forked from luck/tmp_suning_uos_patched
e9d9df4473
When I review the sensitive code ftrace_nmi_enter(), I found the atomic variable nmi_running does protect NMI VS do_ftrace_mod_code(), but it can not protects NMI(entered nmi) VS NMI(ftrace_nmi_enter()). cpu#1 | cpu#2 | cpu#3 ftrace_nmi_enter() | do_ftrace_mod_code() | not modify | | ------------------------|-----------------------|-- executing | set mod_code_write = 1| executing --|-----------------------|-------------------- executing | | ftrace_nmi_enter() executing | | do modify ------------------------|-----------------------|----------------- ftrace_nmi_exit() | | cpu#3 may be being modified the code which is still being executed on cpu#1, it will have undefined results and possibly take a GPF, this patch prevents it occurred. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <49C0B411.30003@cn.fujitsu.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> |
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alpha | ||
arm | ||
avr32 | ||
blackfin | ||
cris | ||
frv | ||
h8300 | ||
ia64 | ||
m32r | ||
m68k | ||
m68knommu | ||
mips | ||
mn10300 | ||
parisc | ||
powerpc | ||
s390 | ||
sh | ||
sparc | ||
um | ||
x86 | ||
xtensa | ||
.gitignore | ||
Kconfig |