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x86/entry/64: Pass SP0 directly to load_sp0() 

load_sp0() had an odd signature:

  void load_sp0(struct tss_struct *tss, struct thread_struct *thread);

Simplify it to:

  void load_sp0(unsigned long sp0);

Also simplify a few get_cpu()/put_cpu() sequences to
preempt_disable()/preempt_enable().

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2655d8b42ed940aa384fe18ee1129bbbcf730a08.1509609304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2017-11-02 00:59:10 -07:00 committed by Ingo Molnar
parent bd7dc5a6af
commit da51da189a
8 changed files with 20 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/x86/include/asm/paravirt.h
View File

@ -15,10 +15,9 @@
#include <linux/cpumask.h>
#include <asm/frame.h>
static inline void load_sp0(struct tss_struct *tss,
struct thread_struct *thread)
static inline void load_sp0(unsigned long sp0)
{
PVOP_VCALL2(pv_cpu_ops.load_sp0, tss, thread);
PVOP_VCALL1(pv_cpu_ops.load_sp0, sp0);
}
/* The paravirtualized CPUID instruction. */

2
arch/x86/include/asm/paravirt_types.h
View File

@ -133,7 +133,7 @@ struct pv_cpu_ops {
void (*alloc_ldt)(struct desc_struct *ldt, unsigned entries);
void (*free_ldt)(struct desc_struct *ldt, unsigned entries);
void (*load_sp0)(struct tss_struct *tss, struct thread_struct *t);
void (*load_sp0)(unsigned long sp0);
void (*set_iopl_mask)(unsigned mask);

9
arch/x86/include/asm/processor.h
View File

@ -517,9 +517,9 @@ static inline void native_set_iopl_mask(unsigned mask)
}
static inline void
native_load_sp0(struct tss_struct *tss, struct thread_struct *thread)
native_load_sp0(unsigned long sp0)
{
tss->x86_tss.sp0 = thread->sp0;
this_cpu_write(cpu_tss.x86_tss.sp0, sp0);
}
static inline void native_swapgs(void)
@ -544,10 +544,9 @@ static inline unsigned long current_top_of_stack(void)
#else
#define __cpuid native_cpuid
static inline void load_sp0(struct tss_struct *tss,
struct thread_struct *thread)
static inline void load_sp0(unsigned long sp0)
{
native_load_sp0(tss, thread);
native_load_sp0(sp0);
}
#define set_iopl_mask native_set_iopl_mask

4
arch/x86/kernel/cpu/common.c
View File

@ -1570,7 +1570,7 @@ void cpu_init(void)
initialize_tlbstate_and_flush();
enter_lazy_tlb(&init_mm, me);
load_sp0(t, &current->thread);
load_sp0(current->thread.sp0);
set_tss_desc(cpu, t);
load_TR_desc();
load_mm_ldt(&init_mm);
@ -1625,7 +1625,7 @@ void cpu_init(void)
initialize_tlbstate_and_flush();
enter_lazy_tlb(&init_mm, curr);
load_sp0(t, thread);
load_sp0(thread->sp0);
set_tss_desc(cpu, t);
load_TR_desc();
load_mm_ldt(&init_mm);

2
arch/x86/kernel/process_32.c
View File

@ -287,7 +287,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
* current_thread_info(). Refresh the SYSENTER configuration in
* case prev or next is vm86.
*/
load_sp0(tss, next);
load_sp0(next->sp0);
refresh_sysenter_cs(next);
this_cpu_write(cpu_current_top_of_stack,
(unsigned long)task_stack_page(next_p) +

2
arch/x86/kernel/process_64.c
View File

@ -465,7 +465,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
this_cpu_write(current_task, next_p);
/* Reload sp0. */
load_sp0(tss, next);
load_sp0(next->sp0);
/*
* Now maybe reload the debug registers and handle I/O bitmaps

14
arch/x86/kernel/vm86_32.c
View File

@ -94,7 +94,6 @@
void save_v86_state(struct kernel_vm86_regs *regs, int retval)
{
struct tss_struct *tss;
struct task_struct *tsk = current;
struct vm86plus_struct __user *user;
struct vm86 *vm86 = current->thread.vm86;
@ -146,13 +145,13 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval)
do_exit(SIGSEGV);
}
tss = &per_cpu(cpu_tss, get_cpu());
preempt_disable();
tsk->thread.sp0 = vm86->saved_sp0;
tsk->thread.sysenter_cs = __KERNEL_CS;
load_sp0(tss, &tsk->thread);
load_sp0(tsk->thread.sp0);
refresh_sysenter_cs(&tsk->thread);
vm86->saved_sp0 = 0;
put_cpu();
preempt_enable();
memcpy(&regs->pt, &vm86->regs32, sizeof(struct pt_regs));
@ -238,7 +237,6 @@ SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg)
static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
{
struct tss_struct *tss;
struct task_struct *tsk = current;
struct vm86 *vm86 = tsk->thread.vm86;
struct kernel_vm86_regs vm86regs;
@ -366,8 +364,8 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
vm86->saved_sp0 = tsk->thread.sp0;
lazy_save_gs(vm86->regs32.gs);
tss = &per_cpu(cpu_tss, get_cpu());
/* make room for real-mode segments */
preempt_disable();
tsk->thread.sp0 += 16;
if (static_cpu_has(X86_FEATURE_SEP)) {
@ -375,8 +373,8 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
refresh_sysenter_cs(&tsk->thread);
}
load_sp0(tss, &tsk->thread);
put_cpu();
load_sp0(tsk->thread.sp0);
preempt_enable();
if (vm86->flags & VM86_SCREEN_BITMAP)
mark_screen_rdonly(tsk->mm);

7
arch/x86/xen/enlighten_pv.c
View File

@ -810,15 +810,14 @@ static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
}
}
static void xen_load_sp0(struct tss_struct *tss,
struct thread_struct *thread)
static void xen_load_sp0(unsigned long sp0)
{
struct multicall_space mcs;
mcs = xen_mc_entry(0);
MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
MULTI_stack_switch(mcs.mc, __KERNEL_DS, sp0);
xen_mc_issue(PARAVIRT_LAZY_CPU);
tss->x86_tss.sp0 = thread->sp0;
this_cpu_write(cpu_tss.x86_tss.sp0, sp0);
}
void xen_set_iopl_mask(unsigned mask)