From: Simon Marchi <simark@simark.ca>
To: Kamil Rytarowski <kamil@netbsd.org>, gdb-patches@sourceware.org
Cc: tom@tromey.com
Subject: Re: [PATCH v2 08/10] Avoid double free in startup_inferior
Date: Mon, 7 Sep 2020 22:21:49 -0400 [thread overview]
Message-ID: <ae7ef6ea-4b26-bfea-8375-e3ad54d409a4@simark.ca> (raw)
In-Reply-To: <0a7f8dbb-a48f-0fc9-77f8-a03c2efe3444@netbsd.org>
On 2020-09-07 8:54 p.m., Kamil Rytarowski wrote:
> On 07.09.2020 21:19, Simon Marchi wrote:
>> On 2020-09-03 8:29 p.m., Kamil Rytarowski wrote:
>>> Do not free the last execd pathname as it will be used in
>>> prepare_resume_reply(), after attaching a client side.
>>
>> Ok, so this function returns to its caller the last waitstatus. So indeed we
>> want to clean up all the watstatus objects except the last one, which we hand
>> over to the caller.
>>
>>> gdb/ChangeLog:
>>>
>>> * fork-inferior.c (startup_inferior): Avoid double free.
>>> ---
>>> gdb/ChangeLog | 4 ++++
>>> gdb/nat/fork-inferior.c | 5 ++++-
>>> 2 files changed, 8 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
>>> index b96e7bf08e8..1013f6a0b3c 100644
>>> --- a/gdb/ChangeLog
>>> +++ b/gdb/ChangeLog
>>> @@ -1,3 +1,7 @@
>>> +2020-09-04 Kamil Rytarowski <n54@gmx.com>
>>> +
>>> + * fork-inferior.c (startup_inferior): Avoid double free.
>>> +
>>> 2020-09-04 Kamil Rytarowski <n54@gmx.com>
>>>
>>> * netbsd-nat.h (netbsd_nat::qxfer_siginfo): Add.
>>> diff --git a/gdb/nat/fork-inferior.c b/gdb/nat/fork-inferior.c
>>> index 1185ef8998b..94ab0b9cbc2 100644
>>> --- a/gdb/nat/fork-inferior.c
>>> +++ b/gdb/nat/fork-inferior.c
>>> @@ -526,7 +526,10 @@ startup_inferior (process_stratum_target *proc_target, pid_t pid, int ntraps,
>>>
>>> case TARGET_WAITKIND_EXECD:
>>> /* Handle EXEC signals as if they were SIGTRAP signals. */
>>> - xfree (ws.value.execd_pathname);
>>> + /* Do not free the last execd pathname as it will be used in
>>> + prepare_resume_reply(), after attaching a client side. */
>>
>> Since this is common code, let's just write it in a gdbserver or gdb agnostic way.
>>
>> I'd suggest something like: Free the exec'ed pathname, but only if this isn't the
>> waitstatus we are returning to the caller.
>>
>
> Please be more specific how to fix.
Sorry, I just meant "write the comment in a gdbserver of gdb agnostic way". In particular,
don't mention prepare_resume_reply, which is gdbserver-specific (whereas the code is shared.
I suggest using the phrasing above for the comment.
Simon
next prev parent reply other threads:[~2020-09-08 2:21 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-04 0:28 [PATCH v2 00/10] Add minimal NetBSD/amd64 gdbserver support Kamil Rytarowski
2020-09-04 0:28 ` [PATCH v2 01/10] Add handle_eintr to wrap EINTR handling in syscalls Kamil Rytarowski
2020-09-07 14:06 ` Simon Marchi
2020-09-07 14:59 ` Kamil Rytarowski
2020-10-12 17:56 ` [PATCH] gdb::handle_eintr, remove need to specify return type (Re: [PATCH v2 01/10] Add handle_eintr to wrap EINTR handling in syscalls) Pedro Alves
2020-10-13 13:43 ` Kamil Rytarowski
2020-10-13 14:17 ` [PATCH v2] gdb::handle_eintr, remove need to specify return type Pedro Alves
2020-10-13 14:54 ` Kamil Rytarowski
2020-10-16 20:51 ` Tom Tromey
2020-10-26 14:00 ` Pedro Alves
2020-10-26 14:20 ` Tom Tromey
2020-10-26 18:59 ` Pedro Alves
2020-09-04 0:28 ` [PATCH v2 02/10] Register a placeholder for NetBSD shared functions in gdb/nat Kamil Rytarowski
2020-09-07 18:44 ` Simon Marchi
2020-09-07 19:49 ` Kamil Rytarowski
2020-09-04 0:28 ` [PATCH v2 03/10] Build nat/netbsd-nat.o for the NetBSD native target Kamil Rytarowski
2020-09-04 0:28 ` [PATCH v2 04/10] Add netbsd_nat::pid_to_exec_file Kamil Rytarowski
2020-09-07 7:57 ` Andrew Burgess
2020-09-07 13:36 ` Kamil Rytarowski
2020-09-07 18:48 ` Simon Marchi
2020-09-07 18:47 ` Simon Marchi
2020-09-07 19:51 ` Kamil Rytarowski
2020-09-04 0:29 ` [PATCH v2 05/10] Add gdb/nat common functions for listing threads Kamil Rytarowski
2020-09-07 18:59 ` Simon Marchi
2020-09-07 19:57 ` Kamil Rytarowski
2020-09-04 0:29 ` [PATCH v2 06/10] Add netbsd_nat::enable_proc_events in gdb/nat Kamil Rytarowski
2020-09-04 0:29 ` [PATCH v2 07/10] Add a common utility function to read and write siginfo_t in inferior Kamil Rytarowski
2020-09-04 0:29 ` [PATCH v2 08/10] Avoid double free in startup_inferior Kamil Rytarowski
2020-09-07 19:19 ` Simon Marchi
2020-09-08 0:54 ` Kamil Rytarowski
2020-09-08 2:21 ` Simon Marchi [this message]
2020-09-04 0:29 ` [PATCH v2 09/10] Switch local native code to gdb/nat shared functions Kamil Rytarowski
2020-09-07 19:24 ` Simon Marchi
2020-09-08 0:04 ` Kamil Rytarowski
2020-09-04 0:29 ` [PATCH v2 10/10] Add minimal and functional NetBSD/amd64 gdbserver Kamil Rytarowski
2020-09-07 19:58 ` Simon Marchi
2020-09-08 0:03 ` Kamil Rytarowski
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