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authorThomas Gleixner <tglx@linutronix.de>2017-10-12 11:02:50 +0200
committerThomas Gleixner <tglx@linutronix.de>2017-10-12 11:02:50 +0200
commit331b57d14829c49d75076779cdc54d7e4537bbf0 (patch)
tree79a70eadb04ed2fd65d3280021ec6ad5266d1cc1 /kernel/extable.c
parent79761ce80aa0232157e428bde28c0cef6d43ac5f (diff)
parente43b3b58548051f8809391eb7bec7a27ed3003ea (diff)
Merge branch 'irq/urgent' into x86/apic
Pick up core changes which affect the vector rework.
Diffstat (limited to 'kernel/extable.c')
-rw-r--r--kernel/extable.c45
1 files changed, 31 insertions, 14 deletions
diff --git a/kernel/extable.c b/kernel/extable.c
index 38c2412401a1..9aa1cc41ecf7 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -102,15 +102,7 @@ int core_kernel_data(unsigned long addr)
int __kernel_text_address(unsigned long addr)
{
- if (core_kernel_text(addr))
- return 1;
- if (is_module_text_address(addr))
- return 1;
- if (is_ftrace_trampoline(addr))
- return 1;
- if (is_kprobe_optinsn_slot(addr) || is_kprobe_insn_slot(addr))
- return 1;
- if (is_bpf_text_address(addr))
+ if (kernel_text_address(addr))
return 1;
/*
* There might be init symbols in saved stacktraces.
@@ -127,17 +119,42 @@ int __kernel_text_address(unsigned long addr)
int kernel_text_address(unsigned long addr)
{
+ bool no_rcu;
+ int ret = 1;
+
if (core_kernel_text(addr))
return 1;
+
+ /*
+ * If a stack dump happens while RCU is not watching, then
+ * RCU needs to be notified that it requires to start
+ * watching again. This can happen either by tracing that
+ * triggers a stack trace, or a WARN() that happens during
+ * coming back from idle, or cpu on or offlining.
+ *
+ * is_module_text_address() as well as the kprobe slots
+ * and is_bpf_text_address() require RCU to be watching.
+ */
+ no_rcu = !rcu_is_watching();
+
+ /* Treat this like an NMI as it can happen anywhere */
+ if (no_rcu)
+ rcu_nmi_enter();
+
if (is_module_text_address(addr))
- return 1;
+ goto out;
if (is_ftrace_trampoline(addr))
- return 1;
+ goto out;
if (is_kprobe_optinsn_slot(addr) || is_kprobe_insn_slot(addr))
- return 1;
+ goto out;
if (is_bpf_text_address(addr))
- return 1;
- return 0;
+ goto out;
+ ret = 0;
+out:
+ if (no_rcu)
+ rcu_nmi_exit();
+
+ return ret;
}
/*