Re: [PATCHv10 man-pages 5/5] execveat.2: initial man page for execveat(2)
From: Al Viro <hidden>
Date: 2015-01-09 21:09:48
Also in:
linux-arch, lkml, sparclinux
From: Al Viro <hidden>
Date: 2015-01-09 21:09:48
Also in:
linux-arch, lkml, sparclinux
On Fri, Jan 09, 2015 at 03:59:26PM -0500, Rich Felker wrote:
quoted
For fsck sake, folks, if you have bloody /proc, you don't need that shite at all! Just do execve on /proc/self/fd/n, and be done with that. The sole excuse for merging that thing in the first place had been "would anybody think of children^Wsclerotic^Whardened environments where they have no /proc at all".That doesn't work. With O_CLOEXEC, /proc/self/fd/n is already gone at the time the interpreter runs, whether you're using fexecveat or execve with "/proc/self/fd/n" to implement POSIX fexecve(). That's the problem. This breaks the intended idiom for fexecve.
Just what will your magical symlink do in case when the file is opened, unlinked and marked O_CLOEXEC? When should actual freeing of disk blocks, etc. happen? And no, you can't assume that interpreter will open the damn thing even once - there's nothing to oblige it to do so. Al, more and more tempted to ask reverting the whole thing - this hardcoded /dev/fd/... (in fs/exec.c, no less) is disgraceful enough, but threats of even more revolting kludges in the name of "intended idiom for fexecve"...