Re: [Crash-utility] [PATCH] x86_64: Fix check for __per_cpu_offset initialisation

-----Original Message----- > -----Original Message----- > > Since at least kernel v2.6.30 the __per_cpu_offset gets initialized to > > __per_cpu_load. So first check if the __per_cpu_offset was set to a > > proper value before reading any per cpu variable to prevent potential > > bugs. > > > > Signed-off-by: Philipp Rudo <prudo(a)redhat.com&gt; > > Thanks for the fix. > > Acked-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; > > Kazu > > > --- > > x86_64.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/x86_64.c b/x86_64.c > > index 6eb7d67..0bb8705 100644 > > --- a/x86_64.c > > +++ b/x86_64.c > > @@ -1327,6 +1327,8 @@ x86_64_per_cpu_init(void) > > ms->stkinfo.isize = 16384; > > > > for (i = cpus = 0; i < NR_CPUS; i++) { > > + if (kt->__per_cpu_offset[i] == symbol_value("__per_cpu_load")) > > + break; Rethought this, if __per_cpu_load is gone or renamed, crash cannot even start. This check is not essential, so I will modify both hunks as follows and apply.