cregit-Linux how code gets into the kernel

Release 4.14 arch/x86/math-emu/load_store.c

// SPDX-License-Identifier: GPL-2.0
/*---------------------------------------------------------------------------+
 |  load_store.c                                                             |
 |                                                                           |
 | This file contains most of the code to interpret the FPU instructions     |
 | which load and store from user memory.                                    |
 |                                                                           |
 | Copyright (C) 1992,1993,1994,1997                                         |
 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
 |                       Australia.  E-mail   billm@suburbia.net             |
 |                                                                           |
 |                                                                           |
 +---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------+
 | Note:                                                                     |
 |    The file contains code which accesses user memory.                     |
 |    Emulator static data may change when user memory is accessed, due to   |
 |    other processes using the emulator while swapping is in progress.      |
 +---------------------------------------------------------------------------*/

#include <linux/uaccess.h>

#include "fpu_system.h"
#include "exception.h"
#include "fpu_emu.h"
#include "status_w.h"
#include "control_w.h"


#define _NONE_ 0		
/* st0_ptr etc not needed */

#define _REG0_ 1		
/* Will be storing st(0) */

#define _PUSH_ 3		
/* Need to check for space to push onto stack */

#define _null_ 4		
/* Function illegal or not implemented */


#define pop_0()	{ FPU_settag0(TAG_Empty); top++; }

/* index is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */

static u_char const type_table[32] = {
	_PUSH_, _PUSH_, _PUSH_, _PUSH_, /* /0: d9:fld f32,  db:fild m32,  dd:fld f64,  df:fild m16 */
	_null_, _REG0_, _REG0_, _REG0_, /* /1: d9:undef,    db,dd,df:fisttp m32/64/16 */
	_REG0_, _REG0_, _REG0_, _REG0_, /* /2: d9:fst f32,  db:fist m32,  dd:fst f64,  df:fist m16 */
	_REG0_, _REG0_, _REG0_, _REG0_, /* /3: d9:fstp f32, db:fistp m32, dd:fstp f64, df:fistp m16 */
	_NONE_, _null_, _NONE_, _PUSH_,
	_NONE_, _PUSH_, _null_, _PUSH_,
	_NONE_, _null_, _NONE_, _REG0_,
	_NONE_, _REG0_, _NONE_, _REG0_
};


u_char const data_sizes_16[32] = {
	4, 4, 8, 2,
	0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */
	4, 4, 8, 2,
	4, 4, 8, 2,
	14, 0, 94, 10, 2, 10, 0, 8,
	14, 0, 94, 10, 2, 10, 2, 8
};


static u_char const data_sizes_32[32] = {
	4, 4, 8, 2,
	0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */
	4, 4, 8, 2,
	4, 4, 8, 2,
	28, 0, 108, 10, 2, 10, 0, 8,
	28, 0, 108, 10, 2, 10, 2, 8
};


int FPU_load_store(u_char type, fpu_addr_modes addr_modes, void __user * data_address) { FPU_REG loaded_data; FPU_REG *st0_ptr; u_char st0_tag = TAG_Empty; /* This is just to stop a gcc warning. */ u_char loaded_tag; int sv_cw; st0_ptr = NULL; /* Initialized just to stop compiler warnings. */ if (addr_modes.default_mode & PROTECTED) { if (addr_modes.default_mode == SEG32) { if (access_limit < data_sizes_32[type]) math_abort(FPU_info, SIGSEGV); } else if (addr_modes.default_mode == PM16) { if (access_limit < data_sizes_16[type]) math_abort(FPU_info, SIGSEGV); } #ifdef PARANOID else EXCEPTION(EX_INTERNAL | 0x140); #endif /* PARANOID */ } switch (type_table[type]) { case _NONE_: break; case _REG0_: st0_ptr = &st(0); /* Some of these instructions pop after storing */ st0_tag = FPU_gettag0(); break; case _PUSH_: { if (FPU_gettagi(-1) != TAG_Empty) { FPU_stack_overflow(); return 0; } top--; st0_ptr = &st(0); } break; case _null_: FPU_illegal(); return 0; #ifdef PARANOID default: EXCEPTION(EX_INTERNAL | 0x141); return 0; #endif /* PARANOID */ } switch (type) { /* type is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */ case 000: /* fld m32real (d9 /0) */ clear_C1(); loaded_tag = FPU_load_single((float __user *)data_address, &loaded_data); if ((loaded_tag == TAG_Special) && isNaN(&loaded_data) && (real_1op_NaN(&loaded_data) < 0)) { top++; break; } FPU_copy_to_reg0(&loaded_data, loaded_tag); break; case 001: /* fild m32int (db /0) */ clear_C1(); loaded_tag = FPU_load_int32((long __user *)data_address, &loaded_data); FPU_copy_to_reg0(&loaded_data, loaded_tag); break; case 002: /* fld m64real (dd /0) */ clear_C1(); loaded_tag = FPU_load_double((double __user *)data_address, &loaded_data); if ((loaded_tag == TAG_Special) && isNaN(&loaded_data) && (real_1op_NaN(&loaded_data) < 0)) { top++; break; } FPU_copy_to_reg0(&loaded_data, loaded_tag); break; case 003: /* fild m16int (df /0) */ clear_C1(); loaded_tag = FPU_load_int16((short __user *)data_address, &loaded_data); FPU_copy_to_reg0(&loaded_data, loaded_tag); break; /* case 004: undefined (d9 /1) */ /* fisttp are enabled if CPUID(1).ECX(0) "sse3" is set */ case 005: /* fisttp m32int (db /1) */ clear_C1(); sv_cw = control_word; control_word |= RC_CHOP; if (FPU_store_int32 (st0_ptr, st0_tag, (long __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ control_word = sv_cw; break; case 006: /* fisttp m64int (dd /1) */ clear_C1(); sv_cw = control_word; control_word |= RC_CHOP; if (FPU_store_int64 (st0_ptr, st0_tag, (long long __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ control_word = sv_cw; break; case 007: /* fisttp m16int (df /1) */ clear_C1(); sv_cw = control_word; control_word |= RC_CHOP; if (FPU_store_int16 (st0_ptr, st0_tag, (short __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ control_word = sv_cw; break; case 010: /* fst m32real */ clear_C1(); FPU_store_single(st0_ptr, st0_tag, (float __user *)data_address); break; case 011: /* fist m32int */ clear_C1(); FPU_store_int32(st0_ptr, st0_tag, (long __user *)data_address); break; case 012: /* fst m64real */ clear_C1(); FPU_store_double(st0_ptr, st0_tag, (double __user *)data_address); break; case 013: /* fist m16int */ clear_C1(); FPU_store_int16(st0_ptr, st0_tag, (short __user *)data_address); break; case 014: /* fstp m32real */ clear_C1(); if (FPU_store_single (st0_ptr, st0_tag, (float __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ break; case 015: /* fistp m32int */ clear_C1(); if (FPU_store_int32 (st0_ptr, st0_tag, (long __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ break; case 016: /* fstp m64real */ clear_C1(); if (FPU_store_double (st0_ptr, st0_tag, (double __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ break; case 017: /* fistp m16int */ clear_C1(); if (FPU_store_int16 (st0_ptr, st0_tag, (short __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ break; case 020: /* fldenv m14/28byte */ fldenv(addr_modes, (u_char __user *) data_address); /* Ensure that the values just loaded are not changed by fix-up operations. */ return 1; case 022: /* frstor m94/108byte */ frstor(addr_modes, (u_char __user *) data_address); /* Ensure that the values just loaded are not changed by fix-up operations. */ return 1; case 023: /* fbld m80dec */ clear_C1(); loaded_tag = FPU_load_bcd((u_char __user *) data_address); FPU_settag0(loaded_tag); break; case 024: /* fldcw */ RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_READ, data_address, 2); FPU_get_user(control_word, (unsigned short __user *)data_address); RE_ENTRANT_CHECK_ON; if (partial_status & ~control_word & CW_Exceptions) partial_status |= (SW_Summary | SW_Backward); else partial_status &= ~(SW_Summary | SW_Backward); #ifdef PECULIAR_486 control_word |= 0x40; /* An 80486 appears to always set this bit */ #endif /* PECULIAR_486 */ return 1; case 025: /* fld m80real */ clear_C1(); loaded_tag = FPU_load_extended((long double __user *)data_address, 0); FPU_settag0(loaded_tag); break; case 027: /* fild m64int */ clear_C1(); loaded_tag = FPU_load_int64((long long __user *)data_address); if (loaded_tag == TAG_Error) return 0; FPU_settag0(loaded_tag); break; case 030: /* fstenv m14/28byte */ fstenv(addr_modes, (u_char __user *) data_address); return 1; case 032: /* fsave */ fsave(addr_modes, (u_char __user *) data_address); return 1; case 033: /* fbstp m80dec */ clear_C1(); if (FPU_store_bcd (st0_ptr, st0_tag, (u_char __user *) data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ break; case 034: /* fstcw m16int */ RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE, data_address, 2); FPU_put_user(control_word, (unsigned short __user *)data_address); RE_ENTRANT_CHECK_ON; return 1; case 035: /* fstp m80real */ clear_C1(); if (FPU_store_extended (st0_ptr, st0_tag, (long double __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ break; case 036: /* fstsw m2byte */ RE_ENTRANT_CHECK_OFF; FPU_access_ok(VERIFY_WRITE, data_address, 2); FPU_put_user(status_word(), (unsigned short __user *)data_address); RE_ENTRANT_CHECK_ON; return 1; case 037: /* fistp m64int */ clear_C1(); if (FPU_store_int64 (st0_ptr, st0_tag, (long long __user *)data_address)) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ break; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)93483.69%1470.00%
Denys Vlasenko13111.74%15.00%
Al Viro262.33%15.00%
Ingo Molnar100.90%15.00%
Randy Dunlap90.81%15.00%
Linus Torvalds30.27%15.00%
Jesper Juhl30.27%15.00%
Total1116100.00%20100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)118985.54%1664.00%
Denys Vlasenko14710.58%14.00%
Al Viro261.87%14.00%
Ingo Molnar100.72%14.00%
Randy Dunlap90.65%14.00%
Linus Torvalds40.29%28.00%
Jesper Juhl30.22%14.00%
Greg Kroah-Hartman10.07%14.00%
Adrian Bunk10.07%14.00%
Total1390100.00%25100.00%
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