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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-01 18:41:02 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-01 18:41:02 +0200 |
commit | aa5ff93523ebc9f4cfd9fb37d021b5204ce14657 (patch) | |
tree | fb32c9e5ae708888d9a56066f994975dab68191b /kernel | |
parent | Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/... (diff) | |
parent | ftrace: Move RCU is watching check after recursion check (diff) | |
download | linux-aa5ff93523ebc9f4cfd9fb37d021b5204ce14657.tar.xz linux-aa5ff93523ebc9f4cfd9fb37d021b5204ce14657.zip |
Merge tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Two tracing fixes:
- Fix temp buffer accounting that caused a WARNING for
ftrace_dump_on_opps()
- Move the recursion check in one of the function callback helpers to
the beginning of the function, as if the rcu_is_watching() gets
traced, it will cause a recursive loop that will crash the kernel"
* tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Move RCU is watching check after recursion check
tracing: Fix trace_find_next_entry() accounting of temp buffer size
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/trace/ftrace.c | 6 | ||||
-rw-r--r-- | kernel/trace/trace.c | 10 |
2 files changed, 8 insertions, 8 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 603255f5f085..541453927c82 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6993,16 +6993,14 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, { int bit; - if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching()) - return; - bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); if (bit < 0) return; preempt_disable_notrace(); - op->func(ip, parent_ip, op, regs); + if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) + op->func(ip, parent_ip, op, regs); preempt_enable_notrace(); trace_clear_recursion(bit); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2a7c26345e83..d3e5de717df2 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3546,13 +3546,15 @@ struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, if (iter->ent && iter->ent != iter->temp) { if ((!iter->temp || iter->temp_size < iter->ent_size) && !WARN_ON_ONCE(iter->temp == static_temp_buf)) { - kfree(iter->temp); - iter->temp = kmalloc(iter->ent_size, GFP_KERNEL); - if (!iter->temp) + void *temp; + temp = kmalloc(iter->ent_size, GFP_KERNEL); + if (!temp) return NULL; + kfree(iter->temp); + iter->temp = temp; + iter->temp_size = iter->ent_size; } memcpy(iter->temp, iter->ent, iter->ent_size); - iter->temp_size = iter->ent_size; iter->ent = iter->temp; } entry = __find_next_entry(iter, ent_cpu, NULL, ent_ts); |