From mboxrd@z Thu Jan 1 00:00:00 1970 From: Namhyung Kim Subject: Re: [PATCH] rtld-audit.7: tfix Date: Thu, 3 Dec 2015 10:03:55 +0900 Message-ID: <20151203010355.GA4554@sejong> References: <1446509897-21059-1-git-send-email-namhyung@gmail.com> <565F18F7.4060704@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Return-path: In-Reply-To: <565F18F7.4060704-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Content-Disposition: inline Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Michael Kerrisk (man-pages)" Cc: linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org Hi Michael, On Wed, Dec 02, 2015 at 05:14:47PM +0100, Michael Kerrisk (man-pages) wrote: > Hello Namhyung Kim, > > I need some explanation here. This is not a simple > typo fix, I believe. Why do you think the current text > is wrong? Actually la_pltenter() is called regardless of the value of framesizep but la_pltexit() is called only if la_pltenter() returns with non-zero framesizep set. I spent long time to figure out why la_pltexit() is not called at all. Quoting comments in glibc/sysdeps/x86_64/dl-trampoline.h: /* There's nothing in the frame size, so there will be no call to the _dl_call_pltexit. */ and /* At this point we need to prepare new stack for the function which has to be called. We copy the original stack to a temporary buffer of the size specified by the 'framesize' returned from _dl_profile_fixup */ I think it's because it needs to preserve 'inregs' to be passed to la_pltexit(). The _dl_profile_fixup() sets the '*framesizep' to maximum value of what la_pltenter() sets. Please see glibc/elf/dl-runtime.c file. Thanks, Namhyung > > On 11/03/2015 01:18 AM, Namhyung Kim wrote: > > Signed-off-by: Namhyung Kim > > --- > > man7/rtld-audit.7 | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/man7/rtld-audit.7 b/man7/rtld-audit.7 > > index d0f7563..643bc57 100644 > > --- a/man7/rtld-audit.7 > > +++ b/man7/rtld-audit.7 > > @@ -400,7 +400,7 @@ If different > > invocations for this symbol return different values, > > then the maximum returned value is used. > > The > > -.BR la_pltenter () > > +.BR la_pltexit () > > function is called only if this buffer is > > explicitly set to a suitable value. > > > > > > > -- > Michael Kerrisk > Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ > Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html