[PATCH 1/2] Undo the split of setup_cpu_entry_area

From: Andy Lutomirski
Date: Sat Dec 02 2017 - 01:20:46 EST


This is obviously a hack. Either the patch should be adjusted back to
the version I sent or trap_init should forcibly initialize all PMDs
by something like __set_fixmap(..., __mkpte(0)); or however it's spelled.
---
arch/x86/kernel/smpboot.c | 2 ++
arch/x86/kernel/traps.c | 6 +++++-
2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 26317716559d..1325844b930a 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1232,8 +1232,10 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
* The boot CPU area has been set up in trap_init()
* already.
*/
+ /*
if (i)
setup_cpu_entry_area(i);
+ */
}

/*
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index ff4e6b595ae4..0ad92f35a75b 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -945,8 +945,12 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)

void __init trap_init(void)
{
+ int cpu;
/* Init cpu_entry_area before IST entries are set up */
- setup_cpu_entry_area(smp_processor_id());
+ for_each_possible_cpu(cpu) {
+ pr_err("setup_cpu_entry_area(%d)\n", cpu);
+ setup_cpu_entry_area(cpu);
+ }

idt_setup_traps();

--
2.13.6