Re: [PATCH 02/14] prctl.2: Add health warning
From: Michael Kerrisk (man-pages) <hidden>
Date: 2020-05-13 10:10:38
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linux-arch, linux-man
Hi Dave, On 5/12/20 6:36 PM, Dave Martin wrote:
In reality, almost every prctl interferes with assumptions that the compiler and C library / runtime rely on. prctl() can therefore make userspace explode in a variety ways that are likely to be hard to debug. This is not obvious to the uninitiated, so add a warning.
Patch applied. But see my comments on patch 04. I may want to circle back on this patch later, since the wording feels a little strong to me (we simply must use prctl for some things, and not all of those things break user-space/runtime as far as I know). If you have some thoughts on softening the warning, let me know. Cheers, Michael
quoted hunk ↗ jump to hunk
Signed-off-by: Dave Martin <Dave.Martin@arm.com> --- man2/prctl.2 | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/man2/prctl.2 b/man2/prctl.2 index 7932ada..a35b748 100644 --- a/man2/prctl.2 +++ b/man2/prctl.2@@ -66,6 +66,11 @@ prctl \- operations on a process or thread manipulates various aspects of the behavior of the calling thread or process. .PP +Note that careless use of +.BR prctl () +can confuse the userspace run-time environment, +so these operations should be used with care (if at all). +.PP .BR prctl () is called with a first argument describing what to do (with values defined in \fI<linux/prctl.h>\fP), and further
-- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel