Hello Eugene, I've applied this patch, and tweaked a few pieces, but need help on one point. On 11/20/2016 02:16 AM, Eugene Syromyatnikov wrote: > Changes since v2: > * Commit IDs from historic repositories removed. > * Note regarding intended purpose of PROT_SEM written up. > * Comment format changed to .\" > * "VMA" renamed to "mapping" > * Removed note regarding PROT_GROWS*. > > --- > man2/mprotect.2 | 63 +++++++++++++++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 55 insertions(+), 8 deletions(-) > > diff --git a/man2/mprotect.2 b/man2/mprotect.2 > index 440fa65..8f4c09f 100644 > --- a/man2/mprotect.2 > +++ b/man2/mprotect.2 > @@ -30,12 +30,6 @@ > .\" 2007-06-02, mtk: Fairly substantial rewrites and additions, and > .\" a much improved example program. > .\" > -.\" FIXME The following protection flags need documenting: > -.\" PROT_SEM > -.\" PROT_GROWSDOWN > -.\" PROT_GROWSUP > -.\" PROT_SAO (PowerPC) > -.\" > .TH MPROTECT 2 2015-07-23 "Linux" "Linux Programmer's Manual" > .SH NAME > mprotect, pkey_mprotect \- set protection on a region of memory > @@ -60,7 +54,7 @@ that violates the protection, then the kernel generates a > signal for the process. > .PP > .I prot > -is either > +is a combination of the following access flags: > .B PROT_NONE > or a bitwise-or of the other values in the following list: > .TP 1.1i > @@ -75,6 +69,40 @@ The memory can be modified. > .TP > .B PROT_EXEC > The memory can be executed. > +.TP > +.BR PROT_SEM " (since Linux 2.5.7)" > +The memory can be used for atomic operations. It was introduced as part of > +.BR futex (2) > +implementation (in order to guarantee ability to perform atomic > +operations required by its commands such as > +.BR FUTEX_WAIT ), > +but not actually used in any currently supported architecture so far. > +.\" aba46c5027cb59d98052231b36efcbbde9c77a1d ef3d3246a0d06be622867d21af25f997aeeb105f > +.TP > +.BR PROT_SAO " (since Linux 2.6.26)" > +The memory should have strong access ordering. This feature is specific to > +PowerPC architecture (version 2.06 of architecture specification adds SAO CPU > +feature, and it is available on POWER 7 or PowerPC A2, for example). > +.PP > +Additionally (since Linux 2.6.0), > +.I prot > +can have one of the following flags set: > +.TP 1.1i > +.\" mm/mmap.c: > +.\" vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | > +.\" mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; > +.\" And calc_vm_flag_bits converts only GROWSDOWN/DENYWRITE/LOCKED. > +.B PROT_GROWSUP > +Apply protection mode up to the end of the mapping which grows up (it should be a > +stack segment on HP PA-RISC, since there are no other ways to map a segment with > +.B VM_GROWSUP > +even if architecture has support for it.) We need a different way to talk about VM_GROWSUP, since that is a detail internal to the kernel. Do you have a suggestion? Cheers, Michael -- 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@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
