[Bug 1860610] [NEW] cap_disas_plugin leaks memory

[Bug 1860610] [NEW] cap_disas_plugin leaks memory

[Robert Henry]

Public bug reported:

Looking at origin/master head, the function cap_disas_plugin leaks
memory.

per capstone's examples using their ABI, cs_free(insn, count); needs to
called just before cs_close.

I discovered this running qemu under valgrind.

** Affects: qemu
     Importance: Undecided
         Status: New

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Title:
  cap_disas_plugin leaks memory

Status in QEMU:
  New

Bug description:
  Looking at origin/master head, the function cap_disas_plugin leaks
  memory.

  per capstone's examples using their ABI, cs_free(insn, count); needs
  to called just before cs_close.

  I discovered this running qemu under valgrind.

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[Bug 1860610] Re: cap_disas_plugin leaks memory

[Alex Bennée]

It looks like this will fail on all the other capstone cases as well. Is
this an API change across versions?

** Tags added: plugin tcg

** Changed in: qemu
     Assignee: (unassigned) => Alex Bennée (ajbennee)

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Title:
  cap_disas_plugin leaks memory

Status in QEMU:
  New

Bug description:
  Looking at origin/master head, the function cap_disas_plugin leaks
  memory.

  per capstone's examples using their ABI, cs_free(insn, count); needs
  to called just before cs_close.

  I discovered this running qemu under valgrind.

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[Bug 1860610] Re: cap_disas_plugin leaks memory

[Robert Henry]

I run git blame in the capstone repository, and cs_free has been around
for at least 4 years in the capstone ABI. I can not tell if the need to
call cs_free is a (new) requirement. Documentation capstone is a little
informal...

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Title:
  cap_disas_plugin leaks memory

Status in QEMU:
  New

Bug description:
  Looking at origin/master head, the function cap_disas_plugin leaks
  memory.

  per capstone's examples using their ABI, cs_free(insn, count); needs
  to called just before cs_close.

  I discovered this running qemu under valgrind.

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[Bug 1860610] Re: cap_disas_plugin leaks memory

[Alex Bennée]

What command line where you using? I've been unable to replicate the
valgrind warning with a riscv64-linux-user run of hello with the
libhowvec.so plugin. Valgrind does complain about a bunch of other stuff
though.

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Title:
  cap_disas_plugin leaks memory

Status in QEMU:
  New

Bug description:
  Looking at origin/master head, the function cap_disas_plugin leaks
  memory.

  per capstone's examples using their ABI, cs_free(insn, count); needs
  to called just before cs_close.

  I discovered this running qemu under valgrind.

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[Bug 1860610] Re: cap_disas_plugin leaks memory

[Alex Bennée]

Looking at the way disas is structured it seems cap_insn is allocated
once (per thread) and re-used for each disassembly so we shouldn't be
free'ing it after each usage. In fact the comments to cap_disas_start
imply we want to do better than re-initialising the library for every
set of instructions we disassemble.

It is true that we don't clean-up any of the disassembly machinery on
exit but the same can be said for a lot of QEMU's static state. So
currently I don't see a leak rather than a one-time allocation. Unless I
can reproduce the leak I'm going to mark this as incomplete for now.

** Changed in: qemu
       Status: New => Incomplete

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Title:
  cap_disas_plugin leaks memory

Status in QEMU:
  Incomplete

Bug description:
  Looking at origin/master head, the function cap_disas_plugin leaks
  memory.

  per capstone's examples using their ABI, cs_free(insn, count); needs
  to called just before cs_close.

  I discovered this running qemu under valgrind.

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[Bug 1860610] Re: cap_disas_plugin leaks memory

[Thomas Huth]

** Changed in: qemu
     Assignee: Alex Bennée (ajbennee) => (unassigned)

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Title:
  cap_disas_plugin leaks memory

Status in QEMU:
  Incomplete

Bug description:
  Looking at origin/master head, the function cap_disas_plugin leaks
  memory.

  per capstone's examples using their ABI, cs_free(insn, count); needs
  to called just before cs_close.

  I discovered this running qemu under valgrind.

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[Bug 1860610] Re: cap_disas_plugin leaks memory

[Launchpad Bug Tracker]

[Expired for QEMU because there has been no activity for 60 days.]

** Changed in: qemu
       Status: Incomplete => Expired

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Title:
  cap_disas_plugin leaks memory

Status in QEMU:
  Expired

Bug description:
  Looking at origin/master head, the function cap_disas_plugin leaks
  memory.

  per capstone's examples using their ABI, cs_free(insn, count); needs
  to called just before cs_close.

  I discovered this running qemu under valgrind.

To manage notifications about this bug go to:
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