Fix a few leaks in VG_(make_core_dump)

Probably not very critical, as very surely the process will die
shortly after, but better still clean the memory, as the code
was already doing some effort to free memory (e.g. VG_(free)(seg_starts);).

Note that when testing on debian 9/amd64, the resulting core dump
was not very usable (e.g. was not really showing what the guest threads
are doing). So, there must be a bug in the core dumping logic.

diff --git a/coregrind/m_coredump/coredump-elf.c b/coregrind/m_coredump/coredump-elf.c
index 647338ace96c71da67e9618a2cd6d43ea141fb13..b85196821b3ec900a3f967b3ceabcd9fba7743a3 100644 (file)
--- a/coregrind/m_coredump/coredump-elf.c
+++ b/coregrind/m_coredump/coredump-elf.c
@@ -580,14 +580,14 @@ void make_elf_coredump(ThreadId tid, const vki_siginfo_t *si, ULong max_size)
    Int core_fd;
    NSegment const * seg;
    ESZ(Ehdr) ehdr;
-   ESZ(Phdr) *phdrs;
+   ESZ(Phdr) *phdrs = NULL;
    Int num_phdrs;
    Int i, idx;
    UInt off;
    struct note *notelist, *note;
    UInt notesz;
    struct vki_elf_prpsinfo prpsinfo;
-   Addr *seg_starts;
+   Addr *seg_starts = NULL;
    Int n_seg_starts;
 
    if (VG_(clo_log_fname_unexpanded) != NULL) {
@@ -598,7 +598,7 @@ void make_elf_coredump(ThreadId tid, const vki_siginfo_t *si, ULong max_size)
 
    vg_assert(coreext);
    vg_assert(basename);
-   buf = VG_(malloc)( "coredump-elf.mec.1", 
+   buf = VG_(malloc)( "coredump-elf.mec.1",
                       VG_(strlen)(coreext) + VG_(strlen)(basename)
                          + 100/*for the two %ds. */ );
 
@@ -625,7 +625,7 @@ void make_elf_coredump(ThreadId tid, const vki_siginfo_t *si, ULong max_size)
       }
 
       if (sr_isError(sres) && sr_Err(sres) != VKI_EEXIST)
-        return;                /* can't create file */
+        goto cleanup; /* can't create file */
    }
 
    /* Get the client segments */
@@ -700,7 +700,7 @@ void make_elf_coredump(ThreadId tid, const vki_siginfo_t *si, ULong max_size)
 
       fill_phdr(&phdrs[idx], seg, off,
                 (seg->end - seg->start + 1 + off) < max_size);
-      
+
       off += phdrs[idx].p_filesz;
 
       idx++;
@@ -712,7 +712,7 @@ void make_elf_coredump(ThreadId tid, const vki_siginfo_t *si, ULong max_size)
 
    for(note = notelist; note != NULL; note = note->next)
       write_note(core_fd, note);
-   
+
    VG_(lseek)(core_fd, phdrs[1].p_offset, VKI_SEEK_SET);
 
    for(i = 0, idx = 1; i < n_seg_starts; i++) {
@@ -731,9 +731,14 @@ void make_elf_coredump(ThreadId tid, const vki_siginfo_t *si, ULong max_size)
       idx++;
    }
 
-   VG_(free)(seg_starts);
-
    VG_(close)(core_fd);
+
+ cleanup:
+   if (VG_(clo_log_fname_unexpanded) != NULL)
+      VG_(free)(basename);
+   VG_(free)(buf);
+   VG_(free)(seg_starts);
+   VG_(free)(phdrs);
 }
 
 void VG_(make_coredump)(ThreadId tid, const vki_siginfo_t *si, ULong max_size)