[PATCH] Add ability to override kernel release check

[PATCH] Add ability to override kernel release check

[Nikolay Borisov]

From: Nikolay Borisov <n.borisov@siteground.com>

In some situation it might be useful to disable checking the
kernel release. This happens when a kernel module is being rebuilt
and then probed. Without this override one has to reboot the machine
with the new kernel (and module) and then use systemtap.

To rectify the situation add a new define STP_NO_VERREL_CHECK,
which disables the relevant code in the resulting systemtap module.

This can be used with the following syntax: 
stap -DSTP_NO_VERREL_CHECK script.stp

Signed-off-by: Nikolay Borisov <n.borisov@siteground.com>
---
 translate.cxx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/translate.cxx b/translate.cxx
index 489bd2e2de1a..f792343e0cae 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -1728,6 +1728,7 @@ c_unparser::emit_module_init ()
       // run a probe compiled for a different version.  Catch this early,
       // just in case modversions didn't.
       o->newline() << "{";
+      o->newline() << "#ifndef STP_NO_VERREL_CHECK";
       o->newline(1) << "const char* release = UTS_RELEASE;";
       o->newline() << "#ifdef STAPCONF_GENERATED_COMPILE";
       o->newline() << "const char* version = UTS_VERSION;";
@@ -1762,6 +1763,7 @@ c_unparser::emit_module_init ()
       o->newline() << "rc = -EINVAL;";
       o->newline(-1) << "}";
       o->newline() << "#endif";
+      o->newline() << "#endif";
 
       // perform buildid-based checking if able
       o->newline() << "if (_stp_module_check()) rc = -EINVAL;";
-- 
2.5.0

Re: [PATCH] Add ability to override kernel release check

[Nikolay Borisov]

On 09/29/2016 04:14 PM, Nikolay Borisov wrote:
> From: Nikolay Borisov <n.borisov@siteground.com>
> 
> In some situation it might be useful to disable checking the
> kernel release. This happens when a kernel module is being rebuilt
> and then probed. Without this override one has to reboot the machine
> with the new kernel (and module) and then use systemtap.
> 
> To rectify the situation add a new define STP_NO_VERREL_CHECK,
> which disables the relevant code in the resulting systemtap module.
> 
> This can be used with the following syntax: 
> stap -DSTP_NO_VERREL_CHECK script.stp
> 
> Signed-off-by: Nikolay Borisov <n.borisov@siteground.com>
> ---
>  translate.cxx | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/translate.cxx b/translate.cxx
> index 489bd2e2de1a..f792343e0cae 100644
> --- a/translate.cxx
> +++ b/translate.cxx
> @@ -1728,6 +1728,7 @@ c_unparser::emit_module_init ()
>        // run a probe compiled for a different version.  Catch this early,
>        // just in case modversions didn't.
>        o->newline() << "{";
> +      o->newline() << "#ifndef STP_NO_VERREL_CHECK";
>        o->newline(1) << "const char* release = UTS_RELEASE;";
>        o->newline() << "#ifdef STAPCONF_GENERATED_COMPILE";
>        o->newline() << "const char* version = UTS_VERSION;";
> @@ -1762,6 +1763,7 @@ c_unparser::emit_module_init ()
>        o->newline() << "rc = -EINVAL;";
>        o->newline(-1) << "}";
>        o->newline() << "#endif";
> +      o->newline() << "#endif";
>  
>        // perform buildid-based checking if able
>        o->newline() << "if (_stp_module_check()) rc = -EINVAL;";
> 

Please ignore, that was clearly an error... silly me :(