Hello Dave, On 5/12/20 6:36 PM, Dave Martin wrote: > Add the PR_SPEC_INDIRECT_BRANCH "misfeature" added in Linux 4.20 > for PR_SET_SPECULATION_CTRL and PR_GET_SPECULATION_CTRL. > > Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> > Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Thanks. Patch applied, but not yet pushed while I wait to see if any Review/Ack arrives. Also, could you please check the tweaks I note below. > --- > man2/prctl.2 | 24 ++++++++++++++++++------ > 1 file changed, 18 insertions(+), 6 deletions(-) > > diff --git a/man2/prctl.2 b/man2/prctl.2 > index e8eaf95..66417cf 100644 > --- a/man2/prctl.2 > +++ b/man2/prctl.2 > @@ -1213,11 +1213,20 @@ arguments must be specified as 0; otherwise the call fails with the error > .\" commit 356e4bfff2c5489e016fdb925adbf12a1e3950ee > Sets the state of the speculation misfeature specified in > .IR arg2 . > -Currently, the only permitted value for this argument is > +Currently, this argument must be one of: > +.RS > +.TP > .B PR_SPEC_STORE_BYPASS > -(otherwise the call fails with the error > +speculative store bypass control, or s/speculative/enable speculative/ > +.\" commit 9137bb27e60e554dab694eafa4cca241fa3a694f > +.TP > +.BR PR_SPEC_INDIRECT_BRANCH " (since Linux 4.20)" > +indirect branch speculation control. s/indirect/enable indirect/ > +.RE > +.IP > +(Otherwise the call fails with the error > .BR ENODEV ). > -This setting is a per-thread attribute. > +These settings are per-thread attributes. > The > .IR arg3 > argument is used to hand in the control value, > @@ -1235,13 +1244,16 @@ Same as > .BR PR_SPEC_DISABLE , > but cannot be undone. > A subsequent > -.B > -prctl(..., PR_SPEC_ENABLE) > +.BR prctl (\c > +.IR arg2 , > +.BR PR_SPEC_ENABLE ) > +with the same value for > +.I arg2 > will fail with the error > .BR EPERM . > .RE > .IP > -Any other value in > +Any unsupported value in > .IR arg3 > will result in the call failing with the error > .BR ERANGE . Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
