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[clang][analyzer] Move unix.BlockInCriticalSection out of alpha (#93815)
After recent improvements (#80029) and testing on open-source projects, the checker is ready to move out of the alpha package.
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‎clang/docs/analyzer/checkers.rst‎

Lines changed: 44 additions & 43 deletions
Original file line numberDiff line numberDiff line change
@@ -1235,6 +1235,50 @@ Check calls to various UNIX/Posix functions: ``open, pthread_once, calloc, mallo
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.. literalinclude:: checkers/unix_api_example.c
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:language: c
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.. _unix-BlockInCriticalSection:
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unix.BlockInCriticalSection (C, C++)
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""""""""""""""""""""""""""""""""""""
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Check for calls to blocking functions inside a critical section.
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Blocking functions detected by this checker: ``sleep, getc, fgets, read, recv``.
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Critical section handling functions modeled by this checker:
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``lock, unlock, pthread_mutex_lock, pthread_mutex_trylock, pthread_mutex_unlock, mtx_lock, mtx_timedlock, mtx_trylock, mtx_unlock, lock_guard, unique_lock``.
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.. code-block:: c
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void pthread_lock_example(pthread_mutex_t *m) {
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pthread_mutex_lock(m); // note: entering critical section here
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sleep(10); // warn: Call to blocking function 'sleep' inside of critical section
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pthread_mutex_unlock(m);
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}
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.. code-block:: cpp
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void overlapping_critical_sections(mtx_t *m1, std::mutex &m2) {
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std::lock_guard lg{m2}; // note: entering critical section here
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mtx_lock(m1); // note: entering critical section here
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sleep(10); // warn: Call to blocking function 'sleep' inside of critical section
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mtx_unlock(m1);
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sleep(10); // warn: Call to blocking function 'sleep' inside of critical section
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// still inside of the critical section of the std::lock_guard
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}
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**Limitations**
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* The ``trylock`` and ``timedlock`` versions of acquiring locks are currently assumed to always succeed.
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This can lead to false positives.
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.. code-block:: c
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void trylock_example(pthread_mutex_t *m) {
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if (pthread_mutex_trylock(m) == 0) { // assume trylock always succeeds
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sleep(10); // warn: Call to blocking function 'sleep' inside of critical section
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pthread_mutex_unlock(m);
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} else {
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sleep(10); // false positive: Incorrect warning about blocking function inside critical section.
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}
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}
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.. _unix-Errno:
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unix.Errno (C)
@@ -3130,49 +3174,6 @@ For a more detailed description of configuration options, please see the
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alpha.unix
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^^^^^^^^^^
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.. _alpha-unix-BlockInCriticalSection:
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alpha.unix.BlockInCriticalSection (C)
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"""""""""""""""""""""""""""""""""""""
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Check for calls to blocking functions inside a critical section.
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Blocking functions detected by this checker: ``sleep, getc, fgets, read, recv``.
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Critical section handling functions modelled by this checker: ``lock, unlock, pthread_mutex_lock, pthread_mutex_trylock, pthread_mutex_unlock, mtx_lock, mtx_timedlock, mtx_trylock, mtx_unlock, lock_guard, unique_lock``.
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.. code-block:: c
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void pthread_lock_example(pthread_mutex_t *m) {
3144-
pthread_mutex_lock(m); // note: entering critical section here
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sleep(10); // warn: Call to blocking function 'sleep' inside of critical section
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pthread_mutex_unlock(m);
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}
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.. code-block:: cpp
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void overlapping_critical_sections(mtx_t *m1, std::mutex &m2) {
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std::lock_guard lg{m2}; // note: entering critical section here
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mtx_lock(m1); // note: entering critical section here
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sleep(10); // warn: Call to blocking function 'sleep' inside of critical section
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mtx_unlock(m1);
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sleep(10); // warn: Call to blocking function 'sleep' inside of critical section
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// still inside of the critical section of the std::lock_guard
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}
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**Limitations**
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* The ``trylock`` and ``timedlock`` versions of acquiring locks are currently assumed to always succeed.
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This can lead to false positives.
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.. code-block:: c
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void trylock_example(pthread_mutex_t *m) {
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if (pthread_mutex_trylock(m) == 0) { // assume trylock always succeeds
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sleep(10); // warn: Call to blocking function 'sleep' inside of critical section
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pthread_mutex_unlock(m);
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} else {
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sleep(10); // false positive: Incorrect warning about blocking function inside critical section.
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}
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}
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.. _alpha-unix-Chroot:
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alpha.unix.Chroot (C)

‎clang/include/clang/StaticAnalyzer/Checkers/Checkers.td‎

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -509,6 +509,10 @@ def UnixAPIMisuseChecker : Checker<"API">,
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HelpText<"Check calls to various UNIX/Posix functions">,
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Documentation<HasDocumentation>;
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def BlockInCriticalSectionChecker : Checker<"BlockInCriticalSection">,
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HelpText<"Check for calls to blocking functions inside a critical section">,
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Documentation<HasDocumentation>;
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def DynamicMemoryModeling: Checker<"DynamicMemoryModeling">,
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HelpText<"The base of several malloc() related checkers. On it's own it "
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"emits no reports, but adds valuable information to the analysis "
@@ -619,10 +623,6 @@ def SimpleStreamChecker : Checker<"SimpleStream">,
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HelpText<"Check for misuses of stream APIs">,
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Documentation<HasDocumentation>;
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622-
def BlockInCriticalSectionChecker : Checker<"BlockInCriticalSection">,
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HelpText<"Check for calls to blocking functions inside a critical section">,
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Documentation<HasDocumentation>;
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} // end "alpha.unix"
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//===----------------------------------------------------------------------===//

‎clang/test/Analysis/analyzer-enabled-checkers.c‎

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Original file line numberDiff line numberDiff line change
@@ -42,6 +42,7 @@
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// CHECK-NEXT: security.insecureAPI.mktemp
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// CHECK-NEXT: security.insecureAPI.vfork
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// CHECK-NEXT: unix.API
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// CHECK-NEXT: unix.BlockInCriticalSection
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// CHECK-NEXT: unix.cstring.CStringModeling
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// CHECK-NEXT: unix.DynamicMemoryModeling
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// CHECK-NEXT: unix.Errno

‎clang/test/Analysis/block-in-critical-section.c‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.unix.BlockInCriticalSection -verify %s
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// RUN: %clang_analyze_cc1 -analyzer-checker=core,unix.BlockInCriticalSection -verify %s
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// expected-no-diagnostics
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// This should not crash

‎clang/test/Analysis/block-in-critical-section.cpp‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
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// RUN: %clang_analyze_cc1 \
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// RUN: -analyzer-checker=alpha.unix.BlockInCriticalSection \
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// RUN: -analyzer-checker=unix.BlockInCriticalSection \
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// RUN: -std=c++11 \
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// RUN: -analyzer-output text \
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// RUN: -verify %s

‎clang/test/Analysis/block-in-critical-section.m‎

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Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
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// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.unix.BlockInCriticalSection -verify -Wno-objc-root-class %s
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// RUN: %clang_analyze_cc1 -analyzer-checker=core,unix.BlockInCriticalSection -verify -Wno-objc-root-class %s
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// expected-no-diagnostics
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@interface SomeClass

‎clang/test/Analysis/std-c-library-functions-arg-enabled-checkers.c‎

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Original file line numberDiff line numberDiff line change
@@ -50,6 +50,7 @@
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// CHECK-NEXT: security.insecureAPI.mktemp
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// CHECK-NEXT: security.insecureAPI.vfork
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// CHECK-NEXT: unix.API
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// CHECK-NEXT: unix.BlockInCriticalSection
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// CHECK-NEXT: unix.cstring.CStringModeling
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// CHECK-NEXT: unix.DynamicMemoryModeling
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// CHECK-NEXT: unix.Errno

‎clang/www/analyzer/alpha_checks.html‎

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@@ -780,39 +780,6 @@ <h3 id="unix_alpha_checkers">Unix Alpha Checkers</h3>
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<tbody>
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<tr><td><a id="alpha.unix.BlockInCriticalSection"><div class="namedescr expandable"><span class="name">
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alpha.unix.BlockInCriticalSection</span><span class="lang">
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(C)</span><div class="descr">
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Check for calls to blocking functions inside a critical section. Applies to:
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<div class=functions>
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lock<br>
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unlock<br>
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sleep<br>
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getc<br>
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fgets<br>
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read<br>
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revc<br>
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pthread_mutex_lock<br>
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pthread_mutex_unlock<br>
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mtx_lock<br>
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mtx_timedlock<br>
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mtx_trylock<br>
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mtx_unlock<br>
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lock_guard<br>
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unique_lock</div>
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</div></div></a></td>
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<td><div class="exampleContainer expandable">
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<div class="example"><pre>
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void test() {
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std::mutex m;
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m.lock();
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sleep(3); // warn: a blocking function sleep is called inside a critical
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// section
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m.unlock();
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}
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</pre></div></div></td></tr>
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<tr><td><a id="alpha.unix.Chroot"><div class="namedescr expandable"><span class="name">
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alpha.unix.Chroot</span><span class="lang">
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(C)</span><div class="descr">

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