Re: [Crash-utility] [PATCH 2/2] Fix for memory leaks

----- Original Message ----- > Without this patch, the storage reserved with the call > to strdup won't be freed. Did you even test this patch? It causes this: $ patch -p1 < /tmp/leaks.patch patching file configure.c Hunk #1 succeeded at 768 (offset 64 lines). Hunk #2 succeeded at 1723 (offset 75 lines). $ make *** glibc detected *** ./configure: munmap_chunk(): invalid pointer: 0x0000000000404e50 *** ======= Backtrace: ========= /lib64/libc.so.6[0x3e43e7ae16] ./configure[0x401e77] ./configure[0x400edd] /lib64/libc.so.6(__libc_start_main+0xf5)[0x3e43e21735] ./configure[0x400d89] ======= Memory map: ======== 00400000-00407000 r-xp 00000000 fd:01 167898 /var/CVS/crash-7.1.0/configure 00607000-00608000 rw-p 00007000 fd:01 167898 /var/CVS/crash-7.1.0/configure 0184e000-0186f000 rw-p 00000000 00:00 0 [heap] 3e43a00000-3e43a20000 r-xp 00000000 fd:01 1836136 /usr/lib64/ld-2.15.so 3e43c1f000-3e43c20000 r--p 0001f000 fd:01 1836136 /usr/lib64/ld-2.15.so 3e43c20000-3e43c21000 rw-p 00020000 fd:01 1836136 /usr/lib64/ld-2.15.so 3e43c21000-3e43c22000 rw-p 00000000 00:00 0 3e43e00000-3e43fac000 r-xp 00000000 fd:01 1836137 /usr/lib64/libc-2.15.so 3e43fac000-3e441ac000 ---p 001ac000 fd:01 1836137 /usr/lib64/libc-2.15.so 3e441ac000-3e441b0000 r--p 001ac000 fd:01 1836137 /usr/lib64/libc-2.15.so 3e441b0000-3e441b2000 rw-p 001b0000 fd:01 1836137 /usr/lib64/libc-2.15.so 3e441b2000-3e441b7000 rw-p 00000000 00:00 0 3e46a00000-3e46a15000 r-xp 00000000 fd:01 1853385 /usr/lib64/libgcc_s-4.7.2-20120921.so.1 3e46a15000-3e46c14000 ---p 00015000 fd:01 1853385 /usr/lib64/libgcc_s-4.7.2-20120921.so.1 3e46c14000-3e46c15000 rw-p 00014000 fd:01 1853385 /usr/lib64/libgcc_s-4.7.2-20120921.so.1 7ff116e8b000-7ff116e8e000 rw-p 00000000 00:00 0 7ff116ea7000-7ff116eab000 rw-p 00000000 00:00 0 7fff84a52000-7fff84a73000 rw-p 00000000 00:00 0 [stack] 7fff84b0c000-7fff84b0e000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] make: *** [all] Aborted (core dumped) $ It crashes because gdb_conf_flags is initialized to one of several possible built-in strings before it is passed to get_extra_flags(): void build_configure(struct supported_gdb_version *sp) { FILE *fp1, *fp2; char buf[512]; char *target; char *target_CFLAGS; char *gdb_conf_flags; char *ldflags; char *cflags; get_current_configuration(sp); target = target_CFLAGS = NULL; gdb_conf_flags = GDB_TARGET_DEFAULT; ... [ cut ] ... or it may be set to one of these: gdb_conf_flags = GDB_TARGET_X86_ON_X86_64; gdb_conf_flags = GDB_TARGET_PPC_ON_PPC64; gdb_conf_flags = GDB_TARGET_PPC64_ON_X86_64; gdb_conf_flags = GDB_TARGET_ARM_ON_X86; gdb_conf_flags = GDB_TARGET_ARM_ON_X86_64; gdb_conf_flags = GDB_TARGET_ARM64_ON_X86_64; gdb_conf_flags = GDB_TARGET_MIPS_ON_X86; gdb_conf_flags = GDB_TARGET_MIPS_ON_X86_64; ... [ cut ] ... gdb_conf_flags = get_extra_flags("GDBFLAGS.extra", gdb_conf_flags); And in the normal case where "GDBFLAGS.extra" does not exist, the hardwired string is passed back, and then the crash occurs when your patch tries to free it: char * get_extra_flags(char *filename, char *initial) { FILE *fp; char inbuf[512]; char buf[512]; if (!file_exists(filename)) return (initial ? initial : NULL); ... Since configure.c simply runs and exits immediately when "make" is entered, it's hard to qualify these as serious memory leaks. They fall more under the category of "who cares?".

Dave > > Signed-off-by: Wei,Jiangang <weijg.fnst(a)cn.fujitsu.com&gt; > --- > configure.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/configure.c b/configure.c > index 77ac81d..f78ad61 100755 > --- a/configure.c > +++ b/configure.c > @@ -704,6 +704,10 @@ build_configure(struct supported_gdb_version *sp) > > } > > + free(ldflags); > + free(cflags); > + free(gdb_conf_flags); > + > makefile_create(&fp1, &fp2); > show_configuration(); > make_build_data(&target[strlen("TARGET=")]); > @@ -1644,6 +1648,9 @@ add_extra_lib(char *option) > add_lsnappy++; > } > > + free(ldflags); > + free(cflags); > + > if ((lzo || snappy) && > file_exists("diskdump.o") && (unlink("diskdump.o") < 0)) { > perror("diskdump.o"); > -- > 1.9.3 > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility > -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility