* [PATCH] seccomp_unotify.2: Add doc for SECCOMP_ADDFD_FLAG_SEND @ 2021-07-02 16:37 Rodrigo Campos 2021-07-03 21:25 ` Alejandro Colomar (man-pages) 0 siblings, 1 reply; 5+ messages in thread From: Rodrigo Campos @ 2021-07-02 16:37 UTC (permalink / raw) To: linux-man, Alejandro Colomar, Michael Kerrisk Cc: linux-kernel, Alban Crequy, Mauricio Vásquez Bernal, Sargun Dhillon, Rodrigo Campos This flag was recently added to Linux 5.14 by a patch I wrote: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ae71c7720e3ae3aabd2e8a072d27f7bd173d25c This patch adds documentation for the flag, the error code that the flag added and explains in the caveat when it is useful. Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io> --- Hi! Here goes the documentation for the flag I just added. Please feel free to amend as you want and let me know if something is not clear :) man2/seccomp_unotify.2 | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/man2/seccomp_unotify.2 b/man2/seccomp_unotify.2 index 2673d9bc7..9bd27214f 100644 --- a/man2/seccomp_unotify.2 +++ b/man2/seccomp_unotify.2 @@ -739,6 +739,17 @@ When allocating the file descriptor in the target, use the file descriptor number specified in the .I newfd field. +.TP +.BR SECCOMP_ADDFD_FLAG_SEND +Available since Linux 5.14, combines the +.B SECCOMP_IOCTL_NOTIF_ADDFD +ioctl with +.B SECCOMP_IOCTL_NOTIF_SEND +into an atomic operation. On successful invocation, the target process's +errno will be 0 and the return value will be the file descriptor number that was +installed in the target. If allocating the file descriptor in the tatget fails, +the target's syscall continues to be blocked until a successful response is +sent. .RE .TP .I srcfd @@ -801,6 +812,13 @@ Allocating the file descriptor in the target would cause the target's limit to be exceeded (see .BR getrlimit (2)). .TP +.B EBUSY +If the flag +.B SECCOMP_IOCTL_NOTIF_SEND +is used, this means the operation can't proceed until other +.B SECCOMP_IOCTL_NOTIF_ADDFD +requests are processed. +.TP .B EINPROGRESS The user-space notification specified in the .I id @@ -1131,6 +1149,14 @@ that would normally be restarted by the .BR SA_RESTART flag. +.PP +Furthermore, if the supervisor response is a file descriptor +added with +.B SECCOMP_IOCTL_NOTIF_ADDFD, +then the flag +.B SECCOMP_ADDFD_FLAG_SEND +can be used to atomically add the file descriptor and return that value, +making sure no file descriptors are inadvertently leaked into the target. .\" FIXME .\" About the above, Kees Cook commented: .\" -- 2.30.2 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] seccomp_unotify.2: Add doc for SECCOMP_ADDFD_FLAG_SEND 2021-07-02 16:37 [PATCH] seccomp_unotify.2: Add doc for SECCOMP_ADDFD_FLAG_SEND Rodrigo Campos @ 2021-07-03 21:25 ` Alejandro Colomar (man-pages) 2021-07-04 11:25 ` Alejandro Colomar (man-pages) 2021-07-05 10:11 ` Rodrigo Campos 0 siblings, 2 replies; 5+ messages in thread From: Alejandro Colomar (man-pages) @ 2021-07-03 21:25 UTC (permalink / raw) To: Rodrigo Campos Cc: linux-kernel, Alban Crequy, Mauricio Vásquez Bernal, Sargun Dhillon, linux-man, Michael Kerrisk Hi Rodrigo, On 7/2/21 6:37 PM, Rodrigo Campos wrote: > This flag was recently added to Linux 5.14 by a patch I wrote: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ae71c7720e3ae3aabd2e8a072d27f7bd173d25c > > This patch adds documentation for the flag, the error code that the flag > added and explains in the caveat when it is useful. > > Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io> > --- > Hi! Here goes the documentation for the flag I just added. Please feel free to > amend as you want and let me know if something is not clear :) Thanks for documenting your own addition! That makes things much easier :-) It looks quite good to me. There are a few minor changes that I applied in a following patch. I'll explain why in your patch inline. And then you have the diff below your patch. Cheers, Alex > > > man2/seccomp_unotify.2 | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/man2/seccomp_unotify.2 b/man2/seccomp_unotify.2 > index 2673d9bc7..9bd27214f 100644 > --- a/man2/seccomp_unotify.2 > +++ b/man2/seccomp_unotify.2 > @@ -739,6 +739,17 @@ When allocating the file descriptor in the target, > use the file descriptor number specified in the > .I newfd > field. > +.TP > +.BR SECCOMP_ADDFD_FLAG_SEND > +Available since Linux 5.14, combines the We usually append that info to the paragraph tag (i.e., the line just after .TP), and with a common syntax, so that it's easier to read.. > +.B SECCOMP_IOCTL_NOTIF_ADDFD > +ioctl with > +.B SECCOMP_IOCTL_NOTIF_SEND > +into an atomic operation. On successful invocation, the target process's > +errno will be 0 and the return value will be the file descriptor number that was > +installed in the target. If allocating the file descriptor in the tatget fails, > +the target's syscall continues to be blocked until a successful response is > +sent. See the following extract from man-pages(7): $ man 7 man-pages | sed -n '/Use semantic newlines/,/^$/p'; Use semantic newlines In the source of a manual page, new sentences should be started on new lines, and long sentences should split into lines at clause breaks (commas, semicolons, colons, and so on). This convention, sometimes known as "semantic new‐ lines", makes it easier to see the effect of patches, which often operate at the level of individual sentences or sen‐ tence clauses. > .RE > .TP > .I srcfd > @@ -801,6 +812,13 @@ Allocating the file descriptor in the target would cause the target's > limit to be exceeded (see > .BR getrlimit (2)). > .TP > +.B EBUSY > +If the flag > +.B SECCOMP_IOCTL_NOTIF_SEND > +is used, this means the operation can't proceed until other > +.B SECCOMP_IOCTL_NOTIF_ADDFD > +requests are processed. > +.TP > .B EINPROGRESS > The user-space notification specified in the > .I id > @@ -1131,6 +1149,14 @@ that would > normally be restarted by the > .BR SA_RESTART > flag. > +.PP > +Furthermore, if the supervisor response is a file descriptor > +added with > +.B SECCOMP_IOCTL_NOTIF_ADDFD, > +then the flag > +.B SECCOMP_ADDFD_FLAG_SEND > +can be used to atomically add the file descriptor and return that value, > +making sure no file descriptors are inadvertently leaked into the target. I moved your paragraph below the FIXME, as I the FIXME applies to the previous paragraph ("About the above"). > .\" FIXME > .\" About the above, Kees Cook commented: > .\" > diff --git a/man2/seccomp_unotify.2 b/man2/seccomp_unotify.2 index 9bd27214f..ae449ae36 100644 --- a/man2/seccomp_unotify.2 +++ b/man2/seccomp_unotify.2 @@ -740,16 +740,18 @@ use the file descriptor number specified in the .I newfd field. .TP -.BR SECCOMP_ADDFD_FLAG_SEND -Available since Linux 5.14, combines the +.BR SECCOMP_ADDFD_FLAG_SEND " (since Linux 5.14)" +Combines the .B SECCOMP_IOCTL_NOTIF_ADDFD ioctl with .B SECCOMP_IOCTL_NOTIF_SEND -into an atomic operation. On successful invocation, the target process's -errno will be 0 and the return value will be the file descriptor number that was -installed in the target. If allocating the file descriptor in the tatget fails, -the target's syscall continues to be blocked until a successful response is -sent. +into an atomic operation. +On successful invocation, the target process's errno will be 0 +and the return value will be the file descriptor number +that was installed in the target. +If allocating the file descriptor in the tatget fails, +the target's syscall continues to be blocked +until a successful response is sent. .RE .TP .I srcfd @@ -1149,14 +1151,6 @@ that would normally be restarted by the .BR SA_RESTART flag. -.PP -Furthermore, if the supervisor response is a file descriptor -added with -.B SECCOMP_IOCTL_NOTIF_ADDFD, -then the flag -.B SECCOMP_ADDFD_FLAG_SEND -can be used to atomically add the file descriptor and return that value, -making sure no file descriptors are inadvertently leaked into the target. .\" FIXME .\" About the above, Kees Cook commented: .\" @@ -1176,6 +1170,14 @@ making sure no file descriptors are inadvertently leaked into the target. .\" calls because it's impossible for the kernel to restart the call .\" with the right timeout value. I wonder what happens when those .\" system calls are restarted in the scenario we're discussing.) +.PP +Furthermore, if the supervisor response is a file descriptor +added with +.B SECCOMP_IOCTL_NOTIF_ADDFD, +then the flag +.B SECCOMP_ADDFD_FLAG_SEND +can be used to atomically add the file descriptor and return that value, +making sure no file descriptors are inadvertently leaked into the target. .SH BUGS If a .BR SECCOMP_IOCTL_NOTIF_RECV -- Alejandro Colomar Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/ http://www.alejandro-colomar.es/ ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] seccomp_unotify.2: Add doc for SECCOMP_ADDFD_FLAG_SEND 2021-07-03 21:25 ` Alejandro Colomar (man-pages) @ 2021-07-04 11:25 ` Alejandro Colomar (man-pages) 2021-07-05 10:12 ` Rodrigo Campos 2021-07-05 10:11 ` Rodrigo Campos 1 sibling, 1 reply; 5+ messages in thread From: Alejandro Colomar (man-pages) @ 2021-07-04 11:25 UTC (permalink / raw) To: Rodrigo Campos Cc: linux-kernel, Alban Crequy, Mauricio Vásquez Bernal, Sargun Dhillon, linux-man, Michael Kerrisk On 7/3/21 11:25 PM, Alejandro Colomar (man-pages) wrote: > Hi Rodrigo, > > On 7/2/21 6:37 PM, Rodrigo Campos wrote: >> This flag was recently added to Linux 5.14 by a patch I wrote: >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ae71c7720e3ae3aabd2e8a072d27f7bd173d25c >> >> This patch adds documentation for the flag, the error code that the flag >> added and explains in the caveat when it is useful. >> >> Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io> >> --- >> Hi! Here goes the documentation for the flag I just added. Please feel free to >> amend as you want and let me know if something is not clear :) > > Thanks for documenting your own addition! > That makes things much easier :-) > > It looks quite good to me. > > There are a few minor changes that I applied in a following patch. I'll > explain why in your patch inline. And then you have the diff below your And I meant: patch applied! Thanks, Alex > patch. > > Cheers, > > Alex > >> >> >> man2/seccomp_unotify.2 | 26 ++++++++++++++++++++++++++ >> 1 file changed, 26 insertions(+) >> >> diff --git a/man2/seccomp_unotify.2 b/man2/seccomp_unotify.2 >> index 2673d9bc7..9bd27214f 100644 >> --- a/man2/seccomp_unotify.2 >> +++ b/man2/seccomp_unotify.2 >> @@ -739,6 +739,17 @@ When allocating the file descriptor in the target, >> use the file descriptor number specified in the >> .I newfd >> field. >> +.TP >> +.BR SECCOMP_ADDFD_FLAG_SEND >> +Available since Linux 5.14, combines the > > We usually append that info to the paragraph tag (i.e., the line just > after .TP), and with a common syntax, so that it's easier to read.. > >> +.B SECCOMP_IOCTL_NOTIF_ADDFD >> +ioctl with >> +.B SECCOMP_IOCTL_NOTIF_SEND >> +into an atomic operation. On successful invocation, the target process's >> +errno will be 0 and the return value will be the file descriptor number that was >> +installed in the target. If allocating the file descriptor in the tatget fails, >> +the target's syscall continues to be blocked until a successful response is >> +sent. > > See the following extract from man-pages(7): > > $ man 7 man-pages | sed -n '/Use semantic newlines/,/^$/p'; > Use semantic newlines > In the source of a manual page, new sentences should be > started on new lines, and long sentences should split into > lines at clause breaks (commas, semicolons, colons, and so > on). This convention, sometimes known as "semantic new‐ > lines", makes it easier to see the effect of patches, which > often operate at the level of individual sentences or sen‐ > tence clauses. > >> .RE >> .TP >> .I srcfd >> @@ -801,6 +812,13 @@ Allocating the file descriptor in the target would cause the target's >> limit to be exceeded (see >> .BR getrlimit (2)). >> .TP >> +.B EBUSY >> +If the flag >> +.B SECCOMP_IOCTL_NOTIF_SEND >> +is used, this means the operation can't proceed until other >> +.B SECCOMP_IOCTL_NOTIF_ADDFD >> +requests are processed. >> +.TP >> .B EINPROGRESS >> The user-space notification specified in the >> .I id >> @@ -1131,6 +1149,14 @@ that would >> normally be restarted by the >> .BR SA_RESTART >> flag. >> +.PP >> +Furthermore, if the supervisor response is a file descriptor >> +added with >> +.B SECCOMP_IOCTL_NOTIF_ADDFD, >> +then the flag >> +.B SECCOMP_ADDFD_FLAG_SEND >> +can be used to atomically add the file descriptor and return that value, >> +making sure no file descriptors are inadvertently leaked into the target. > > I moved your paragraph below the FIXME, as I the FIXME applies to the > previous paragraph ("About the above"). > >> .\" FIXME >> .\" About the above, Kees Cook commented: >> .\" >> > > > diff --git a/man2/seccomp_unotify.2 b/man2/seccomp_unotify.2 > index 9bd27214f..ae449ae36 100644 > --- a/man2/seccomp_unotify.2 > +++ b/man2/seccomp_unotify.2 > @@ -740,16 +740,18 @@ use the file descriptor number specified in the > .I newfd > field. > .TP > -.BR SECCOMP_ADDFD_FLAG_SEND > -Available since Linux 5.14, combines the > +.BR SECCOMP_ADDFD_FLAG_SEND " (since Linux 5.14)" > +Combines the > .B SECCOMP_IOCTL_NOTIF_ADDFD > ioctl with > .B SECCOMP_IOCTL_NOTIF_SEND > -into an atomic operation. On successful invocation, the target process's > -errno will be 0 and the return value will be the file descriptor number > that was > -installed in the target. If allocating the file descriptor in the > tatget fails, > -the target's syscall continues to be blocked until a successful response is > -sent. > +into an atomic operation. > +On successful invocation, the target process's errno will be 0 > +and the return value will be the file descriptor number > +that was installed in the target. > +If allocating the file descriptor in the tatget fails, > +the target's syscall continues to be blocked > +until a successful response is sent. > .RE > .TP > .I srcfd > @@ -1149,14 +1151,6 @@ that would > normally be restarted by the > .BR SA_RESTART > flag. > -.PP > -Furthermore, if the supervisor response is a file descriptor > -added with > -.B SECCOMP_IOCTL_NOTIF_ADDFD, > -then the flag > -.B SECCOMP_ADDFD_FLAG_SEND > -can be used to atomically add the file descriptor and return that value, > -making sure no file descriptors are inadvertently leaked into the target. > .\" FIXME > .\" About the above, Kees Cook commented: > .\" > @@ -1176,6 +1170,14 @@ making sure no file descriptors are inadvertently > leaked into the target. > .\" calls because it's impossible for the kernel to restart the call > .\" with the right timeout value. I wonder what happens when those > .\" system calls are restarted in the scenario we're discussing.) > +.PP > +Furthermore, if the supervisor response is a file descriptor > +added with > +.B SECCOMP_IOCTL_NOTIF_ADDFD, > +then the flag > +.B SECCOMP_ADDFD_FLAG_SEND > +can be used to atomically add the file descriptor and return that value, > +making sure no file descriptors are inadvertently leaked into the target. > .SH BUGS > If a > .BR SECCOMP_IOCTL_NOTIF_RECV > > -- Alejandro Colomar Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/ http://www.alejandro-colomar.es/ ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] seccomp_unotify.2: Add doc for SECCOMP_ADDFD_FLAG_SEND 2021-07-04 11:25 ` Alejandro Colomar (man-pages) @ 2021-07-05 10:12 ` Rodrigo Campos 0 siblings, 0 replies; 5+ messages in thread From: Rodrigo Campos @ 2021-07-05 10:12 UTC (permalink / raw) To: Alejandro Colomar (man-pages) Cc: LKML, Alban Crequy, Mauricio Vásquez Bernal, Sargun Dhillon, linux-man, Michael Kerrisk On Sun, Jul 4, 2021 at 1:25 PM Alejandro Colomar (man-pages) <alx.manpages@gmail.com> wrote: > On 7/3/21 11:25 PM, Alejandro Colomar (man-pages) wrote: > > It looks quite good to me. > > > > There are a few minor changes that I applied in a following patch. I'll > > explain why in your patch inline. And then you have the diff below your > > And I meant: patch applied! Oh, thanks! Rodrigo Campos --- Kinvolk GmbH | Adalbertstr.6a, 10999 Berlin | tel: +491755589364 Geschäftsführer/Directors: Benjamin Owen Orndorff Registergericht/Court of registration: Amtsgericht Charlottenburg Registernummer/Registration number: HRB 171414 B Ust-ID-Nummer/VAT ID number: DE302207000 ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] seccomp_unotify.2: Add doc for SECCOMP_ADDFD_FLAG_SEND 2021-07-03 21:25 ` Alejandro Colomar (man-pages) 2021-07-04 11:25 ` Alejandro Colomar (man-pages) @ 2021-07-05 10:11 ` Rodrigo Campos 1 sibling, 0 replies; 5+ messages in thread From: Rodrigo Campos @ 2021-07-05 10:11 UTC (permalink / raw) To: Alejandro Colomar (man-pages) Cc: LKML, Alban Crequy, Mauricio Vásquez Bernal, Sargun Dhillon, linux-man, Michael Kerrisk On Sat, Jul 3, 2021 at 11:25 PM Alejandro Colomar (man-pages) <alx.manpages@gmail.com> wrote: > > Hi Rodrigo, > > On 7/2/21 6:37 PM, Rodrigo Campos wrote: > > This flag was recently added to Linux 5.14 by a patch I wrote: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ae71c7720e3ae3aabd2e8a072d27f7bd173d25c > > > > This patch adds documentation for the flag, the error code that the flag > > added and explains in the caveat when it is useful. > > > > Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io> > > --- > > Hi! Here goes the documentation for the flag I just added. Please feel free to > > amend as you want and let me know if something is not clear :) > > Thanks for documenting your own addition! > That makes things much easier :-) No problem, thank you! :) > > It looks quite good to me. Thanks! It helps to know that the explanation makes sense for others too :) > > There are a few minor changes that I applied in a following patch. I'll > explain why in your patch inline. And then you have the diff below your > patch. Thanks very much for the explanations, I will try to remember for the next time. And thanks for sending the patch here :) Best, Rodrigo Campos --- Kinvolk GmbH | Adalbertstr.6a, 10999 Berlin | tel: +491755589364 Geschäftsführer/Directors: Benjamin Owen Orndorff Registergericht/Court of registration: Amtsgericht Charlottenburg Registernummer/Registration number: HRB 171414 B Ust-ID-Nummer/VAT ID number: DE302207000 ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-07-05 10:13 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-07-02 16:37 [PATCH] seccomp_unotify.2: Add doc for SECCOMP_ADDFD_FLAG_SEND Rodrigo Campos 2021-07-03 21:25 ` Alejandro Colomar (man-pages) 2021-07-04 11:25 ` Alejandro Colomar (man-pages) 2021-07-05 10:12 ` Rodrigo Campos 2021-07-05 10:11 ` Rodrigo Campos
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