diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2019-04-14 17:59:53 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2019-04-17 14:29:22 +0200 |
| commit | f6ef73224a0f0400c3979c8bc68b383f9d2eb9d8 (patch) | |
| tree | 9399fc608cd864db80370ba7e3bb0547b9f7708f /arch/x86/kernel/cpu/common.c | |
| parent | afcd21dad88b68d646e91ed36948117d58b4c197 (diff) | |
x86/cpu: Prepare TSS.IST setup for guard pages
Convert the TSS.IST setup code to use the cpu entry area information
directly instead of assuming a linear mapping of the IST stacks.
The store to orig_ist[] is no longer required as there are no users
anymore.
This is the last preparatory step towards IST guard pages.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160145.061686012@linutronix.de
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 35 |
1 files changed, 7 insertions, 28 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 24b801ea7522..4b01b71415f5 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -507,19 +507,6 @@ void load_percpu_segment(int cpu) DEFINE_PER_CPU(struct cpu_entry_area *, cpu_entry_area); #endif -#ifdef CONFIG_X86_64 -/* - * Special IST stacks which the CPU switches to when it calls - * an IST-marked descriptor entry. Up to 7 stacks (hardware - * limit), all of them are 4K, except the debug stack which - * is 8K. - */ -static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = { - [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, - [ESTACK_DB] = DEBUG_STKSZ -}; -#endif - /* Load the original GDT from the per-cpu structure */ void load_direct_gdt(int cpu) { @@ -1690,17 +1677,14 @@ static void setup_getcpu(int cpu) * initialized (naturally) in the bootstrap process, such as the GDT * and IDT. We reload them nevertheless, this function acts as a * 'CPU state barrier', nothing should get across. - * A lot of state is already set up in PDA init for 64 bit */ #ifdef CONFIG_X86_64 void cpu_init(void) { - struct orig_ist *oist; + int cpu = raw_smp_processor_id(); struct task_struct *me; struct tss_struct *t; - unsigned long v; - int cpu = raw_smp_processor_id(); int i; wait_for_master_cpu(cpu); @@ -1715,7 +1699,6 @@ void cpu_init(void) load_ucode_ap(); t = &per_cpu(cpu_tss_rw, cpu); - oist = &per_cpu(orig_ist, cpu); #ifdef CONFIG_NUMA if (this_cpu_read(numa_node) == 0 && @@ -1753,16 +1736,12 @@ void cpu_init(void) /* * set up and load the per-CPU TSS */ - if (!oist->ist[0]) { - char *estacks = (char *)&get_cpu_entry_area(cpu)->estacks; - - for (v = 0; v < N_EXCEPTION_STACKS; v++) { - estacks += exception_stack_sizes[v]; - oist->ist[v] = t->x86_tss.ist[v] = - (unsigned long)estacks; - if (v == ESTACK_DB) - per_cpu(debug_stack_addr, cpu) = (unsigned long)estacks; - } + if (!t->x86_tss.ist[0]) { + t->x86_tss.ist[ESTACK_DF] = __this_cpu_ist_top_va(DF); + t->x86_tss.ist[ESTACK_NMI] = __this_cpu_ist_top_va(NMI); + t->x86_tss.ist[ESTACK_DB] = __this_cpu_ist_top_va(DB); + t->x86_tss.ist[ESTACK_MCE] = __this_cpu_ist_top_va(MCE); + per_cpu(debug_stack_addr, cpu) = t->x86_tss.ist[ESTACK_DB]; } t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET; |