https://github.com/torvalds/linux
Tip revision: dfd42facf1e4ada021b939b4e19c935dcdd55566 authored by Linus Torvalds on 06 February 2022, 20:20:50 UTC
Linux 5.17-rc3
Linux 5.17-rc3
Tip revision: dfd42fa
fpu_system.h
/* SPDX-License-Identifier: GPL-2.0 */
/*---------------------------------------------------------------------------+
| fpu_system.h |
| |
| Copyright (C) 1992,1994,1997 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail billm@suburbia.net |
| |
+---------------------------------------------------------------------------*/
#ifndef _FPU_SYSTEM_H
#define _FPU_SYSTEM_H
/* system dependent definitions */
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <asm/desc.h>
#include <asm/mmu_context.h>
static inline struct desc_struct FPU_get_ldt_descriptor(unsigned seg)
{
static struct desc_struct zero_desc;
struct desc_struct ret = zero_desc;
#ifdef CONFIG_MODIFY_LDT_SYSCALL
seg >>= 3;
mutex_lock(¤t->mm->context.lock);
if (current->mm->context.ldt && seg < current->mm->context.ldt->nr_entries)
ret = current->mm->context.ldt->entries[seg];
mutex_unlock(¤t->mm->context.lock);
#endif
return ret;
}
#define SEG_TYPE_WRITABLE (1U << 1)
#define SEG_TYPE_EXPANDS_DOWN (1U << 2)
#define SEG_TYPE_EXECUTE (1U << 3)
#define SEG_TYPE_EXPAND_MASK (SEG_TYPE_EXPANDS_DOWN | SEG_TYPE_EXECUTE)
#define SEG_TYPE_EXECUTE_MASK (SEG_TYPE_WRITABLE | SEG_TYPE_EXECUTE)
static inline unsigned long seg_get_base(struct desc_struct *d)
{
unsigned long base = (unsigned long)d->base2 << 24;
return base | ((unsigned long)d->base1 << 16) | d->base0;
}
static inline unsigned long seg_get_limit(struct desc_struct *d)
{
return ((unsigned long)d->limit1 << 16) | d->limit0;
}
static inline unsigned long seg_get_granularity(struct desc_struct *d)
{
return d->g ? 4096 : 1;
}
static inline bool seg_expands_down(struct desc_struct *d)
{
return (d->type & SEG_TYPE_EXPAND_MASK) == SEG_TYPE_EXPANDS_DOWN;
}
static inline bool seg_execute_only(struct desc_struct *d)
{
return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_EXECUTE;
}
static inline bool seg_writable(struct desc_struct *d)
{
return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_WRITABLE;
}
#define I387 (¤t->thread.fpu.fpstate->regs)
#define FPU_info (I387->soft.info)
#define FPU_CS (*(unsigned short *) &(FPU_info->regs->cs))
#define FPU_SS (*(unsigned short *) &(FPU_info->regs->ss))
#define FPU_DS (*(unsigned short *) &(FPU_info->regs->ds))
#define FPU_EAX (FPU_info->regs->ax)
#define FPU_EFLAGS (FPU_info->regs->flags)
#define FPU_EIP (FPU_info->regs->ip)
#define FPU_ORIG_EIP (FPU_info->___orig_eip)
#define FPU_lookahead (I387->soft.lookahead)
/* nz if ip_offset and cs_selector are not to be set for the current
instruction. */
#define no_ip_update (*(u_char *)&(I387->soft.no_update))
#define FPU_rm (*(u_char *)&(I387->soft.rm))
/* Number of bytes of data which can be legally accessed by the current
instruction. This only needs to hold a number <= 108, so a byte will do. */
#define access_limit (*(u_char *)&(I387->soft.alimit))
#define partial_status (I387->soft.swd)
#define control_word (I387->soft.cwd)
#define fpu_tag_word (I387->soft.twd)
#define registers (I387->soft.st_space)
#define top (I387->soft.ftop)
#define instruction_address (*(struct address *)&I387->soft.fip)
#define operand_address (*(struct address *)&I387->soft.foo)
#define FPU_access_ok(y,z) if ( !access_ok(y,z) ) \
math_abort(FPU_info,SIGSEGV)
#define FPU_abort math_abort(FPU_info, SIGSEGV)
#define FPU_copy_from_user(to, from, n) \
do { if (copy_from_user(to, from, n)) FPU_abort; } while (0)
#undef FPU_IGNORE_CODE_SEGV
#ifdef FPU_IGNORE_CODE_SEGV
/* access_ok() is very expensive, and causes the emulator to run
about 20% slower if applied to the code. Anyway, errors due to bad
code addresses should be much rarer than errors due to bad data
addresses. */
#define FPU_code_access_ok(z)
#else
/* A simpler test than access_ok() can probably be done for
FPU_code_access_ok() because the only possible error is to step
past the upper boundary of a legal code area. */
#define FPU_code_access_ok(z) FPU_access_ok((void __user *)FPU_EIP,z)
#endif
#define FPU_get_user(x,y) do { if (get_user((x),(y))) FPU_abort; } while (0)
#define FPU_put_user(x,y) do { if (put_user((x),(y))) FPU_abort; } while (0)
#endif