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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-11 15:30:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-11 15:30:05 -0700 |
| commit | db0457338ece7482378d88e50ad298191c3e6947 (patch) | |
| tree | 459378b5005622cdf9b3bccfb798229c20aa41a2 /kernel/livepatch | |
| parent | 1f7563f743d7081710a9d186a8b203997d09f383 (diff) | |
| parent | 38195dd5e916f3e55aec585703f2432562c2db02 (diff) | |
| download | linux-db0457338ece7482378d88e50ad298191c3e6947.tar.bz2 | |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching
Pull livepatching updates from Jiri Kosina:
- stacktrace handling improvements from Miroslav benes
- debug output improvements from Petr Mladek
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
livepatch: Remove duplicate warning about missing reliable stacktrace support
Revert "livepatch: Remove reliable stacktrace check in klp_try_switch_task()"
stacktrace: Remove weak version of save_stack_trace_tsk_reliable()
livepatch: Use static buffer for debugging messages under rq lock
livepatch: Remove stale kobj_added entries from kernel-doc descriptions
Diffstat (limited to 'kernel/livepatch')
| -rw-r--r-- | kernel/livepatch/transition.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index abb2a4a2cbb2..cdf318d86dd6 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -247,7 +247,6 @@ static int klp_check_stack(struct task_struct *task, char *err_buf) int ret, nr_entries; ret = stack_trace_save_tsk_reliable(task, entries, ARRAY_SIZE(entries)); - WARN_ON_ONCE(ret == -ENOSYS); if (ret < 0) { snprintf(err_buf, STACK_ERR_BUF_SIZE, "%s: %s:%d has an unreliable stack\n", @@ -281,11 +280,11 @@ static int klp_check_stack(struct task_struct *task, char *err_buf) */ static bool klp_try_switch_task(struct task_struct *task) { + static char err_buf[STACK_ERR_BUF_SIZE]; struct rq *rq; struct rq_flags flags; int ret; bool success = false; - char err_buf[STACK_ERR_BUF_SIZE]; err_buf[0] = '\0'; @@ -294,6 +293,13 @@ 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. @@ -328,7 +334,6 @@ done: pr_debug("%s", err_buf); return success; - } /* |