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authorLinus Torvalds <torvalds@linux-foundation.org>2017-12-18 19:59:15 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-12-18 19:59:15 +0300
commit64a48099b3b31568ac45716b7fafcb74a0c2fcfe (patch)
tree0652431aeb450bbfa74b9be8b7d813ac8511aec3 /arch/x86/power
parent1291a0d5049dbc06baaaf66a9ff3f53db493b19b (diff)
parent6cbd2171e89b13377261d15e64384df60ecb530e (diff)
downloadlinux-64a48099b3b31568ac45716b7fafcb74a0c2fcfe.tar.xz
Merge branch 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 syscall entry code changes for PTI from Ingo Molnar: "The main changes here are Andy Lutomirski's changes to switch the x86-64 entry code to use the 'per CPU entry trampoline stack'. This, besides helping fix KASLR leaks (the pending Page Table Isolation (PTI) work), also robustifies the x86 entry code" * 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) x86/cpufeatures: Make CPU bugs sticky x86/paravirt: Provide a way to check for hypervisors x86/paravirt: Dont patch flush_tlb_single x86/entry/64: Make cpu_entry_area.tss read-only x86/entry: Clean up the SYSENTER_stack code x86/entry/64: Remove the SYSENTER stack canary x86/entry/64: Move the IST stacks into struct cpu_entry_area x86/entry/64: Create a per-CPU SYSCALL entry trampoline x86/entry/64: Return to userspace from the trampoline stack x86/entry/64: Use a per-CPU trampoline stack for IDT entries x86/espfix/64: Stop assuming that pt_regs is on the entry stack x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0 x86/entry: Remap the TSS into the CPU entry area x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct x86/dumpstack: Handle stack overflow on all stacks x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss x86/kasan/64: Teach KASAN about the cpu_entry_area x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area x86/entry/gdt: Put per-CPU GDT remaps in ascending order x86/dumpstack: Add get_stack_info() support for the SYSENTER stack ...
Diffstat (limited to 'arch/x86/power')
-rw-r--r--arch/x86/power/cpu.c16
1 files changed, 9 insertions, 7 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 36a28eddb435..a7d966964c6f 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -152,17 +152,19 @@ static void do_fpu_end(void)
static void fix_processor_context(void)
{
int cpu = smp_processor_id();
- struct tss_struct *t = &per_cpu(cpu_tss, cpu);
#ifdef CONFIG_X86_64
struct desc_struct *desc = get_cpu_gdt_rw(cpu);
tss_desc tss;
#endif
- set_tss_desc(cpu, t); /*
- * This just modifies memory; should not be
- * necessary. But... This is necessary, because
- * 386 hardware has concept of busy TSS or some
- * similar stupidity.
- */
+
+ /*
+ * We need to reload TR, which requires that we change the
+ * GDT entry to indicate "available" first.
+ *
+ * XXX: This could probably all be replaced by a call to
+ * force_reload_TR().
+ */
+ set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
#ifdef CONFIG_X86_64
memcpy(&tss, &desc[GDT_ENTRY_TSS], sizeof(tss_desc));