From: Gonglei <arei.gonglei@huawei.com>
To: Eric Blake <eblake@redhat.com>
Cc: "kwolf@redhat.com" <kwolf@redhat.com>,
"Huangweidong (C)" <weidong.huang@huawei.com>,
Zhanghailiang <zhang.zhanghailiang@huawei.com>,
"qemu-trivial@nongnu.org" <qemu-trivial@nongnu.org>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"stefanha@redhat.com" <stefanha@redhat.com>,
"pbonzini@redhat.com" <pbonzini@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] oslib-posix: change free to g_free
Date: Sat, 11 Oct 2014 11:32:50 +0800 [thread overview]
Message-ID: <5438A4E2.4090007@huawei.com> (raw)
In-Reply-To: <5438A349.9090403@redhat.com>
On 2014/10/11 11:26, Eric Blake wrote:
> On 10/10/2014 09:21 PM, Gonglei wrote:
>
>>
>> Actually, I had noted that C standard says it is a no-operation.
>> But that doesn't mean that every C-library handles it like that.
>
> EVERY libc that is C89 compliant handles it like that. The last
> platform that failed on free(NULL) was SunOS 4, which is such
> museum-ware it's not funny. There is no need to cater to platforms from
> 25 years ago.
>
OK.Thanks for explanation!
>> Some people saw crashes for free(NULL), so it's best to avoid
>> calling the free in the first place (caller) or using g_free() in qemu_vfree().
>
> Absolutely not. g_free is unsafe to use except for pointers from
> g_malloc, which is NOT the case that qemu_vfree is used on.
>
Got it, thanks :)
But why some callers make a check,
but some other callers don't do this check?
Can I consider those check is superfluous?
-Best regards,
-Gonglei
next prev parent reply other threads:[~2014-10-11 3:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-11 2:54 [Qemu-devel] [PATCH] oslib-posix: change free to g_free arei.gonglei
2014-10-11 3:10 ` zhanghailiang
2014-10-11 3:21 ` Gonglei
2014-10-11 3:26 ` Eric Blake
2014-10-11 3:32 ` Gonglei [this message]
2014-10-11 3:44 ` Eric Blake
2014-10-11 3:47 ` Gonglei
2014-10-11 3:23 ` Eric Blake
2014-10-12 7:44 ` Kevin Wolf
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