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| author | Miroslav Benes <mbenes@suse.cz> | 2019-06-11 16:13:19 +0200 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2019-06-20 16:08:41 +0200 |
| commit | 67059d65f7da537c41513fc52e78eff096092b8c (patch) | |
| tree | dfad02a0ea99db7a64df350cf8a1d803fc66a423 /kernel/livepatch | |
| parent | 380178ef7fde58f2040788a1bab972ce4867ac58 (diff) | |
| download | lwn-67059d65f7da537c41513fc52e78eff096092b8c.tar.gz lwn-67059d65f7da537c41513fc52e78eff096092b8c.zip | |
Revert "livepatch: Remove reliable stacktrace check in klp_try_switch_task()"
This reverts commit 1d98a69e5cef3aeb68bcefab0e67e342d6bb4dad. Commit
31adf2308f33 ("livepatch: Convert error about unsupported reliable
stacktrace into a warning") weakened the enforcement for architectures
to have reliable stack traces support. The system only warns now about
it.
It only makes sense to reintroduce the compile time checking in
klp_try_switch_task() again and bail out early.
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'kernel/livepatch')
| -rw-r--r-- | kernel/livepatch/transition.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index 0a3889c4f617..cb85dae09ce5 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -306,6 +306,13 @@ static bool klp_try_switch_task(struct task_struct *task) return true; /* + * For arches which don't have reliable stack traces, we have to rely + * on other methods (e.g., switching tasks at kernel exit). + */ + if (!klp_have_reliable_stack()) + return false; + + /* * Now try to check the stack for any to-be-patched or to-be-unpatched * functions. If all goes well, switch the task to the target patch * state. |