From: Linus Torvalds <torvalds@linux-foundation.org>
To: Rob Landley <rob@landley.net>
Cc: Jann Horn <jannh@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Hellwig <hch@lst.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
"Eric W . Biederman" <ebiederm@xmission.com>,
Oleg Nesterov <oleg@redhat.com>,
Russell King <linux@armlinux.org.uk>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Mark Salter <msalter@redhat.com>,
Aurelien Jacquiot <jacquiot.aurelien@gmail.com>,
linux-c6x-dev@linux-c6x.org,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Rich Felker <dalias@libc.org>,
Linux-sh list <linux-sh@vger.kernel.org>
Subject: Re: [PATCH 2/5] coredump: Fix handling of partial writes in dump_emit()
Date: Tue, 28 Apr 2020 09:40:21 -0700 [thread overview]
Message-ID: <CAHk-=wg2uw09tJMKTooQBr=AJPzzLTaq95b+SSS513Gm0gy5sw@mail.gmail.com> (raw)
In-Reply-To: <94141fbb-9559-1851-54c1-cdc5fc529a1a@landley.net>
On Tue, Apr 28, 2020 at 9:34 AM Rob Landley <rob@landley.net> wrote:
>
> Writes to a local filesystem should never be short unless disk full/error.
Well, that code is definitely supposed to also write to pipes.
But it also has "was I interrupted" logic, which stops the core dump.
So short writes can very much happen, it's just that they also imply
that the core dump should be aborted.
So the loop seems to be unnecessary. The situations where short writes
can happen are all the same situations where we want to abort anyway,
so the loop count should probably always be just one.
The same would go for any potential network filesystem with the
traditional NFS intr-like behavior.
Linus
next prev parent reply other threads:[~2020-04-28 16:40 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 3:27 [PATCH 0/5] Fix ELF / FDPIC ELF core dumping, and use mmap_sem properly in there Jann Horn
2020-04-28 3:27 ` [PATCH 1/5] binfmt_elf_fdpic: Stop using dump_emit() on user pointers on !MMU Jann Horn
2020-04-28 3:27 ` [PATCH 2/5] coredump: Fix handling of partial writes in dump_emit() Jann Horn
2020-04-28 3:35 ` Linus Torvalds
2020-04-28 5:52 ` Jann Horn
2020-04-28 16:40 ` Rob Landley
2020-04-28 16:40 ` Linus Torvalds [this message]
2020-04-28 3:27 ` [PATCH 3/5] coredump: Refactor page range dumping into common helper Jann Horn
2020-04-28 3:27 ` [PATCH 4/5] binfmt_elf, binfmt_elf_fdpic: Use a VMA list snapshot Jann Horn
2020-04-28 3:27 ` [PATCH 5/5] mm/gup: Take mmap_sem in get_dump_page() Jann Horn
2020-04-28 3:50 ` Linus Torvalds
2020-04-28 6:10 ` Jann Horn
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