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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

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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
This commit is contained in:
Linus Torvalds
2019-07-11 15:30:05 -07:00
parent 1f7563f743 38195dd5e9
commit db0457338e
3 changed files with 8 additions and 14 deletions
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11
kernel/livepatch/transition.c
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@@ -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';
@@ -293,6 +292,13 @@ static bool klp_try_switch_task(struct task_struct *task)
if (task->patch_state == klp_target_state)
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
@@ -328,7 +334,6 @@ done:
pr_debug("%s", err_buf);
return success;
}
/*