<div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Apr 24, 2015 at 12:29 PM, David Blaikie <span dir="ltr"><<a href="mailto:dblaikie@gmail.com" target="_blank">dblaikie@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I'm seeing a couple of these warnings on Ubuntu:<br>
<br>
ld: warning: Cannot export local symbol '__lsan_do_recoverable_leak_check'<br></blockquote><div><br></div><div>Thanks for pointing it out! Please check if r235761 fixes this.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="HOEnZb"><div class="h5"><br>
On Fri, Apr 24, 2015 at 9:53 AM, Sergey Matveev <<a href="mailto:earthdok@google.com">earthdok@google.com</a>> wrote:<br>
> Author: smatveev<br>
> Date: Fri Apr 24 11:53:15 2015<br>
> New Revision: 235728<br>
><br>
> URL: <a href="http://llvm.org/viewvc/llvm-project?rev=235728&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=235728&view=rev</a><br>
> Log:<br>
> [lsan] Add an interface function for on-demand leak checking.<br>
><br>
> Summary:<br>
> Add an interface function which can be used to periodically trigger<br>
> leak detection in a long-running process.<br>
><br>
> NB: The meaning of the kIgnored tag has been changed to allow easy clean-up<br>
> between subsequent leak checks. Previously, this tag was applied to explicitly<br>
> ignored (i.e. with __lsan_disable() or __lsan_ignore_object()) chunks *and* any<br>
> chunks only reachable from those. With this change, it's only applied to<br>
> explicitly ignored chunks.<br>
><br>
> Reviewers: samsonov<br>
><br>
> Reviewed By: samsonov<br>
><br>
> Subscribers: llvm-commits<br>
><br>
> Differential Revision: <a href="http://reviews.llvm.org/D9159" target="_blank">http://reviews.llvm.org/D9159</a><br>
><br>
> Added:<br>
> compiler-rt/trunk/test/lsan/TestCases/recoverable_leak_check.cc<br>
> Modified:<br>
> compiler-rt/trunk/include/sanitizer/lsan_interface.h<br>
> compiler-rt/trunk/lib/lsan/lsan_common.cc<br>
> compiler-rt/trunk/lib/lsan/lsan_common_linux.cc<br>
><br>
> Modified: compiler-rt/trunk/include/sanitizer/lsan_interface.h<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/include/sanitizer/lsan_interface.h?rev=235728&r1=235727&r2=235728&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/include/sanitizer/lsan_interface.h?rev=235728&r1=235727&r2=235728&view=diff</a><br>
> ==============================================================================<br>
> --- compiler-rt/trunk/include/sanitizer/lsan_interface.h (original)<br>
> +++ compiler-rt/trunk/include/sanitizer/lsan_interface.h Fri Apr 24 11:53:15 2015<br>
> @@ -41,14 +41,25 @@ extern "C" {<br>
> void __lsan_register_root_region(const void *p, size_t size);<br>
> void __lsan_unregister_root_region(const void *p, size_t size);<br>
><br>
> - // Calling this function makes LSan enter the leak checking phase immediately.<br>
> - // Use this if normal end-of-process leak checking happens too late (e.g. if<br>
> - // you have intentional memory leaks in your shutdown code). Calling this<br>
> - // function overrides end-of-process leak checking; it must be called at<br>
> - // most once per process. This function will terminate the process if there<br>
> - // are memory leaks and the exit_code flag is non-zero.<br>
> + // Check for leaks now. This function behaves identically to the default<br>
> + // end-of-process leak check. In particular, it will terminate the process if<br>
> + // leaks are found and the exit_code flag is non-zero.<br>
> + // Subsequent calls to this function will have no effect and end-of-process<br>
> + // leak check will not run. Effectively, end-of-process leak check is moved to<br>
> + // the time of first invocation of this function.<br>
> + // By calling this function early during process shutdown, you can instruct<br>
> + // LSan to ignore shutdown-only leaks which happen later on.<br>
> void __lsan_do_leak_check();<br>
><br>
> + // Check for leaks now. Returns zero if no leaks have been found or if leak<br>
> + // detection is disabled, non-zero otherwise.<br>
> + // This function may be called repeatedly, e.g. to periodically check a<br>
> + // long-running process. It prints a leak report if appropriate, but does not<br>
> + // terminate the process. It does not affect the behavior of<br>
> + // __lsan_do_leak_check() or the end-of-process leak check, and is not<br>
> + // affected by them.<br>
> + int __lsan_do_recoverable_leak_check();<br>
> +<br>
> // The user may optionally provide this function to disallow leak checking<br>
> // for the program it is linked into (if the return value is non-zero). This<br>
> // function must be defined as returning a constant value; any behavior beyond<br>
><br>
> Modified: compiler-rt/trunk/lib/lsan/lsan_common.cc<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/lsan/lsan_common.cc?rev=235728&r1=235727&r2=235728&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/lsan/lsan_common.cc?rev=235728&r1=235727&r2=235728&view=diff</a><br>
> ==============================================================================<br>
> --- compiler-rt/trunk/lib/lsan/lsan_common.cc (original)<br>
> +++ compiler-rt/trunk/lib/lsan/lsan_common.cc Fri Apr 24 11:53:15 2015<br>
> @@ -126,13 +126,14 @@ static inline bool CanBeAHeapPointer(upt<br>
><br>
> // Scans the memory range, looking for byte patterns that point into allocator<br>
> // chunks. Marks those chunks with |tag| and adds them to |frontier|.<br>
> -// There are two usage modes for this function: finding reachable or ignored<br>
> -// chunks (|tag| = kReachable or kIgnored) and finding indirectly leaked chunks<br>
> +// There are two usage modes for this function: finding reachable chunks<br>
> +// (|tag| = kReachable) and finding indirectly leaked chunks<br>
> // (|tag| = kIndirectlyLeaked). In the second case, there's no flood fill,<br>
> // so |frontier| = 0.<br>
> void ScanRangeForPointers(uptr begin, uptr end,<br>
> Frontier *frontier,<br>
> const char *region_type, ChunkTag tag) {<br>
> + CHECK(tag == kReachable || tag == kIndirectlyLeaked);<br>
> const uptr alignment = flags()->pointer_alignment();<br>
> LOG_POINTERS("Scanning %s range %p-%p.\n", region_type, begin, end);<br>
> uptr pp = begin;<br>
> @@ -146,9 +147,7 @@ void ScanRangeForPointers(uptr begin, up<br>
> // Pointers to self don't count. This matters when tag == kIndirectlyLeaked.<br>
> if (chunk == begin) continue;<br>
> LsanMetadata m(chunk);<br>
> - // Reachable beats ignored beats leaked.<br>
> - if (m.tag() == kReachable) continue;<br>
> - if (m.tag() == kIgnored && tag != kReachable) continue;<br>
> + if (m.tag() == kReachable || m.tag() == kIgnored) continue;<br>
><br>
> // Do this check relatively late so we can log only the interesting cases.<br>
> if (!flags()->use_poisoned && WordIsPoisoned(pp)) {<br>
> @@ -287,7 +286,7 @@ static void MarkIndirectlyLeakedCb(uptr<br>
> LsanMetadata m(chunk);<br>
> if (m.allocated() && m.tag() != kReachable) {<br>
> ScanRangeForPointers(chunk, chunk + m.requested_size(),<br>
> - /* frontier */ 0, "HEAP", kIndirectlyLeaked);<br>
> + /* frontier */ nullptr, "HEAP", kIndirectlyLeaked);<br>
> }<br>
> }<br>
><br>
> @@ -297,8 +296,11 @@ static void CollectIgnoredCb(uptr chunk,<br>
> CHECK(arg);<br>
> chunk = GetUserBegin(chunk);<br>
> LsanMetadata m(chunk);<br>
> - if (m.allocated() && m.tag() == kIgnored)<br>
> + if (m.allocated() && m.tag() == kIgnored) {<br>
> + LOG_POINTERS("Ignored: chunk %p-%p of size %zu.\n",<br>
> + chunk, chunk + m.requested_size(), m.requested_size());<br>
> reinterpret_cast<Frontier *>(arg)->push_back(chunk);<br>
> + }<br>
> }<br>
><br>
> // Sets the appropriate tag on each chunk.<br>
> @@ -306,26 +308,33 @@ static void ClassifyAllChunks(SuspendedT<br>
> // Holds the flood fill frontier.<br>
> Frontier frontier(1);<br>
><br>
> + ForEachChunk(CollectIgnoredCb, &frontier);<br>
> ProcessGlobalRegions(&frontier);<br>
> ProcessThreads(suspended_threads, &frontier);<br>
> ProcessRootRegions(&frontier);<br>
> FloodFillTag(&frontier, kReachable);<br>
> +<br>
> // The check here is relatively expensive, so we do this in a separate flood<br>
> // fill. That way we can skip the check for chunks that are reachable<br>
> // otherwise.<br>
> LOG_POINTERS("Processing platform-specific allocations.\n");<br>
> + CHECK_EQ(0, frontier.size());<br>
> ProcessPlatformSpecificAllocations(&frontier);<br>
> FloodFillTag(&frontier, kReachable);<br>
><br>
> - LOG_POINTERS("Scanning ignored chunks.\n");<br>
> - CHECK_EQ(0, frontier.size());<br>
> - ForEachChunk(CollectIgnoredCb, &frontier);<br>
> - FloodFillTag(&frontier, kIgnored);<br>
> -<br>
> // Iterate over leaked chunks and mark those that are reachable from other<br>
> // leaked chunks.<br>
> LOG_POINTERS("Scanning leaked chunks.\n");<br>
> - ForEachChunk(MarkIndirectlyLeakedCb, 0 /* arg */);<br>
> + ForEachChunk(MarkIndirectlyLeakedCb, nullptr);<br>
> +}<br>
> +<br>
> +// ForEachChunk callback. Resets the tags to pre-leak-check state.<br>
> +static void ResetTagsCb(uptr chunk, void *arg) {<br>
> + (void)arg;<br>
> + chunk = GetUserBegin(chunk);<br>
> + LsanMetadata m(chunk);<br>
> + if (m.allocated() && m.tag() != kIgnored)<br>
> + m.set_tag(kDirectlyLeaked);<br>
> }<br>
><br>
> static void PrintStackTraceById(u32 stack_trace_id) {<br>
> @@ -371,35 +380,33 @@ static void PrintMatchedSuppressions() {<br>
> Printf("%s\n\n", line);<br>
> }<br>
><br>
> -struct DoLeakCheckParam {<br>
> +struct CheckForLeaksParam {<br>
> bool success;<br>
> LeakReport leak_report;<br>
> };<br>
><br>
> -static void DoLeakCheckCallback(const SuspendedThreadsList &suspended_threads,<br>
> - void *arg) {<br>
> - DoLeakCheckParam *param = reinterpret_cast<DoLeakCheckParam *>(arg);<br>
> +static void CheckForLeaksCallback(const SuspendedThreadsList &suspended_threads,<br>
> + void *arg) {<br>
> + CheckForLeaksParam *param = reinterpret_cast<CheckForLeaksParam *>(arg);<br>
> CHECK(param);<br>
> CHECK(!param->success);<br>
> ClassifyAllChunks(suspended_threads);<br>
> ForEachChunk(CollectLeaksCb, ¶m->leak_report);<br>
> + // Clean up for subsequent leak checks. This assumes we did not overwrite any<br>
> + // kIgnored tags.<br>
> + ForEachChunk(ResetTagsCb, nullptr);<br>
> param->success = true;<br>
> }<br>
><br>
> -void DoLeakCheck() {<br>
> - EnsureMainThreadIDIsCorrect();<br>
> - BlockingMutexLock l(&global_mutex);<br>
> - static bool already_done;<br>
> - if (already_done) return;<br>
> - already_done = true;<br>
> +static bool CheckForLeaks() {<br>
> if (&__lsan_is_turned_off && __lsan_is_turned_off())<br>
> - return;<br>
> -<br>
> - DoLeakCheckParam param;<br>
> + return false;<br>
> + EnsureMainThreadIDIsCorrect();<br>
> + CheckForLeaksParam param;<br>
> param.success = false;<br>
> LockThreadRegistry();<br>
> LockAllocator();<br>
> - DoStopTheWorld(DoLeakCheckCallback, ¶m);<br>
> + DoStopTheWorld(CheckForLeaksCallback, ¶m);<br>
> UnlockAllocator();<br>
> UnlockThreadRegistry();<br>
><br>
> @@ -423,14 +430,33 @@ void DoLeakCheck() {<br>
> PrintMatchedSuppressions();<br>
> if (unsuppressed_count > 0) {<br>
> param.leak_report.PrintSummary();<br>
> - if (flags()->exitcode) {<br>
> - if (common_flags()->coverage)<br>
> - __sanitizer_cov_dump();<br>
> - internal__exit(flags()->exitcode);<br>
> - }<br>
> + return true;<br>
> + }<br>
> + return false;<br>
> +}<br>
> +<br>
> +void DoLeakCheck() {<br>
> + BlockingMutexLock l(&global_mutex);<br>
> + static bool already_done;<br>
> + if (already_done) return;<br>
> + already_done = true;<br>
> + bool have_leaks = CheckForLeaks();<br>
> + if (!have_leaks) {<br>
> + return;<br>
> + }<br>
> + if (flags()->exitcode) {<br>
> + if (common_flags()->coverage)<br>
> + __sanitizer_cov_dump();<br>
> + internal__exit(flags()->exitcode);<br>
> }<br>
> }<br>
><br>
> +static int DoRecoverableLeakCheck() {<br>
> + BlockingMutexLock l(&global_mutex);<br>
> + bool have_leaks = CheckForLeaks();<br>
> + return have_leaks ? 1 : 0;<br>
> +}<br>
> +<br>
> static Suppression *GetSuppressionForAddr(uptr addr) {<br>
> Suppression *s = nullptr;<br>
><br>
> @@ -676,6 +702,14 @@ void __lsan_do_leak_check() {<br>
> #endif // CAN_SANITIZE_LEAKS<br>
> }<br>
><br>
> +int __lsan_do_recoverable_leak_check() {<br>
> +#if CAN_SANITIZE_LEAKS<br>
> + if (common_flags()->detect_leaks)<br>
> + return __lsan::DoRecoverableLeakCheck();<br>
> +#endif // CAN_SANITIZE_LEAKS<br>
> + return 0;<br>
> +}<br>
> +<br>
> #if !SANITIZER_SUPPORTS_WEAK_HOOKS<br>
> SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE<br>
> int __lsan_is_turned_off() {<br>
><br>
> Modified: compiler-rt/trunk/lib/lsan/lsan_common_linux.cc<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/lsan/lsan_common_linux.cc?rev=235728&r1=235727&r2=235728&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/lsan/lsan_common_linux.cc?rev=235728&r1=235727&r2=235728&view=diff</a><br>
> ==============================================================================<br>
> --- compiler-rt/trunk/lib/lsan/lsan_common_linux.cc (original)<br>
> +++ compiler-rt/trunk/lib/lsan/lsan_common_linux.cc Fri Apr 24 11:53:15 2015<br>
> @@ -110,7 +110,7 @@ static void ProcessPlatformSpecificAlloc<br>
> reinterpret_cast<ProcessPlatformAllocParam *>(arg);<br>
> chunk = GetUserBegin(chunk);<br>
> LsanMetadata m(chunk);<br>
> - if (m.allocated() && m.tag() != kReachable) {<br>
> + if (m.allocated() && m.tag() != kReachable && m.tag() != kIgnored) {<br>
> u32 stack_id = m.stack_trace_id();<br>
> uptr caller_pc = 0;<br>
> if (stack_id > 0)<br>
><br>
> Added: compiler-rt/trunk/test/lsan/TestCases/recoverable_leak_check.cc<br>
> URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/lsan/TestCases/recoverable_leak_check.cc?rev=235728&view=auto" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/lsan/TestCases/recoverable_leak_check.cc?rev=235728&view=auto</a><br>
> ==============================================================================<br>
> --- compiler-rt/trunk/test/lsan/TestCases/recoverable_leak_check.cc (added)<br>
> +++ compiler-rt/trunk/test/lsan/TestCases/recoverable_leak_check.cc Fri Apr 24 11:53:15 2015<br>
> @@ -0,0 +1,32 @@<br>
> +// Test for on-demand leak checking.<br>
> +// RUN: LSAN_BASE="use_stacks=0:use_registers=0"<br>
> +// RUN: %clangxx_lsan %s -o %t<br>
> +// RUN: LSAN_OPTIONS=$LSAN_BASE %run %t foo 2>&1 | FileCheck %s<br>
> +// RUN: LSAN_OPTIONS=$LSAN_BASE %run %t 2>&1 | FileCheck %s<br>
> +<br>
> +#include <assert.h><br>
> +#include <stdio.h><br>
> +#include <stdlib.h><br>
> +#include <unistd.h><br>
> +#include <sanitizer/lsan_interface.h><br>
> +<br>
> +void *p;<br>
> +<br>
> +int main(int argc, char *argv[]) {<br>
> + p = malloc(23);<br>
> +<br>
> + assert(__lsan_do_recoverable_leak_check() == 0);<br>
> +<br>
> + fprintf(stderr, "Test alloc: %p.\n", malloc(1337));<br>
> +// CHECK: Test alloc:<br>
> +<br>
> + assert(__lsan_do_recoverable_leak_check() == 1);<br>
> +// CHECK: SUMMARY: {{(Leak|Address)}}Sanitizer: 1337 byte<br>
> +<br>
> + // Test that we correctly reset chunk tags.<br>
> + p = 0;<br>
> + assert(__lsan_do_recoverable_leak_check() == 1);<br>
> +// CHECK: SUMMARY: {{(Leak|Address)}}Sanitizer: 1360 byte<br>
> +<br>
> + _exit(0);<br>
> +}<br>
><br>
><br>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr">Alexey Samsonov<br><a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a></div></div>
</div></div>