On Thu, Nov 06, 2014 at 08:39:07AM -0600, Seth Jennings wrote:
> This adds a new taint flag to indicate when the kernel or a kernel
> module has been live patched. This will provide a clean indication in
> bug reports that live patching was used.
>
> Additionally, if the crash occurs in a live patched function, the live
> patch module will appear beside the patched function in the backtrace.
>
> Signed-off-by: Seth Jennings <sjenning@xxxxxxxxxx>
> ---
> Documentation/oops-tracing.txt | 2 ++
> Documentation/sysctl/kernel.txt | 1 +
> include/linux/kernel.h | 1 +
> kernel/panic.c | 2 ++
> 4 files changed, 6 insertions(+)
>
> diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt
> index beefb9f..f3ac05c 100644
> --- a/Documentation/oops-tracing.txt
> +++ b/Documentation/oops-tracing.txt
> @@ -270,6 +270,8 @@ characters, each representing a particular tainted value.
>
> 15: 'L' if a soft lockup has previously occurred on the system.
>
> + 16: 'K' if the kernel has been live patched.
> +
> The primary reason for the 'Tainted: ' string is to tell kernel
> debuggers if this is a clean kernel or if anything unusual has
> occurred. Tainting is permanent: even if an offending module is
> diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
> index d7fc4ab..085f73b 100644
> --- a/Documentation/sysctl/kernel.txt
> +++ b/Documentation/sysctl/kernel.txt
> @@ -831,6 +831,7 @@ can be ORed together:
> 8192 - An unsigned module has been loaded in a kernel supporting module
> signature.
> 16384 - A soft lockup has previously occurred on the system.
> +32768 - The kernel has been live patched.
>
> ==============================================================
>
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index 446d76a..a6aa2df 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -473,6 +473,7 @@ extern enum system_states {
> #define TAINT_OOT_MODULE 12
> #define TAINT_UNSIGNED_MODULE 13
> #define TAINT_SOFTLOCKUP 14
> +#define TAINT_LIVEPATCH 15
>
> extern const char hex_asc[];
> #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
Note, this conflicts with a taint value that others are proposing for
something else, so be aware you might run into problems when you hit
linux-next.
thanks,
greg k-h
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