diff options
| author | David S. Miller <davem@davemloft.net> | 2017-10-05 17:57:03 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-10-05 18:19:22 -0700 |
| commit | 53954cf8c5d205624167a2bfd117cc0c1a5f3c6d (patch) | |
| tree | a287f0c80eb616758bb5212523c8fb3d8fc350a4 /kernel/extable.c | |
| parent | 4b54db1375757aa3e870c075065a8ab9350d26c4 (diff) | |
| parent | 7a92616c0bac849e790283723b36c399668a1d9f (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Just simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/extable.c')
| -rw-r--r-- | kernel/extable.c | 45 |
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; } /* |