);
+/** Structured library versioning info */
+extern const struct qb_version {
+ uint8_t major; /**< Major component */
+ uint8_t minor; /**< Minor component */
+ uint8_t micro; /**< Micro component */
+ const char *rest; /**< Rest (pertaining the mid-release-point) */
+} qb_ver;
+
+/** Complete library versioning info as a string */
+extern const char *const qb_ver_str;
+
/* *INDENT-OFF* */
#ifdef __cplusplus
}
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 1572cff..6ca6b15 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -30,7 +30,7 @@ AM_CPPFLAGS = -I$(top_builddir)/include -I$(top_srcdir)/include
lib_LTLIBRARIES = libqb.la
-libqb_la_LDFLAGS = -version-info 18:2:18
+libqb_la_LDFLAGS = -version-info 19:0:19
source_to_lint = util.c hdb.c ringbuffer.c ringbuffer_helper.c \
array.c loop.c loop_poll.c loop_job.c \
diff --git a/lib/log.c b/lib/log.c
index 290f29f..cbad262 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -892,10 +892,12 @@ qb_log_init(const char *name, int32_t facility, uint8_t priority)
#ifdef QB_HAVE_ATTRIBUTE_SECTION
/* sanity check that target chain supplied QB_ATTR_SECTION_ST{ART,OP}
symbols and hence the local references to them are not referencing
- the proper libqb's ones (locating libqb-self by it's relatively
- unique -- and currently only such per-linkage global one --
- non-functional symbol, due to possible confusion otherwise) */
- if (dladdr(dlsym(RTLD_DEFAULT, "facilitynames"), &work_dli)
+ the proper libqb's ones (locating libqb by it's relatively unique
+ non-functional symbols -- the two are mutually exclusive, the
+ ordinarily latter was introduced by accident, the former is
+ intentional -- due to possible confusion otherwise) */
+ if ((dladdr(dlsym(RTLD_DEFAULT, "qb_ver_str"), &work_dli)
+ || dladdr(dlsym(RTLD_DEFAULT, "facilitynames"), &work_dli))
&& (work_handle = dlopen(work_dli.dli_fname,
RTLD_LOCAL|RTLD_LAZY)) != NULL) {
work_s1 = (struct qb_log_callsite *)
diff --git a/lib/log_format.c b/lib/log_format.c
index 712f447..e7e1f40 100644
--- a/lib/log_format.c
+++ b/lib/log_format.c
@@ -49,7 +49,7 @@ static struct syslog_names prioritynames[] = {
{NULL, -1}
};
-struct syslog_names facilitynames[] = {
+static struct syslog_names facilitynames[] = {
{"auth", LOG_AUTH},
#if defined(LOG_AUTHPRIV)
{"authpriv", LOG_AUTHPRIV},
diff --git a/lib/util.c b/lib/util.c
index 6181a25..a510bd1 100644
--- a/lib/util.c
+++ b/lib/util.c
@@ -23,6 +23,7 @@
#include "util_int.h"
#include <pthread.h>
#include <sys/stat.h>
+#include <qb/qbconfig.h>
#include <qb/qbdefs.h>
#include <qb/qbutil.h>
@@ -372,3 +373,12 @@ qb_util_stopwatch_time_split_get(qb_util_stopwatch_t *sw,
}
return (time_start - time_end) / QB_TIME_NS_IN_USEC;
}
+
+const struct qb_version qb_ver = {
+ .major = QB_VER_MAJOR,
+ .minor = QB_VER_MINOR,
+ .micro = QB_VER_MICRO,
+ .rest = QB_VER_REST,
+};
+
+const char *const qb_ver_str = QB_VER_STR;
diff --git a/tests/functional/log_client.c b/tests/functional/log_client.c
index c60d657..d5d8089 100644
--- a/tests/functional/log_client.c
+++ b/tests/functional/log_client.c
@@ -53,6 +53,11 @@ main(int32_t argc, char *argv[])
qb_log_tags_stringify_fn_set(my_tags_stringify);
qb_log_format_set(QB_LOG_STDERR, "[%5g|%p] %f:%l:%b");
+#if 0
+ printf("\n==%s consists of: %d, %d, %d, %s==\n\n", qb_ver_str,
+ qb_ver.major, qb_ver.minor, qb_ver.micro, qb_ver.rest);
+#endif
+
#if 0
printf("--\n");
qb_log_callsites_dump();
diff --git a/tests/functional/log_test_client.err b/tests/functional/log_test_client.err
index 19fca2c..98df44c 100644
--- a/tests/functional/log_test_client.err
+++ b/tests/functional/log_test_client.err
@@ -1,2 +1,2 @@
-[MAIN |debug] ../log_client.c:64:hello
+[MAIN |debug] ../log_client.c:69:hello
[libqb|error] log_blackbox.c:196:qb_log_blackbox_print_from_file:
--
2.15.1

19
libqb.spec
View File

@ -1,26 +1,20 @@
%bcond_without check
Name: libqb
Version: 1.0.2
Release: 15%{?dist}
Version: 1.0.3
Release: 1%{?dist}
Summary: An IPC library for high performance servers
Group: System Environment/Libraries
License: LGPLv2+
URL: https://github.com/ClusterLabs/libqb
Source0: https://github.com/ClusterLabs/libqb/releases/download/v%{version}/%{name}-%{version}.tar.xz
Patch0: 01-Med-qblog.h-better-explanation-behaviour-of-QB_LOG_I.patch
Patch1: 02-build-configure-check-section-boundary-symbols-prese.patch
Patch2: 03-tests-new-sort-of-tests-dubbed-functional-cover-link.patch
Patch3: 04-Med-add-extra-run-time-client-libqb-checks-that-logg.patch
Patch4: 05-High-bare-fix-for-libqb-logging-not-working-with-ld..patch
Patch5: 06-Low-fix-internal-object-symbol-s-leak-expose-run-tim.patch
BuildRequires: autoconf automake libtool doxygen procps check-devel
# https://fedoraproject.org/wiki/Packaging:C_and_C%2B%2B#BuildRequires_and_Requires
BuildRequires: gcc
# git-style patch application
BuildRequires: git
#BuildRequires: git # for when patches around
%description
libqb provides high-performance, reusable features for client-server
@ -28,7 +22,8 @@ architecture, such as logging, tracing, inter-process communication (IPC),
and polling.
%prep
%autosetup -p1 -S git_am
%setup
#autosetup -p1 -S git_am # for when patches around
%build
./autogen.sh
@ -75,6 +70,10 @@ developing applications that use %{name}.
%{_mandir}/man3/qb*3*
%changelog
* Thu Dec 21 2017 Jan Pokorný <jpokorny+rpm-libqb@redhat.com> - 1.0.3-1
- Update to libqb-1.0.3, for list of changes see:
https://github.com/ClusterLabs/libqb/releases/tag/v1.0.3
* Tue Dec 12 2017 Jan Pokorný <jpokorny+rpm-libqb@redhat.com> - 1.0.2-15
- Evolution of the previous (rhbz#1478089)

2
sources
View File

@ -1 +1 @@
SHA512 (libqb-1.0.2.tar.xz) = 5f852d2abc8062ec9314b0fe163ca008a7c0780aded387a77fd7d8b0a7ff3237e0ff1f90c3e8f447a7e31604dea33d6d26901e701d5d149d932dfb8d75db7756
SHA512 (libqb-1.0.3.tar.xz) = 9264fed8479238dadcb8d33fa5d9467d7f4dff820f361ae2e302fe1c0818ddf0bd14e069b9ec6589e466d5c7c6ed787714b081924be27c141bfc9022615cb7a8