Commit e1d20bea authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 asm updates from Ingo Molnar:
 "The main changes in this cycle were the fsgsbase related preparatory
  patches from Chang S. Bae - but there's also an optimized
  memcpy_flushcache() and a cleanup for the __cmpxchg_double() assembly
  glue"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fsgsbase/64: Clean up various details
  x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
  x86/vdso: Initialize the CPU/node NR segment descriptor earlier
  x86/vdso: Introduce helper functions for CPU and node number
  x86/segments/64: Rename the GDT PER_CPU entry to CPU_NUMBER
  x86/fsgsbase/64: Factor out FS/GS segment loading from __switch_to()
  x86/fsgsbase/64: Convert the ELF core dump code to the new FSGSBASE helpers
  x86/fsgsbase/64: Make ptrace use the new FS/GS base helpers
  x86/fsgsbase/64: Introduce FS/GS base helper functions
  x86/fsgsbase/64: Fix ptrace() to read the FS/GS base accurately
  x86/asm: Use CC_SET()/CC_OUT() in __cmpxchg_double()
  x86/asm: Optimize memcpy_flushcache()
parents cbbfb0ae ec3a9418

arch/x86/entry/vdso/vgetcpu.c

+1 −7
Original line number Diff line number Diff line
@@ -13,14 +13,8 @@ 
notrace long

__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)

{

	unsigned int p;

	vdso_read_cpunode(cpu, node);



	p = __getcpu();



	if (cpu)

		*cpu = p & VGETCPU_CPU_MASK;

	if (node)

		*node = p >> 12;

	return 0;

}

arch/x86/entry/vdso/vma.c

+1 −37
Original line number Diff line number Diff line
@@ -332,40 +332,6 @@ static __init int vdso_setup(char *s) 
	return 0;

}

__setup("vdso=", vdso_setup);

#endif



#ifdef CONFIG_X86_64

static void vgetcpu_cpu_init(void *arg)

{

	int cpu = smp_processor_id();

	struct desc_struct d = { };

	unsigned long node = 0;

#ifdef CONFIG_NUMA

	node = cpu_to_node(cpu);

#endif

	if (static_cpu_has(X86_FEATURE_RDTSCP))

		write_rdtscp_aux((node << 12) | cpu);



	/*

	 * Store cpu number in limit so that it can be loaded

	 * quickly in user space in vgetcpu. (12 bits for the CPU

	 * and 8 bits for the node)

	 */

	d.limit0 = cpu | ((node & 0xf) << 12);

	d.limit1 = node >> 4;

	d.type = 5;		/* RO data, expand down, accessed */

	d.dpl = 3;		/* Visible to user code */

	d.s = 1;		/* Not a system segment */

	d.p = 1;		/* Present */

	d.d = 1;		/* 32-bit */



	write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);

}



static int vgetcpu_online(unsigned int cpu)

{

	return smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1);

}



static int __init init_vdso(void)

{
@@ -375,9 +341,7 @@ static int __init init_vdso(void) 
	init_vdso_image(&vdso_image_x32);

#endif



	/* notifier priority > KVM */

	return cpuhp_setup_state(CPUHP_AP_X86_VDSO_VMA_ONLINE,

				 "x86/vdso/vma:online", vgetcpu_online, NULL);

	return 0;

}

subsys_initcall(init_vdso);

#endif /* CONFIG_X86_64 */

arch/x86/include/asm/cmpxchg.h

+6 −4
Original line number Diff line number Diff line
@@ -242,10 +242,12 @@ extern void __add_wrong_size(void) 
	BUILD_BUG_ON(sizeof(*(p2)) != sizeof(long));			\

	VM_BUG_ON((unsigned long)(p1) % (2 * sizeof(long)));		\

	VM_BUG_ON((unsigned long)((p1) + 1) != (unsigned long)(p2));	\

	asm volatile(pfx "cmpxchg%c4b %2; sete %0"			\

		     : "=a" (__ret), "+d" (__old2),			\

		       "+m" (*(p1)), "+m" (*(p2))			\

		     : "i" (2 * sizeof(long)), "a" (__old1),		\

	asm volatile(pfx "cmpxchg%c5b %1"				\

		     CC_SET(e)						\

		     : CC_OUT(e) (__ret),				\

		       "+m" (*(p1)), "+m" (*(p2)),			\

		       "+a" (__old1), "+d" (__old2)			\

		     : "i" (2 * sizeof(long)),				\

		       "b" (__new1), "c" (__new2));			\

	__ret;								\

})

arch/x86/include/asm/elf.h

+3 −3
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <asm/ptrace.h>

#include <asm/user.h>

#include <asm/auxvec.h>

#include <asm/fsgsbase.h>



typedef unsigned long elf_greg_t;
@@ -204,7 +205,6 @@ void set_personality_ia32(bool); 


#define ELF_CORE_COPY_REGS(pr_reg, regs)			\

do {								\

	unsigned long base;					\

	unsigned v;						\

	(pr_reg)[0] = (regs)->r15;				\

	(pr_reg)[1] = (regs)->r14;				\
@@ -227,8 +227,8 @@ do { \ 
	(pr_reg)[18] = (regs)->flags;				\

	(pr_reg)[19] = (regs)->sp;				\

	(pr_reg)[20] = (regs)->ss;				\

	rdmsrl(MSR_FS_BASE, base); (pr_reg)[21] = base;		\

	rdmsrl(MSR_KERNEL_GS_BASE, base); (pr_reg)[22] = base;	\

	(pr_reg)[21] = x86_fsbase_read_cpu();			\

	(pr_reg)[22] = x86_gsbase_read_cpu_inactive();		\

	asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v;	\

	asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v;	\

	asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v;	\

arch/x86/include/asm/fsgsbase.h

0 → 100644
+49 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_FSGSBASE_H

#define _ASM_FSGSBASE_H



#ifndef __ASSEMBLY__



#ifdef CONFIG_X86_64



#include <asm/msr-index.h>



/*

 * Read/write a task's FSBASE or GSBASE. This returns the value that

 * the FS/GS base would have (if the task were to be resumed). These

 * work on the current task or on a non-running (typically stopped

 * ptrace child) task.

 */

extern unsigned long x86_fsbase_read_task(struct task_struct *task);

extern unsigned long x86_gsbase_read_task(struct task_struct *task);

extern int x86_fsbase_write_task(struct task_struct *task, unsigned long fsbase);

extern int x86_gsbase_write_task(struct task_struct *task, unsigned long gsbase);



/* Helper functions for reading/writing FS/GS base */



static inline unsigned long x86_fsbase_read_cpu(void)

{

	unsigned long fsbase;



	rdmsrl(MSR_FS_BASE, fsbase);



	return fsbase;

}



static inline unsigned long x86_gsbase_read_cpu_inactive(void)

{

	unsigned long gsbase;



	rdmsrl(MSR_KERNEL_GS_BASE, gsbase);



	return gsbase;

}



extern void x86_fsbase_write_cpu(unsigned long fsbase);

extern void x86_gsbase_write_cpu_inactive(unsigned long gsbase);



#endif /* CONFIG_X86_64 */



#endif /* __ASSEMBLY__ */



#endif /* _ASM_FSGSBASE_H */

CRA Git | Maintained and supported by SUSTech CRA and CCSE