From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 0E6E53858C27; Tue, 12 Apr 2022 17:39:14 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0E6E53858C27 From: "redi at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug libbacktrace/105240] backtrace_pcinfo leaks memory Date: Tue, 12 Apr 2022 17:39:14 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libbacktrace X-Bugzilla-Version: 12.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: redi at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Apr 2022 17:39:15 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105240 --- Comment #4 from Jonathan Wakely --- The report in comment 0 is from libstdc++ which uses a local static variabl= e to hold the state. Modifying the comment 1 example to use a global: #include int cb_pcinfo(void*, uintptr_t, const char*, int, const char* function) { return function !=3D nullptr; } int cb(void* p, uintptr_t pc) { *static_cast(p) =3D pc; return = 1; } backtrace_state* state; int main() { state =3D backtrace_create_state(nullptr, 1, nullptr, nullptr); uintptr_t pc; backtrace_simple(state, 0, cb, nullptr, &pc); backtrace_pcinfo(state, pc, cb_pcinfo, nullptr, nullptr); } I get: =3D=3D494586=3D=3D Memcheck, a memory error detector =3D=3D494586=3D=3D Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward= et al. =3D=3D494586=3D=3D Using Valgrind-3.18.1 and LibVEX; rerun with -h for copy= right info =3D=3D494586=3D=3D Command: ./a.out =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D HEAP SUMMARY: =3D=3D494586=3D=3D in use at exit: 112,638,181 bytes in 729,676 blocks =3D=3D494586=3D=3D total heap usage: 729,861 allocs, 185 frees, 115,412,6= 94 bytes allocated =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D 84 bytes in 3 blocks are definitely lost in loss record = 6 of 35 =3D=3D494586=3D=3D at 0x484086F: malloc (vg_replace_malloc.c:381) =3D=3D494586=3D=3D by 0x406FF1: backtrace_alloc (alloc.c:57) =3D=3D494586=3D=3D by 0x409283: read_lnct (dwarf.c:2543) =3D=3D494586=3D=3D by 0x409283: read_line_header_format_entries (dwarf.c= :2618) =3D=3D494586=3D=3D by 0x40B08A: read_line_header (dwarf.c:2712) =3D=3D494586=3D=3D by 0x40B08A: read_line_info (dwarf.c:2965) =3D=3D494586=3D=3D by 0x40B08A: dwarf_lookup_pc (dwarf.c:3747) =3D=3D494586=3D=3D by 0x40C1BE: dwarf_fileline (dwarf.c:3935) =3D=3D494586=3D=3D by 0x401357: main (bt.cc:15) =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D 2,839 bytes in 1 blocks are possibly lost in loss record= 19 of 35 =3D=3D494586=3D=3D at 0x484086F: malloc (vg_replace_malloc.c:381) =3D=3D494586=3D=3D by 0x406FF1: backtrace_alloc (alloc.c:57) =3D=3D494586=3D=3D by 0x406ED6: backtrace_get_view (read.c:68) =3D=3D494586=3D=3D by 0x40667B: elf_add (elf.c:4381) =3D=3D494586=3D=3D by 0x406D83: backtrace_initialize (elf.c:4877) =3D=3D494586=3D=3D by 0x4014B1: fileline_initialize (fileline.c:261) =3D=3D494586=3D=3D by 0x401581: backtrace_pcinfo (fileline.c:295) =3D=3D494586=3D=3D by 0x401357: main (bt.cc:15) =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D 13,920 bytes in 1 blocks are definitely lost in loss rec= ord 23 of 35 =3D=3D494586=3D=3D at 0x484086F: malloc (vg_replace_malloc.c:381) =3D=3D494586=3D=3D by 0x406FF1: backtrace_alloc (alloc.c:57) =3D=3D494586=3D=3D by 0x406ED6: backtrace_get_view (read.c:68) =3D=3D494586=3D=3D by 0x40568A: elf_get_view (elf.c:426) =3D=3D494586=3D=3D by 0x40568A: elf_add (elf.c:4329) =3D=3D494586=3D=3D by 0x406BC8: phdr_callback (elf.c:4848) =3D=3D494586=3D=3D by 0x4D2A314: dl_iterate_phdr (dl-iteratephdr.c:75) =3D=3D494586=3D=3D by 0x406DDD: backtrace_initialize (elf.c:4892) =3D=3D494586=3D=3D by 0x4014B1: fileline_initialize (fileline.c:261) =3D=3D494586=3D=3D by 0x401581: backtrace_pcinfo (fileline.c:295) =3D=3D494586=3D=3D by 0x401357: main (bt.cc:15) =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D 69,736 bytes in 2 blocks are possibly lost in loss recor= d 26 of 35 =3D=3D494586=3D=3D at 0x484086F: malloc (vg_replace_malloc.c:381) =3D=3D494586=3D=3D by 0x406FF1: backtrace_alloc (alloc.c:57) =3D=3D494586=3D=3D by 0x406ED6: backtrace_get_view (read.c:68) =3D=3D494586=3D=3D by 0x40568A: elf_get_view (elf.c:426) =3D=3D494586=3D=3D by 0x40568A: elf_add (elf.c:4329) =3D=3D494586=3D=3D by 0x406BC8: phdr_callback (elf.c:4848) =3D=3D494586=3D=3D by 0x4D2A314: dl_iterate_phdr (dl-iteratephdr.c:75) =3D=3D494586=3D=3D by 0x406DDD: backtrace_initialize (elf.c:4892) =3D=3D494586=3D=3D by 0x4014B1: fileline_initialize (fileline.c:261) =3D=3D494586=3D=3D by 0x401581: backtrace_pcinfo (fileline.c:295) =3D=3D494586=3D=3D by 0x401357: main (bt.cc:15) =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D 451,020 bytes in 7 blocks are possibly lost in loss reco= rd 31 of 35 =3D=3D494586=3D=3D at 0x484086F: malloc (vg_replace_malloc.c:381) =3D=3D494586=3D=3D by 0x406FF1: backtrace_alloc (alloc.c:57) =3D=3D494586=3D=3D by 0x406ED6: backtrace_get_view (read.c:68) =3D=3D494586=3D=3D by 0x40667B: elf_add (elf.c:4381) =3D=3D494586=3D=3D by 0x406BC8: phdr_callback (elf.c:4848) =3D=3D494586=3D=3D by 0x4D2A314: dl_iterate_phdr (dl-iteratephdr.c:75) =3D=3D494586=3D=3D by 0x406DDD: backtrace_initialize (elf.c:4892) =3D=3D494586=3D=3D by 0x4014B1: fileline_initialize (fileline.c:261) =3D=3D494586=3D=3D by 0x401581: backtrace_pcinfo (fileline.c:295) =3D=3D494586=3D=3D by 0x401357: main (bt.cc:15) =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D LEAK SUMMARY: =3D=3D494586=3D=3D definitely lost: 14,004 bytes in 4 blocks =3D=3D494586=3D=3D indirectly lost: 0 bytes in 0 blocks =3D=3D494586=3D=3D possibly lost: 523,595 bytes in 10 blocks =3D=3D494586=3D=3D still reachable: 112,100,582 bytes in 729,662 blocks =3D=3D494586=3D=3D suppressed: 0 bytes in 0 blocks =3D=3D494586=3D=3D Reachable blocks (those to which a pointer was found) ar= e not shown. =3D=3D494586=3D=3D To see them, rerun with: --leak-check=3Dfull --show-leak= -kinds=3Dall =3D=3D494586=3D=3D=20 =3D=3D494586=3D=3D For lists of detected and suppressed errors, rerun with:= -s =3D=3D494586=3D=3D ERROR SUMMARY: 5 errors from 5 contexts (suppressed: 0 f= rom 0) So that's still 14kB definitely lost, 500kB possibly lost.=