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-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)
102 102
103int __kernel_text_address(unsigned long addr) 103int __kernel_text_address(unsigned long addr)
104{ 104{
105 if (core_kernel_text(addr)) 105 if (kernel_text_address(addr))
106 return 1;
107 if (is_module_text_address(addr))
108 return 1;
109 if (is_ftrace_trampoline(addr))
110 return 1;
111 if (is_kprobe_optinsn_slot(addr) || is_kprobe_insn_slot(addr))
112 return 1;
113 if (is_bpf_text_address(addr))
114 return 1; 106 return 1;
115 /* 107 /*
116 * There might be init symbols in saved stacktraces. 108 * There might be init symbols in saved stacktraces.
@@ -127,17 +119,42 @@ int __kernel_text_address(unsigned long addr)
127 119
128int kernel_text_address(unsigned long addr) 120int kernel_text_address(unsigned long addr)
129{ 121{
122 bool no_rcu;
123 int ret = 1;
124
130 if (core_kernel_text(addr)) 125 if (core_kernel_text(addr))
131 return 1; 126 return 1;
127
128 /*
129 * If a stack dump happens while RCU is not watching, then
130 * RCU needs to be notified that it requires to start
131 * watching again. This can happen either by tracing that
132 * triggers a stack trace, or a WARN() that happens during
133 * coming back from idle, or cpu on or offlining.
134 *
135 * is_module_text_address() as well as the kprobe slots
136 * and is_bpf_text_address() require RCU to be watching.
137 */
138 no_rcu = !rcu_is_watching();
139
140 /* Treat this like an NMI as it can happen anywhere */
141 if (no_rcu)
142 rcu_nmi_enter();
143
132 if (is_module_text_address(addr)) 144 if (is_module_text_address(addr))
133 return 1; 145 goto out;
134 if (is_ftrace_trampoline(addr)) 146 if (is_ftrace_trampoline(addr))
135 return 1; 147 goto out;
136 if (is_kprobe_optinsn_slot(addr) || is_kprobe_insn_slot(addr)) 148 if (is_kprobe_optinsn_slot(addr) || is_kprobe_insn_slot(addr))
137 return 1; 149 goto out;
138 if (is_bpf_text_address(addr)) 150 if (is_bpf_text_address(addr))
139 return 1; 151 goto out;
140 return 0; 152 ret = 0;
153out:
154 if (no_rcu)
155 rcu_nmi_exit();
156
157 return ret;
141} 158}
142 159
143/* 160/*