Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1625785 > unrolled thread
| Started by | Li Qiang <liq3ea@gmail.com> |
|---|---|
| First post | 2017-04-19 04:00 +0200 |
| Last post | 2017-04-20 23:10 +0200 |
| Articles | 4 — 3 participants |
Back to article view | Back to linux.kernel
[PATCH] Documentation: DocBook: kgdb: update CONFIG_STRICT_KERNEL_RWX info Li Qiang <liq3ea@gmail.com> - 2017-04-19 04:00 +0200
Re: [PATCH] Documentation: DocBook: kgdb: update CONFIG_STRICT_KERNEL_RWX info Daniel Thompson <daniel.thompson@linaro.org> - 2017-04-20 17:30 +0200
Re: [PATCH] Documentation: DocBook: kgdb: update CONFIG_STRICT_KERNEL_RWX info Daniel Thompson <daniel.thompson@linaro.org> - 2017-04-21 11:30 +0200
Re: [PATCH] Documentation: DocBook: kgdb: update CONFIG_STRICT_KERNEL_RWX info Jonathan Corbet <corbet@lwn.net> - 2017-04-20 23:10 +0200
| From | Li Qiang <liq3ea@gmail.com> |
|---|---|
| Date | 2017-04-19 04:00 +0200 |
| Subject | [PATCH] Documentation: DocBook: kgdb: update CONFIG_STRICT_KERNEL_RWX info |
| Message-ID | <txN4u-5t3-3@gated-at.bofh.it> |
CONFIG_STRICT_KERNEL_RWX is no longer selectable on most architectures.
Update this info to the documentation.
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
---
Documentation/DocBook/kgdb.tmpl | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/Documentation/DocBook/kgdb.tmpl b/Documentation/DocBook/kgdb.tmpl
index 856ac20..ef0b67b 100644
--- a/Documentation/DocBook/kgdb.tmpl
+++ b/Documentation/DocBook/kgdb.tmpl
@@ -121,7 +121,9 @@
If kgdb supports it for the architecture you are using, you can
use hardware breakpoints if you desire to run with the
CONFIG_STRICT_KERNEL_RWX option turned on, else you need to turn off
- this option.
+ this option. In most architectures, this option is not selectable.
+ For this situation, it can be turned off by adding a runtime parameter
+ 'rodata=off'.
</para>
<para>
Next you should choose one of more I/O drivers to interconnect
--
2.7.4
[toc] | [next] | [standalone]
| From | Daniel Thompson <daniel.thompson@linaro.org> |
|---|---|
| Date | 2017-04-20 17:30 +0200 |
| Subject | Re: [PATCH] Documentation: DocBook: kgdb: update CONFIG_STRICT_KERNEL_RWX info |
| Message-ID | <tymbU-2cW-9@gated-at.bofh.it> |
| In reply to | #1625785 |
On 19/04/17 02:58, Li Qiang wrote: > CONFIG_STRICT_KERNEL_RWX is no longer selectable on most architectures. > Update this info to thedocumentation. "git grep STRICT_KERNEL_RWX" comes up with nothing. It is selectable on any architecture? If not we should remove it entirely! Daniel. > > Signed-off-by: Li Qiang <liqiang6-s@360.cn> > --- > Documentation/DocBook/kgdb.tmpl | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/Documentation/DocBook/kgdb.tmpl b/Documentation/DocBook/kgdb.tmpl > index 856ac20..ef0b67b 100644 > --- a/Documentation/DocBook/kgdb.tmpl > +++ b/Documentation/DocBook/kgdb.tmpl > @@ -121,7 +121,9 @@ > If kgdb supports it for the architecture you are using, you can > use hardware breakpoints if you desire to run with the > CONFIG_STRICT_KERNEL_RWX option turned on, else you need to turn off > - this option. > + this option. In most architectures, this option is not selectable. > + For this situation, it can be turned off by adding a runtime parameter > + 'rodata=off'. > </para> > <para> > Next you should choose one of more I/O drivers to interconnect >
[toc] | [prev] | [next] | [standalone]
| From | Daniel Thompson <daniel.thompson@linaro.org> |
|---|---|
| Date | 2017-04-21 11:30 +0200 |
| Subject | Re: [PATCH] Documentation: DocBook: kgdb: update CONFIG_STRICT_KERNEL_RWX info |
| Message-ID | <tyD34-45V-17@gated-at.bofh.it> |
| In reply to | #1627588 |
On 21/04/17 03:26, Li Qiang wrote: > > @Daniel > > 2017-04-20 23:28 GMT+08:00 Daniel Thompson <daniel.thompson@linaro.org > <mailto:daniel.thompson@linaro.org>>: > > On 19/04/17 02:58, Li Qiang wrote: > > CONFIG_STRICT_KERNEL_RWX is no longer selectable on most > architectures. > Update this info to thedocumentation. > > > "git grep STRICT_KERNEL_RWX" comes up with nothing. > > > It was introduced in commit 0f5bf6d0afe4be6e1391908ff2d6dc9730e91550. Oops. I did the grep on the wrong machine :-( and therefore on an older kernel than I thought... > It is selectable on any architecture? If not we should remove it > entirely! > > The 'STRICT_KERNEL_RWX' is renamed from 'CONFIG_DEBUG_RODATA > '. The original option is selectable. > > I'm not sure is this selectable on any architecture. So... having found the right kernel, it looks to me like only arm, arm64, parisc, s390 and x86 define ARCH_HAS_STRICT_KERNEL_RWX. Of these five, only arm defines ARCH_OPTIONAL_KERNEL_RWX and makes it user selectable. > > @Jonathan > > On Tue, 18 Apr 2017 18:58:45 -0700 > Li Qiang <liq3ea@gmail.com <mailto:liq3ea@gmail.com>> wrote: > > > CONFIG_STRICT_KERNEL_RWX is no longer selectable on most architectures. > > Update this info to the documentation. > > > > Signed-off-by: Li Qiang <liqiang6-s@360.cn <mailto:liqiang6-s@360.cn>> > > --- > > Documentation/DocBook/kgdb.tmpl | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/DocBook/kgdb.tmpl b/Documentation/DocBook/kgdb.tmpl > > index 856ac20..ef0b67b 100644 > > --- a/Documentation/DocBook/kgdb.tmpl > > +++ b/Documentation/DocBook/kgdb.tmpl > > @@ -121,7 +121,9 @@ > > If kgdb supports it for the architecture you are using, you can > > use hardware breakpoints if you desire to run with the > > CONFIG_STRICT_KERNEL_RWX option turned on, else you need to turn off > > - this option. > > + this option. In most architectures, this option is not selectable. > > + For this situation, it can be turned off by adding a runtime parameter > > + 'rodata=off'. > > So this is an improvement, I guess, though the paragraph remains kind of > confusing. Is there any chance we could actually just say which > architectures can use hardware breakpoints, and which should boot with > rodata=off? > > > I think this is unnecessary as it is not common to change the > default CONFIG_STRICT_KERNEL_RWX /add rodata=off. > We here give this hint because CONFIG_STRICT_KERNEL_RWX is renamed > from CONFIG_DEBUG_RODATA. > And the latter is selectable, this can help the peoples who > think CONFIG_STRICT_KERNEL_RWX is also selectable. Having looked at the earlier part of the paragraph I think the info about rodata actually needs to be introduced slightly earlier (and rodata should be presented as the primary way to do it because 4 of the 5 architectures don't make STRICT_KERNEL_RWX optional). Something like: If the architecture that you are using supports making the text section read-only (CONFIG_STRICT_KERNEL_RWX), you should consider turning it off by adding 'rodata=off' to the kernel commandline or, if your architecture makes CONFIG_STRICT_KERNEL_RWX optional, by disabling this config option. Alternatively, if your architecture supports hardware breakpoints, these can be used to provide limited breakpoint support if you desire to run with a read-only text section. Daniel.
[toc] | [prev] | [next] | [standalone]
| From | Jonathan Corbet <corbet@lwn.net> |
|---|---|
| Date | 2017-04-20 23:10 +0200 |
| Subject | Re: [PATCH] Documentation: DocBook: kgdb: update CONFIG_STRICT_KERNEL_RWX info |
| Message-ID | <tyruW-5v5-25@gated-at.bofh.it> |
| In reply to | #1625785 |
On Tue, 18 Apr 2017 18:58:45 -0700 Li Qiang <liq3ea@gmail.com> wrote: > CONFIG_STRICT_KERNEL_RWX is no longer selectable on most architectures. > Update this info to the documentation. > > Signed-off-by: Li Qiang <liqiang6-s@360.cn> > --- > Documentation/DocBook/kgdb.tmpl | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/Documentation/DocBook/kgdb.tmpl b/Documentation/DocBook/kgdb.tmpl > index 856ac20..ef0b67b 100644 > --- a/Documentation/DocBook/kgdb.tmpl > +++ b/Documentation/DocBook/kgdb.tmpl > @@ -121,7 +121,9 @@ > If kgdb supports it for the architecture you are using, you can > use hardware breakpoints if you desire to run with the > CONFIG_STRICT_KERNEL_RWX option turned on, else you need to turn off > - this option. > + this option. In most architectures, this option is not selectable. > + For this situation, it can be turned off by adding a runtime parameter > + 'rodata=off'. So this is an improvement, I guess, though the paragraph remains kind of confusing. Is there any chance we could actually just say which architectures can use hardware breakpoints, and which should boot with rodata=off? Thanks, jon
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web